Significance of CD20-positive lymphocytes infiltrating in renal allograft biopsies with chronic allograft nephropathy / 中华器官移植杂志

ABSTRACT

ObjectiveTo investigate the action mechanism of CD20 lymphocyte infiltration in the renal allograft biopsy with chronic allograft nephropathy (CAN).MethodsCAN cases confirmed by renal biopsy within 2 years after renal transplantation served as study subjects. By using immunohistochemistry,the deposition of C4d and the CD20-positive lymphocytes infiltration in the renal grafts were examined.The clinical follow-up data were analyzed.ResultsForty-four cases of CAN were enrolled in the study, including 13 cases (29.5％ ) of CD20-positive lymphocytes infiltration,and 31cases (70.5％ )of CD20-negative lymphocytes infiltration. CD20-positive lymphocytes in biopsy showed nodular and scattered lymphocytes infiltration.There were 5 (26.3％)cases of CAN Ⅰ,4 cases (25.0％) of CAN Ⅱ,and 4 (44.4％) of CAN Ⅲ in CD20-positive group.There was no statistically significant difference between the only CAN group and CAN with AR group in CD20-positive rate.Immunohistochemical staining showed there were 12 cases (27.3％) with C4d linear deposition in peritubular capillary endothelial cells (PTC).C4d positive rate had no significant difference among the CAN classifications. There was no significant relationship between C4d deposition and CD20-positive lymphocytic infiltration.The average serum creatinine in CD20-negtive group and CD20-posigtive group was 140.8 ± 22.0 and 183.5 ± 25.5μmol/L before biopsy,and 165.6 ± 37.6 and 242.2 ± 59.1 μmol/L one year after biopsy.The average serum creatinine level in CD20-positive group was higher than in CD20-negtive group before and after biopsy.ConclusionProgressive chronic humoral immunity is high risk in the process of CAN. The CD20-positive lymphocyte infiltration has no relevance with CAN grade and C4d deposition in PTC,but is associated with circulating antibody PRA and allograft long-term outcome. Pathogenetic mechanism may not contribute to chronic humoral immune,but B cells presenting donor antigens,are recognized and activated by T cells as antigen-presenting cells.