Figure 5.

Multidimensional analysis of biomarkers and T-cell phenotypes distinguishes patients with HLH-IRIS from those with IRIS not meeting HLH criteria. Principal component analysis combining the IFNγ–IL-18 axis biomarkers and T-cell phenotypes (activated CD4⁺, CD8⁺ T cells, and regulatory T cells) depicting the clustering of patients across the study groups at the IRIS time point. Individuals are represented by small colored circles for each group, whereas the overall group is represented by large colored circles. The week 4 time point was used for the non-IRIS cohort. There is a distinct separation of the HLH-IRIS cluster, emphasizing the unique pathophysiology in this subset of patients, which portends more severe inflammatory disease and the need for greater immunosuppression and close clinical monitoring. Analysis was performed in R using the FactoMineR and factoextra packages (R Foundation for Statistical Computing). Abbreviations: HLH, hemophagocytic lymphohistiocytosis; IFNγ, interferon-γ; IL, interleukin; IRIS, immune reconstitution inflammatory syndrome; PC, principal component.