The Relationship of P1 and Lewis Antigens with Peritoneal Dialysis–Related Escherichia Coli Peritonitis

Abstract

It has been known that the P1 and Lewis antigens on red blood cells (RBCs) affect the risk of Escherichia coli–related urinary tract infection. In the present study, we investigated the associations between those antigens and peritoneal dialysis (PD)–related peritonitis and E. coli peritonitis. We recruited 155 patients (66 men, 89 women) who were under PD treatment in July 2005, checked the P1 and Lewis antigen status of their RBCs, reviewed their medical charts, and recorded the dates and the causative pathogens of peritonitis episodes. The relationships between peritonitis and the antigens were analyzed. The mean age of these PD patients was 52.5 ± 14.9 years, and the mean PD duration was 39.8 ± 38.2 months. A total of 66 peritonitis episodes occurred (over 93.4 patient– months) in 41 patients, with 8 patients having more than 1 episode. In particular, E. coli peritonitis accounted for 16 of the 66 peritonitis episodes. We fitted two multiple Cox proportional hazards models (with the robust variance method) for predicting the hazard rates of peritonitis-free and E. coli peritonitis-free survival times to our right-censored data with recurrent events. We found that patients on PD treatment for less than 4 years with (A) lower serum albumin, (B) one or more previous peritonitis episodes, or (C) negative Lewis a and positive Lewis b antigens (secretor) would be at higher risk of peritonitis. And, conditioning on blood type, the PD patients with one or more previous peritonitis episodes and (A) positive P1 antigen, (B) negative Lewis a and positive Lewis b antigens (secretor), or (C) positive Lewis a and negative Lewis b antigens (non-secretor) would be at higher risk of E. coli peritonitis.