Is there a link between Cow´s Milk Protein Allergy and Renal Tubular Acidosis? (original) (raw)

Introduction: Renal tubular acidosis (RTA) is a syndrome characterized by hyperchloremic metabolic acidosis, in which there is tubular dysfunction for the regulation of acid-base equilibrium, with normal or little impairment of glomerular function. The Cow´s Milk Protein Allergy (CMPA) is a disease with high prevalence worldwide which varies from 1-12%. Its diagnosis is clinical but there are diagnostic tests with variable sensitivity and specificity. Materials and Methods: A prospective, cross-sectional, and observational study was carried out in 37 children with clinical suspicion of CMPA, who were treated at Gastroenterology and Nutrition Department of Instituto Nacional de Pediatría, from March 2008 to November 2009. Inclusion criteria: 1-6 months old male and female infants, not weaning, negative hydrogen test, and parent's signed consent. Exclusion criteria: malnutrition, positive serology for HIV, metabolic disorders and neurological damage. A complete medical history was done for each patient under study. Laboratory studies performed included total IgE, milk precipitins, prick test, 24 hours esophageal pH metric measurements, endos-copy and rectosigmoidoscopy. An extensively hydrolyzed formula and/or elementary diet were indicated. Results: 37 patients (21 females and 16 males) with median age range of 3.39±1.7 were included in the study. The main clinical manifestations were digestive problems in 97.2% of the patients, renal tubular acidosis (RTA) in 32%, derma-tologic problems in 29%, and respiratory in 27%. Laboratory studies showed a positive result for IgE in 8.1% of the patients, in 37.8% for prick test, and in 40.5% for compatible biopsy, while a positive 24-hour esophageal pH metric measurement was found in 8.1% of the cases. Treatment with extensively hydrolyzed formula showed efficacy of 72.9%. Conclusions: CMPA is a clinical diagnosis, with up to 40.5% rectal histopathological changes. However, we found a high frequency of RTA (32%) and a low gastroesophageal reflux diseases (8.1%).