Cytokines and soluble CD14 in breast milk in relation with atopic manifestations in mother and infant (KOALA Study)

BACKGROUND: Conflicting evidence exists concerning the protective role of breastfeeding in allergy and atopic disease aetiology. Breast milk contains biologically active molecules influencing the innate immune system of newborns. OBJECTIVE: We aim to assess whether cytokines (TGF-beta1, IL-10 and IL-12) and soluble CD14 (sCD14) in breast milk are influenced by maternal atopic constitution and modify the development of atopic manifestations in infants. METHODS: Milk samples were collected at 1 month post-partum of 315 lactating mothers participating in the ongoing KOALA Birth Cohort Study. The cytokines and sCD14 were analysed by ELISA in the aqueous fraction. We compared the concentrations of cytokines and sCD14 in breast milk between mothers with and without an allergic history and also with and without allergic sensitization (specific IgE). Associations of cytokines and sCD14 with the development of eczema, wheezing in the first 2 years of life and allergic sensitization of infants at the age of 2 years were analysed by multivariate logistic regression analyses to correct for confounders. RESULTS: We found higher sCD14 levels in mothers with a positive vs. negative allergic history (7.6 vs. 7.0 microg/mL; P = 0.04) and in mothers who were sensitized vs. non-sensitized (7.8 vs. 7.1 microg/mL; P = 0.03). None of the studied immune factors were associated with infant's atopic outcomes. IL-10 was not detected above the detection limit of 0.2 pg/mL. CONCLUSION: Taking together the results of the present and previous studies, we conclude that there is no convincing evidence for a relation between TGF-beta1, sCD14, IL-10 or IL-12 in breast milk and atopic manifestations in infants.     

Allergological study of breast feeding, ovalbumin and specific IgG, IgM and IgA antibodies to ovalbumin in human milk

Ovalbumin (OA) and specific antibodies to OA were evaluated by ELISA in 92 colostrum, 366 mature milk and 12 cord blood samples. Anti-OA IgG antibody titers in colostrum were lower than those in cord blood and were not detectable in several samples. Anti-OA IgM antibody titers in colostrum were comparatively high and decreased on the days following postpartum. Anti-OA IgA antibody titers were the highest in the colostrum and decreased on the following days, but remained constant in mature milk. On the other hand, OA was detected in 27.2% of colostrum and 17.2% of mature milk samples, in concentrations from 0.5-59.0 ng/ml. In mature milk, the positive rates of OA were significantly elevated by egg ingestion by the mothers. OA in mature milk from allergic mothers tended to be more readily detectable than that from non-allergic mothers. These results suggest that avoidance of the specific food antigens by mothers is important for therapy and prevention on allergic disease in their breast-fed infants.     

Transforming growth factor-beta1 in mothers' colostrum and immune responses to cows' milk proteins in infants with cows' milk allergy.

BACKGROUND: Breast milk contains immune factors that compensate for the underdeveloped defenses of the gut of the newborn infant. OBJECTIVE: We sought to study the importance of these factors in the immune responses of infants with cows' milk allergy (CMA) to the proteins in cows' milk (CM). METHODS: We prospectively followed the development of CMA in 6209 healthy infants and collected samples of colostrum from mothers. Samples from mothers of infants with CMA and from control subjects were analyzed for immunoglobulins, CM-specific antibodies, and cytokines. In infants with CMA, correlations between the concentration of transforming growth factor (TGF)-beta1 in colostrum and the extent of the immune response to CM proteins were studied. RESULTS: The concentration of TGF-beta1 in colostrum samples from mothers of infants with IgE-mediated CMA (n = 65) was lower (mean, 589 pg/mL; 95% confidence interval [CI], 413-840) than from mothers of infants with non-IgE-mediated CMA (n = 37; mean, 1162 pg/mL; 95% CI, 881-1531; t = 2.57, P =.012). In 126 control subjects the mean concentration was 807 pg/mL (95% CI, 677-963). In the infants with CMA (n = 96-100), the concentration of TGF-beta1 in colostrum was positively correlated with IgA antibodies to beta-lactoglobulin and IgG antibodies to alpha-casein and whole formula and negatively with the diameter of a skin prick test response to CM and lymphocyte stimulation indices to alpha-casein and beta-lactoglobulin. CONCLUSIONS: In an infant prone to having CMA, the TGF-beta1 content of mother's colostrum may promote IgG-IgA antibody production and inhibit IgE- and cell-mediated reactions to CM.     

