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.