Risk factors of early death in adult patients with secondary hemophagocytic lymphohistiocytosis: a single-institution study of 171 Chinese patients

Background: Adult secondary hemophagocytic lymphohistiocytosis (HLH) is a potentially life-threatening syndrome characterized by excessive activation of mononuclear-phagocytic system resulting in hyperinflammatory response. To date, the factors influencing early death of HLH are still not fully elucidated. Patients and Methods: We did a retrospective study of 171 adult patients with newly diagnosed HLH at our institution from January 2012 to April 2018. All patients' clinical features, laboratory findings, treatments and prognosis were reviewed. Results: The median age was 49 years (range, 18-88 years), and 110 (64.3%) were male. The major underlying trigger of HLH was malignancy (88/171, 51.5%), especially non-Hodgkin lymphoma. In a multivariate analysis, age ≥54 years (P = 0.002), platelet ≤39.5 × 10⁹/L (P = 0.028), activated partial thromboplastin time (APTT) ≥54 sec (P = 0.048), triglyceride ≥3.23 mmol/L (P < 0.001), lactate dehydrogenase (LDH) ≥1300 U/L (P = 0.012) and malignancy (P = 0.001) were significantly associated with early death in HLH. Then, patients were classified into four groups according to the number of risk factors at the time of diagnosis: low risk (zero, one or two risk factors), low intermediate risk (three risk factors), high intermediate risk (four risk factors) and high risk (at least five risk factors), with the 30-day overall survival (OS) of 92.4%, 58.8%, 30.0% and 4.8%, respectively (P < 0.001). Conclusions: Patients with old age, thrombocytopenia, prolonged APTT, hypertriglyceridemia, elevated LDH and malignancy had inferior survival. It is important to identify those patients at risk of early death, which may guide treatment and reduce mortality.