Transforming growth factor-beta in breast milk: a potential regulator of atopic disease at an early age

BACKGROUND: According to data from animal and in vitro studies, transforming growth factor-beta (TGF-beta) has a crucial effect on 2 essential parts of the mucosal immune system: IgA production and oral tolerance induction. OBJECTIVE: We sought to ascertain whether TGF-beta in breast milk is associated with specific IgA production and atopic disease in human subjects. METHODS: Forty-seven infants with several atopic family members were followed during their first year of life. The concentrations of TGF-beta1 and TGF-beta2 in maternal colostrum, mature milk, and the infants' sera were determined. The enzyme-linked immunospot assay was used to assess the infants' specific IgA production in response to beta-lactoglobulin, casein, gliadin, and ovalbumin. RESULTS: At 12 months, atopic dermatitis was confirmed in 29 of 47 infants; in 11, atopic disease had begun during exclusive breast-feeding (preweaning onset), whereas in 18 the disease manifested itself after weaning (postweaning onset). The concentrations of both TGF-beta1 and TGF-beta2 were higher in maternal colostrum, but not in mature milk and infants' serum, in infants with postweaning-onset atopic disease compared with those with preweaning-onset disease (P =.0008 and P =. 015, respectively). The concentration of TGF-beta2 was, and that of TGF-beta1 tended to be, higher in the colostrum of mothers whose infants had specific IgA-secreting cells at 3 months in response to at least one of the dietary antigens tested compared with those who did not have such cells (P =.048 and P =.076, respectively). CONCLUSION: TGF-beta in colostrum may prevent the development of atopic disease during exclusive breast-feeding and promote specific IgA production in human subjects.     

Probiotics during pregnancy and breast-feeding might confer immunomodulatory protection against atopic disease in the infant.

The prevalence of atopic diseases is increasing throughout the Western world, and means of primary prevention are needed to reverse this trend. The role of breast-feeding, the best source of infant nutrition, in protection against atopic disease remains elusive. In this double-blinded, placebo-controlled study of 62 mother-infant pairs, it is shown that administering probiotics to the pregnant and lactating mother increased the immunoprotective potential of breast milk, as assessed by the amount of anti-inflammatory transforming growth factor beta2 (TGF-beta2) in the milk (2885 pg/mL [95% CI, 1624-4146] in mothers receiving probiotics vs 1340 pg/mL [95% CI, 978-1702] in mothers receiving placebo; P =.018). The risk of developing atopic eczema during the first 2 years of life in infants whose mothers received probiotics was significantly reduced in comparison with that in infants whose mothers received placebo (15% and 47%, respectively; relative risk, 0.32 [95% CI, 0.12-0.85]; P =.0098). Maternal atopy was a clear risk factor for atopic eczema in the infant. The infants most likely to benefit from maternal probiotic supplementation were those with an elevated cord blood IgE concentration. Administering probiotics during pregnancy and breast-feeding thus offers a safe and effective mode of promoting the immunoprotective potential of breast-feeding and provides protection against atopic eczema during the first 2 years of life.     

Increased secretion of IL-18 in vitro by peripheral blood mononuclear cells of patients with bronchial asthma and atopic dermatitis.

This study was performed to determine whether or not IL-18, formerly called IFN-gamma-inducing factor, is involved in the pathogeneses of allergic disorders. Peripheral blood mononuclear cells (PBMC) were obtained from patients with allergic bronchial asthma (BA), patients with atopic dermatitis (AD) and controls who did not have any allergic disease, and then cultured with lipopolysaccharide (LPS) or phytohaemagglutinin (PHA). The concentrations of IL-18, IFN-gamma and IL-13 in supernatant fluids were determined by enzymatic immunoassaying, and the expression of IFN-gamma messenger (m) RNA in the cells was measured by colorimetric microplate assaying. IL-18 secretion in the BA patients (geometric mean (gm) = 189 pg/ml) and AD patients (gm = 172 pg/ml) was significantly higher than that in non-allergic controls (gm = 118 pg/ml). In contrast, IFN-gamma secretion in the BA patients (gm = 7.3 IU/ml) and AD patients (gm = 6.8 IU/ml) was significantly lower than that in non-allergic controls (gm = 20.7 IU/ml). The amounts of IL-13 in supernatant fluids and IFN-gamma mRNA in cells were not statistically different among the BA patients, AD patients and non-allergic controls. The possible involvement of IL-18 in allergic disorders is discussed.     

