Dilemma of Tocilizumab therapy for a patient with critical COVID-19 disease and neutropenia: Case report and review of the literature.

Infection following SARS-Co V-2 leading to COVID-19 disease is associated with significant morbidity and mortality. The clinical entity, COVID-19 cytokine storm syndrome (CSS) is a severe immunological manifestation of the disease associated with ominous consequences. Tocilizumab is interleukin-6 inhibitors that has been shown to hamper the catastrophic outcomes of CCS including the need for mechanical ventilation as well as reduce mortality, but the usage is limited by warnings of reactivation of potential latent infections or immune dysfunctions including severe neutropenia. We describe a case of 39-year-old Nepalese male patient with a background of scleritis maintained on azathioprine and rituximab therapy with normal baseline parameters including complete blood count who presented with acute COVID-19 infection including associated leukopenia as well as severe neutropenia (absolute neutrophil count of 300 cells/µl), then progressed to critical disease culminating into CSS. Based on risks and benefits evaluation, the patient was treated with tocilizumab reinforced with granulocytes-colony stimulating factor (G-CSF, Filgrastim) to full recovery and safe outcome including reversal of neutropenia.