Abstract: OBJECTIVES:: HIV-infected patients using combination antiretroviral therapy (ART) have an increased cardiovascular risk. We aimed to identify the effects of HIV, ART, and lipodystrophy (LD) on carotid artery intima-media thickness (C-IMT), a surrogate measure of atherosclerosis, and arterial stiffness, a marker of cardiovascular risk. DESIGN:: Case-control study of 77 HIV-infected men (55 exposed to ART, 22 ART naive, and 23 with LD) and 52 controls. METHODS:: C-IMT was measured ultrasonically, and arterial stiffness was estimated by distensibility (DC) and compliance (CC) coefficients of the carotid, femoral, and brachial arteries, by the carotid Young elastic modulus and pulse wave velocity. RESULTS:: After adjustment for cardiovascular risk factors, HIV-infected patients had a 0.067 mm (10.8%) greater C-IMT than controls, 13.6% and 29.5% lower DC, and 14.1% and 31% lower CC of the carotid and femoral arteries, respectively, but similar Young elastic modulus and pulse wave velocity. Patients exposed to ART had similar C-IMT compared with ART-naive patients but 25.9% lower DC and 21.7% lower CC of the femoral artery. Arterial properties did not differ between patients with and without LD. CONCLUSIONS:: HIV infection is independently associated with C-IMT and generally increased arterial stiffness. ART use is associated with increased stiffness of the femoral artery.
Abstract: BACKGROUND: Patients with antiretroviral therapy (ART)-associated lipodystrophy frequently have disturbances in glucose metabolism associated with insulin resistance. It is not known whether changes in body composition are necessary for the development of these disturbances in ART-naive patients starting treatment with different combination ART regimens. METHODS: Glucose metabolism and body composition were assessed before and after 3 months of ART in a prospective randomized clinical trial of HIV-1-positive ART-naive men taking lopinavir/ritonavir within either a nucleoside reverse transcriptase inhibitor (NRTI)-containing regimen (zidovudine/lamivudine; n = 11) or a NRTI-sparing regimen (nevirapine; n = 9). Glucose disposal, glucose production and lipolysis were measured after an overnight fast and during a hyperinsulinaemic-euglycaemic clamp using stable isotopes. Body composition was assessed by computed tomography and dual-energy X-ray absorptiometry. RESULTS: In the NRTI-containing group, body composition did not change significantly in 3 months; insulin-mediated glucose disposal decreased significantly (25%; P < 0.001); and fasting glycerol turnover increased (22%; P < 0.005). Hyperinsulinaemia suppressed glycerol turnover equally before and after treatment. The disturbances in glucose metabolism were not accompanied by changes in adiponectin or other glucoregulatory hormones. In contrast, glucose metabolism did not change in the NRTI-sparing arm. Glucose disposal significantly differed over time between the arms (P < 0.01). CONCLUSIONS: Treatment for 3 months with a NRTI-containing, but not a NRTI-sparing, regimen resulted in a 25% decrease in insulin-mediated glucose disposal and a 22% increase in fasting lipolysis. In the absence of discernable changes in body composition, NRTI may directly affect glucose metabolism, the mechanism by which remains to be elucidated.
Abstract: High anion gap metabolic acidosis might be caused by 5-oxoproline (pyroglutamic acid). As it is very easy to treat, it might be worth drawing attention to this uncommon and probably often overlooked diagnosis. We present three cases of high anion gap metabolic acidosis due to 5-oxoproline seen within a period of six months.
Abstract: OBJECTIVE:: To assess the efficacy of ritonavir-boosted protease inhibitor monotherapy. DESIGN AND METHODS:: Systematic review of all protease inhibitor-monotherapy studies published in peer-reviewed journals or presented at conferences to date. Data of randomized controlled trials were pooled to yield common odds ratios. RESULTS:: Twenty-two protease inhibitor-monotherapy studies were identified. In the intent-to-treat analysis, 395 out of 582 (67.9%) patients had undetectable HIV-RNA at the end of follow-up. In the six randomized controlled trials (all lopinavir/ritonavir monotherapy), the risk of therapy failure was greater on monotherapy: 121 out of 364 (33.2%) patients on monotherapy against 64 out of 280 (22.9%) patients on HAART [pooled odds ratio 1.48 (95% confidence interval 1.02-2.13, P = 0.037)]. Regarding patients with successfully resuppressed HIV-RNA upon (re-)introducing nucleoside reverse transcriptase inhibitors (NRTIs) as nonfailures, the risk of therapy failure was comparable: 98 out of 364 (26.9%) against 64 out of 280 (22.9%) patients [odds ratio 1.05 (95% confidence interval 0.72-1.53, P = 0.81)]. CONCLUSION:: The overall efficacy of ritonavir-boosted protease inhibitor monotherapy is inferior to HAART. The efficacy improves in patients started on monotherapy after suppressed HIV-RNA for at least 6 months. Ten percent of patients have viral rebound with HIV-RNA levels between 50 and 500 copies/ml. Possible explanations are lack of HIV suppression in particular cells or compartments, alternative resistance mechanisms, and nonadherence. Once proven that reintroduction of NRTIs, in patients with loss of viral suppression, is safe and effective, a broader use of simplification of HAART to protease inhibitor monotherapy might be justified. This review supports that the majority of patients with prolonged viral suppression on HAART can successfully be treated with protease inhibitor monotherapy. Arguments for this strategy are NRTI/NNRTI side effects, NRTI/NNRTI resistance, and costs.
