IgG2 deficiency in young children treated with continuous ambulatory peritoneal dialysis (CAPD).

In most series of children treated with continuous ambulatory peritoneal dialysis (CAPD), the incidence of peritonitis is higher than in adults. This phenomenon has been insufficiently explained. In the serum of 12 young children treated with CAPD, the serum immunoglobulins IgA, IgM, and IgG, as well as the IgG subclasses, were evaluated. In 11 of them, IgG2 was not detectable. Total IgG was also slightly decreased in these patients. In control groups, consisting of children before CAPD was started, children treated with hemodialysis, and adult CAPD patients, no clear abnormalities were found. It is concluded that in young patients peritoneal dialysis causes IgG loss leading to IgG2 deficiency.