Abstract: Most cases of parvovirus B19 infection are asymptomatic and occur in childhood; half of all 15-year-old adolescents have specific anti-parvovirus B19 antibodies. Here, we report a rare case of parvovirus B19 primary infection, rare due to (1) its occurrence in a geriatric patient (an 82-year-old woman), (2) its lupus-like presentation, and (3) its potential role in precipitating congestive heart failure.
Abstract: OBJECTIVE: Host defense, cationic anti-microbial peptides are recognized as an important component of innate immune response in most multicellular organisms. NEW FEATURES: These cationic amphipathic peptides include 20 to 50 amino acids and several hundreds of peptides have been identified. They have a broad spectrum activity against bacterial, fungal, and viral pathogens. The mode of action is best known for cecropins and magainins, which act on the cytoplasmic membrane of microorganisms, causing its disruption by a detergent-like activity and pore formation. Several of these peptides or analogs (from magainin, protegrin, indolicidin, and histatin) are under advanced clinical development, especially when used for localized infections. PROJECTS AND PERSPECTIVES: Several other molecules (rBPI, heliomicin, and thanatine) are currently under development for various systemic infections. These will probably be important drugs for future anti-infectious therapy.
Abstract: Regulatory T cells (Treg) are key players in the maintenance of peripheral tolerance. As a result of suppressive effects on CD4+ and CD8+ effector T cells, Treg control the adaptive immune system and prevent autoimmunity. In addition, they inhibit B lymphocytes, dendritic cells, and monocytes/macrophages. It is interesting that several recent papers show that CD4+CD25+ Treg are also able to inhibit NK cells. Thus, Treg exert their control on immune responses from the onset (triggering of innate immune cells) to the effector phase of adaptive immunity (B and T cell-mediated responses). That Treg inhibit NK cells suggests that their uncontrolled activation might break self-tolerance and induce "innate" autoimmune pathology. Conversely, Treg-mediated suppression of NK cell functions might have negative effects, as these cells are important in defense against infections and cancer. It is conceivable that Treg might dampen efficient activation of NK cells in these diseases.
Abstract: PURPOSE: During last decades, several progresses have been made in the diagnosis of cobalamin (vitamin B12) deficiency. Routine used of cobalamin standardized assays have potentially modified the frequency and the type of hematologic abnormalities. CURRENT KNOWLEDGE AND KEY POINTS: Current studies on cobalamin deficiency, including more precise definitions and the description of new etiologies of cobalamin deficiency in adults, as the food-cobalamin malabsorption syndrome, show that hematological abnormalities are generally incomplete compared to historical descriptions of megaloblastic anemia. Nevertheless, they include severe manifestations in 10% of the patients: pancytopenia, severe anemia (hemoglobin < 6 g/dl) or hemolytic anemia and pseudo thrombotic microangiopathy related to cobalamin deficiency. These studies also show the efficacy of new treatment modalities including oral cobalamin administration. PROSPECTS AND PROJECTS: Future studies will confirm these data with the routine use of the new cobalamin assay: holotranscobalamin and validate the usefulness of oral cobalamin therapy.
Abstract: Objective: the aim of this study is to determine the clinical characteristics of drug-induced agranulocytosis in rheumatology. Patients and method: it is a retrospective monocentric study, including all cases of rheumatologic drug-induced agranulocytosis followed between January 1985 and December 2005. Results: eight female and 4 men, mean age 62.5 years (range: 17-79), were included in the present study. The causative drugs were: anti-inflammatory agents (n=5, 41.6%), methotrexate (n=3, 25%), sulfasalazine (n=2, 16.6%), noramidopyrine (n=1) and dapsone (n=1). Main clinical features included infectious disorders in 9 cases (75%) with 4 cases of septicemia (33.3%) and 2 cases of septic shock (16.6%). The mean neutrophils count was 0.132 x 10(9)/L (range, 0-0.4). Outcome was favorable in 11 patients (91.6%). One patient died of septic complications. Conclusion: in rheumatology, drug-induced agranulocytosis is a rare but life-threatening disorder.
