The association between CD2+ peripheral blood lymphocyte subsets and the relapse of bladder cancer in prophylactically BCG-treated patients

The effect of intravesical Bacillus Calmette–Guerin instillations on the expression of inducible nitric oxide synthase in humans

The activation of the inducible isoform of nitric oxide synthase (NOS) is associated with the production of large quantities of nitric oxide in response to cytokine stimulation. Bacillus Calmette-Guerin (BCG) mode of action against bladder carcinoma remains unclear, although a plethora of local and systemic events may follow its intravesical instillation. The present study was designed to investigate the expression of inducible NOS in normal and neoplastic urothelium and its alteration following tumor resection and subsequent intravesical immunotherapy. Bladder carcinoma and autologous normal bladder tissue specimens were procured from 36 patients undergoing transurethral resection. Tissue specimens were obtained from the same patients at first cystoscopy following six weekly intravesical instillations. Inducible NOS protein expression was assessed by immunohistochemistry in all tissue specimens. Immunostaining of normal urothelium for iNOS before treatment was negative in all but four cases. BCG treatment induced iNOS expression in tumor-free bladder tissue in 24 cases (66.6%). There were only four early tumor recurrences; interestingly, they corresponded to the cases with tumor cells expressing iNOS before BCG treatment, while novel tumors were also iNOS immunoreactive. BCG upregulated iNOS expression in normal human urothelial cells in vivo suggesting a role for nitric oxide in BCG mediated antitumor activity. Inducible NOS was detected in certain tumor specimens before and after BCG treatment implying a possible involvement in pro-tumor action.

Relationship between response to interferon-alpha and function of peripheral blood mononuclear cells in chronic hepatitis C patients

The factors responsible for the low response of chronic hepatitis C patients to interferon-a treatment are not fully understood, although it is known that interferon requires an efficient host immune response to achieve viral clearance. This study was designed to test the hypothesis that hepatitis C virus infection is associated with functional impairment of peripheral blood mononuclear cells, which influence the response to interferon. The proliferative and apoptotic responses of peripheral blood mononuclear cells and purified T cells stimulated with polyclonal mitogenic signals were assessed in 35 chronic hepatitis C patients and 30 healthy controls. Patients were divided into responders and nonresponders according to their sustained response to a course of alpha-interferon-a (3 MU three times weekly for 12 months). The proliferative response to polyclonal mitogens (PHA, TPA) was significantly decreased in nonresponders compared to responders and controls. The defective response was partially normalized by the exogenous addition of interleukin-2 or interleukin-4, and cannot be ascribed to increased apoptosis. Interestingly, the proliferative response of enriched T cells to the same signals was normal. In conclusion, the clinical response to interferon-a defines two different patterns of proliferation by mononuclear cells in chronic hepatitis C patients. This suggests that an alteration of the immune system in these patients may underlie their inadequate response to antiviral therapy.