Abstract: Of 21 patients diagnosed with Whipple's disease (WD) by polymerase chain reaction (PCR), 3 were mentally retarded. We describe 2 of these patients, both of whom had WD in the central nervous system. WD was confirmed with PCR on blood and, for 1 patient, also on cerebrospinal fluid (CSF).
Abstract: We retrospectively screened 1836 men who have sex with men (MSM) participating in the Amsterdam Cohort Studies (1984-2003) for hepatitis C virus (HCV) antibodies. HCV incidence was 0.18/100 person-years (PY) in human immunodeficiency virus (HIV)-positive MSM (8/4408 PY [95% confidence interval {CI}, 0.08-0.36]) but was 0/100 PY in MSM without HIV (0/7807 PY [95% CI, 0.00-0.05]). After 2000, HCV incidence among HIV-positive men increased 10-fold to 0.87/100 PY (5/572 PY [95% CI, 0.28-2.03]). Additional hospital cases (n=34) showed that MSM in Amsterdam who acquired HCV infection after 2000 reported high rates of ulcerative sexually transmitted infections (59%) and rough sexual techniques (56%), denied injection drug use, and were infected mainly with the difficult-to-treat HCV genotypes 1 (56%) and 4 (36%). Phylogenetic analysis showed 3 monophyletic clusters of MSM-specific HCV strains. The emergence of an MSM-specific transmission network suggests that HIV-positive MSM with high-risk sexual behaviors are at risk for sexually acquired HCV. Targeted prevention and routine HCV screening among HIV-positive MSM is needed to deter the spread of HCV.
Abstract: Anti-tumour necrosis factor (TNF) therapy is associated with an increased risk of infection. There are sparse data and no evidence-based guidelines on how to deal with this problem in daily practice. However, recommendations can be made based on theoretical considerations and by extrapolating from recommendations for other types ofimmunodeficiency. Before starting anti-TNF therapy, screening for tuberculosis and other possible infections is indicated. During therapy, alertness is required to the increased risk of infection, infections with a more serious clinical course or unusual manifestations and opportunistic infections. Flu vaccination during anti-TNF therapy is indicated. Travel vaccinations with live microbial inocula should not be given.
Abstract: PURPOSE OF REVIEW: To examine the type and risk of infections in humans and mice deficient in proinflammatory cytokines. Naturally occurring or manipulated genetic defects of tumor necrosis factor, interleukins-1, -6, -12, and -15, and interferon-gamma are examined for their increased susceptibility to, or protection from, infection. RECENT FINDINGS: Interleukin-12p40 and interferon-gamma-blockers may lead to increased incidence of infections with intracellular bacteria, parasites, and fungi. In addition, we may see viral infections with interferon-gamma-blockers. Increased risk of infections is unlikely with either interleukin-1- or interleukin-15-blockers. Interleukin-6-blockers may lead to increased risk of infection with extracellular bacteria, viruses, parasites and fungi. SUMMARY: In tumor necrosis factor knockout mice, increased susceptibility to pathogens are reported that are normally controlled by granuloma formation. In patients treated with tumor necrosis factor-blockers, a two-fold increase of granulomatous infections, predominantly reactivation of latent tuberculosis, is found. The infections detected in tumor necrosis factor knockout mice were accurate for predicting the infections observed when using tumor necrosis factor-blockers. If a similar correlation exists for other cytokines, the use of interferon-gamma and interleukin-12p40 blockers, and possibly interleukin-6 blockers, will lead to an increased risk for severe infections. Care should be taken when new cytokine blockers/antagonists are introduced.
Abstract: We report a patient with a rare presentation of extra-intestinal salmonellosis after infliximab therapy for rheumatoid arthritis. We discuss the increasing incidence of primary infections and reactivation of intracellular microorganisms after treatment with TNF-alpha blockage, with emphasis on salmonellosis.
