Table 1.

Moderately severe to severe COVID-19 as a form of sHLH. sHLH—secondary haemophagocytic lymphohistiocytosis; COVID-19—coronavirus disease 2019; HLH—haemophagocytic lymphohistiocytosis; IL-6—interleukin 6.

Moderately Severe to Severe COVID-19	sHLH
prevalence in pregnant women—rarely diagnosed
aetiology
viral infection	viral infection in most cases
hyperferritinaemia
marker of poor prognosis in COVID-19 patients	the most characteristic laboratory result of HLH
treatment
treatment aimed at suppressing the cytokine storm
high mortality
increased levels of IL-6