Analiza immunofenotypowa i znaczenie kliniczne w pediatrycznej limfohistiocytozie hemofagocytarnej

This study characterizes changes in peripheral blood lymphocyte subsets among pediatric hemophagocytic lymphohistiocytosis (HLH) patients. Compared to healthy controls, HLH patients exhibited significantly elevated levels of CD8⁺ T cells, with concomitant reductions in B cells, CD4⁺ T cells, DPT cells, DNT cells, and the CD4⁺/CD8⁺ T cell ratio as determined by multiparametric flow cytometry. Organ dysfunction was further correlated with distinct immunophenotypic alterations. Specifically, respiratory dysfunction was associated with decreased CD4⁺ CM T cells, naïve B cells, plasmablasts, and transitional B cells; hepatic dysfunction with increased CD4⁺ Temra T cells; circulatory failure with reduced transitional B cells; and neurological dysfunction with elevated CD4⁺ Temra T cells and CD8⁺ EM T cells. Moreover, HLH patients exhibiting three or more organ dysfunctions demonstrated significantly lower levels of DPT cells, memory B cells, transitional B cells, and plasmablasts. Additionally, CD8⁺ T cells and CD8⁺ CM T cells showed positive correlations with pro-inflammatory cytokines (IL-6, TNF-α). These results suggest that depletion of CD4⁺ T cells and B cells, along with aberrant CD8⁺ T cell differentiation, may contribute to the pathogenesis of cytokine storms. These findings support dynamic monitoring of lymphocyte subsets, demonstrating potential utility for early HLH diagnosis and organ damage assessment.