Abstract: PURPOSE: The aim of this study is to report personal experience of pancytopenia related to low-dose methotrexate and to review the literature. METHODS: We included retrospectively all cases of pancytopenia related to low-dose methotrexate (<25 mg/week), followed between January 1997 and December 2006, in the university hospital of Strasbourg, France. RESULTS: Five women, mean age 75.6 years, were included in the present study. Clinical manifestations included: symptomatic anemia (n=4), infection (n=3) and hemorrhagic manifestations (n=2); one patient had no feature. Mean hemoglobin concentration was 8,8 g/dl; mean white cell and platelet counts were 1500 /mm(3) and 16000 /mm(3), respectively. Potential risk factors were identified in all patients: renal failure and low serum albumin levels (n=5), anti-inflammatory drug intake (n=2), folate deficiency (n=4) and cobalamin deficiency (n=1). One patient died of septic and hemorrhagic cerebral complications. CONCLUSION: Pancytopenia related to tow-dose methotrexate is a rare but life-threatening disorder. Search and prevention of potential risk factors are required in all patients; determination of MTHFR genotype may be of several interests as folate supplementation.
Abstract: Human deficiency in transporter associated with antigen processing (TAP) is characterized by a very low surface expression of human leukocyte antigen (HLA) class I molecules in hematopoietic and non hematopoietic cells. Among the latter, TAP-deficient skin fibroblasts have previously been shown by us to be very sensitive to lysis by activated autologous NK cells, even in the presence of cytokines that up-regulate HLA class I expression, a mechanism sufficient to protect normal fibroblasts from NK cell-mediated killing. Our complementary investigations on two TAP-deficient skin fibroblast cell lines surprisingly revealed that in response to proinflammatory cytokines, up-regulation of HLA-DR molecules at the cell surface is much less marked than in the case of normal skin fibroblasts. In contrast, the surface molecules CD40 and CD54 increase as much as observed on normal cells, suggesting that TAP-deficient fibroblasts are able to efficiently transduce cytokine-mediated stimulating signals. Transfection of an intact TAP gene into one of the TAP-deficient fibroblast cell lines restored a normal HLA class I expression that strongly increased upon IFN-gamma-mediated stimulation, whereas HLA-DR still remained lower than in control cells. These results suggest that, in addition to the defect in the HLA class I antigen presentation pathway, HLA-DR up-regulation is affected in TAP-deficient skin fibroblasts through an unknown mechanism probably independent from TAP.
Abstract: In this paper, we review the literature on idiosyncratic drug-induced agranulocytosis, a rare but life-threatening potential adverse event of most drugs. Articles were identified through MEDLINE searches (1966-2005). Additional references were localized through a review of textbooks on hematology and internal medicine, and information gleaned from international meetings. Additional unpublished data from our cohort with drug-induced agranulocytosis at the University Hospital of Strasbourg, France, were also considered. Searches were done using the following key words: "agranulocytosis", "drug-induced agranulocytosis", and "idiosyncratic agranulocytosis" and were restricted to: English- and French-language, human subjects, clinical trial, review, and guidelines. All of the papers and abstracts were reviewed by at least two senior researchers who selected the data used in the study. What we found is that, over the last 20 years, the incidence of idiosyncratic drug-induced agranulocytosis has remained stable - 2.4-15.4 cases per million - despite the emergence of new causative drugs, mainly antibiotics, antiplatelet agents, and antithyroid drugs. To date, drug-induced agranulocytosis remains a serious adverse event due to the frequency of severe sepsis with severe deep infections (such as pneumonia), septicemia, and septic shock in about two-thirds of all patients. In this setting, old age (>65 years), septicemia or shock, metabolic disorders such as renal failure, and a neutrophil count below 0.1x10(9)/L are poor prognostic factors. Nevertheless, with appropriate management using pre-established procedures, with intravenous broad-spectrum antibiotic therapy, and hematopoietic growth factors, the mortality rate is currently around 5%. Given the increased life expectancy and subsequent longer exposure to drugs, as well as the development of new agents, health care professionals should be aware of this adverse event and its management.
