HISTOPATHOLOGICAL SPECTRUM OF GLOMERULAR LESIONS IN RENAL TRANSPLANT RECIPIENTS R Duggal*, A Rana*, D Gautam*, V Raina*, R Ahlawat#, V Kher** Departments of Lab Medicine*, Urology # and Nephrology ** Medanta, The Medicity Hospital, Gurgaon, Haryana-122001, India Objectives: To study the spectrum of glomerular lesion in renal transplant recipients presenting with significant proteinuria and correlating them with clinical parameters. Methods: A total of 270 indicated renal transplant biopsies received over 2 years (May 2011 to May 2013) were reviewed and assessed for glomerular pathology. 50/270 biopsies (of 223 patients) had glomerular lesion which was further categorized based on the pattern of immunofluorescence (C4d, IgG, IgA, IgM, C3,C1q, kappa and lambda) and electron microscopic evaluation (in 20 cases). Results: All the selected 50 renal transplant recipients received triple drug immunosuppression and presented with >1g/day proteinuria. In addition, 24 patients presented with worsening renal function with progressive rise in serum creatinine (range 1.3 – 8.5mg/dl). Post-transplant biopsy period ranged from 1- 144 months. Transplant glomerulopathy (TG) is the most common glomerular lesion constituting 42%(21/50 cases) of all allograft biopsies with significant glomerular lesions. C4d staining in peritubular capillaries(PTC) was detected in 61.9% (13/21 cases) of histologically proven TG cases. The remaining cases with no C4d staining in peritubular capillaries showed diffuse and strong staining along glomerular capillary loops. The degree of proteinuria in TG cases correlated with percentage of globally sclerosed glomeruli rather than chronic glomerulopathy(cg) scores. C4d deposition was more commonly noted in cases of TG with peritubular capillaritis and glomerulitis and correlated with more rapid progression to graft dysfunction. Electron microscopic examination reveals peritubular capillary basement membrane multilayering (>7 layers) in all cases of TG and circumferential glomerular basement membrane multilamellations (in 6 cases). Other than TG, the remaining glomerular lesions noted were of IgA nephropathy (9 cases), focal segmental glomerulosclerosis (5 cases), moderate arterionephrosclerosis (7 cases), membranous glomerulonephritis (4 cases), diabetic nephropathy (3 cases) and recurrent C3 glomerulonephritis (1 case). The mean time posttransplant when the biopsy diagnosis was made was 32 months for transplant glomerulopathy (TG); 21 months for IgA nephropathy (IgAN); 14 months for focal segmental glomerulosclerosis (FSGS); 92 months for arterionephrosclerosis, 34 months for membranous glomerulonephritis (GN); and 84 months for diabetic nephropathy. Conclusions: Glomerular diseases contribute significantly to allograft dysfunction and a complete diagnosis needs proper evaluation of H&E together with special stains, immunofluorescence and electron microscopy.