Minimal Change Disease in a Patient with Sickle Cell Disease

Introduction: Renal complications of sickle cell disease (SCD) are common, however, minimal change disease (MCD) as a cause of nephrotic syndrome in SCD patients, to our knowledge, has not been reported. While controversial, there is evidence that focal segmental glomerulosclerosis (FSGS) and MCD may represent different presentations of the same disease process. We present an interesting case of nephrotic syndrome in a patient with SCD, with MCD demonstrated on biopsy and a clinical course detailed over a 9-year period. We propose that our patient’s case provides further support that idiopathic MCD and FSGS are presentations of the same disease process. Case Description: A 17-year-old female with history of SCD presented with one week of fever, left plank pain, and hematuria. BP was 128/74, HR 78, RR 14, and SpO2 98%. No edema was present. sCr was 2.3 mg/dL and she had 24 g/d proteinuria. Hemoglobin variants revealed Hgb S 64%. Renal biopsy showed diffuse foot process effacement, moderate to severe interstitial fibrosis and tubular atrophy, and no glomerular basement membrane changes. Biopsy findings were consistent with MCD. Our patient was initially treated with IV steroids for 3 days, then continued on oral prednisone and ACE-i, with reduction in Cr to 0.5 after 12 months. At extended follow-up 9 years later, Cr has remained stable at 0.8, however mild proteinuria of 1g/g has persisted. Urine protein to creatinine ratio remains elevated at 1600 mg/g and urine microalbumin remains elevated at 698.8 mg/L. At this time, she has CKD stage G2A3, attributed to a combination of previous biopsy proven MCD with interstitial fibrosis and tubular atrophy, hypertension, and sickle cell disease. Discussion: We propose that while our patient’s renal biopsy was consistent with MCD, her persistent steroid resistant nephropathy and significant interstitial fibrosis and tubular atrophy which has likely progressed given her prolonged proteinuria, suggests progression to FSGS. This aligns with ongoing study suggesting that MCD and FSGS are presentations of the same progressive disease. While both MCD and FSGS are histopathological forms of idiopathic nephrotic syndrome, potentially caused by circulating permeability factors, abnormal T cell function, or cytokine alterations impacting glomerular membrane permeability, these pathologies may be related with steroid resistant MCD potentially progressing to FSGS.