Elevated Interleukin-10 Levels Are Associated with Low Platelet Count and Poor Prognosis in 90 Adult Patients with Hemophagocytic Lymphohistiocytosis

Abstract

Introduction: Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening syndrome characterized by excessive inflammatory responses. This study explored the association between laboratory characteristics and outcomes in adult patients with HLH. Methods: The adult patients diagnosed with HLH at the Second Hospital of Shanxi Medical University from September 2016 to September 2021 were retrospectively analyzed in this study. Results: A total of 90 HLH patients were included. Among them, 60% were males, with a median age at diagnosis of 54 years. More than 85% of HLH patients presented with fever, splenomegaly, and cytopenias. IL-10 and IL-6 were elevated in 93.3% and 91.1% of patients, respectively. Elevated IL-10 levels were associated with lower platelet counts (r = −0.37, p < 0.001). Infections were seen in 46.7% (42/90) of cases. 29 patients with malignancy-associated HLH had T- or NK-cell (n = 16) or B-cell (n = 12) lymphoma. Autoimmune diseases accounted for 21.1% (19/90). Treatment was variable. In total, 36 patients survived (40%). The median overall survival (OS) was 1.5 months (95% confidence intervals [CI]: 0.2–2.8 months), with a 1-year OS of 40.9%. Patients with autoimmune diseases had markedly longer survival than those triggered by infection and malignancy (p < 0.001). Multivariate Cox regression analysis indicated that treatment delays (hazard ratios 0.36, 95% CI: 0.14–0.94, p = 0.036), platelet count (2.33, 1.30–4.18, p = 0.005), and IL-10 (2.07, 1.16–3.68, p = 0.014) were independent risk factors for poor outcome. Conclusion: Infection and lymphoma are the leading causes of HLH in adult patients with heterogeneous clinical manifestations. Survival of adult HLH is frustrating, especially those associated with malignancies. Besides, elevated IL-10 levels were associated with lower platelet counts, and these two markers were independent risk factors for poor prognosis. Earlier treatment led to better outcomes.