Collapsing FSGS in COVID-19

ABSTRACT

Introduction: The pandemic of novel coronavirus disease (COVID-19) has been complicated by high incidences of acute kidney injury (AKI). A virus-associated focal segmental glomerulosclerosis (FSGS) has been reported. We present a case of collapsing FSGS in a patient with severe acute respiratory syndrome coronavirus 2. Case Description A 56-year-old African-American (AA) man with hyperlipidemia and new diagnosis of COVID-19 the week prior, was admitted for vomiting, abdominal pain, and non-oliguric AKI with creatinine (Cr) of 4.97 mg/dL. Labs done within the year showed Cr of 1.1 mg/dL and microalbuminuria of 44 mcg/mg. An ER visit 3 days prior for fever and cough revealed a serum Cr of 1.47 mg/dL. CT abdomen/pelvis with IV contrast showed no obstruction. Urinalysis showed +2 protein and 2 RBCs/hpf. A 24-hour urine protein showed proteinuria of 15 grams. HIV and drug screen was negative. Renal biopsy showed FSGS with collapsing features, no cellular crescents, and severe acute tubular injury. Electron microscopy did not show viral particles. Two months later, the patient remained on hemodialysis. Discussion: A challenge facing this pandemic is lack of knowledge of the pathology of COVID-19. Reports from post-mortem renal biopsies in China showed the majority were due to acute tubular injury with only 2 of 26 cases due to FSGS, none of the collapsing variant. However, there are at least 5 reports in the literature of COVID-19 complicated by De novo collapsing FSGS in patients of African descent, of which 2 tested positive for the APOL1 genotype. The collapsing variant of FSGS is known to occur more commonly in AA patients, who are high risk for APOL1 genotype. In viral infections, this genotype can be upregulated and promote development of FSGS. Although not directly tested, it cannot be excluded as a predisposing factor in our patient. In patients with COVID-19 and proteinuric AKI, especially in African-Americans, collapsing FSGS should be considered.