Urinary secretory IgA after nutritional rehabilitation

We studied the secretory IgA (sIgA) response of the mucosal urinary tract of malnourished children before and after nutritional rehabilitation. sIgA concentration (mg/l) was determined by ELISA in 187 children aged 3 months to 5 years. The children, who frequented a day care center, were divided into four groups, according to nutritional status: 57 were eutrophic, 49 were undergrown, 57 were moderately malnourished and 24 were severely malnourished. In addition, dip slide (Urotube, Roche) and dip-stick (Combur 9-Boehringer) tests showed that children had no bacteriuria or any other urinary abnormalities. Plasma albumin concentration (g/dl) was significantly lower (P<0.005) in the severely malnourished group (mean 3.0 + ou - 0.3 SD) than in the eutrophic group (mean 4.0 + ou - 0.5 SD). When each nutritional state was analyzed, no significant differences in the sIgA were found between the 0 --- 1 and 1 -- 5 year age range. In the moderately and severely malnourished groups, sIgA (0.36 and 0.45, respectively) was significantly lower than in the eutrophic (0.69) and undergrown (0.75) groups. Ninety-five children were included in the 8-month follow-up study; 30 children were excluded from the follow-up because 4 had bacteriuria, 11 had leukocyturia, 8 had proteinuria and 7 had hematuria. Among the malnourished children, 40 per cent showed nutritional improvement (P<0.05) and significantly increased sIgA as compared to reference values for the eutrophic and undergrown groups. These data suggest that malnourished children have a significantly lower urinary sIgA than eutrophic children. After nutritional rehabilitation, they develop local immunity with a significant increase in sIgA.

IgA secretoria na urina de criancas portadoras de infeccao do trato urinario (ITU) e diferentes estados nutricionais: seguimento de 12 meses

Com o objetivo de estudar as variacoes da IgA secretoria (IgAs) durante o curso evolutivo da infeccao do trato urinario (ITU), determinaram-se (empregando-se ELISA) a concentracao da IgAs (mg/1) e o seu indice de excrecoes (mg IgAs/g creatinina) na urina de 60 criancas (36 meninos e 24 meninas), de 3 meses a 5 anos de idade. Em todos foi diagnosticada esta infeccao atraves do metodo por dip-slide (Urotube - Roche). Os microrganismos foram isolados e identificados por testes bioquimicos, sendo aE.coli responsavel por 60 por cento das infeccoes, seguida do Proteus mirabilis (27 por cento ), Klebsiella pneumoniae (12 por cento ) e pseudonomas aeruginosa (2 por cento ). Foram estudados quatro grupos de criancas de acordo com o estado nutricional, avaliados pelos percentis do peso e estatura em relacao ao sexoe idade: euforicas (E), com estatura baixa e peso normal (EB), desnutridas moderadas (DM) e graves (DG). As medianas da concentracao e do indice de excrecao da IgAs em cada grupo foram respectivamente: 1.50 e 2.50 (E), 1.10 e 2.89 (EB), 1.20 e 3.25 (DM) e 1.15 e 3.96 (DG). Nao houve diferenca significante quanto aos parametros da IgAs entre os estados nutricionais. Apos a cura, ocorreu significante reducao da IgAs urinaria, o que nao aconteceu com aquelas criancas que permaneceram com a infeccao ou eram recidivistas. Os presentes resultados sugerem que criancas desnutridas sao capases de desenvolver resposta imune local com aumentoda IgAs durante a ITU. E ainda, apos a cura, apresentam reducao significante da IgAs, enquanto aquelas que novamente se infeccionam ou manten a bacteriuria ou a IgAs permanece elevada. No entanto, sao necessarios estudos prospectivos, a longo prazo, identificando os anticorpos locais especificos contra os antigenos do microrganismo infectante, com vistas a avaliar a intensidade e a especificidade da resposta imune local .