Risk factors for secondary hemophagocytic lymphohistiocytosis in severe coronavirus disease 2019 adult patients

BACKGROUND: Secondary hemophagocytic lymphohistiocytosis (sHLH) is a life-threatening hyperinflammatory event and a fatal complication of viral infections Whether sHLH may also be observed in patients with a cytokine storm induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is still uncertain We aimed to determine the incidence of sHLH in severe COVID-19 patients and evaluate the underlying risk factors METHOD: Four hundred fifteen severe COVID-19 adult patients were retrospectively assessed for hemophagocytosis score (HScore) A subset of 7 patients were unable to be conclusively scored due to insufficient patient data RESULTS: In 408 patients, 41 (10 04%) had an HScore >=169 and were characterized as "suspected sHLH positive" Compared with patients below a HScore threshold of 98, the suspected sHLH positive group had higher D-dimer, total bilirubin, alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen, serum creatinine, triglycerides, ferritin, interleukin-6, C-reactive protein, procalcitonin, lactate dehydrogenase, creatine kinase isoenzyme, troponin, Sequential Organ Failure Assessment (SOFA) score, while leukocyte, hemoglobin, platelets, lymphocyte, fibrinogen, pre-albumin, albumin levels were significantly lower (all P 1922 58 ng/mL), low platelets (9/L) and high triglycerides (>2 28 mmol/L) were independent risk factors for suspected sHLH in COVID-19 patients Importantly, COVID-19 patients that were suspected sHLH positive had significantly more multi-organ failure Additionally, a high HScore (>98) was an independent predictor for mortality in COVID-19 CONCLUSIONS: HScore should be measured as a prognostic biomarker in COVID-19 patients In particular, it is important that HScore is assessed in patients with high ferritin, triglycerides and low platelets to improve the detection of suspected sHLH