Déficits immunitaires primitifs: approche diagnostique pour les pays émergents

International audiencePrimary immunodeficiencies (PIDs) correspond to various genetic diseases characterized by a heterogeneous clinical expression in children and a frequent revelation in adults Faced to clinical suspicion of an immune deficiency, the existence of syndrome features may evoke defined PID entities that need specific immunological analysis Otherwise, the diagnostic approach of PID requires four steps the first one is to rule out an acquired immune deficiency mainly HIV infection The second step is based on elementary biological investigations cell blood count, measure of G, A, and M immunoglobulins combined or not to protein electrophoresis, and an assessment of total hemolytic complement This line of analysis permit to discriminate cellular, humoral, phagocytic or complement deficiencies which can be further illustrated using specialized immunological investigations such as lymphocyte subpopulations phenotyping, quantification of immunoglobulin subclasses, detection of specific antibodies, T lymphocytes proliferation assay, nitroblue tetrazolium reduction (NBT) test, CD18 phenotyping, measure of C3 and C4 complement components The last step needs collaboration with genetic research laboratories in order to establish the genotype of the immunodeficiency (C) 2010 Elsevier Masson SAS All rights reservedLes déficits immunitaires primitifs (DIP) correspondent à environ 300 maladies génétiques actuellement connues, d’expression clinique hétérogène se révélant parfois tardivement chez l’adulte. Devant la suspicion d’un déficit immunitaire, la présence de signes syndromiques permet d’emblée d’évoquer des entités de DIP bien définies nécessitant un bilan étiologique spécifique. Sinon, dans l’optique d’optimiser les moyens exploratoires, la mise en évidence d’un DIP impose une démarche diagnostique en étapes. La première étape vise surtout à éliminer un déficit immunitaire acquis notamment, une infection à VIH ; la deuxième étape repose sur un bilan biologique de base (numération formule sanguine-plaquette, dosage des immunoglo-bulines [IgG, IgA, IgM] et/ou électrophorèse des protides, étude du complément hémolytique CH50). Confronté à la clinique, ce bilan initial permettra de distinguer quatre catégories de déficits : cellulaire, humoral, phagocytaire ou du complément pour lesquels la troisième étape grâceà des explorations immunologiques spécialisées (étude des sous-populations lymphocytaires, dosage des sous-classes d’Ig, recherche d’anticorps spécifiques, tests de prolifération lymphoctaire, test au NBT, étude phénotypique de CD18, dosage des fractions du complément... ) permettra de confirmer le DIP et de préciser sa nature. Enfin, la quatrième étape sera menée en collaboration avec des laboratoires de recherche spécialisés pour déterminer le type moléculaire du déficit

Clinical and immunological status of a newly diagnosed HIV positive population, in Marrakech, Morocco

Objective: To evaluate the clinical and the immune status of newly HIV diagnosed patients, in Marrakech city and its neighboring area, in Morocco. Methods: We performed a retrospective study on 235 patients who have been previously confirmed for HIV infection, and underwent a CD4 T cells using flow cytometry (FacsCount, Becton Dickinson®). Results: The mean age of patients was 34,3 ± 8,4 years (range: 14-55), with a male predominance (sex-ratio M/F=1.4). On basis of clinical data of the patients, 62% (n=146) of them were categorized as "category C", 18.4% (n=43) as "category B", and 19.6% (n=46) as "category A" according to CDC (Center for Disease Control) HIV classification. Among all of them, 60.4% (n=142) had less than 200 CD4T cells, 26% (n=61) had between 200 and 499 CD4T cells, and only 13.6% (n=32) showed a number of CD4T cells less or equal to 500/mm3. Conclusion: The results of this study reflect a significant delay in the diagnosis of HIV infected patients. Therefore, this delay may compromise timely management of HIV infected individuals and enhances propagation of the epidemic in our country. These data confirm the need for intensifying prevention efforts among high-risk population. Moreover, continuing education in HIV/AIDS among healthcare providers should be reinforced