Prostaglandin D2 measurement in nasal secretions is not a reliable marker for mast cell activation in atopic patients

Background Prosia gland in D2 (PGD2) is a very important mast cell product during the early-phase nasal allergic reaction. However, the quantification of PGD2 in nasal secretions has not yet been well established. Objective Quantitative determination of PGD2 in nasal secretions of atopic patients (n=17) after nasal allergen challenge (NAC) and in non-allergic healthy volunteers (n=10). Methods The nasal microsuction sampling technique was used to obtain the nasal secretions with an exactly known and minimally diluted volume. A sensitive and specific enzyme immunoassay was chosen to measure the more stable 11-methoxime derivative of PGD2. which was obtained after extraction in acelone/ethanol and conversion using methoxamine-HCl. The concentrations of PGD2 in nasal secretions obtained from 10 non-allergic healthy volunteers were used as reference values. Results There was no significant difference in the concentrations of PGD2 between men (median: 569pg/mL) and women (median: 407pg/mL), nor between the baseline concentrations from atopic patients (median: 410pg/mL) and non-allergic controls (median: 477 pg/mL). In the atopic patient group, PGD2 did not significantly increase during the entire sampling period after NAC. The absence of PGD2 response contrasted with the nasal symptoms manifested by sneezing, increased nasal airway resistance, and the significant increases of the concentrations of histamine, tryptase, and leukotriene C4 (LTC4) 5min after NAC. Conclusion This observation suggests that the measurement of PGD2 alone in the nasal secretions does not give reliable information on mast cell activation during a nasal allergic reaction.     

Detection of IgA antibodies to cat, β-lactoglobulin, and ovalbumin allergens in human milk

Background: The relationship between the development of allergy during infancy and breast-feeding remains controversial. This controversy may be due to individual variations in the composition of human milk. Antibodies to food antigens to which the mother is commonly exposed are present in the milk, but their relationship to allergy is still unknown. IgA antibodies to inhalant allergens have not been previously detected. Objective: Our purpose was to analyze secretory IgA antibody levels to cat, β-lactoglobulin, and ovalbumin allergens in colostrum and mature milk in relation to maternal allergy. Methods: Colostrum and samples of mature milk were obtained after 1 and 3 months of lactation from 53 nursing mothers (17 allergic and 36 nonallergic mothers) and were analyzed for total secretory IgA levels by ELISA and secretory IgA antibodies to cat, β-lactoglobulin, and ovalbumin by an enzyme-amplified ELISA. The specificity of the assays was confirmed by inhibition experiments. Results: Secretory IgA to cat, β-lactoglobulin, and ovalbumin allergens were detected in colostrum as well as mature milk. The levels of secretory IgA to ovalbumin were lower in colostrum from allergic mothers with P = .016, whereas the levels to β-lactoglobulin and cat were similar in the 2 groups. IgA antibodies to ovalbumin were detected in 94% of the colostrum samples from allergic and in all samples from nonallergic mothers, in 82% and 96%, respectively at 1 month, and 53% and 65% at 3 months. Fewer samples had detectable secretory IgA antibodies to β-lactoglobulin than to ovalbumin and cat, and only 33% and 10% of the samples from the allergic and nonallergic mothers, respectively, remained positive at 3 months. All the allergic mothers had detectable IgA to cat in colostrum, whereas 83% and 73% of the samples were positive at 1 and 3 months. The corresponding numbers were 93%, 81%, and 81% in the nonallergic mothers (not significant). Conclusion: Even a low level of exposure of the mucosa (eg, by inhalant allergens) can induce antibody secretion into the milk, both in allergic and nonallergic mothers. (J Allergy Clin Immunol 2000;105:1236-40.)     