Abstract: Direct detection of bacterial DNA in blood offers a fast alternative to blood culture and is presumably unaffected by the prior use of antibiotics. We evaluated the performance of two real-time PCR assays for the quantitative detection of Staphylococcus aureus bacteremia and for Enterococcus faecalis bacteremia directly in blood samples, without prior cultivation. Whole-blood samples for PCR were obtained simultaneously with blood cultures from patients admitted to the intensive care unit of our hospital. After the extraction of DNA from 200 mul of blood, real-time PCR was performed for the specific detection and quantification of S. aureus and E. faecalis DNA. The sensitivity for bacteremia of the S. aureus PCR was 75% and that of the E. faecalis PCR was 73%, and both tests had high specificity values (93 and 96%, respectively). PCR amplification reactions were positive for S. aureus for 10 (7%) blood samples with negative blood cultures, and 7 (4%) PCR reactions were positive for E. faecalis. The majority of these PCR results were likely (50%) or possibly (42%) related to infection with the specific microorganism, based on clinical data and radiological and microbiological investigations. PCR results were concordant for 95% of paired whole-blood samples, and blood culture results were concordant for 97% of the paired samples. We conclude that the detection of S. aureus and E. faecalis DNA in blood by real-time PCR enables a rapid diagnosis of bacteremia and that a positive DNAemia is related to proven or possible infection with the specific microorganism in the majority of patients with negative blood cultures.
Abstract: OBJECTIVES: Improvement of the efficacy of drug treatment in mycobacterial infection by the development and application of targeted drug delivery. METHODS: In disseminated Mycobacterium avium infection in mice, the relative efficacy of the antimycobacterial agents that are currently used in combination therapy was investigated. Next, the effect of the addition of targeted delivery of amikacin to the infected tissues in the initial phase of treatment was studied. Amikacin was chosen because of its unique rapid and high mycobacterial killing capacity. As drug delivery tool, long-circulating sterically stabilized liposomes were used. RESULTS: Treatment with clarithromycin alone daily (6 days a week) slowly killed most of the mycobacteria in the lung, liver, spleen, inguinal and mesenterial lymph nodes. However, after 24 weeks of treatment, persistence of substantial numbers of mycobacteria in the infected organs was observed. The addition of ethambutol to the clarithromycin regimen did not significantly enhance the efficacy of treatment, neither did rifampicin as a third agent. In contrast, the addition of liposomal amikacin in the initial phase of therapy resulted in rapid and complete elimination of the mycobacteria in all infected organs within 12 weeks of treatment without relapse of infection. As a result, total treatment duration could be significantly reduced to 12 weeks. CONCLUSIONS: In M. avium infection in mice, the approach of targeted drug delivery was successful. The rapid decrease in the mycobacterial load followed by complete killing, including the persistent mycobacteria considered responsible for relapse of infection, allows a significant reduction of the total treatment duration.
Abstract: Bloodstream infection (BSI) in febrile patients is associated with high mortality. Clinical and laboratory variables, such as procalcitonin (PCT), may predict BSI and help decision-making concerning empirical treatment. This study compared two models for prediction of BSI, and evaluated the role of PCT vs. clinical variables, collected daily in 300 consecutive febrile inpatients, for 48 h after onset of fever. Multiple logistic regression (MLR) and classification and regression tree (CART) models were compared for discriminatory power and diagnostic performance. BSI was present in 17% of cases. MLR identified the presence of intravascular devices, nadir albumin and thrombocyte counts, and peak temperature, respiratory rate and leukocyte counts, but not PCT, as independent predictors of BSI. In contrast, a peak PCT level of >2.45 ng/mL was the principal discriminator in the decision tree based on CART. The latter was more accurate (94%) than the model based on MLR (72%; p <0.01). Hence, the presence of BSI in febrile patients is predicted more accurately and by different variables, e.g., PCT, in CART analysis, as compared with MLR models. This underlines the value of PCT plus CART analysis in the diagnosis of a febrile patient.
Abstract: We evaluated a modified fluorescence in situ hybridization (FISH) assay for rapid (<1 h) identification of microorganisms in growth-positive blood cultures. The results were compared to those of the standard FISH technique and conventional culturing. The rapid identification of microorganisms with modified FISH can have important effects on clinical management of patients with bloodstream infections.
