Objective  To determine differences in the immunohistochemical (IHC) expression of Bcl‐2 protein and Ki‐67 antigen in patients with prostatic cancer who underwent radical prostatectomy with or without neo‐adjuvant hormonal therapy. Materials and methods  Ki‐67 antigen and Bcl‐2 protein were detected by IHC using MIB‐1 and Bcl‐2 antibodies in prostatectomy specimens from 28 patients who received hormonal therapy before surgery (group 1) and 51 patients who did not (group 2). Results  In group 2, the mean MIB‐1 index increased with increasing grade of tumour, from 11.6% in low‐grade to 24.7% in high‐grade tumours (P=0.002). Bcl‐2 expression did not correlate with either tumour grade or stage. In group 1, there were no correlations between Bcl‐2 expression or MIB‐1 index and tumour grade or stage. More tumours in group 1 were Bcl‐2‐positive (16 of 28, 57%) than were tumours in group 2 (11 of 51, 22%; P=0.003). The mean (sd) MIB‐1 index of tumours in group 2 [15.6 (14.4)%], was significantly greater than that of tumours in group 2 [6.8 (7.5)%; P=0.004]. Conclusions  These results indicate that Bcl‐2 positivity is increased by androgen ablation therapy and conversely, that the proliferative activity of cancer cells is significantly reduced. The expression of Bcl‐2 protein may play a role in the ability of prostate cancer cells to survive in an androgen‐deprived environment.

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Whether T cells circulating peripherally express changes at a clonal level after renal transplantation is uncertain. To clarify this issue, we analyzed T-cell clonality of peripheral blood lymphocytes (PBLs) in 12 renal transplant recipients by a novel polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) method that can discriminate T-cell clones with different T-cell receptor (TCR) Vb motifs. The PCR-SSCP study showed that after transplantation, only a few distinct T-cell clonotypes accumulated in the absence of clinical episodes, irrespective of the compatibility of HLA antigens. In contrast, various T-cell clones appeared in cases of acute rejection (AR) and infection. These subsided immediately after the AR was resolved; however, they remained long after the resolution of the infection. In a case of AR followed by an infectious episode, distinct T-cell clones appeared concomitantly with each episode. Several of them disappeared or remained thereafter. In one case, significant numbers of accumulating bands were observed by in-vitro stimulation by mixed lymphocyte reaction (MLR); several were identical to those found in vivo. However, some of those that did not appear in vitro were apparent in vivo. In conclusion, the appearance of Tcell clonotypes at a peripheral level indicates the existence of immunologically activated T-cell clones, which were significantly affected by immunosuppressive therapy. It was also determined that the T-cell immune system is much more complicated in vivo than in vitro.