Infection-Associated Immune Reconstitution Inflammatory Syndrome in Hematopoietic Cell Transplantation

Area of Science:

• Immunology
• Hematology
• Infectious Diseases

Background:

• Immune reconstitution inflammatory syndrome (IRIS) is a known complication in HIV patients starting ART.
• Data on IRIS in hematopoietic cell transplantation (HCT) recipients are limited.
• This review addresses the knowledge gap regarding IRIS in the HCT population.

Purpose of the Study:

• To review the literature on IRIS in HCT recipients.
• To describe the clinical characteristics, triggers, and outcomes of IRIS in this population.
• To highlight the under-recognized nature of IRIS in HCT.

Main Methods:

• Narrative literature review.
• Inclusion of 21 studies with 53 HCT patients.
• Analysis of patient demographics, IRIS types (BCG-IRIS, non-BCG-IRIS), timing, and management.

Main Results:

• Most patients had inborn errors of immunity (IEI) and developed BCG-IRIS.
• Non-BCG-IRIS was linked to Aspergillus and non-tuberculous mycobacteria.
• Median time to IRIS was 3 months, but could occur years post-transplant.
• Inflammatory biomarkers and pathology aided diagnosis.
• Antimicrobial therapy was crucial for prevention and treatment.
• Recrudescence occurred with reduced immunosuppression.
• Graft-versus-host disease (GVHD) affected one-third of patients.
• Graft failure rate was 8% and mortality was 15%.

Conclusions:

• IRIS is an under-recognized complication in HCT recipients.
• Distinguishing IRIS from infection is critical.
• Appropriate antimicrobial therapy and immunosuppression management are vital.
• Further research into IRIS pathogenesis, risk factors, and management in HCT is needed.