Immunoglobulins in chronic renal failure of childhood:: Effects of dialysis modalities

Background. It is not clear whether low serum levels of IgG (subclasses), previously demonstrated in children on peritoneal dialysis (PD), are related to the PD procedure or to factors associated with chronic renal failure (CRF). The aim of our study was to analyze the effect of PD on serum and PD effluent (PDE) IgG and subclass levels in children with end-stage renal failure. Methods. We measured albumin, IgG, IgA, IgM, and IgG subclasses in serum and PDE from children on PD (N = 40) and compared the serum values with those of children treated with hemodialysis (HD, N = 23) or presenting with CRF but not yet dialyzed (CRF; N = 63), and with a group of healthy controls (HCs; N = 67). Sixteen PD children could be followed sequentially from before starting PD and eight during a peritonitis episode. Results. Forty percent of the PD children showed reduced serum IgG(2) levels (P = 0.0003) compared with 35% in HD (P = 0.006), 33% in CRF (P = 0.001), and 9% in HC children. IgG(1) deficiencies were observed in 25% of PD patients (P < 0.0001), 4% of HD (P = NS), 16% of CRF (P = 0.0005), and 0% of HC children. IgG(3) and IgG(4) deficiencies were observed less frequently. Peritoneal clearances were similar for total IgG, IgG(1), IgG(2), and IgG(4), but were lower for IgG(3) (P < 0.05). No relationships were found between clearances and age or duration of PD treatment. Total IgG (P = 0.003) and IgG(1) (P = 0.002) levels declined just after starting PD. Peritonitis was associated with temporarily increased peritoneal loss of Ig, while the serum concentrations were unaffected. No significant relationship was found between the peritonitis incidence and reduced IgG or subclasses. However, all children with two or more peritonitis episodes per year had a reduced Ig level. Conclusions. Although the mean serum concentrations of immunoglobulins were normal in all studied groups: a deficiency of one or more IgG subclasses was present in all groups with renal failure, suggesting inhibition of their synthesis by the uremic state. Ig deficiencies were more frequently found in PD, likely caused by protein loss in PDE. A high peritonitis incidence was associated with reduced serum Ig levels.