association of hscore parameters with severe covid-19: a systematic review and meta-analysis

background: several reports have associated the severe coronavirus disease-2019 (scovid-19) with secondaryhemophagocytic lymphohistiocytosis (shlh) and proposed utilizing the hemophagocytic syndrome diagnostic score (hscore) for scovid-19 patients. we conducted a systematic review and meta-analysis to find the possible association of hscore parameters with severity in covid-19 patients. methods: a systematic search was performed in medline via pubmed, embase, and cochrane databases using all hscore and covid-19 keywords. the studies were all from 2020, and the study language was limited to english. the records were screened based on inclusion/exclusion criteria. random/ fixed-effect models were employed for meta-analysis, based on the i2 index of parameters. the pooled mean differences were estimated for continuous parameters. the pooled odds-ratio was estimated for fever. the level of significance was set at 0.05. results: eighteen studies (comprising 2459 patients) out of 26151 screened studies were included in this meta-analysis. the results showed that the level of leukocyte, neutrophil, aspartate transaminase (ast), ferritin, and fibrinogen were significantly higher in scovid-19 patients than in non-severe ones. significant lower levels of lymphocyte, platelet, and hemoglobin were also found in scovid-19 patients than nonsevere patients. fever was nearly associated with two times increased odds of scovid-19 (p=0.051). conclusion: lymphopenia, thrombocytopenia, hypohemoglobinemia, hyperferritinemia, high levels of ast, and fever are common features of both scovid-19 and hlh. however, the leukocytosis, neutrophilia, and hyperfibrinogenemia found in scovid-19 are in contrast with hscore. conclusively, hscore parameters could be risk factors for scovid-19. however, some parameters’ roles are contradictory, suggesting the need for further investigation and a new way of hscore interpretation in scovid-19 patients.