Immune Reconstitution Inflammatory Syndrome (IRIS)
Hannah Angle
Background
- An inflammatory syndrome characterized by the worsening of a pre-existing infection in patients with HIV after antiretroviral therapy (ART) initiation
- Typically develops between 1 week to a couple months after starting ART
- Patients with lower CD4 counts and higher viral loads who respond well to ART are at higher risk of IRIS
Evaluation
- IRIS is a clinical diagnosis
- Presentation consistent with either a systemic or localized inflammatory response (specific clinical features dependent on underlying infection)
- Most often seen in patients with significantly decreased CD4 counts who have a profound virologic and immunologic response to ART
- Infections most associated with IRIS include CMV, PJP, HSV, HBV, HHV-8, Cryptococcus neoformans, Mycobacterium tuberculosis, and Mycobacterium avium complex (MAC)
- Need to rule out drug-resistant infection or nonadherence to antimicrobials, bacterial superinfection, or medication adverse effect
Management
- Prior to ART initiation, must evaluate for all opportunistic infections (OI), especially when an inflammatory response could cause swelling in an enclosed space (cryptococcal meningitis/encephalitis, tuberculous meningitis, CMV retinitis)
- If these serious CNS infections are identified, initiation of ART is often delayed until OI is well-controlled with antimicrobials
- IRIS is usually a self-limited syndrome as long as infection is adequately treated
- Patients with IRIS should continue both ART and antimicrobial treatment for underlying OI
- In severe cases, glucocorticoids can be used to decrease inflammation
