Alternaria,Cladosporium : dispersion atmosphérique,rythmes nycthéméral et saisonnier

Are respiratory allergies due to atmospheric moulds a myth or a reality? The aim of the present report is to present the results obtained by the National Network of Aerobiology Monitoring (RNSA) from traps that are distributed throughout France. The results show both geographical and inter-annual variability of the dispersion of the principal airborne allergenic moulds, Alternaria and Cladosporium. Likewise, the intensity of the emission of these moulds throughout the day is not regular, and it has often been noted that there are hourly peaks, which are concomitant with certain peaks of air pollution.     

Élévation modérée,persistante et inexpliquée des transaminases

Unexplained, subclinical chronically elevated transaminases is mainly a marker of non-alcoholic fatty liver disease, metabolic syndrome, alcoholism and diabetes, which are very common situations but viral hepatitis and iatrogenic origin must also be considered. Before looking for hepatic or genetic rare diseases, it is worth considering hypertransaminasemia as a clue for muscular disease, particularly in paediatric settings, and creatine phosphokinase is a specific marker. Then, patient history, examination and appropriate biologic requests can permit the identification of less frequent disorders where isolated hypertransaminasemia is possibly the unique marker of the disease for a long while: hemochromatosis, celiac disease, autoimmune hepatitis, Wilson's disease, α1-anti-trypsine deficiency, thyroid dysfunctions, Addison's disease. Liver biopsy should be performed only in patients with aspartate aminotransferases upper the normal range or alanine aminotransferases higher than twice the normal range after 6 months delay with dietetic corrections.     

Cellules endothéliales circulantes, microparticules et progéniteurs : vers la définition de la « vasculocompétence »

Exposure to deleterious processes of metabolic, infectious, autoimmune or mechanical origin, alters the endothelium which progresses towards a proinflammatory and procoagulant activation, senescence and apoptosis. This “response to injury” of the endothelium plays a key role in the initiation and progression of cardiovascular disorders. In the last 10 years, identification in peripheral blood of circulating endothelial cells (CEC) and endothelial-derived microparticles (EMP) reflecting endothelium damage has led to the development of new noninvasive methods for endothelium exploration. Indeed, these biomarkers were associated with most of the cardiovascular risk factors, were correlated with established parameters of endothelial dysfunction, and were indicative of a poor clinical outcome. Moreover, they behave as biological vectors able to disseminate deleterious signals in the vascular compartment. More recently, this concept has been enlarged by the discovery of a potent repair mechanism based on the recruitment of the circulating endothelial progenitors cells (EPC) from the bone marrow, able to regenerate injured endothelial cells. Cardiovascular risk factors alter EPC number and function. Because the damage/repair balance plays a critical role in the endothelium homeostasis, CEC, EMP and EPC could be combined in an endothelium phenotype that defines the “vascular competence” of each individual. In the future, progress in standardization of available methodologies to measure these emerging biomarkers is a crucial step to establish their clinical interest for assessment of vascular risk and monitoring of vascular-directed therapeutics.     

Virus de l’hépatite B, manifestations extrahépatiques immunologiques et risque de réactivation virale

Hepatitis B virus (HBV) infection is frequent with about 400 million individuals infected worldwide. Extrahepatic manifestations may be observed in up to 20% of patients infected with HBV, in both acute and chronic infections. The best-described manifestations are polyarteritis nodosa and glomerulonephritis. Besides manifestations related to HBV, patients presenting with primary autoimmune disorders and infected with HBV may exhibit reactivation of hepatitis B during immunosuppressive therapy that may be life-threatening. This article focuses on autoimmune manifestations related to HBV and its treatment, and on the risk of reactivation of HBV hepatitis in patients with primary autoimmune disorders treated with immunosuppressive agents.     

Les réactions allergiques et pseudoallergiques aux antalgiques,antipyrétiques et anti-inflammatoires non stéroïdiens

Antalgics, antipyretics and non-steroidal anti-inflammatory drugs (NSAIDs) are widely used, but suspected allergic reactions to these drugs are rare, especially in children. Most frequent reactions are cutaneous (urticaria, angioedema) and respiratory (rhinitis, asthma). Other reactions (anaphylaxis or anaphylactoid reactions, potentially harmful toxidermias) are rare. In a few patients, reactions may result from a specific (allergic) hypersensitivity (HS), with positive responses in prick and intradermal tests (anaphylaxis, immediate urticaria and/or angioedema) and in intradermal and patch tests (non-immediate reactions). However, most reactions result from a non-specific (non-allergic) HS (intolerance), with a frequent cross-reactivity between the various families of antalgics, antipyretics and NSAIDs, including acetaminophen (paracetamol). Based on a convincing clinical history and/or positive responses in challenge tests, intolerance to antalgics, antipyretics and NSAIDs has been diagnosed in 13 to 50% of the patients with allergic-like reactions to these drugs. Risk factors for HS to antalgics, antipyretics and NSAIDs are a personal atopy and age. In our experience, 50% of the children with allergic-like reactions to antipyretics, antalgics and NSAIDs were diagnosed intolerant to these drugs. Risk was high in children reporting reactions to NSAIDs (aspirin, ibuprofen) and lower in children reporting reactions to paracetamol. All the children intolerant to paracetamol were also intolerant to NSAIDs. In contrast, most children with NSAID intolerance were tolerant to paracetamol. A personal history of atopy and a mean age ≥ 8 years were significant risk factors for intolerance to antalgics, antipyretics and NSAIDs.     

Artériopathie et hétérogénéité artérielle

More and more clinical observations and trials support the concept of heterogeneity of atheroma according to the arterial bed. In a pilot study named “Étude Comparative des Lésions Athéromateuses” (ECLA), we have shown that carotid and femoral plaques possess different characteristics. Carotid arteries display increased lipid content compared to femoral arteries whereas femoral arteries are more prone to calcify and to develop osteoid metaplasia. These observations should lead the researcher and the clinician to look at the cellular and molecular mechanisms governing the heterogeneity of atheromas. At last, a better understanding of the characteristics of plaques should help us to determine plaque stability, to prevent cardiovascular events and to choose the best medical, endovascular or surgical option.     

Protéine Z,polymorphismes du gène de la protéine Z et thromboses

Protein Z (PZ) is a vitamin K dependent protein acting as the cofactor of the protein Z dependent inhibitor (ZPI), in the inhibition of activated factor X bound on the phospholipids. Normal plasma protein Z concentrations have wide variations among individuals, partly explained by a genetic control. Several protein Z gene polymorphisms influence plasma concentration, separately and in combination. The role of PZ in blood coagulation regulation has been demonstrated in vitro. The responsibility of low PZ level in the occurrence of thrombosis has been questioned. However, the roles of PZ plasma level and PZ gene polymorphisms remain debated with conflicting results in arterial, venous, or placental thrombosis. These discrepancies can be explained by the heterogeneity of populations chosen as control, by the PZ interindividual variability, by the small size of the cohorts in mainly retrospective studies and perhaps by the lack of real important influence of this protein on coagulation. PZ measurement is not actually considered as a biological marker of thrombophilia. Large prospective studies remain to be done to investigate its possible role in thrombosis.