Abstract: CD1d-restricted NKT cells play important regulatory roles in various immune responses and are rapidly and selectively depleted upon infection with HIV-1. The cause of this selective depletion is incompletely understood, although it is in part due to the high susceptibility of CD4+ NKT cells to direct infection and subsequent cell death by HIV-1. Here, we demonstrate that highly active antiretroviral therapy (HAART) results in the rapid recovery of predominantly CD4(-) NKT cells with kinetics that are strikingly similar to those of mainstream T cells. As it is well known that the early recovery of mainstream T cells in response to HAART is due to their redistribution from tissues to the circulation, our data suggest that the selective depletion of circulating NKT cells is likely due to a combination of cell death and tissue sequestration and indicates that HAART can improve immune functions by reconstituting both conventional T cells and immunoregulatory NKT cells.
Abstract: Rapid identification of microorganisms in blood cultures is required to optimize empirical treatment at an early stage. Fluorescence in situ hybridization (FISH) can reduce the time to identification of microorganisms in growth-positive blood cultures. In this study, we evaluated the performance, time to identification, and potential clinical benefits of FISH compared to those of conventional culture methods in routine practice. After Gram staining, blood culture fluids were simultaneously further identified with FISH and with conventional culture methods. Results and points in time of FISH and culture identification (provisional and final identifications) were collected and compared. For 91% of microorganisms, the genus or family name was identified, and for 79%, the species name could be attributed. The sensitivity and specificity of the individual probes exceeded 95%, except for the Enterobacteriaceae probe (sensitivity, 89%). Cross-hybridization was obtained with the Klebsiella pneumoniae probe for Klebsiella oxytoca. The time gains of FISH and final culture identification were more than 18 h for bacteria and 42 h for yeasts. With FISH, Staphylococcus aureus was differentiated from coagulase-negative staphylococci 1.4 h faster than by provisional identification (P < 0.001). In conclusion, FISH allows rapid and reliable identification of the majority of microorganisms in growth-positive blood cultures. The substantial time gain of identification with FISH may allow same-day adjustment of antimicrobial therapy, and FISH is especially useful if no provisional identification is obtained. With further extension of the number of probes and a reduction in turnaround time, FISH will become a very useful diagnostic tool in the diagnosis of bloodstream infections.
Abstract: A 65-year-old patient with systemic lupus erythematodes (SLE) developed fever and gonarthritis whilst taking prednisone and hydrochloroquine. Salmonella typhimurium, sensitive to amoxicillin, was grown in cultures of synovial fluid, blood and urine. After high dosages of intravenous amoxicillin, blood cultures and knee punctate became negative, but fever seemingly without a clinical focus persisted. By means of a fluoro-18-deoxyglucose positron emission tomography (FDG-PET) scan, an abscess was located in the left upper leg and successfully treated. In patients with impaired cell-mediated immunity, an extra-intestinal manifestation of Salmonella should be taken into consideration particularly if there appears to be no clinical focus. This may be detected by FDG-PET.
Abstract: A number of antimycobacterial agents were evaluated with respect to their bacteriostatic activity (growth inhibition) versus the bactericidal activity against a clinical isolate of Mycobacterium avium (Mycobacterium avium complex [MAC] strain 101) in relation to the time of exposure and the growth phase of the mycobacteria. In terms of growth inhibition the MAC in the active phase of growth was susceptible to clarithromycin, ethambutol, rifampin, amikacin, and the quinolones moxifloxacin, ciprofloxacin, and sparfloxacin. In terms of bactericidal activity in relation to the time of exposure these agents differed substantially with respect to the killing rate. An initial high killing capacity at low concentration was observed for amikacin, which in this respect was superior to the other agents. The bactericidal activity of clarithromycin and ethambutol was only seen at relatively high concentrations and increased with time. Killing by rifampin was concentration dependent as well as time dependent. The bactericidal activity of moxifloxacin was marginally dependent on the concentration or the time of exposure. The activity of clarithromycin in combination with ethambutol was not significantly enhanced compared to single-agent exposure. Only an additive effect was observed. The addition of rifampin or moxifloxacin as a third agent only marginally effected increased killing of MAC. However, by addition of amikacin the activity of the clarithromycin-ethambutol combination was significantly improved. The combination of amikacin and amoxicillin-clavulanic acid exhibited synergistic antimycobacterial activity. Towards MAC at low growth rates, only the quinolones exhibited a bactericidal effect.
