Likely Recurrence of C3 Glomerulonephritis in Kidney Transplantation: An Entity to Bear in Mind: Case Report.

Abstract Background C3 glomerulonephritis (C3GN) is an unusual entity that is caused by dysregulation and hyperactivity of the alternative complement pathway. Renal biopsy immunofluorescence study shows C3 deposits with absence of immunoglobulins and markers of the classical complement pathway. More than 50% of cases develop end-stage renal disease. Less well-known is the course of C3GN after kidney transplantation. Case Report We present the case of a 60-year-old woman with chronic kidney disease secondary to chronic glomerulonephritis of unknown origin who received a kidney transplant. Two years later, she presented worsening renal function with non-nephrotic proteinuria and microhematuria. Complement testing revealed low serum levels of C3. Kidney biopsy showed alterations compatible with C3GN that we interpreted as a relapse of the underlying disease.