Comparison of Blood and Peritoneal Lymphocytes from Continuous Ambulatory Peritoneal Dialysis Patients, Asymptomatic and with Peritonitis

Objective. The purpose of this study was to compare the characteristics of the blood immunophenotype of CAPD patients with and without peritonitis and to compare the phenotypes of peripheral blood lymphocytes (PBL) and peritoneal lymphocytes (PL) in CAPD patients with peritonitis. Methods. Fifty-seven CAPD patients (20 with peritonitis and 37 without peritonitis) were recruited in the study (mean age 66,88 ± 13,48, male/female 16/21). Lymphocyte subsets (CD2+, CD3+, CD3+/4+, CD3+/8+, CD3-/16 + 56+, CD4/CD8 ratio) were quantitated by using monoclonal antibodies and dual-color flow cytometric analysis. With the above method we measured PBL in patients with and without peritonitis. In patients with peritonitis we also measured PL. Results. CD2 were slightly decreased in patients with peritonitis. Those patients also had more intense CD3 + /CD4+ lymphopenia (p < 0.05) and larger expansion of NK cells (p < 0.05). Patients with peritonitis appeared to have a lower ratio of CD4/CD8 (p < 0.05). All the above results are shown to Table 2. Following the onset of peritonitis, a consistent finding in all patients was a significant increase in CD2 population of PL compared with PBL (85.71 ± 9.20 versus 82.60 ± 7.34, p < 0.05) as well as in CD3 population (77.01 ± 13.09 versus 68.74 ± 13.43, p < 0.05). An increased number of CD3/8 in PL compared with PBL (33.70 ± 9.34 versus 27.98 ± 10.77, p < 0.05) was also noted. Conclusions. In the present study, we found important immune activation in asymptomatic CAPD patients. The activation increases during peritonitis. The causes and the clinical consequences of chronic activation remain unknown.