Abstract: HLA-B27 is known for its strong association with inflammatory spondyloarthropathies (SpA), a group of rheumatic diseases. Apart from playing its role in the onset of these inflammatory diseases, HLA-827 is so ubiquitous in the world that the carrying of this gene must have also have an advantage. There are some indications that a beneficial effect can be found as a less severe course of viral infections among B27-carriers. The literature on this subject was reviewed and revealed a favorable course of infection with influenza virus, herpes simplex type 2 virus, Epstein-Barr virus and, even more interesting, a protective effect of HLA-B27 in the progression of HIV infections. The course of HIV infection differs among individuals and is thought to be partly related to host-factor variability, reflecting broad genetic heterogeneity. The polymorphic human leukocyte antigens (HLA) are herein analyzed intensively with respect to this relationship. Cytotoxic T lymphocyte (CTL) responses, activated by HLA antigen presentation, are implicated in the control of HIV replication. An immunological explanation for the protective role for HLA B27 in HIV disease is that B27+ patients have a specific and strong CTL response against the p24 epitope, a conservative HIV protein that does not easily mutate. Some HLA genes seen in long-term non-progressors (LTNP) (>10 years disease free) are associated with a favorable prognosis. One of the alleles found predominantly in LTNPs is HLA-B27. More genetic factors seem to influence disease progression in HIV infections. Therefore, it would be interesting to further explore the influence of the genetic make up of these HIV-infected individuals. Knowledge of the immunogenetic profile might give clues for the individual course of the HIV infection, may influence the development of drug-resistant viruses and will possibly lead to a tailored therapeutic strategy in HIV-infected persons.
Abstract: We applied real-time broad-range polymerase chain reaction (PCR) to detect bacteraemia in blood from febrile patients. Interpretation of amplification results in relation to clinical data and blood culture outcome was complex, although the reproducibility of the PCR results was good. Sequencing analysis of the PCR products revealed the presence of Burkholderia species DNA while no Burkholderia species grew in culture. The source of this contamination was shown to be the commercial DNA isolation kit used in the automated MagNA Pure Isolation Robot. A high degree of suspicion is required when uncommon or unexpected pathogens are diagnosed by molecular methods as clinical consequences can be serious.
Abstract: We report a patient with Legionella pneumophila pneumonia after infliximab therapy for rheumatoid arthritis. Arguments are discussed for an emerging incidence of infections with intracellular microorganisms, granulomatous and non-granulomatous, in patients having received anti-TNFalpha therapy. These discussions consist of clinical and epidemiological data, experimental data in animals, theoretical evidence, and we provide a possible pathogenetic mechanism.
Abstract: New techniques have emerged for the detection of bacteria in blood, because the blood culture as gold standard is slow and insufficiently sensitive when the patient has previously received antibiotics or in the presence of fastidious organisms. DNA-based techniques, hybridisation probes, and PCR-based detection or protein-based detection by mass spectroscopy are aimed at rapid identification of bacteria and provide results within 2 h after the first signal of growth in conventional blood cultures. Also, detection of microorganisms directly in blood by pathogen-specific or broad-range PCR assays (eubacterial or panfungal) shows promising results. Interpretation is complex, however, because of detection of DNA rather than living pathogens, the risk of interfering contamination, the presence of background DNA in blood, and the lack of a gold standard. As these techniques are emerging, clinical value and cost-effectiveness have to be assessed. Nevertheless, molecular assays are expected eventually to replace the current conventional microbiological techniques for detection of bloodstream infections.
Abstract: Two men, aged 41 and 28 years, both known to be HIV-positive, contracted multiple sexually-transmitted diseases (STDs) through unprotected anal sexual contact. These included lymphogranuloma venereum (LGV) proctitis and hepatitis C. Recently in The Netherlands and Belgium there has been an outbreak of LGV proctitis in HIV-positive men who have sex with men, caused by Chlamydia trachomatis serovar L2, an STD which up to now has been rare in Europe. Due to information about the epidemic received a few days previously, the LGV proctitis in the second patient could be diagnosed and treated rapidly. The incidence of STDs in men having sex with men is increasing, also in HIV-positive men. STDs with ulcerative lesions, such as LGV, facilitate transmission of other pathogenic micro-organisms, including HIV. This, in combination with high-risk sexual behaviour such as unprotected anal sexual intercourse, will increase the chance of blood-blood contact and hence the chance of contracting multiple STDs concurrently. Hepatitis C is not normally considered as an STD, but ulcerative lesions in one of the partners combined with high-risk sexual behaviour enables the hepatitis C virus to be sexually transmitted.
Abstract: A 52-year-old woman presented several months after returning from a visit to Turkey with stomach-ache and fever. Laboratory results showed leucocytosis with marked eosinophilia. Furthermore, serum liver enzyme activities were slightly elevated. A CT scan of the abdomen showed several spots which, on a later scan, had migrated. Serologic tests confirmed the clinical diagnosis of fascioliasis. The patient was successfully treated with triclabendazole. Infection presumably occurred after eating watercress which the patient had bought on a market in Turkey.
