COVID-19 ASSOCIATED COLLAPSING VARIANT OF FOCAL SEGMENTAL GLOMERULOSCLEROSIS: A CASE SERIES OF 7 PATIENTS FROM A SINGLE UK CENTRE

ABSTRACT

BACKGROUND AND AIMS: Cases of collapsing glomerulopathy in association with COVID-19 infection have been reported worldwide, frequently referred to as COVAN (COVID-19 Associated Nephropathy). Affected patients are almost exclusively of Black ethnicity, likely associated with APOL-1 renal risk variants. There remains a paucity of data on patient outcomes, however, and it is unclear how the natural history of this disease may vary from HIV-associated nephropathy (HIVAN) and other non-viral causes of collapsing FSGS. Here, we present a case series of seven patients with presumed COVAN from a single tertiary UK renal centre;highlighting patient demography, biopsy findings, clinical management and short-term renal outcomes. METHOD: We identified all adult patients presenting to our centre with nephrotic syndrome and a renal biopsy demonstrating collapsing glomerulopathy, in association with a positive COVID-19 PCR swab result. Detailed case note reviews were undertaken using electronic health records to extract data relevant to patient demography, co-morbidities, COVID -19 symptoms, renal biopsy findings, treatment and biochemical parameters, both at the time of presentation and during follow-up at 1, 3, 6 and 12 months respectively (where available). RESULTS: In total, we identified seven patients with presumed COVAN. Three of the seven patients were male, median age was 60 years (range 25-80 years). Six of the seven patients were of Black ethnicity and one patient was of South Asian ethnicity (renal transplant recipient with donor ethnicity unknown). All seven patients had a background of hypertension, 5/7 had known chronic kidney disease (CKD), 5/7 had type 2 diabetes mellitus (T2DM) and 4/7 were obese (BMI > 30). In the vast majority of cases, associated COVID-19 symptoms were mild. All patients had profound nephrotic syndrome at the time of renal biopsy, with median urine ACR 1085 mg/mmol (range 682-1380 mg/mmol) and median serum albumin 15 g/L (range 8-20 g/L). Two of seven patients had mild AKI (stage 1) and 5/7 patients had severe AKI (stage 3), with 3 of these patients receiving acute haemodialysis therapy. Management of glomerulopathy was supportive in all cases, including diuresis and anticoagulation (two patients received a short course of oral dexamethasone for their COVID-19 symptoms). ACE inhibitors/angiotensin receptor blockers were re-introduced in two patients and newly commenced in two further patients during follow-up. At 6 months follow-up, one patient remained dialysis dependant and one patient had ongoing decline in renal function (renal transplant recipient);all other patients achieved at least partial remission, with > 50% reduction in urine ACR and some (but not complete) recovery in renal function (Fig. 1). There were no viral particles identified on direct examination of renal biopsy specimens, but 4/7 biopsies exhibited tubulo-reticular inclusions, suggesting an interferon-driven systemic inflammatory process. CONCLUSION: In this case series of seven COVAN cases from a single tertiary UK centre, we noted that in keeping with reports from North America, Black ethnicity patients were disproportionately affected. Partial remission was achieved in most of our cases with supportive treatment only;however, ongoing monitoring of this cohort is required to better understand longer-term patient outcomes. Testing for APOL-1 gene mutations and molecular testing of biopsy samples for this cohort is also ongoing to facilitate better insights into pathophysiology and risk factors associated with this novel disease. (Figure Presented).