Transplant Glomerulopathy and Dual Disease: An Uncommon Occurrence in Renal Allograft Biopsies
Srinivas Gottipati, Steven Wagner, Eduardo Vasquez-Martel, Joseph Gaut, Helen Liapis. Washington University, St Louis, MO; Complejo University Hospital, La Coruna, Spain
Background: Transplant glomerulopathy (TG) and recurrent glomerular disease are currently leading causes of renal allograft loss. Alloimmunity underscores TG in most cases and is a target for intervention. Whereas, both TG and recurrent glomerular disease are independent risk factors for decreased graft survival, the effect on outcome of concurrent TG and recurrent native glomerular disease has not been investigated.
Design: A retrospective review of the renal biopsy databases at Washington University in St. Louis and the Complejo University Hospital, La Coruna, Spain was performed. Clinical, laboratory data and follow up were collected. The biopsies were evaluated for acute/chronic rejection, IFTA, C4d deposition, cyclosporine toxicity and glomerular pathology. TG was scored on electron microscopy 1-3+ as follows: g1: subendothelial edema; g2: segmental glomerular basement membrane (GBM) duplication or multilamellation; g3: diffuse GBM duplication.
Results: 9 cases (from 1182 allograft biopsies) with dual glomerular disease were identified. TG with concurrent IgA (n=5), TG with DDD (n=1), TG with membranous glomerulonephritis (n=1), TG with collapsing glomerulopathy (n=1) and TG with thrombotic microangiopathy involving the glomeruli (n=1). Mean age was 47 ± 13 years; average 7.5 ± 7.9 years from transplant to biopsy. Mean follow up after diagnosis of TG was 1.7 ± 1.8 years. Mean proteinuria was 1802 ± 2685 mg/day at biopsy and 2252 ± 3210 mg/day at 1 year after biopsy. One pt. had acute rejection. IFTA 1-2+ was seen in all cases; chronic CNI in 3; acute glomerulitis in 2. Glomerular C4d+ in all cases but 1 IgA. Focal (2+) or diffuse (4+) C4d in PTC was present in 6; 3 IgA were C4d-. TG score was g1 in 3 (all IgA); TG g2 in 3 (2 IgA and 1 TMA) and TG=g3 in the rest. Two patients with concurrent IgA lost their graft 8 days and 38 months respectively. One pt with CNI toxicity, TG g2 and IgA had persistent functional decline and was re-listed for transplantation. 75% (6/9) of patients had slow renal function decline.
Conclusions: Dual disease is rare in allograft renal biopsies; TG with concurrent IgA is the most frequent. The distinct electron microscopic findings of TG are essential for definitive diagnosis of superimposed glomerular diseases. Rapid graft loss is more frequent in advanced TG with other co-existing risk factors, e.g., cyclosporine toxicity, or acute rejection, not just concurrent disease.
Category: Kidney (does not include tumors)
Wednesday, March 21, 2012 1:00 PM
Poster Session VI # 301, Wednesday Afternoon