RESUMEN
Secretory immunoglobulin A [SIgA], an immunoglobulin synthetized locally in, mucosal surfaces, plays a vital role in preventing mucosal localization by pathogenic bacteria. Its protective effect in urinary tract is still less well documented. This study was done to elucidate the role of SIgA in children with urinary tract infection. The work was carried out in Pediatric Department Zagazig University Hospitals in association with Clinical Pathology and Radiological Departments. 115 children [54 males-61 females] their age ranged between 1.5-14 years with a mean age of 5.4 years. They were classified into 4 clinical groups: Control Group: 40 healthy children who denied any history of urinary tract infection [UTI] and urine culture free. Group I: 30 cases subjects studied at the time of the first symptomatic [UTI]. Group II: 30 cases subjects who had a history of at least 2 documented episodes of UTI but had normal urinary tract and had negative bacterial culture at the time of the study.Group III: 15 cases subjects with symptomatic UTI and had an abnormal urinary tract .All subjects were age matched and subjected to full history taking-complete physical examination and laboratory aids and various radiological investigations. Urinary SIg A excretion rate was determined by immunodiffusion plates [L.C.partigen immunodiffusion plates from Behring AG Marburg, Germany]. Our results showed that: Urinary SIg A excretion rate was high among group I [1.74 +/- 0.13 mg/gm creatinine]-very high among group III [2.247 +/- .22 mg/gm creatinine] and low among group II [0.446 +/- 0.05 mg/gm creatinine]. The variation of SlgA urinary excretion among manifested our cases [group I, group Ill] was related to type of urinary pathogens involved. There was no correlation between urinary SIgA and number of bacterial colonies on urine culture.In localizing the site of UTI using SlgA excretion rate versus scintigraphy urinary SlgA was significant in localizing UTI in cases of group I and has no significance in cases of group Ill. Reflux, stricture urethra and stone Kidney were the commonest urinary abnormalities in our studied cases of group III and there were accompanied by high urinary SlgA excretion