Low serum level of
IgG,
complement C3 and C4 in
nephrotic syndrome children may cause increased susceptibility to
infection. Serum level of
IgG and complements in nephrotic children (NS) with UTI has been analyzed in this cross sectional study. It was carried out in the department of Pediatric nephrology, National Institute of
Kidney Diseases & Urology (NIKDU), Dhaka, Bangladesh. The study subjects were followed up prospectively for one year to see and compare the frequency of relapse of NS and UTI. Patients were selected in a nonrandom purposive technique.
Nephrotic syndrome children with initial attack between 1-12 year of age were included over a period of one year. The patients were grouped into Group I - UTI positive and Group II - UTI negative depending on urine culture positivity and colony count >10⁵ CFU/ml. Serum
IgG and complements C3, C4 levels were done in both groups during
nephrosis and were compared. A total of 101 children M: F 1.7:1, mean age 5.96±3.2 years were included in this study. Group I, n=45 vs. Group II, n=56. The mean serum level of
IgG was low in Group I (549.91±210.71 vs. 728.64±235.81mg/dl, p<0.001). Serum
IgG level less than 700mg/dl was found in 37 vs. 23 children {x² (¹) 17.52 p<0.001, OR=6.63}. Mean serum
complement C3 level was also low in Group I (123.09±40.52 vs. 143.38±37.06mg/dl, p<0.05). But
complement C3 and C4 level do not carry any risk of developing UTI in nephrotic children. Higher number of children in Group II were at remission (n=24) during follow up, while frequent relapsers were high in Group I (n=22). Increased frequency of UTI attack (88 episodes) was found in Group I children compared to none in Group II during follow up. So low serum level of
IgG in children with NS during
nephrosis can predict UTI with an odds ratio of 6.63 as well as relapse. Serum level of C3, C4 do not associated with any risk of development of UTI in NS children.