title: Immune defects in chronic renal impairment: evidence for defective regulation of lymphocyte response by macrophages from patients with chronic renal impairment on haemodialysis.
abstract: Cellular mechanisms contributing to impaired lymphocyte proliferative responses in chronic renal impairment (CRI) were investigated using peripheral blood mononuclear cells (PBMC) from 25 patients receiving haemodialysis. Impaired T cell proliferative responses to phytohaemagglutinin were demonstrated. The hyporeactive PBMC from patients with CRI suppressed the responses of PBMC from normals to a greater degree than did control PBMC. This immunosuppression was reversed significantly by depleting adherent monocytes (M phi). To further determine if these impairments might be critically dependent on cell-cell contact, M phi from an additional 10 patients on haemodialysis were examined for ability to support B and T cell colony formation in semi-solid cultures stimulated by Staphylococcus protein A (SpA). When compared to normal controls, significantly fewer B and T cell colonies were observed with M phi from CRI patients than when autologous M phi were used. Also, T cells from patients were significantly less effective than controls in supporting B cell colony growth. Decreased T and B cell colony responses in patients were not due to a primary abnormality of these cells, since allogeneic mixing experiments showed that B and T cells from patients were able to form a sufficient number of colonies when control M phi or T cells from normals were used as accessory and helper cells. These findings suggest that although M phi-mediated suppressor activity is an important mechanism contributing to impaired lymphocyte responsiveness in patients with chronic renal impairment on haemodialysis, additional or related abnormalities in M phi 'accessory' function may also exist.
mesh_terms: D000328:Adult; D001402:B-Lymphocytes / Q000276:immunology; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000276:immunology* / Q000628:therapy; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000276:immunology*; D006435:Renal Dialysis; D013205:Staphylococcal Protein A / Q000494:pharmacology; D013601:T-Lymphocytes / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology
chemical_list: D013205:Staphylococcal Protein A