Influence of Functionally Active Plasma Cells in Acute Cellular Rejection in Renal Allografts
Xu Zeng, Dongping Shi, Seema Sethi, Mona Doshi, Zeenat Bhat. Wayne State University, Detroit, MI
Background: Acute rejection (AR) includes T-cell mediated and antibody mediated rejection. Under light microscopy, the inflammatory infiltrate is comprised of not only T-Cells, but also varying amount of B cells (CD20+) and plasma cells (CD138+). The latter are associated with anti-body mediated rejection, which has shown poor clinical outcomes following current treatment regimens. However, the function status of these B cells/plasma cells, i.e. active antibody production, is not very clear. The phosphorylation of S6 rebosomal protein (P-S6RP) is present in cells that are metabolically active, thus identifying functional active antibody secreting plasma cells. This study is designed to evaluate the clinical significance of functional active P-S6RP plasma cells in acute rejection in renal allografts.
Design: Renal allografts with biopsy proven AR in the Detroit Medical Center during 2006-2009 were included this study. Immunohistochemistry staining for CD20, CD138 and P-S6RP was performed on paraffin slides. Renal cortex in the areas of greatest involvement is semi-quantitatively scored as 0-6. Response to anti-rejection treatment is assessed by the percentage change of serum creatinine (PC-Cr) to baseline at rejection episode (time 0) and following treatment (4 & 12 wks). Patients with lower scores (0-2) were compared to a higher scored group (3-6). The T-test for equality of means was conducted using statistical significance of P<0.05. C4D scores were also collected and correlate to P-s6rp, CD20 and CD138 scores.
Results: A total of 28 patients (40.7 ± 14.3 ys, M:F=15:13) were diagnosed with AR (I and II) during the study time frame. The higher scored P-s6rp group had significantly higher PC-Cr (p<.05) compared to the lower scored group at time 0, 4 & 12 wks following treatment, indicating poor response to treatment.
There is no significant (P>.05) difference in PC-Cr between higher and lower CD20 or CD138 groups. C4D scores are poorly correlated to P-S6RP, CD20 and CD138 scores.
Conclusions: The present study demonstates that the functional antibody secreting P-S6RP plasma cells are actively participating in acute rejection and are associated with poor response to treatment in renal allografts.
Category: Kidney (does not include tumors)
Wednesday, March 21, 2012 1:00 PM
Poster Session VI # 304, Wednesday Afternoon