Fluctuation of Specific IgA Antibodies in Human Milk

ABSTRACT. The concentration of secretory IgA and the levels of IgA specific antibodies against Escherichia coli labile-toxin, Shigella flexneri 6, and rotaviruses were determined in milk samples obtained serially from women during the first 16 weeks postpartum. The mean concentration of secretory IgA followed the expected pattern; the levels of specific antibodies fluctuated in an unpredictable manner and independently of milk secretory IgA content, becoming undetectable in many instances. Under some circumstances, continued breast-feeding may not guarantee continued intake of antibodies against intestinal pathogens by the breast-fed infant.     

Mumps IgA Antibodies Are Not Absorbed from Human Milk

ABSTRACT. We measured mumps virus specific IgA antibodies in the sera of preterm infants after a feeding period on human milk rich in such antibodies. In full-term infants the possibility of absorption was determined from the content of these antibodies in the child's mother's milk, an umbilical cord blood sample and a later serum sample. No absorption of IgA antibodies was found.     

Persistence of Human Milk Proteins in the Breast-Fed Infant

Several proteins in human milk are postulated to have physiological functions in the breastfed infant. Therefore, survival of human milk proteins after passage through the gastrointestinal tract of the breast-fed infant was investigated. Fecal samples were collected from exclusively breast-fed term infants and milk samples from their mothers. Soluble proteins in the feces were extracted and analyzed for total protein, nitrogen, lactoferrin, secretory IgA, serum albumin and lysozyme. Significant amounts of lactoferrin and secretory IgA were excreted by the infants and this excretion decreased throughout the study period in a trend similar to the decreasing milk concentrations of these proteins. Gel filtration demonstrated excreted lactoferrin and secretory IgA to be intact. No serum albumin or lysozyme was detected in the fecal extracts. Crossed Immunoelectrophoresis showed three human milk proteins to be present in the feces—the third was identified as α₁-antitrypsin. Excretion of these proteins indicates the total protein content of human milk is an over-estimation of the protein nutritionally available to the infant.     

Daily Ingestion of Immunologic Components in Human Milk during the. First Four Months of Life

ABSTRACT. The amounts of lactoferrin, lysozyme, SIgA and SIgA antibodies to E. coli somatic antigens in human milk ingested per day and per kg per day by breast-fed infants were determined during the first four months of life. A gradual decline in the amounts of lactoferrin, SIgA, and SIgA antibodies ingested per day or per kg per day was found, whereas the quantities of lysozyme ingested by the infants rose during that period. These data suggest that the production and secretion of these immunologic factors by the mammary gland may be linked to the ontogeny of the production or catabolism of those components at mucosal tissues of the recipient infant.     

Daily Ingestion of Immunologic Components in Human Milk during the. First Four Months of Life

ABSTRACT. The amounts of lactoferrin, lysozyme, SIgA and SIgA antibodies to E. coli somatic antigens in human milk ingested per day and per kg per day by breast-fed infants were determined during the first four months of life. A gradual decline in the amounts of lactoferrin, SIgA, and SIgA antibodies ingested per day or per kg per day was found, whereas the quantities of lysozyme ingested by the infants rose during that period. These data suggest that the production and secretion of these immunologic factors by the mammary gland may be linked to the ontogeny of the production or catabolism of those components at mucosal tissues of the recipient infant.     

Plasma Antibodies to Cow's Milk Are Increased by Early Weaning and Consumption of Unmodified Milk, but Production of Plasma IgA and IgM Cow's Milk Antibodies Is Stimulated Even during Exclusive Breast-Feeding

ABSTRACT. We measured levels of cow's milk-specific (CM) antibodies of immunoglobulin classes G, A and M by enzyme-linked immunosorbent assay in plasma of 198 healthy infants; a variable number of samples taken at birth and at ages of 2, 4, 6, 9, 12 and 28 months were available (altogether 765 samples). The rise in the level of IgG CM antibodies was highest and most rapid in infants exposed to CM formula before the age of 1 month. The level fell by 9 months, but rose again by 12 months. This second rise was attributed to the introduction of dairy milk. Partially breast-fed and fully weaned infants had similar levels of IgG CM antibodies. The levels of IgG CM antibodies were unaffected by the infants' own atopy, their heredity for atopy, and the umbilical serum level of IgG CM antibodies. IgA and IgM CM antibodies were absent at birth. Their levels increased similarly in exclusively breast-fed infants and infants fed CM formula. We conclude that plasma IgG antibodies to cow's milk are increased by early weaning and by consumption of unmodified cow's milk. Production of plasma IgA and IgM antibodies to cow's milk is stimulated even during exclusive breast-feeding.     

