Characterization of binding capability of human breast milk to hepatitis B surface antigen / 中华围产医学杂志

ABSTRACT

Objective To investigate whether human breast milk may bind to hepatitis B surface antigen (HBsAg) and its characteristics.Methods Breast milk samples from five women with negative HBsAg and hepatitis B surface antibody (anti-HBs) at one to two months post delivery were fractioned into cream and skimmed milk by centrifugation.The human breast milk and each fraction as well as cow and goat milk samples,served as controls,were separately incubated with highly purified yeast recombinant HBsAg,followed by determination of their binding capability to HBsAg by enzyme linked immunosorbent assay (ELISA) and the inhibition rate for binding of HBsAg to anti-HBs by quantitative chemiluminescence microparticle immunoassay.After boiled for 1 min or pasteurized in 65 ℃ for 30 min,the thermal stability of the active components of milk was detected.One-way ANOVA and SNK tests were performed for statistical analysis.Results The operative concentration of HBsAg was 0.1 μg/ml.Breast milk from all five women showed significantly better binding capability to HBsAg than cow or goat milk (1.306±0.300 vs 2.157±0.150 and 2.232±0.093,F=34.303,P＜0.01).The quantitative experiments showed that the inhibition rate of human breast milk was higher than that of the control group [(74.26± 17.26)％ vs (0.00±5.50)％,F=57.806,P＜0.01].The binding ability to HBsAg of skimmed milk was comparable with that of whole milk,indicating milk protein(s) played critical roles in binding to HBsAg (0.877 ± 0.486 vs 0.513 ± 0.069 and 0.376 ± 0.146,F=44.475,P＜0.01).After boiled for 1 min or Pasteurization,the binding ability to HBsAg of whole breast milk remained,but that of skimmed milk went down (F=16.598,P＜0.01).Both whole breast milk and skimmed milk could inhibit the binding of HBsAg to anti-HBs (F=278.341 and 269.408,both P＜0.01).Conclusions The inhibition of binding to HBsAg by human breast milk indicates that human milk may interact with HBsAg.The active components mainly exist in milk proteins and are thermal stable.