Late onset reactions to oral food challenge are linked to low serum interleukin-10 concentrations in patients with atopic dermatitis and food allergy

BACKGROUND: Aberrant cytokine production in vitro has been associated with atopic disease. No study has as yet been made of the circulating cytokine profiles in atopic patients with food allergy in response to oral allergen challenge. OBJECTIVE: To assess the effect of oral allergen challenge on the serum cytokine concentrations in patients with atopic dermatitis and food allergy. METHODS: Serum concentrations of interleukin (IL)-10, transforming growth factor beta 1, IL-1ra, IL-6, IL-5, IL-4 and interferon (IFN)-gamma were measured before and after double-blind, placebo-controlled food challenges (DBPCFC) (n = 73). Before DBPCFC, combined skin prick and patch testing was performed for cow milk, egg, soybean and cereals, and production of IFNgamma, IL-4, IL-10 and tumour necrosis factor alpha (TNFalpha) was determined in supernatants of cultures of peripheral blood mononuclear cells (PBMCs) stimulated by cow milk. RESULTS: The oral food challenge triggered immediate onset exanthematous reactions in 22 cases and late onset eczematous reactions in 29. The late-reacting cases had more positive skin patch test and negative skin prick test reactivities with allergenic food, and they had lower serum IL10 concentrations than immediate-reacting cases. In challenge-positive cases, IL-10 concentrations increased from 2.9 (0.1-5.04) pg/mL to 3. 9 (1.2-8.3) pg/mL in response to DBPCFC, P = 0.05, median (interquartile ranges), but not in those tolerant to cow milk. PBMCs of patients with cow milk allergy but not of those tolerant to cow milk generated TNFalpha in response to cow milk in vitro. CONCLUSION: These results indicate that oral allergen challenge in atopic patients with food allergy triggers systemic release of IL-10. Patients with late onset reactions were found to have lower serum IL-10 concentrations than their immediate-reacting counterparts. Considering that IL-10 is an inhibitory cytokine of delayed-type hypersensitivity, low IL-10 in late-reacting patients may explain the high frequency of their positive skin patch tests combined with negative skin prick tests.     

Serum levels of soluble IL-2 receptor, IL-4 and IgE-binding factors in childhood allergic diseases.

The serum levels of soluble IL-2 receptor (sIL-2R), IL-4 and IgE-binding factors were examined in children with allergic diseases, and compared with those in non-allergic controls of the same age and sex. The results showed age-related decreases in the serum levels of sIL-2R and IgE-binding factors, but not in that of IL-4 in both allergic and non-allergic individuals. Significant elevation of sIL-2R was observed in sera from children with atopic eczema or history of an anaphylactic reaction to food, as compared with that in non-allergic controls. The serum concentration of IL-4 was elevated in all allergic groups, including cases of atopic eczema, bronchial asthma and anaphylaxis to food, compared with non-allergic controls, and was correlated significantly with the serum level of IgE (r = 0.59). The IgE-binding factor levels in sera from patients aged 6-10 years with bronchial asthma, or patients aged 1-5 years with a history of food anaphylaxis were elevated as compared with those in non-allergic controls of same age. There was no significant correlation between the serum levels of IgE-binding factors and IgE. Since sIL-2R is released by activated T cells, the present study is in favour of T cell activation causing allergic skin disorders. The serum levels of IL-4 as well as IgE did not differ among allergic patients of different clinical categories. The role of IgE in atopic eczema and other allergic diseases is not clearly established; however, it seems likely that IL-4 is deeply involved in the increased production of IgE seen in allergic individuals. The possible involvement of IgE-binding factors in the age-related changes of clinical manifestations in childhood allergic diseases was also discussed.     

Associations between fatty acids in colostrum and breast milk and risk of allergic disease

Background Exposure to n‐3 polyunsaturated fatty acids (PUFA) in early life is hypothesized to offer protection against atopic disease. However, there is controversy in this area, and we have previously observed that high levels of n‐3 fatty acid (FA) in colostrum are associated with increased risk of allergic sensitization. Objective The aim of the study was to assess the relationship between FA profile in breast milk and risk of childhood atopic disease. Methods A high‐risk birth cohort was recruited, and a total of 224 mothers provided a sample of colostrum (n=194) and/or 3‐month expressed breast milk (n=118). FA concentrations were determined by gas chromatography. Presence of eczema, asthma and rhinitis were prospectively documented up to 7 years of age. Results High levels of n‐3 22:5 FA (docosapentaenoic acid, DPA) in colostrum were associated with increased risk of infantile atopic eczema [odds ratio (OR)=1.66 per 1 standard deviation increase, 95% confidence interval (CI)=1.11–2.48], while total n‐3 concentration in breast milk was associated with increased risk of non‐atopic eczema (OR=1.60, 95% CI=1.03–2.50). Higher levels of total n‐6 FA in colostrum were associated with increased risk of childhood rhinitis (OR=1.59, 95% CI=1.12–2.25). There was no evidence of associations between FA profile and risk of asthma. Conclusion In this cohort of high‐risk children, a number of modest associations were observed between FA concentrations in colostrum and breast milk and allergic disease outcomes. Further research in this area with larger sample sizes is needed.     

