[Immune reconstitution inflammatory syndrome or IRIS]

The immune reconstitution inflammatory syndrome is a heterogeneous collection of pathological manifestations attributed to an excessive and deregulated immune response to various infectious and non-infectious 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.