Immune reconstitution inflammatory syndrome

Background

• Two main forms:
  • Unmasking: an underlying, previously undiagnosed infection becomes clinically apparent following immune reconstitution
  • Paradoxical: a diagnosed and treated infection worsens following immune reconstitution

Microbiology

• Mycobacteria
  • Mycobacterium tuberculosis
  • Mycobacterium avium complex
• Fungi
  • Cryptococcus neoformans
• Viruses
  • Cytomegalovirus
  • Kaposi sarcoma-associated herpesvirus

Risk Factors

• High viral load
• Low CD4 count

Clinical Manifestations

• Varies by underlying infection
• Onset usually a month following starting antiretrovirals, but can be up to a year
  • Mostly within 4 to 8 weeks of starting or changing ART, but with a range from 3 days to several months (or in case reports up to years)

Further Reading

• Central Nervous System Immune Reconstitution Inflammatory Syndrome. Curr Infect Dis Rep. 2013;15(6). doi: 10.1007/s11908-013-0378-5
  • Provides an overview of CNS-related IRIS syndromes.