# Distinguishing Hemophagocytic Lymphohistiocytosis, Immune Reconstitution Inflammatory Syndrome, and HIV-Associated Immune Thrombocytopenic Purpura: A Challenging Case of Thrombocytopenia in AIDS

## TL;DR

This paper discusses a complex case of thrombocytopenia in an AIDS patient, highlighting the diagnostic challenges in distinguishing between HLH, IRIS, and HIV-ITP.

## Contribution

The study emphasizes the need for a systematic, exclusion-based approach to diagnose overlapping hematologic conditions in immunocompromised patients.

## Key findings

- The patient's thrombocytopenia was most likely due to HIV-ITP after ruling out HLH and IRIS.
- A systematic diagnostic approach is crucial in complex cases with overlapping clinical features.
- Inconsistent ART adherence can complicate the clinical presentation and diagnosis.

## Abstract

Thrombocytopenia is a frequent hematologic complication in advanced HIV/AIDS, presenting significant diagnostic challenges due to overlapping etiologies. Hemophagocytic lymphohistiocytosis (HLH), immune reconstitution inflammatory syndrome (IRIS), and HIV-associated immune thrombocytopenic purpura (HIV-ITP) can all manifest with overlapping clinical features, which, despite their differing frequencies, may complicate diagnosis and management. We present a case of a 33-year-old male patient with advanced HIV/AIDS, metastatic Kaposi sarcoma, and inconsistent antiretroviral therapy (ART) adherence, who developed progressive thrombocytopenia, anemia, and pancytopenia. Initial workup, including an elevated HScore, suggested a possible HLH diagnosis; however, further immunologic testing did not meet HLH criteria. In the absence of definitive findings, HIV-ITP was identified as the most likely etiology. This case highlights the importance of a systematic, exclusion-based diagnostic approach in evaluating thrombocytopenia in immunocompromised patients, particularly when multiple concurrent conditions obscure the clinical picture.