THE MUCOSAL IMMUNE RESPONSE IN THE NEONATE

Hanson LÅ, Brinton C, Carlsson B, Dahlgren U, Mellander L, Sutton A and Söderström T. (Departments of Clinical Immunology and Paediatrics, University of Göteborg, Sweden, Bureau of Biologies, FDA, Bethesda, and Department of Life Sciences, University of Pittsburg, USA). The mucosal immune response in the neonate. Acta Paediatr Scand, Suppl. 296:53, 1982. — Human infants are relatively deficient in the IgA system defending mucosal membranes, but are provided via the maternal milk with considerable amounts of SIgA directed against microbes and food antigens to which both mother and infant are exposed. It is possible that serum antibodies may support the mucosal defense as do the lactoferrin, lysozyme and other defense factors present in the milk.     

Passage of Gliadin into Human Breast Milk

ABSTRACT. Samples of breast milk were taken from 53 women following the ingestion of 20 g of gluten. The samples were analysed for the presence of gliadin by a double-antibody sandwich enzyme immunoassay. Gliadin (5–95 ng/ml) was detected in 54/80 samples collected at various stages of lactation. Maximum levels in milk were found 2–4 hours after ingestion; gliadin could not be detected in serum. The transfer of gliadin from mother to infant might be critical for the development of an appropriate specific immune response to gliadin later in life.     

Variable increases of IgG and IgM antibodies in milk of IgA deficient women

Serum, milk and saliva from seven IgA deficient mothers were studied for the presence of IgA, IgG and IgM antibodies to Escherichia coli and polio virus antigens. Different variable patterns were obtained. One mother had very much increased IgM and IgG antibodies in milk and saliva against both antigens; the milk IgG antibodies were 11–14 times higher than the reference milk pool. Another mother showed also striking increases of both IgM and IgG antibodies in milk, as well as in saliva where the increases were much higher for the poliovirus than the E. coli antibodies. Yet another mother showed a certain increase of IgM but not of IgG antibodies in the milk. The uneven appearance of IgG and IgM antibodies in serum and secretions suggests local production. So do the differences ot antibody avidities, the variations in IgG subclass distribution of antibodies and different patterns after isoelectric focusing (IEF) /immunoblotting analysis of antibody spec-trotypes in secretions and serum.
The study illustrates the variable patterns of compensatory increases of IgG and IgM antibodies which may occur in IgA deficiency. It also shows that the milk from IgA deficient mothers can still be rich in antibodies, in spite of the lack of secretory IgA.     

Breast Milk Anti-Escherichia coli Heat-Labile Toxin IgA Antibodies Protect against Toxin-Induced Infantile Diarrhea

ABSTRACT. A prospective study to assess whether milk IgA antibodies against Escherichia coli heat labile-toxin protect breast-fed children against labile toxin-induced gastroenteritis was carried out among infants of a marginal urban area in Guatemala. One hundred and thirty children were kept under surveillance for diarrhea by periodic home visits. Stool specimens were collected from each child routinely every 2-3 weeks and during diarrheal episodes, to study the excretion of labile toxin-producing Escherichia coli. Milk samples from the children's mothers were obtained concomitantly with the fecal specimens of the infants to be analyzed for anti-labile toxin antibodies. Twenty infections by heat-labile toxin-producing Escherichia coli as a sole agent were documented among breast-fed infants. Nine of these infections resulted in gastroenteritis, while the remaining 11 were asymptomatic. At the time of infection children who became sick were ingesting breast milk with significantly ( p =0.028) lower titers of antilabile toxin IgA than those who remained healthy. Only one of the 8 infected children receiving breast milk with high titers (≥256) of anti labile toxin IgA developed diarrhea, compared to 8 of the 12 subjects being fed milk with low titers (≤64) ( p =0.025). This is the first report documenting protection by IgA antibodies in milk against labile toxin-induced gastroenteritis in infected breast-fed infants.     