Immune regulation by CD4+CD25+ T cells and interleukin-10 in birch pollen-allergic patients and non-allergic controls

BACKGROUND: CD4+CD25+ regulatory T (Treg) cells and the cytokines IL-10 or TGF-beta play key roles in the maintenance of T cell homeostasis and tolerance to infectious and non-infectious antigens such as allergens. OBJECTIVE: To investigate the regulation of immune responses to birch pollen allergen compared with influenza antigen by Treg cells obtained from birch pollen-allergic patients and non-allergic controls. METHODS: Peripheral blood was collected from 10 birch pollen-allergic patients and 10 non-allergic healthy controls. CD4+CD25+ and CD4+CD25- cells isolated by magnetic-activated cell sorting were co-cultured and stimulated with birch pollen extract or influenza vaccine in the absence or presence of anti-IL-10 or soluble TGF-betaRII. RESULTS: CD4+CD25+ cells from non-allergic controls were able to suppress influenza antigen and birch pollen stimulated effector cell proliferation, whereas CD4+CD25+ cells from allergic patients suppressed influenza antigen-, but not birch pollen-stimulated proliferation. The production of Th1 cytokines, but not Th2 cytokines, was suppressed by CD4+CD25+ cells from both allergic patients and controls, upon stimulation with birch pollen extract. Neutralization of IL-10 led to significantly increased production of IFN-gamma in cultures with CD4+CD25- T effector cells. In addition, six-fold higher concentrations of TNF-alpha were detected after neutralization of IL-10 in both CD4+CD25- and CD4+CD25+ cell cultures from allergic patients and controls. CONCLUSION: We demonstrate that the allergen-specific suppressive function of CD4+CD25+ cells from allergic patients is impaired compared with non-allergic controls. Moreover, neutralization of IL-10 enhances the production of TNF-alpha, suggesting counter-acting properties of IL-10 and TNF-alpha, where IL-10 promotes tolerance and suppression by Treg cells and TNF-alpha promotes inflammatory responses.     

Cytokine production by cord blood mononuclear cells stimulated with cows milk proteins in vitro: interleukin-4 and transforming growth factor β-secreting cells detected in the CD45RO T cell population in children of atopic mothers

BACKGROUND: Food antigens from the maternal circulation may sensitize fetal T cells in utero and be an important determinant in the development of food allergy. METHODS: Here we have examined the spontaneous and recall response to cow's milk proteins of cord blood mononuclear cells (CBMC) of newborn children, using single cell ELISPOT assays. RESULTS: In term newborns, confirming previous studies, the spontaneous cytokine response of CBMC is dominated by IL-4, IL-5, IL-10, and as shown here for the first time, TGF-beta. For TGF-beta only, the response of samples from infants of atopic mothers was significantly lower than samples from infants of non-atopic mothers. In vitro stimulation of CBMC with bovine serum albumin, casein and beta-lactoglobulin resulted in a significant increase of all cytokine-secreting cells, again dominated by T helper type 2 (Th2) cytokines. There was a clear tendency for samples from infants of atopic mothers to have lower Th2 responses than samples from infants of non-atopic mothers, which was particularly significant for both IL-4 and TGF-beta. Spontaneous cytokine secreting cells were virtually absent in cord blood from infants < 34 weeks gestation, as were cows milk protein-induced responses, although they were readily detectable in samples from infants aged > 34 weeks. To explore whether the cytokine secreting cells were in the naive CD4+ CD45RA population or memory CD4+ CD45RO T cells, these subsets were purified by positive and negative selection and tested for spontaneous and cows milk protein-induced cytokine responses. Strikingly, although the responses were small, the CD45RO+ cells from children of atopic mothers showed significant spontaneous and antigen-specific IL-4 and TGF-beta responses, whereas the same population from infants of non-atopic mothers showed virtually no response. In addition CD45RA+ cells from infants of mothers with maternal atopy showed decreased IL-4 and TGF-beta responses, especially the latter. CONCLUSIONS: The cows milk antigen-specific IL-4 and TGF-beta responses preferentially seen in the memory cell subset of infants with a maternal history of atopy strongly suggests Th2 skewing to dietary antigens in utero.     

