Relationship of Peritonitis and Serum-Dialysate Immunoglobulin-G Subclass Levels in Continuous Ambulatory Peritoneal Dialysis Patients

OBJECTIVE: Peritonitis is the most important complication of Continuous Ambulatory Peritoneal Dialysis (CAPD) treatment. The most powerful defending elements of peritoneal fluid are IgG and the IgG subclasses. Low levels of IgG subclasses result in recurrent infections. We therefore aimed to investigate the peritonitis frequency and serum-dialysate IgG subclass level relationship. MATERIAL and METHODS: A total of 30 CAPD patients were included in this study. The patients were divided into two groups according to their peritonitis frequency. Patients with two or more peritonitis attack were grouped as High Peritonitis Index (HPI) and those with one or less peritonitis attack as Low Peritonitis Index (LPI). 17 (56.67%) patients were in the LPI and 13 (43.33%) patients in the HPI group. These two groups were compared for their IgG subclass levels. RESULTS: There was no significant difference for serum IgG and subclass levels (p IgG1:0.86, IgG2:0.93, IgG3:0.4, IgG4:0.67, total IgG:0.80 mg/ml). Dialysate IgG and subclass levels were significantly higher in the HPI group (p IgG1:0.006, IgG2:0.01, IgG3:0.007, IgG4:0.01, total IgG:0.003 mg/ml). The loss of total protein, albumin and globulin in the dialysate was significantly higher in the HPI group (respectively p=0.39, 0.26, 0.01). CONCLUSION: Structural changes in the peritoneal membrane and a recurrent inflamatory response may result in high IgG and subclass level for the HPI group. Our results show that low levels of IgG subclasses may not play an important role in the development of peritonitis.