Transplant glomerulopathy may occur in the absence of donor-specific antibody and C4d staining.
OBJECTIVE
Transplant glomerulopathy (TGP) has been proposed to be a component of chronic antibody-mediated rejection (AMR). We have studied 36 patients with TGP and 51 patients with chronic allograft nephropathy (CAN) but without TGP for C4d staining and donor-specific anti-HLA antibodies (DSA) to investigate the alloantibody-mediated mechanisms.


METHODS
Allograft biopsies were stained with C4d staining and DSAs were studied by Luminex Flow Beads. Allograft biopsies were done at a mean of 5.3 +/- 5.0 and 5.6 +/- 4.6 yr after transplantation in patients with CAN and TGP, respectively.


RESULTS
The mean creatinine level at the time of the biopsy was 2.7 +/- 1.2 mg/dl in each group. Proteinuria of >1.0 g/d was more common in patients with TGP (61 versus 25%; P = 0.002). Whereas three patients with TGP had a history of acute AMR, none of the patients with CAN had. Mean chronicity score of the biopsies were 1.7 +/- 0.7 in patients with CAN and 1.9 +/- 0.8 in patients with TGP. Biopsies from only two (4%) patients with CAN and four (11%) patients with TGP had diffuse C4d positivity. DSA were found in 36% of TGP and 33% of CAN patients.


CONCLUSIONS
These results suggest that a substantial number of patients with TGP did not have positive C4d staining or DSA, indicating that a non-alloantibody-mediated process may be involved in the development of TGP in some patients.
Akalin
Enver
E
Renal Division, Mount Sinai School of Medicine, New York, NY 10029-6574, USA. enver.akalin@msnyuhealth.org
Dinavahi
Rajani
R
Dikman
Steven
S
de Boccardo
Graciela
G
Friedlander
Rex
R
Schroppel
Bernd
B
Sehgal
Vinita
V
Bromberg
Jonathan S
JS
Heeger
Peter
P
Murphy
Barbara
B
D000328:Adult; D000368:Aged; D002908:Chronic Disease; D015935:Complement C4b / Q000032:analysis*; D005260:Female; D006084:Graft Rejection / Q000209:etiology* / Q000276:immunology / Q000473:pathology; D006680:HLA Antigens / Q000276:immunology*; D006801:Humans; D007518:Isoantibodies / Q000097:blood*; D007678:Kidney Glomerulus / Q000473:pathology*; D016030:Kidney Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000032:analysis*; D013194:Staining and Labeling; D014019:Tissue Donors; D014184:Transplantation, Homologous
D006680:HLA Antigens; D007518:Isoantibodies; D010446:Peptide Fragments; D015935:Complement C4b; C032261:complement C4d