Electron microscopic peritubular capillary lesions: a new criterion for chronic rejection.
Typical chronic rejection showing prominent glomerular and/or arterial lesions is less common in renal allograft patients treated with cyclosporin A (CsA). We investigated the value of peritubular capillary lesions as a criterion for chronic rejection in the CsA era. A total of 129 renal graft biopsies, taken from recipients showing graft dysfunction after more than 2 months post-operatively, were examined by electron microscopy, and peritubular capillary lesions were studied, especially multi-layered basement membrane lesions (MLPTC). Eighty-two biopsy specimens taken from non-transplantation patients were also studied as a control. Five biopsies (6%) showed mild and atypical MLPTC in the control group. Of the 129 allograft biopsies, MLPTC was seen in 55 (42.6%). The prevalence showed no significant relationship to the interval from operation to biopsy. MLPTC was either typical (n = 10) or incomplete (n = 45). Concomitant membrane disruption, edema and lymphocyte infiltration of the subendothelial space, reflecting acute cellular rejection, were occasionally noted in both groups. Incomplete MLPTC often developed within 1 yr after surgery, in association with acute rejection. It was found in 26-50% of biopsies at any time up to 5 yr post-operatively. The incidence of typical MLPTC was 5.7-12.8% over 1 yr post-operatively. These findings suggest that the development of chronic rejection is closely related to relapsing acute tubulo-interstitial allograft rejection which is often clinically silent. We concluded that MLPTC is useful as a specific criterion for chronic rejection.
Oikawa
T
T
Third Department of Internal Medicine, Nagoya City University Medical School, Nagoya, Japan. oikawa@med.nagoya-cu.ac.jp
Morozumi
K
K
Koyama
K
K
Takeuchi
O
O
Takeda
A
A
Uchida
K
K
Fujinami
T
T
D001485:Basement Membrane / Q000648:ultrastructure; D001706:Biopsy; D002196:Capillaries / Q000648:ultrastructure; D002908:Chronic Disease; D016572:Cyclosporine / Q000627:therapeutic use; D006084:Graft Rejection / Q000473:pathology*; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D016030:Kidney Transplantation / Q000473:pathology*; D007684:Kidney Tubules / Q000473:pathology; D008854:Microscopy, Electron; D013997:Time Factors
D007166:Immunosuppressive Agents; D016572:Cyclosporine