Immune reconstitution syndrome and fungal infections

Purpose of review Fungal infections-related immune reconstitution syndrome (IRS) poses challenging diagnostic and management issues in immunocompromised hosts. This review summarizes the current state of knowledge regarding its pathophysiologic basis, presentation, and treatment strategies. Recent findings Existing evidence suggests that IRS is a state of an imbalance between protective immunity and inflammatory pathology versus anti-inflammatory responses that restrain inflammation. IRS has been observed in diverse hosts including HIV-infected patients initiating potent antiretroviral therapy, transplant recipients, pregnant women, and recipients of iatrogenic biologic agents. Among the most common fungal infections associated with IRS is cryptococcosis, although this entity has been documented during the course of invasive aspergillosis, histoplasmosis, and candidiasis. Unique risk factors for IRS have been recognized in specific hosts. Summary IRS is a culmination of immunologic sequelae of host-pathogen interaction during evolution of an opportunistic infection, and as such the development of biomarkers that differentiate it from progressive disease would represent an important advance. Optimal management of immunosuppression and immunomodulatory approaches that target precise regulatory pathways for IRS warrant future investigations.