Diabetic Nephropathy Complicated by an IgA-Dominant Infectious-Related Glomerulonephritis: A Case Report

Introduction: Acute post-infectious glomerulonephritis (APIGN), in adulthood is common in diabetic, alcoholic, and intravenous drug-abusing patients. APIGN is usually secondary to Staphylococcus aureus infection, occurring after skin infection, deep-seated abscesses and presents a histological pattern identical to acute poststreptococcal glomerulonephritis. This case reported a diabetic nephropathy complicated by an IgA-dominant infectious related glomerulonephritis Case Description: A 27-year-old female with past medical history of hypertension, diabetes mellitus type 1 and chronic kidney disease was admitted due to acute renal failure, high blood pressure and uncontrolled diabetes mellitus. Physical examination showed bilateral periorbital edema, lower extremities pitting edema, and the presence of left frontal skin abscess. Uncontrolled blood glucose, anemia, hyperkalemia, impaired renal function was documented. Urinalysis revealed moderate urine blood with high total protein. The C4 /C3 complements and anti streptolysin O were within normal rage. Immunological workup was normal including antinuclear antibody and anti-DNA. Head abscess culture was positive for Staphylococcus aureus, and due to a massive proteinuria, renal biopsy was performed. The mesangium biopsy shows PAS-positive nodular mesangial expansion and interstitial fibrosis. Immunofluorescence findings showed capillary loops staining for IgA, C3 and lambda, subepithelial immune type electron dense deposits and global effacement of foot processes consistent with diabetic injury, likely with superimposed port-infectious glomerulonephritis. Discussion: Few cases have been reported in Puerto Rico, and a major shift has occurred in the epidemiology of this disease. Worldwide numerous cases of APIGN have been identified with intense deposits of IgA as the sole or dominant immunoglobulin on immunofluorescence, similar to our case,characterizing a new entity named IgA-dominant acute post infection glomerulonephritis (GN) The massive proteinuria and the rapid deterioration of renal function in our diabetic patient should suggest that an additional pathologic condition is affecting the kidneys. An IgA-dominant infection related GN was diagnosed, and after treated with antibiotic therapy our patient recovered from the disease and was discharge to home.