Effects of dog ownership and genotype on immune development and atopy in infancy

BACKGROUND: Exposure to furred pets might confer protection against the development of allergic sensitization through a mechanism that is incompletely understood. OBJECTIVE: The objective of this study was to determine the effects of pet exposure and genotype on immunologic development and the incidence of atopic markers and diseases in the first year of life. METHODS: Pet exposure in the home was compared with cytokine secretion patterns (mitogen-stimulated mononuclear cells at birth and age 1 year) and indicators of atopy (allergen-specific and total IgE, eosinophilia, food allergy, atopic dermatitis) in 285 infants. Interactions with genotype at the CD14 locus were also evaluated in the data analyses. RESULTS: Exposure to dogs was associated with reduced allergen sensitization (19% vs 33%, P =.020) and atopic dermatitis (30% vs 51%, P <.001). The risk for atopic dermatitis was further influenced by genotype at the CD14 locus (P =.006), even after adjusting for exposure to dogs (P =.003). Furthermore, infants with the genotype -159TT were less likely to develop atopic dermatitis if they were exposed to a dog (5% vs 43%, P =.04). Last, dog exposure was associated with increased IL-10 (117 vs 79 pg/mL, P =.002) and IL-13 (280 vs 226 pg/mL, P =.013) responses at age 1 year. CONCLUSIONS: Having a dog in infancy is associated with higher IL-10 and IL-13 cytokine secretion profiles and reduced allergic sensitization and atopic dermatitis. These findings suggest that postnatal exposure to dogs can influence immune development in a genotype-specific fashion and thereby attenuate the development of atopy in at-risk children.     

Developmental cytokine response profiles and the clinical and immunologic expression of atopy during the first year of life

BACKGROUND: Allergic diseases have been linked to abnormal patterns of immune development, and this has stimulated efforts to define the precise patterns of cytokine dysregulation that are associated with specific atopic phenotypes. OBJECTIVE: Cytokine-response profiles were prospectively analyzed over the first year of life and compared with the clinical and immunologic expressions of atopy. METHODS: Umbilical cord and 1-year PBMCs were obtained from 285 subjects from allergic families. PHA-stimulated cytokine-response profiles (IL-5, IL-10, IL-13, and IFN-gamma) were compared with blood eosinophil counts and total and specific IgE levels (dust mites, cat, egg, Alternaria species, peanut, milk, and dog) at age 1 year and at the development of atopic dermatitis and food allergy. RESULTS: For the cohort as a whole, cytokine responses did not evolve according to a strict TH1 or TH2 polarization pattern. PHA-stimulated cord blood cells secreted low levels of IL-5 (2.1 pg/mL), moderate levels of IFN-gamma (57.4 pg/mL), and greater amounts of IL-13 (281.8 pg/mL). From birth to 1 year, IL-5 responses dramatically increased, whereas IL-13 and IFN-gamma responses significantly decreased. Reduced cord blood secretion of IL-10 and IFN-gamma was associated with subsequent sensitization to egg. In addition, there was evidence of TH2 polarization (increased IL-5 and IL-13 levels) associated with blood eosinophilia and increased total IgE levels by age 1 year. CONCLUSION: These findings demonstrate that cytokine responses change markedly during the first year of life and provide further evidence of a close relationship between TH2 skewing of immune responses and the incidence of atopic manifestations in children.     