Abstract: CGP 56697 (Riamet) is a new oral anti-malarial drug composed of artemether and lumefantrine (benflumetol) which combines the fast, short-acting artemether for rapid parasite clearance with the prolonged action of lumefantrine for intended radical cure. In this double-blind, comparative trial, the efficacy and tolerability of CGP 56697, given as a course of 4 x 4 tablets over 48 h, was compared to halofantrine, given as 3 x 2 tablets over 12 h with a second course 1 week later. Patients (mostly non-immune) with acute, uncomplicated Plasmodium falciparum infection were randomly assigned to either CGP 56697 (n = 51) or halofantrine (n = 52). CGP 56697 proved superior with respect to parasite clearance time (median 32 vs. 48 h, P < 0.001) and parasite reduction at 24 h (median 99.7 vs. 89.6%, P < 0.001) with a non-significant difference in resolution of fever (median 24 vs. 32 h, P = 0.835). However, a 28-day cure rate of 82% was observed for CGP 56697 and 100% for halofantrine. Significant QTc prolongations (> 30 ms) were seen 6-12 h after halofantrine intake but not after CGP 56697 intake. CGP 56697 is an effective, well-tolerated treatment for uncomplicated falciparum malaria but for this dosing regimen the recrudescence rate is unacceptablyhigh (18%). For travellers contracting malaria abroad, we propose a six-dose regimen of CGP 56697 over 3 days.
Abstract: Registration in Europe of several artemisinin drugs for the treatment of malaria can soon be expected. Artemisinin is isolated from the herb Artemisia annua, in use in China more than 2000 years as a herbal tea against fever. Artemisinin drugs are being used extensively in South-East Asia and increasingly in Africa. Active derivatives have been synthesized - artemether, arteether and artesunate - which are used for oral, intramuscular, rectal and intravenous administration. The origin, mechanism of action, efficacy and safety in patients, the pharmacokinetics and the position of this group of compounds among existing antimalarials are discussed in this review.
Abstract: BACKGROUND: Artemether is a new and effective treatment for malaria, although relapse is a problem in monotherapy. These relapses could be related to a time-dependent decline in artemether plasma levels described in multiple-dose studies and probably caused by autoinduction. The aim of this study was to evaluate the effect of grapefruit juice on the decreasing bioavailability over time of artemether. METHODS: In a randomized, two-phase crossover study, eight healthy male subjects took 100 mg oral artemether with 350 mL water or with 350 mL double-strength fresh frozen grapefruit juice once daily for 5 days. On day 1 and day 5, 17 blood samples were collected over a period of 8 hours. RESULTS: The mean peak artemether plasma concentration (Cmax) and the mean area under the concentration-time curve (AUC) after the last dose at day 5 were about one third compared with day 1, without a change in the elimination half-life after intake with water (P = .006 for Cmax; P = .005 for AUC) and with grapefruit juice (P < .001 for Cmax and AUC). Grapefruit juice increased Cmax (P = .021) and AUC (P < .001) twofold on day 1 (P = .021) and day 5 (P = .05 for Cmax; P = .004 for AUC). Dihydroartemisinin, the active metabolite, showed a twofold increase in Cmax (P = .006) and AUC (P = .001) with grapefruit juice, without time-dependent changes of pharmacokinetic parameters. CONCLUSIONS: Grapefruit juice significantly increased the oral bioavailability of artemether but did not prevent the time-dependent reduction in bioavailability. It suggests that CYP3A4 in the gut wall is one of the metabolizing enzymes of artemether but seems to not be involved in the autoinduction process.
Abstract: We have produced monoclonal antibodies against artelinic acid and investigated the reactivity with artemisinin drugs and metabolites. Antibody F170-10 is fairly specific for artelinic acid but does bind artemisinin and artemether (3-5% cross-reactivity). Dihydroartemisinin, artesunate, and metabolites of artemisinin showed less reactivity. With this antibody, an inhibition ELISA has been set up to detect artemisinin compounds in urine. In healthy subjects who received a single oral dose of artemisinin, artemether, artesunate or dihydroartemisinin, ELISA reactivity in urine was found. This reactivity in urine paralleled the plasma concentrations of artemether and dihydroartemisinin. The results show that this immunoassay for artelinic acid can be used to detect artemisinin compounds in urine for about 8 hr after intake. With a more sensitive test, this simple method as a urine dipstick may be become useful for drug use and compliance studies in malaria-endemic areas where the artemisinin derivatives are increasingly used.