Zinc and Copper Concentrations in Human Milk and Infant Formulas

Objective

Available accurate data on the concentrations of copper (Cu) and zinc (Zn) in human milk throughout lactation and infant formulas is important both for formulating nutritional requirements for substances and to provide a base line for the understanding the physiology of their secretion. The objective of this study was to analyze the concentrations of zinc and copper in infant formulas and human milk during prolonged lactation. Levels of these metals were examined in relation to selected parameters such as age, weight, height, education and occupation of mothers.

Methods

Thirty mothers referred to the selected clinics in Tehran entered the study. Human milk samples were collected at 2 months postpartum. Zinc and copper concentrations were determined by atomic absorption spectrophotometer.

Findings

The mean values of Zn and Cu in human milk were 2.95±0.77mg/L and 0.36±0.11 mg/L. The mean values of Zn and Cu in infant formulas were 3.98±0.25 mg/L and 0.53±0.17mg/L.

Conclusion

No significant relationship was found between levels of trace elements in human milk and evaluated parameters such as age, weight, height, education and occupation of mothers. The concentrations of zinc and copper in breast milk were lower than those reported in the literature.     

PPD-Induced Monocyte Chemotactic Factor Production by Human Milk Cells

The functional capability of antigen-stimulated breast milk cells to produce an immunologic mediator was examined. Colostrum and comparison peripheral blood samples were obtained from ten women, two to four days postpartum, and supernatants from PPD-stimulated mononuclear cell cultures were assayed for the lymphokine, monocyte chemotactic factor. Five of the ten women studied had a history of a positive tuberculin skin test and one had received BCG immunization. Peripheral blood lymphocyte cultures and colostrum cell cultures from four of these six women produced monocyte chemotactic factor. These results demonstrated the functional capability of antigen-stimulated colostra! cells to produce immunologic mediators.     

Low Colostral IgA Associated with Cow's Milk Allergy

ABSTRACT. During a nutritional study of 198 infants, seven became allergic to cow's milk. The seven infants showed acute cutaneous manifestations during cow's milk challenge tests in hospital and six had increased levels of IgE cow's milk-specific antibodies. Neither in the development of the levels of immunoglobulins G, A and M, nor in that of the cow's milk-specific antibodies of these isotypes did these seven patients differ from the remaining infants. Beta-lactoglobulin content and levels of cow's milk-, and beta-lactoglobulin-specific antibodies and of immunoglobulins A, G and M were measured in samples of colostrum and milk from the mothers of the seven infants with cow's milk allergy and from a comparison group (non-atopic mothers of non-atopic infants). The milk of the mothers whose infants became allergic to cow's milk contained less IgA through the lactation: 95% confidence intervals of the groups did not overlap. The difference was most marked in the colostrum. All other measurements were similar in the two groups. This suggests that an infant is more likely to develop cow's milk allergy if the mother's colostrum had a low total IgA content.     

Specific Antibodies to Poliovirus Type I in Breastmilk of Unvaccinated Mothers before and Seven Years after Start of Community-Wide Vaccination of Their Infants with Live, Oral Poliovirus Vaccine

ABSTRACT. Secretory IgA (SIgA) antibodies against poliovirus type 1 were determined using the ELISA method in breastmilk samples obtained each month from 100 young, healthy, unvaccinated mothers living in urban slum areas of Lahore, Pakistan. The study covered two different groups, one in 1980–1981 and the other in 1987, before and seven years after a nation-wide expanded programme of childhood immunization (EPI) had started. The SIgA titres did not change neither with duration of lactation nor with time after vaccination in the infants of the mothers studied. The seasonal breastmilk IgA antibody titres to poliovirus type 1 corresponded to the epidemiological conditions existing both before (1980–81) and after general vaccination coverage with live, oral poliovirus vaccine (OPV) had reached 80% of the infant population (1987). Neutralization titres did not seem to correlate well with ELISA titres although colostrum samples had high levels of neutralizing antibodies. The wide variation between high (> 10 000) and low (<500) individual breastmilk IgA antibody titres observed during various seasons could be of consequence for the breast-fed baby. Colostrum, which was also found to have significant neutralization capacity, might interfere with the OPV now often given on the day of birth.     

