An Unusual Case of Recurrence of Crescentic IgA Nephropathy in Kidney Allograft

Introduction: IgA nephropathy (IgAN) is the most common cause of primary glomerular disease worldwide. Recurrence rates have been reported at around 20-30%. Long term graft survival was significantly lower in patients with recurrent IgAN. We describe a case of recurrent IgAN after kidney transplant with crescents. Case Description: A 35-year-old female with past medical history of ESKD due to biopsy proven IgAN underwent deceased donor kidney transplant with six antigen mismatches. Immunosuppression consisted of Alemtuzumab with Methylprednisolone, followed by long-acting tacrolimus and Mycophenolate mofetil. The patient experienced multiple urinary tract infections (UTI) and was maintained at low immunosuppression. The patients’ creatinine (cr) began to rise from 1.0 to 1.58 with hematuria and elevated urine UPCR of 0.39 g/g at 2.5 year follow up.Her DSA, non-invasive gene expression profile, and donor-derived cell-free DNA were all negative. A biopsy showed recurrent IgAN with focal crescents and glomerular fibrin (Image-1) . The patient was started on Prednisone 20mg daily for 2 weeks and then 10mg daily along with Losartan 12.5 mg daily for proteinuria. Her cr became stable at 1.23 and UPCR decreased to 0.2 g/g without hematuria. Discussion: Recurrent IgAN is common but recurrent crescentic IgAN is rare. Many factors can contribute to the recurrence of IgAN, such as lowering immunosuppression due to recurrent UTIs and steroid withdrawal. Nephrologists must be aware that IgAN can recur after renal transplantation with aggressive features. Close monitoring should be performed on urine sediment abnormalities, serum creatine, and proteinuria followed by prompt kidney allograft biopsy. Maintaining low dose of prednisone and ACEi or ARB may help to prevent recurrence of IgAN in a renal allograft.Image 1: Masson 's Trichrome (60x) showing a glomerulus with a cellular crescent and fibrin within capillary loops.