A case of severe thrombocytopenia in a patient with COVID-19 receiving continuous venovenous hemodialysis

Introduction: We describe a patient with COVID-19 and clinically significant kidney biopsy proven TMA Case Description: 69-year-old Caucasian female with medical history of asthma came to the ED with productive cough, fever and dyspnea for 2 weeks She was afebrile, tachypneic and hypoxic Initial laboratories showed a normal WBC, hemoglobin level and platelet count Inflammatory markers were elevated SARS-CoV-2 infection was confirmed by PCR assay CXR showed bilateral diffuse patchy opacities Treated with hydroxychloroquine, enoxaparin and oxygen was started Patient received anakinra and tocilizumab On day 12, the patient developed thrombocytopenia, anemia and worsening kidney function concerning for microangiopathic hemolytic anemia Due to worsening hypoxemia, patient received convalescent plasma On day 17, she was intubated due to worsening respiratory failure Findings suggestive of hemolysis were present Urinalysis showed hematuria and proteinuria Patient's kidney function worsened requiring initiation of CRRT On day 20, the patient underwent a kidney biopsy that revealed severe acute TMA with cortical necrosis Beta 2 glycoprotein-1 IgM levels were elevated, antiphospholipid antibodies were absent A disintegrin and ADAMTS13 level were not low C3,C4 were in normal range Heparin induced antibody testing was negative Coagulation parameters were normal Kidney doppler was unremarkable No other systemic findings of macro thrombi were found Low factor H complement antigen, elevated plasma CBb complement and plasma SC5b-9 complement levels suggesting an activation of the alternative complement pathway were found Genetic testing was not done Plasma exchange was not performed, but received a single dose of eculizumab on day 21 Unfortunately, she died on day 23 Discussion: Coagulopathy associated with SARS-CoV-2 has been widely reported Profound hypoxia, inflammation, disseminated intravascular coagulation(DIC) have all been implicated as potential causes, but were not present in our patient To the best of our knowledge, we report the first case of TMA associated with SARS-CoV-2 with presence of diffuse cortical necrosis and widespread microthrombi in kidney biopsy It is not clear if the virus played a direct pathogenic role or unmasked a latent complement defect leading to widespread endothelial damage and micro thrombi