Institute of Pathology, Nephropathology, Friedrich-Alexander-University Erlangen-Nuremberg, 91054 Erlangen, Germany.
Hum Pathol. 2012 Sep;43(9):1453-62. doi: 10.1016/j.humpath.2011.11.006. Epub 2012 Mar 8.
The differential diagnosis of T cell-mediated rejection (TCMR) and BK-virus nephropathy (BKVN) in renal transplant biopsies is notoriously difficult. Therefore, attempts were made to differentiate between the two by characterizing the immune cell infiltrate. Using immunohistochemistry, the distribution of immune cell (sub)populations such as CD4(+) T helper (TH), TH1, TH2, CD8(+) cytotoxic T cells, regulatory T cells, B cells, plasma cells and follicular dendritic cells was determined in a total of 38 renal biopsy specimens. In addition, the expression of the HLA class I antigen presentation machinery (APM) components was investigated. In general, the frequency of T cells was higher than B cells, and TH cells outnumbered cytotoxic T cells with a predominance of TH2 over TH1 cells. In BKVN, a significantly higher number of plasma cells was observed (P = .028), and interstitial fibrosis and tubular atrophy was more pronounced in BKVN (P = .007) compared to TCMR. The expression of components of the HLA class I APM was not affected by the infection with BK virus compared to TCMR. These findings indicate a TH2 shift in renal transplants in the context of alloreactive and virus-induced inflammation maybe as a consequence of immunosuppression, which usually targets T cell reaction. The predominance of plasma cells might underline an important role of humoral immunity in BKVN. Moreover, BK virus does not seem to modulate the expression of HLA class I APM as a strategy of immune evasion.
在肾移植活检中，T 细胞介导的排斥反应（TCMR）和 BK 病毒肾病（BKVN）的鉴别诊断一直极具挑战性。因此，人们尝试通过描述免疫细胞浸润来区分这两种疾病。本研究通过免疫组织化学方法，在总共 38 例肾活检标本中检测了免疫细胞（亚）群（如 CD4+辅助性 T 细胞（TH）、TH1、TH2、CD8+细胞毒性 T 细胞、调节性 T 细胞、B 细胞、浆细胞和滤泡树突状细胞）的分布。此外，还研究了 HLA Ⅰ类抗原呈递机制（APM）成分的表达情况。一般来说，T 细胞的频率高于 B 细胞，TH 细胞数量多于细胞毒性 T 细胞，TH2 细胞多于 TH1 细胞。与 TCMR 相比，BKVN 中观察到的浆细胞数量明显更多（P =.028），且 BKVN 中的间质纤维化和肾小管萎缩更为明显（P =.007）。与 TCMR 相比，BK 病毒感染并未影响 HLA Ⅰ类 APM 成分的表达。这些发现表明，在同种异体和病毒诱导的炎症背景下，肾移植中存在 TH2 偏移，这可能是免疫抑制的结果，而免疫抑制通常靶向 T 细胞反应。浆细胞的优势可能强调了体液免疫在 BKVN 中的重要作用。此外，BK 病毒似乎没有通过调节 HLA Ⅰ类 APM 的表达来作为一种免疫逃避策略。
