Minimal Change Disease and IgA Deposition: Separate Entities or Common Pathophysiology?

Introduction. Minimal Change Disease (MCD) is the most common cause of nephrotic syndrome in children, while IgA nephropathy is the most common cause of glomerulonephritis worldwide. MCD is responsive to glucocorticoids, while the role of steroids in IgA nephropathy remains unclear. We describe a case of two distinct clinical and pathological findings, raising the question of whether MCD and IgA nephropathy are separate entities or if there is a common pathophysiology. Case Report. A 19-year old man with no medical history presented to the Emergency Department with a 20-day history of anasarca and frothy urine, BUN 68？mg/dL, Cr 2.3？mg/dL, urinalysis 3+ RBCs, 3+ protein, and urine protein？:？creatinine ratio 6.4. Renal biopsy revealed hypertrophic podocytes on light microscopy, podocyte foot process effacement on electron microscopy, and immunofluorescent mesangial staining for IgA. The patient was started on prednisone and exhibited dramatic improvement. Discussion. MCD typically has an overwhelming improvement with glucocorticoids, while the resolution of IgA nephropathy is rare. Our patient presented with MCD with the uncharacteristic finding of hematuria. Given the improvement with glucocorticoids, we raise the question of whether there is a shared pathophysiologic component of these two distinct clinical diseases that represents a clinical variant. 1. Introduction Minimal Change Disease (MCD) is the most common cause of nephrotic syndrome in children, while IgA nephropathy is the most common cause of glomerulonephritis worldwide. MCD is responsive to glucocorticoids, while the role of steroids in IgA nephropathy remains unclear. We describe a case of two distinct clinical and pathological findings, raising the question of whether MCD and IgA nephropathy are separate entities or if there is a common pathophysiology. Minimal Change Disease (MCD) is the most common cause of nephrotic syndrome in children. It accounts for 70–90% of cases in children less than 10 years of age and 50% of cases in older children [1]. Clinical symptoms are typically preceded by an upper respiratory infection or recent use of medication. Common clinical manifestations include abrupt onset of edema, proteinuria, hyperlipidemia, and hypoalbuminemia [2]. IgA nephropathy is the most common cause of glomerulonephritis worldwide. The prevalence of IgA nephropathy is significantly higher in Asia than in the United States. IgA nephropathy is present in 40% of biopsies for glomerular disease in Asia, compared to 10% of biopsies in the United States. IgA nephropathy most commonly