Could hemophagocytic lymphohistiocytosis be the core issue of severe COVID-19 cases?

• Published in: BMC medicine 2020-07, Vol.18 (1), p.214-11, Article 214
• Main Authors: Opoka-Winiarska, Violetta, Grywalska, Ewelina, Roliński, Jacek
• Format: Article
• Language: English
• Subjects: Acute respiratory distress syndrome; Bacterial pneumonia; Betacoronavirus; Coronavirus; Coronavirus disease 2019; Coronavirus Infections - complications; Coronavirus Infections - therapy; Coronaviruses; Cough; COVID-19; Cytokine Release Syndrome - virology; Cytokine storm; Cytokines; Development and progression; Dyspnea; Fever; Health aspects; Hemophagocytic lymphohistiocytosis; Histiocytosis; Humans; Hyperthermia; Immunodeficiency; Immunosuppressive agents; Immunotherapy; Infections; Inflammation; Inflammatory response; Laboratory tests; Lymphatic diseases; Lymphocytosis; Lymphohistiocytosis, Hemophagocytic - diagnosis; Lymphohistiocytosis, Hemophagocytic - therapy; Lymphohistiocytosis, Hemophagocytic - virology; Mortality; Myalgia; Opinion; Pandemics; Pathogenesis; Pneumonia; Pneumonia, Viral - complications; Pneumonia, Viral - therapy; Respiration; Respiratory diseases; Respiratory distress syndrome; SARS-CoV-2; Severe acute respiratory syndrome; Severe acute respiratory syndrome coronavirus 2; Signs and symptoms; Viral diseases; Viral infections
• ISSN: 1741-7015; 1741-7015
• DOI: 10.1186/s12916-020-01682-y

COVID-19, a disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), commonly presents as fever, cough, dyspnea, and myalgia or fatigue. Although the majority of patients with COVID-19 have mild symptoms, some are more prone to serious outcomes, including pneumonia, acute respiratory distress syndrome (ARDS), and even death. Hemophagocytic lymphohistiocytosis (HLH) is a severe, life-threatening inflammatory syndrome associated with intense cytokine release (also known as a "cytokine storm"). Similar to COVID-19, HLH is characterized by aggressive course leading to multi-organ failure. The purpose of this review article is to draw attention to the possibility of the complication of HLH in patients with the severe course of COVID-19. Indeed, some of the clinical characteristics observed in the more severe cases of COVID-19 are reminiscent of secondary HLH (which can be triggered by infections, malignancies, rheumatological diseases, or autoimmune/immunodeficiency conditions). The pathogenesis of SARS-CoV-2 infection also suggests that HLH or a similar hyperinflammatory syndrome is the cause of the severe course of the infection. The pathogenesis and clinical symptoms of severe COVID-19 indicate that an increased inflammatory response corresponding to HLH is occurring. Therefore, patients with severe COVID-19 should be screened for hyperinflammation using standard laboratory tests to identify those for whom immunosuppressive therapy may improve outcomes.