Immune Reconstitution Inflammatory Syndrome (IRIS): What pathologists should know

Area of Science:

• Immunology
• Virology
• Infectious Diseases

Background:

• Antiretroviral therapy (ART) has transformed HIV/AIDS care, improving patient quality of life and longevity.
• HIV infection profoundly impacts the immune system, causing defects in both innate and adaptive immunity.
• Advanced HIV stages disrupt lymphoid tissue and impair antigen processing, hindering pathogen-specific responses.

Purpose of the Study:

• To discuss the impact of HIV infection on the immune system.
• To provide an overview of the spectrum of conditions associated with Immune Reconstitution Inflammatory syndrome (IRIS).

Main Methods:

• Review of existing literature on HIV immunopathogenesis.
• Analysis of immune system alterations during HIV infection and ART.
• Documentation of changes in opportunistic infections and histologic reactions.

Main Results:

• HIV infection causes complex immune alterations, including CD4 T cell defects, cytokine loss, and impaired B-cell function.
• Immune reconstitution can lead to atypical inflammatory syndromes (IRIS) during treatment.
• Some immune defects may persist even with effective ART.

Conclusions:

• HIV significantly disrupts immune function, affecting both acute and chronic inflammatory responses.
• IRIS is a significant clinical consideration during immune reconstitution in HIV patients.
• Understanding these immune dynamics is crucial for managing HIV and its complications.