Immunophenotyping Interstitial Inflammatory Cells in Acute Rejection
JM Moore, J Williams, J Du, SR Marino, SM Meehan, A Chong, A Chang. University of Chicago Medical Center, Chicago, IL
Background: The potential role of B lymphocytes and plasma cells (PCs) in antibody-mediated (humoral) rejection is gaining attention, but remains poorly understood. We hypothesize that significant accumulation of intraparenchymal B and PCs may occur in acute antibody-mediated rejection and attempt to characterize the infiltrate in a different manner than those in the literature.
Design: We searched our pathology archives from 2005-2009 and identified 57 human renal biopsies with a diagnosis of acute rejection. The biopsies were divided into 3 groups: 1) cell-mediated rejection only; 2) antibody-mediated rejection only (with positive C4d peritubular capillary deposition); and 3) both cell- and antibody-mediated rejection. Standard immunohistochemistry was performed on paraffin tissue sections using monoclonal antibodies to CD20, CD138, CD3 and CD45 (DAKO, Carpinteria, CA). The number of interstitial cells with strong membranous staining was counted for each antibody and the percentage of positive cells was calculated using the total positive CD45 cells as the denominator. This data was correlated with clinical information, biopsy diagnosis, and presence of HLA antibodies. Statistical analysis was performed using the Mann-Whitney or Kruskal-Wallis test with p<0.05 considered as significant.
|Rejection type||CD20%||CD138%||CD3%||# of cases|
|Cell- and antibody-mediated||15.7%||15.8%||57.9%||21|
|HLA class I/II abs present||11.1%||10.8%||66.8%||27|
|No HLA class I/II abs||25.9%||1.5%||78.6%||4|