Comparison of IgG subclasses in foetal serum, maternal serum at delivery and milk in IgA-deficient and control women

The Mammary Gland in Mucosal and Regional Immunity

The mammary gland (MG) lacks a mucosa but is part of the mucosal immune system because of its role in passive mucosal immunity. The MG is not an inductive site for mucosal immunity. Rather, synthesis of immunoglobulin (Ig)A by plasma cells stimulated at distal inductive sites dominate in the milk of rodents, humans, and swine whereas IgG1 derived from serum predominates in ruminants. Despite the considerable biodiversity in the role of the MG, IgG passively transfers the maternal systemic immunological experience whereas IgA transfers the mucosal immunological experience. Although passive antibodies are protective, they and other lacteal constituents can be immunoregulatory. Immune protection of the MG largely depends on the innate immune system; the monocytes–macrophages group together with intraepithelial lymphocytes is dominant in the healthy gland. An increase in somatic cells (neutrophils) and various interleukins signal infection (mastitis) and a local immune response in the MG. The major role of the MG to mucosal immunity is the passive immunity supplied to the suckling neonate.

Immune markers in breast milk and fetal and maternal body fluids: a systematic review of perinatal concentrations

Breastfeeding represents the continued exposure of the infant to the maternal immune environment.Uterine, perinatal, and postnatal exposure to immune factors may contribute to an infant’s risk of developing immune-mediated disorders, including allergies. A PubMed search was conducted to review studies in humans and analyze concentrations of immune markers (TGF-beta, IFN-gamma, eotaxin, CCL5, CXCL10, TNF-alpha, MCP-1, IL-1beta, IL-4, IL-5, IL-6,IL-8, IL-10, IL-12, IL-13, sCD14, sIgA, IgG4, IgM) found in maternal serum, amniotic fluid, cord serum, colostrum, transition and mature milk. Concentrations of immune markers showed large variations across samples and studies. Reports documented conflicting results. Small sample sizes, differences in population characteristics, inconsistent sample collection times, and various sample collection and measurement methods may have led to wide variations in the concentrations of immune markers. Studies analyzing the associations between immune markers in maternal fluids and infant allergies remain inconclusive because of gaps in knowledge and a lack of standardized methods.

Immune components (IgA, IgM, IgG, immune cells) of colostrum of Bangladeshi mothers

BACKGROUND

Colostrum is the first defense for neonates. It is rich in immune components including immunoglobulins and viable immune cells. In the present study, human colostrum collected from 105 postpartum mothers was analyzed for its IgA, IgM, IgG levels, and peripheral immune cells.

METHODS

Enzyme-linked immunosorbent assay was used to analyze the serum immunoglobulin concentrations. Immune cells were estimated by counting 200 cells.

RESULTS

IgA was the dominant immunoglobulin and ranged from 2.84 to 8.69 g/L (mean 5.61 g/L). Mean IgM and IgG concentrations were 0.4 g/L (0.16-0.66 g/L) and 0.095 g/L (0.04-0.15 g/L), respectively. Neutrophil-macrophage (neu-mac) predominated in cell count (59%) followed by lymphocyte-plasma cells (lymph-plasma; 40%). The influence of maternal nutritional status, age, parity and income levels on the colostral immunological factors was studied. No significant association could be traced for immunoglobulin content, suggesting that maternal characteristics do not have any bearing on the immunoglobulin content of colostrum. Mean value of eosinophils was found to be higher among the underweight than the normal mothers (F= 3.143, r=-0.101). Maternal age was positively correlated with eosinophil (F= 3.296, r= 0.162). Concentration of neu-mac had a positive significant correlation with parity (t=-2.07, r= 0.205), while it was negatively significant for lymphocyte-plasma cells (t= 2.073, r=-0.101). However, the correlation coefficients of the immunologic parameters with other maternal characteristics were statistically insignificant.

CONCLUSION

Colostrum has enough humoral and cellular elements to protect babies. Therefore, immune protection derived from breastfeeding depends on the immunoglobulin level of the colostrum as well as the amount of colostrum ingested.