Abstract: OBJECTIVE: To evaluate the effect of grapefruit juice on the pharmacokinetics of artemether in plasma and saliva after a single oral dose and to detect concentration-dependent electrocardiographic changes (bradycardia and QTc prolongation). METHODS: Six healthy male subjects were given a standard breakfast followed by two tablets of 50-mg artemether administered with water; 1 week later, the tablets were administered with 350 ml double-strength fresh frozen grapefruit juice. For 8 h, 17 blood- and saliva samples were collected, and 17 electrocardiograms were recorded. Drug and metabolite concentrations were measured by means of high-performance liquid chromatography with electrochemical detection. The pharmacokinetic parameters were determined using a one-compartment model. RESULTS: Grapefruit juice significantly (P = 0.001) increased the mean peak concentration (Cmax) of artemether more then twofold from 42 (SD 17) ng/ml to 107 (28) ng/ml. The time to reach Cmax (tmax) with grapefruit juice was 2.1 (0.6) h compared with 3.6 (17) h with water (P = 0.02). The area under the concentration time curve (AUC) almost doubled with grapefruit juice from 177 ng x h/ml to 336 ng x h/ml (P = 0.003). The elimination half-life remained unchanged (1.0 h vs 1.3 h). No major changes in the kinetics of the metabolite dihydroartemisinin were detected. Low artemether levels and zero dihydroartemisinin levels were found in saliva. No influences of artemether were observed on 17 electrocardiograms during the 8 h after drug intake in particular there were no signs of bradycardia or QTc prolongation. CONCLUSION: Grapefruit juice significantly increases the oral bioavailability of artemether without an effect on the elimination half-life. It suggests a role for intestinal CYP3A4 in the presystemic metabolism of artemether.
Abstract: Multiple dose pharmacokinetics of artemether and dihydroartemisinin were investigated in chinese patients treated for malaria. They received over 2 days either 4 x 80 mg artemether orally (n = 48) or 4 x 80-480 mg co-artemether (n = 40), a combination of artemether and lumefantrine (benflumetol). Lag time = 0.48 h (mean), Cmax after first dose = 157 ng/ml, t(max) = 1.73 h and elimination half-life = 1.16 h. The lag and absorption times were 0.5 h longer for co-artemether compared with artemether. Dihydroartemisinin paralleled artemether pharmacokinetics. Artemether Cmax after the last dose was one-third of the Cmax after the first dose while, inversely, dihydroartemisinin Cmax increased over time. We suggest that auto-induction of gut mucosa enzymes and/or liver enzymes causes a time-dependent increase in first-pass metabolisation of artemether.
Abstract: The contribution of the enzymes CYP2D6 and CYP2C19 to the metabolism of artemether was evaluated in a cross-over study in seven healthy adult Caucasian subjects. The pharmacokinetic properties of artemether and its active metabolite dihydroartemisinin were compared when given 100 mg artemether orally alone or in combination with either CYP2D6-inhibitor quinidine or CYP2C19-inhibitor omeprazole. Plasma concentrations of artemether and dihydroartemisinin were measured with reversed phase high performance liquid chromatography with electro-chemical detection (HPLC-ED). Artemether was rapidly absorbed with a mean tmax of 0.8 h (95% confidence interval, CI=0.5-1.1) reaching a mean Cmax of 29 ng/ml (14-45 ng/ml). The mean elimination half-life was 1.3 h (0.8-1.8 h). The pharmacokinetic parameters for dihydroartemisinin were not significantly different from those for artemether. Artemether combined with quinidine revealed no significant changes in the plasma concentrations of either artemether or dihydroartemisinin. No changes were seen in the combination with omeprazole as a CYP2C19 inhibitor. A second peak in the plasma concentration profile was observed 2-4 h after drug intake.This phenomenon was possibly related to variable gastric emptying. No major contribution of the enzymes CYP2D6 or CYP2C19 was found in artemether metabolism. No interethnic differences in artemether metabolism on the basis of a genetic polymorphism of these enzymes is to be expected.
