Regulation of HLA-DR antigen in monocytes from colorectal cancer patients by in vitro treatment with human recombinant interferon-gamma.

During the immune response, a great number of cytokines that modulate the function of mononuclear phagocytes are produced. Since interferons are one of the most important cytokines, the aim of this study was to evaluate the expression of HLA-DR antigen after an 18-h culture with human recombinant interferon-gamma (hrIFN-gamma) on freshly isolated peripheral blood monocytes from 16 colorectal cancer patients and 16 healthy donors, using an indirect immunofluorescence method. The results obtained showed that there was a decreased percentage of HLA-DR+ monocytes in the colorectal cancer patents (51 +/- 3%, p <0.01) compared with the healthy donors (77 +/- 2%). Treatment for 18 h with hrIFN-gamma increased the percentages of monocytes expressing HLA-DR: 71 +/- 3% for the cancer patients and 84 +/- 2% for the healthy donors (p <0.01 and <0.001, respectively). Our results demonstrate that after in vitro treatment with hrIFN-gamma, functionally altered monocytes from colorectal cancer patients can reach major histocompatibility complex II antigen expression values similar to those of healthy donors, thus improving the host's cellular immune response against the tumor.

Cisplatin containing chemotherapy influences HLA-DR expression on monocytes from cancer patients.

The effect of cisplatin-containing chemotherapy regimen was evaluated on the expression of HLA-DR antigen in peripheral blood monocytes from patients with lung (LCP) and colorectal (CCP) cancer. Chemotherapeutic schedules employed in patients were etoposide and cisplatin for LCP and 5-fluorouracil and cisplatin for CCP. The results obtained showed a diminished percentage of monocytes expressing HLA-DR antigen in LCP (52.4 +/- 2.6, p < 0.004) and CCP (50.1 +/- 2.1, p < 0.001) respectively versus healthy donors (71.0 +/- 1.1%), and that their values increased during chemotherapy, raising them up to control level after the second cycle of treatment, independently of the course of the cancer growth. We conclude that both modalities of treatment allowed an increase of monocytes expressing HLA-DR antigen, suggesting that this effect may be due to cisplatin action.

[Relationship between surface HLA-DR expression and NBT reduction in monocytes in patients with colorectal cancer]. / Relación entre expresión de HLA-DR de superficie y reducción del NBT en monocitos de pacientes con cáncer colorrectal.

The expression of HLA-DR antigens and their capacity to reduce nitroblue tetrazolium (NBT) have been evaluated in monocytes (Mo) from 28 patients with colorectal carcinoma (CCa) before antineoplastic treatment as well as in 29 normal control (NC). Simultaneously, circulating immune complexes (CIC) levels were studied in both groups. The results were expressed as the media of percentages. They show a decrease of Mo bearing HLA-DR (p less than 0.001 vs NC) and increase of MO with capacity to reduce NBT (p less than 0.001 vs NC). An increase of CIC levels in CCa compared to the NC (p less than 0.001) was also observed. We can postulate that the decrease in HLA-DR expression could be caused by the increase of toxic oxygen intermediates whose production was induced by CIC or tumoral antigens adherence.