title: Levels of innate immune factors in preterm and term mothers' breast milk during the 1st month postpartum.
abstract: There is a paucity of data on the effect of preterm birth on the immunological composition of breast milk throughout the different stages of lactation. We aimed to characterise the effects of preterm birth on the levels of immune factors in milk during the 1st month postpartum, to determine whether preterm milk is deficient in antimicrobial factors. Colostrum (days 2-5 postpartum), transitional milk (days 8-12) and mature milk (days 26-30) were collected from mothers of extremely preterm (<28 weeks of gestation, n 15), very preterm (28-<32 weeks of gestation, n 15), moderately preterm (32-<37 weeks of gestation, n 15) and term infants (37-41 weeks of gestation, n 15). Total protein, lactoferrin, secretory IgA, soluble CD14 receptor (sCD14), transforming growth factor-β2 (TGF-β2), α defensin 5 (HD5), β defensins 1 (HBD1) and 2, IL-6, IL-10, IL-13, interferon-γ, TNF-α and lysozyme (LZ) were quantified in milk. We examined the effects of lactation stage, gestational age, volume of milk expressed, mode of delivery, parity and maternal infection on milk immune factor concentrations using repeated-measures regression analysis. The concentrations of all factors except LZ and HD5 decreased over the 1st month postpartum. Extremely preterm mothers had significantly higher concentrations of HBD1 and TGF-β2 in colostrum than term mothers did. After controlling for other variables in regression analyses, preterm birth was associated with higher concentrations of HBD1, LZ and sCD14 in milk samples. In conclusion, preterm breast milk contains significantly higher concentrations of some immune proteins than term breast milk.
authors.affiliation: 1Centre for Neonatal Research and Education,The University of Western Australia,Perth,WA 6009,Australia.
authors.forename: Stephanie
authors.identifier: http://orcid.org/0000-0003-0210-3452
authors.initials: S
authors.lastname: Trend
authors.affiliation: 1Centre for Neonatal Research and Education,The University of Western Australia,Perth,WA 6009,Australia.
authors.forename: Tobias
authors.initials: T
authors.lastname: Strunk
authors.affiliation: 4School of Pathology and Laboratory Medicine,The University of Western Australia,Perth,WA 6009,Australia.
authors.forename: Megan L
authors.initials: ML
authors.lastname: Lloyd
authors.affiliation: 1Centre for Neonatal Research and Education,The University of Western Australia,Perth,WA 6009,Australia.
authors.forename: Chooi Heen
authors.initials: CH
authors.lastname: Kok
authors.affiliation: 2School of Paediatrics and Child Health,The University of Western Australia,Perth,WA 6009,Australia.
authors.forename: Jessica
authors.initials: J
authors.lastname: Metcalfe
authors.affiliation: 5School of Chemistry and Biochemistry,The University of Western Australia,Perth,WA 6009,Australia.
authors.forename: Donna T
authors.initials: DT
authors.lastname: Geddes
authors.affiliation: 5School of Chemistry and Biochemistry,The University of Western Australia,Perth,WA 6009,Australia.
authors.forename: Ching Tat
authors.initials: CT
authors.lastname: Lai
authors.affiliation: 2School of Paediatrics and Child Health,The University of Western Australia,Perth,WA 6009,Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Richmond
authors.affiliation: 6School of Women's and Infants' Health,The University of Western Australia,Perth,WA 6009,Australia.
authors.forename: Dorota A
authors.initials: DA
authors.lastname: Doherty
authors.affiliation: 1Centre for Neonatal Research and Education,The University of Western Australia,Perth,WA 6009,Australia.
authors.forename: Karen
authors.initials: K
authors.lastname: Simmer
authors.affiliation: 1Centre for Neonatal Research and Education,The University of Western Australia,Perth,WA 6009,Australia.
authors.forename: Andrew
authors.initials: A
authors.lastname: Currie
mesh_terms: D003126:Colostrum / Q000276:immunology; D023082:Defensins / Q000032:analysis; D005260:Female; D005865:Gestational Age; D006801:Humans; D007071:Immunoglobulin A, Secretory / Q000032:analysis; D007155:Immunologic Factors / Q000032:analysis*; D007371:Interferon-gamma / Q000032:analysis; D007378:Interleukins / Q000032:analysis; D007774:Lactation / Q000502:physiology; D007781:Lactoferrin / Q000032:analysis; D018950:Lipopolysaccharide Receptors / Q000032:analysis; D008895:Milk, Human / Q000276:immunology*; D009113:Muramidase / Q000032:analysis; D049590:Postpartum Period / Q000276:immunology*; D047928:Premature Birth / Q000276:immunology*; D012995:Solubility; D047929:Term Birth; D053781:Transforming Growth Factor beta2 / Q000032:analysis; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis
chemical_list: D023082:Defensins; D007071:Immunoglobulin A, Secretory; D007155:Immunologic Factors; D007378:Interleukins; D018950:Lipopolysaccharide Receptors; D053781:Transforming Growth Factor beta2; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma; D009113:Muramidase; D007781:Lactoferrin
keywords: AMPs antimicrobial proteins and peptides; BSA bovine serum albumin; Breast milk; GEE generalised estimating equations; HBD1 and HBD2 
                    β defensins 1 and 2; HD5 
                    α defensin 5; INF-γ
                  interferon-γ; Immunity; LF lactoferrin; LOS late-onset neonatal sepsis; LZ lysozyme; Lactation; PRR pattern recognition receptors; Preterm birth; TGF-β2 transforming growth factor-β2; sCD14 soluble CD14 receptor; sIgA secretory IgA