Abstract: For the determination of artemisinin (ART) and analogs, a reversed-phase high-performance liquid chromatography method using reductive electrochemical detection (ED) was set up with some important modifications as compared to previously published assays. A different technique of deoxygenating resulted in a factor 2-3 lower background current. A Spectroflow 400 liquid chromatograph in combination with a Triathlon autoinjector coupled to a Decade electrochemical detector was used. The detector was operated in the reductive mode as a closed system under chromatography grade helium to exclude any access of oxygen. The Decade has a glassy carbon electrode and a reference Ag/AgCl electrode. Infrequent electropolishing was required implicating a very stable system. By increasing acetonitril or lowering the pH of the mobile phase, the various derivatives could be determined in the same chromatogram. The assay was validated using artemether (ATM) and dihydroartemisinin (DHA) as test substances. In the concentration range seen in people after usual doses (5 to 220 ng/ml), the assay performs with adequate accuracy and precision. The interassay and intraassay precision are < 6% for ATM. For DHA, the interassay and intraassay precision are < 9%. The accuracy expressed as the deviation from the expected concentration varies from -1% to +4.5% for the intraassay ATM-determinations and from +1% to +6.3% for the interassay measurements. For DHA, the accuracy is somewhat less, varying from -0.3% to -9.5% for the intraassay measurements and -0.6% to +2.6% for the interassay measurements. The reproducibility of the assay, measured over a time period of 3 months, is good for ATM and DHA with an interassay precision of < 18% in 70 repetitive samples and an accuracy varying from -0.6% to +7.6%. In a cross-check with two other reference laboratories who used comparable methods of determination, a strong correlation (correlation coefficient > 0.98) was achieved. The method was applied in a study in which artemether was administered orally to healthy white subjects. We consider high-performance liquid chromatography with electrochemical detection an accurate and precise method for quantitative determination of artemisinin derivatives in pharmacokinetic studies.
Abstract: The clinical significance of differences between antibiotics in endotoxin-liberating potential is unknown. Thirty patients with gram-negative urosepsis were randomized between imipenem and ceftazidime, which have, respectively, a low and a high endotoxin-liberating potential in vitro. In patients treated with ceftazidime, a slower defervescence was noticed. After 4 h of treatment, the blood endotoxin level decreased in all 3 endotoxemic patients receiving imipenem, whereas it increased in 2 of the 4 endotoxemic patients receiving ceftazidime, and in ceftazidime-treated patients, the endotoxin level in urine decreased less than in imipenem-treated subjects. Serum and urine cytokine levels increased 10%-40% after 4 h of ceftazidime treatment compared with no increase in the imipenem-treated patients (P > .05). Endotoxin release during antibiotic killing in vitro, assessed for all microorganisms, was 10-fold higher with ceftazidime (P < .001). These results indicate that differences between antibiotics in endotoxin release may affect the inflammatory response during treatment.
Abstract: BACKGROUND: To evaluate the frequency, presentation, and course of the acute chest syndrome (ACS) in adult Afro-Caribbean patients with sickle cell disease (SCD). PATIENTS AND METHODS: Retrospective cohort study during a 12-year period in patients with SCD at least 14 years of age, discharged with a diagnosis of ACS from the only hospital on the Caribbean island of Curaçao, where 109 patients with SCD (62 HbSS, 47 HbSC) were observed. RESULTS: Eighty-one episodes of ACS occurred (57 in 34 patients with HbSS and 24 in 19 patients with HbSC). The risk (odds ratio, 1.80; P = .13) and incidence (7.6 vs 4.2 per 100 patient-years; P > .2) of ACS did not differ between patients with HbSS and HbSC, but recurrent ACS affected patients with HbSS more (odds ratio, 2.96; P = .09). Abnormal chest sounds (mainly bilateral crepitations) were found in 91% of cases at diagnosis, but 48% had normal chest roentgenograms at that time and had delayed development (5.4 +/- 3.4 days) of radiologic abnormalities. Patients with HbSS and HbSC had similar clinical presentations. Mortality (6%) and hospital stay (20 days) were not influenced by the use of transfusions or anticoagulation. All five nonsurviving female patients with HbSS had had more previous admissions for SCD and ACS. CONCLUSIONS: Acute chest syndrome occurs in 42% of adult Afro-Caribbean patients with SCD; patients with HbSS are more prone to recurrences. Delayed development of radiologic infiltrates is common. Interventions apart from supportive care do not influence the course of ACS. Fatal ACS occurs in patients with a more severe form of SCD.
Abstract: A case is reported, in which fatal pulmonary embolism complicated the course of a neuroleptic malignant syndrome (NMS). This syndrome includes several risk factors for the development of venous thromboembolism, such as: protracted immobility; severe rigidity causing a slowing of blood flow through the deep venous system; hypovolaemia with increased blood viscosity and activation of coagulation by rhabdomyolysis. An analysis of 115 case reports in the literature on NMS showed that 3 out of 13 patients with fatal NMS (23%) died of pulmonary embolism. The reviewed case, the literature findings and the risk factors mentioned cause us to believe that complete anticoagulant therapy may have a place in the therapeutic approach to patients with NMS.
