title: Detection of B lymphocytes (CD20+) in renal allograft biopsy specimens.
abstract: Acute allograft rejection represents an important complication after transplantation with significant impact on long-term graft survival. The involvement and relevance of B lymphocytes in this process is still not clear. The aim of this study was to quantify in renal allograft biopsy specimens the number of cells positive for CD20, a specific marker for B lymphocytes. Immunohistochemical techniques using monoclonal anti-CD20 antibody was used on paraffin sections from 38 renal allograft biopsy specimens. The biopsy specimens were classified into 3 groups, according to clinical and histological criteria: normal kidney, acute rejection, and chronic allograft nephropathy (CAN). In the normal kidney, no CD20(+) cells were detected. In contrast, in all cases of acute rejection and CAN, there were CD20(+) cells. The CD20(+) cells occurred in the infiltrate in 2 distinct patterns: scattered or nodular. In cases of acute rejection, the number of CD20(+) cells was significantly higher than in CAN cases (137.0 +/- 57.2 vs 45.4 +/- 9.8 cells/mm(2); P < 0.05). The nodular pattern was observed in 4 of 11 cases (36%) in the acute rejection group, and in 4 of 20 cases (20%) in the CAN cohort. In the acute rejection group, the presence of B-cell clusters tender to be associated with a higher level of serum creatinine (3.7 +/- 1.8 mg/dL vs 2.8 +/- 0.1 mg/dL in the scattered pattern group; not significant [ns]). In conclusion, these preliminary results demonstrated B lymphocytes in cases of renal allograft dysfunction, which were more pronounced in acute allograft rejection. Further analyses are required to determine whether the detection of CD20(+) cells in renal allograft biopsy specimens can be used as a prognostic marker.
authors.affiliation: Laboratory of Molecular and Cellular Nephrology, University of São Paulo, São Paulo, Brazil.
authors.forename: H L
authors.initials: HL
authors.lastname: Martins
authors.forename: C
authors.initials: C
authors.lastname: Silva
authors.forename: D
authors.initials: D
authors.lastname: Martini
authors.forename: I L
authors.initials: IL
authors.lastname: Noronha
mesh_terms: D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000276:immunology; D018951:Antigens, CD20 / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology*; D001706:Biopsy; D006084:Graft Rejection / Q000276:immunology / Q000473:pathology; D006801:Humans; D016030:Kidney Transplantation / Q000276:immunology* / Q000473:pathology; D008875:Middle Aged; D011379:Prognosis; D014184:Transplantation, Homologous
chemical_list: D015703:Antigens, CD; D018951:Antigens, CD20