Investigation of human colostrum Helicobacter pylori IgA content in lactating women

OBJECTIVE: The objective was to investigate the colostral H. pylori-specific IgA content in a sample of the female population in Turkey where a high endemicity for H. pylori has always been reported. MATERIALS AND METHODS: One hundred and sixty-one pregnant women with positive serum H. pylori IgG antibody at the time of the last trimester were enrolled into the study. During the initial postpartum 24h, we obtained colostrum samples from each mother to test the presence and concentration of H. pylori-specific IgA. Breast milk antibody concentrations of H. pylori were measured by commercial ELISA tests. Sample absorbance/cut-off absorbance (s/c) ratio was used for semiquantitative interpretation. Ratios >1.1 were considered positive, ratios < or =1.1 negative. The statistical significance was tested by the Mann-Whitney U-test, and p < 0.05 was regarded as statistically significant. RESULTS: At least 2 ml of colostrum was obtained and analyzed (mean volume 2.5+/-0.45 ml). The results indicated the absence of H. pylori-specific IgA in 64 colostral samples (39.8%). However, the rest of the women (n = 97; 60.2%) had a mean H. pylori-specific IgA s/c ratio of 4.31+/-2.51 (range 1.2-10.3) in their colostral milk samples. The mean gestational age at the time of delivery was 38 weeks and 5 days, and the mean birth weight was 3, 224+/-433 g (range 4, 300-1, 940 g). Gestational age at birth and mode of delivery were not correlated with the colostral-specific IgA levels. CONCLUSIONS: Most of the lactating women (60.2%), who were seropositive for H. pylori, had some IgA in their colostral milk. Colostral milk theoretically can decrease H. pylori and perhaps many other enteric infections, whether or not it contains H. pylori-specific IgA. Therefore, breastfeeding is of utmost importance for neonates and should be encouraged. The H. pylori-specific IgA antibody concentration of colostral milk should be investigated in large-scale prospective studies for its effectiveness in the protection against neonatal transmission of this infection.