Enrichment of Human Milk Lymphocytes by Discontinuous Density Gradient Sedimentation

ABSTRACT. A simple method is described for the enrichment of lymphocytes from human colostrum and early milk. Washed leucocytes from colostrum or milk were suspended in balanced salt solution containing 25 % human serum and separated by discontinuous density gradient centrifugation over Lymphoprep (1.077 g/ml) and Nycodenz (1.070 g/ml). The cell fraction harvested from the interface between these two media contained a mean of 56 % lymphocytes (9-92 %), as compared to 5.6 % (0-17 %) in the unseparated samples, representing an average enrichment of 12.6 fold. The percentage yield of lymphocytes ranged from 70 to 100 %. Enriched preparations of lymphocytes from human colostrum and early milk should prove valuable in studies of the distribution of lymphocyte subpopulations in breast milk and could lead to more definitive studies of their functions in vitro.     

Dietary Bovine β Mactoglobulin is Transferred to Human Milk

ABSTRACT. Human milk from 38 mothers was analysed by radioimmunological method for content of bovine (5-Iactoglobulin. Detectable amounts (5-33 μg/1) of immunoactive β-lactoglobulin were found in 18 human milk samples. Milk from 3 mothers, whose infants suffered from infantile colic contained high amounts of fi-lactoglobulin (32, 18 and 14 μg/1 respectively). With the mothers on a cow's milk free diet the contents fell to non-detectable amounts in two mothers and to 6 μg/1 in the third. All three infants became free from colic,     

Development of a Human Milk Protein Standard

ABSTRACT. Accurate quantitation of the protein content of human milk (HM) is clinically important for both determining protein and energy intakes of HM-fed infants. Protein can be determined by Kjeldahl analysis or colorimetric assays. Colorimetric assays are rapid and convenient, but usually overestimate the protein content when compared to Kjeldahl protein (KP). In this study a protein standard based on human milk protein (HMPS) was isolated by size exclusion column chromatography. Purity and composition of the standard was determined by gel electrophoresis, Kjeldahl and amino acid analyses. The protein content of 20 mature milk samples was determined by the Lowry, BCA and BioRad colorimetric assays, using bovine serum albumin, human serum albumin/IgG, and HMPS as standards. These results were compared with KP results using Student's f-test. All colorimetric assays overestimated milk protein content; however, the Lowry assay gave the lowest protein levels, with our protein standard yielding values closest to the KP value.     

Human milk banking

It is universally accepted that breast milk is the optimum exclusive source of nutrition for the first six months of life, and may remain part of the healthy infant diet for the first two years of life and beyond. Despite advances in infant formulas, human breast milk provides a bioactive matrix of benefits that cannot be replicated by any other source of nutrition. When the mother's own milk is unavailable for the sick, hospitalized newborn, pasteurized human donor breast milk should be made available as an alternative feeding choice followed by commercial formula. There is a limited supply of donor breast milk in Canada and it should be prioritized to sick, hospitalized neonates who are the most vulnerable and most likely to benefit from exclusive human milk feeding.     

Anti-inflammatory Properties of Human Milk

ABSTRACT. An hypothesis was developed which predicts that human milk protects against infections of the alimentary tract of the breast-fed infant by non-inflammatory mechanisms. Human milk is poor in the initiators and mediators of inflammation and rich in anti-inflammatory agents. Furthermore, many of the anti-inflammatory agents are comparatively resistant to digestive enzymes and therefore might be expected to remain active in the gastrointestinal tract of the recipient. Further studies of these factors in in vivo models will be required to validate the hypothesis.