Severe Immune-Mediated Steroid-Refractory Thrombocytopenia in a Patient With COVID-19

Coronavirus disease 19 (COVID-19) has been associated with a wide variety of clinical signs and symptoms involving the respiratory, cardiovascular, and hematopoietic systems.Few cases of severe thrombocytopenia secondary to COVID-19 have been reported.COVID-19 can cause thrombocytopenia through mechanisms of disseminated intravascular coagulation (DIC), immune thrombocytopenic purpura (ITP), thrombotic thrombocytopenic purpura (TTP), deep venous thrombosis (DVT), pulmonary embolism (PE), autoimmune hemolytic anemia (AIHA), and bone marrow suppression.We present a case of a 65-year-old man who was recently diagnosed with lung cancer, presented with shortness of breath and cough, and was diagnosed with COVID-19.He was noted to have an abrupt platelet drop from 500,000 cells per mm³ to counts <2.Laboratory workup showed lactate dehydrogenase (LDH), bilirubin, and haptoglobin within normal limits and no evidence of schistocytes in the peripheral blood smear, but severe thrombocytopenia.His condition remained steroid-refractory.He was initiated on intravenous immunoglobulin (IVIG) by hematology, with subsequent improvement in platelet count to normal.COVID-19 is known to cause thrombocytopenia by various mechanisms.In patients with multiple risk factors, the risk of thrombocytopenia increases further.This patient had a diagnosis of rapidly progressing lung cancer, which puts him at risk of DIC, DVT, and PE, causing consumptive coagulopathy.He also had right-sided lung infiltrates and was initiated on empiric bacterial coverage with IV vancomycin and IV piperacillin-tazobactam, which may cause drug-induced thrombocytopenia.Bacterial pneumonia/sepsis also puts him at risk of thrombocytopenia, predominantly by consumption.When several etiologies for thrombocytopenia are possible, careful assessment of clinical findings, laboratory data, and temporal relationships is required to determine the most probable diagnosis.