Syndrome inflammatoire de reconstitution immune

Abstract

Le syndrome de reconstitution immune regroupe l’ensemble des manifestations inflammatoires survenant lors de la reconstitution d’une réponse immune excessive et insuffisamment régulée vis-à-vis d’antigènes infectieux ou non infectieux, chez un individu au décours d’une phase d’immunodépression. Ce syndrome est observé dans des contextes d’immunodépression/ reconstitution très divers : reconstitution immune obtenue grâce aux antirétroviraux au cours de l’infection par le VIH, diminution d’un traitement immunosuppresseur au décours d’une transplantation, sortie d’aplasie après chimiothérapie, ou encore période du post-partum. La reconnaissance d’une entité unique commune à toutes ces situations pourra aider à en déterminer la physiopathologie qui reste encore incertaine. Cette compréhension est en effet un prérequis pour le développement de thérapies, en particulier préventives.

The immune reconstitution inflammatory syndrome is a heterogeneous collection of pathological manifestations attributed to an excessive and deregulated immune response to various infectious and noninfectious pathogens consecutive to the modification of immune status. Mycobacteria and mycoses in the context of an HIV infection are the main causes of IRIS but this syndrome is also observed with many infectious pathogens in the context of auto-immune or inflammatory diseases. An excessive specific CD4 Th1 response leading to delayed hypersensitivity with imbalanced effector and regulatory cellular immune responses is suggested. The role played by host polymorphisms remains to be investigated. The emergence of a unique syndrome gathering multiple immune-depression/reconstitution such as HIV infection and antiretroviral therapy, decrease of immune depression in transplant, recovery from neutropenia after chemotherapy for cancer, and even post-partum period, could link various specialties and help to better understand physiopathology which is crucial to elaborate preventive therapies.