Prospective oral food challenge study of two soybean protein isolates in patients with possible milk or soy protein enterocolitis.

The soybean protein isolate used in powdered soybean formula is hydrolyzed more extensively than the isolate which is used in liquid soybean formula in most commercial soybean formulas. Previous in vitro studies have shown differences in human antibody response to these soybean protein isolates. Therefore, a prospective clinical study was undertaken to determine if there were differences in adverse reaction rates to these soybean protein isolates. Forty-three patients with possible milk- and/or soy-protein enterocolitis were enrolled in this study. Patients had 3 separate oral food challenges; using milk formula, soybean powder formula and soybean liquid formula. Ten (23%) patients challenged with milk had positive challenges. Fourteen (33%) patients challenged with powdered soy formula had positive challenges while thirteen (30%) challenged with liquid soy formula had positive challenges. In the 10 patients with positive milk challenges, 6 (60%) had a positive soy challenge. In the group with positive soy challenges, 5 reacted to the powdered soy challenge done first, but not the second challenge with the liquid soy formula, and 4 patients reacted to the liquid soy formula challenge done first, but not the second challenge with the powdered soy formula. These results indicate that a significant number of patients with milk protein enterocolitis have soy protein enterocolitis. In addition, an order effect can be demonstrated in the soy challenges because of the tendency to react to the first soy challenge regardless of the type of isolate. These results suggest that a local immune effect caused by the protein may be present.

The role of Helicobacter pylori in recurrent, functional abdominal pain in children.

Recurrent abdominal pain in children usually is considered to be functional in nature. We hypothesized that Helicobacter pylori infection might be the etiology of abdominal pain symptoms in some children with presumed functional abdominal pain. Therefore, we studied 20 children with a previous diagnosis of functional abdominal pain, using a 13C-urea breath test and an enzyme-linked immunosorbent assay for antibody to the H. pylori high molecular weight, cell-associated antigens. Two children had evidence of H. pylori infection, and both had clinical histories that suggested an acute H. pylori infection, at the onset of their abdominal pain. Seven children who had abrupt onset of their chronic abdominal symptoms were then identified prospectively. None of these patients had evidence of active H. pylori infection. We conclude that H. pylori infections are not common among children with recurrent abdominal pain, and are not predictable in such children, based on symptom patterns.

Factors influencing the epidemiology of Helicobacter pylori infection in children.

The epidemiology of Helicobacter pylori infection was studied in 245 healthy children (between 3 and 20 years of age) who presented for day surgery at Arkansas Children's Hospital. H pylori infection was identified serologically using an enzyme-linked immunosorbent assay to detect the presence of IgG against the high molecular weight, cell-associated antigens of H pylori. Demographic information collected included age, gender, race, family income, type of housing, location of housing, water supply, health status, upper gastrointestinal symptoms, and keeping pets. One hundred eighty-nine white children and 56 black children were studied; 139 were boys and 106 were girls. The data were analyzed by logistic regression analysis. H pylori infection increased significantly with age (P less than .05). The frequency of H pylori infection was higher in blacks than whites (P less than .01), and this difference remained after adjusting for age, gender, and family income. Family income was used as a measure of socioeconomic class and was an important factor related to infection; the rate of acquisition of H pylori in those children with family income less than +5000/year was twice that of those with incomes greater than +75,000/year (P less than .001). There were no significant differences in H pylori infection related to gender, type of housing, location of housing, or source of water supply. It is concluded that the rate of acquisition of H pylori infection increases with age, is higher in blacks than whites, and is inversely related to socioeconomic class.

Breath methane production in children with constipation and encopresis.

Breath methane excretion is uncommon in children compared with adults. Certain intracolonic conditions, however, have been associated with enhanced methane generation. We hypothesized that encopretic and constipated children, who have abnormal colonic transit times, more likely would excrete methane than healthy children. To determine the prevalence of methane excretion among children with encopresis or simple constipation, we performed breath methane analysis on such patients and age-, race-, and sex-matched control subjects. Encopretic patients (mean age, 8.3 +/- 3.0 years) had daily, involuntary passage of feces and clinical evidence of constipation. Constipated patients (mean age, 7.1 +/- 2.9 years) had a history of hard stools and at least one of the following symptoms: infrequent defecation, dyschezia, hematochezia, difficult stool expulsion, or abdominal pain during bowel movements. Methane excretion was present in 26 of 40 (65%) encopretic patients versus 6 of 40 (15%) control patients (P less than 0.001). In contrast, 3 of 27 (11%) constipated patients were methane excreters, versus 2 of 27 (7%) controls (P = 0.4). Fourteen asymptomatic encopretic patients were retested after successful therapy; eight were methane excreters initially, but five of eight did not excrete methane after treatment. We conclude that methane is produced in a large number of children with encopresis. Treatment appears to alter methanogenesis in such patients. The prevalence of methane producers among constipated children is not different from the prevalence in healthy subjects. Methanogenesis in encopretic patients may be enhanced by prolonged colonic transit time or abnormal intracolonic conditions.