Polyunsaturated fatty acids in maternal diet, breast milk, and serum lipid fatty acids of infants in relation to atopy

Background: The increased consumption of n-6 polyunsaturated fatty acids (PUFA) has been shown to coincide with the increased prevalence of atopic diseases. We aimed to investigate whether maternal diet and atopic status influence the PUFA composition of breast milk and the serum lipid fatty acids of infants.
Methods: Maternal diet was assessed by a food questionnaire. The PUFA composition of breast milk obtained at 3 months from 20 allergic and 20 healthy mothers and of their infants' (10 atopic and 10 nonatopic/group of mothers) serum lipids was analyzed.
Results: Although no differences in maternal PUFA intake were observed, the breast milk of allergic mothers contained less γ-linolenic acid (18:3 n-6) than that of healthy mothers. Similarly, atopic infants had less γ-linolenic acid in phospholipids than healthy infants, although n-6 PUFA were elevated in other serum lipid fractions in atopic infants. The serum lipid fatty acids in atopic infants did not correlate with those in maternal breast milk.
Conclusions: Our results suggest that dietary n-6 PUFA are not as readily transferred into breast milk or incorporated into serum phospholipids, but may be utilized for other purposes, such as eicosanoid precursors, in allergic/atopic individuals. Subsequently, high dietary proportions of n-6 PUFA, or reduced proportions of regulatory PUFA, such as γ-linolenic acid and n-3 PUFA, may be a risk factor for the development of atopic disease.     

Soluble Fas and soluble Fas ligand proteins in human milk: possible significance in the development of immunological tolerance

Human milk contains a complex uncharacterized, immune system able to exert actions both locally and systemically. This study reports the results of an ELISA-based quantitation of soluble Fas and soluble Fas ligand in human milk which may modulate the Fas/FasL system that is critical for the expression of immune tolerance and apoptosis. Production of Fas/FasL mRNAs by milk cells was also examined using RT-PCR. Fas is ubiquitously expressed in various cells and when bound by its ligand FasL, present predominantly on activated T- and NK cells, Fas-expressing cells are killed. A large amount of soluble Fas (1746-4320 pg/ml) is detected in colostrum, transitional milk and the mature milk of mothers delivering prematurely or at full-term, whereas FasL is present only in the range 123-310 pg/ml. Milk cells are positive for Fas mRNA, but negative for FasL mRNA. An excess of soluble Fas in human milk may bind to FasL preventing apoptosis and preserving epithelial barriers, and may represent an additional new mechanism whereby human milk favours immune tolerance and normal gastrointestinal development.     

Inflammation markers and cytokines in breast milk of atopic and nonatopic women

BACKGROUND: Breast milk is thought to contain its own complex immune system. Whether or not this is altered in allergic individuals is not yet known. METHODS: By ELISA techniques, inflammatory markers (MIP-1alpha, sICAM-1) and T(H)1 (interferon-gamma [IFN-gamma]), as well as T(H)2 cytokines (interleukin [IL]-4, IL-10), were investigated in serum and milk samples from nonallergic (n = 23) lactating women and those with respiratory allergies (n = 19) during the first week postpartum. RESULTS: IFN-gamma was not detected in either serum or milk. IL-10 was more often found to be above the detection limit in both milk and serum samples from allergic mothers. IL-4 was detected in almost all serum samples with a wide variation. In milk, IL-4 was found in about 20% of the samples. MIP-1alpha was not detected in the serum but was detected in the milk of 23% of the nonatopic and 53% of the allergic mothers. Soluble ICAM-1 was present in all samples. Surprisingly, serum levels of sICAM-1 in allergic mothers (271+/-97 ng/ml) were significantly lower (P<0.001) than in nonatopic subjects (375+/-86 ng/ml). Concentrations of sICAM-1 in milk were similar in both groups. CONCLUSIONS: The concentrations of proinflammatory markers and cytokines in breast milk did not differ significantly between allergic and nonatopic mothers. In some individuals, high levels of MIP-1alpha, IL-10, and sICAM-1 could be found. However, the significance of these components for the breastfed infant is still unclear.     

IL-16 inhibits IL-5 production by antigen-stimulated T cells in atopic subjects

BACKGROUND: We have previously shown increased expression of the CD4+ cell chemoattractant IL-16 at sites of airway allergic inflammation. Little is known about the significance of IL-16 in allergic inflammation and its role in allergen-driven T-cell cytokine responses. Because IL-16 interacts specifically with CD4+ T cells, we hypothesized that IL-16 released at sites of inflammation may modulate the pattern of cytokines produced by CD4+ T cells. OBJECTIVE: We investigated the effects of exogenous rhIL-16 on cytokine production of PBMCs from atopic and nonatopic subjects in response to antigen and PHA. METHODS: Primary cultures of freshly isolated PBMCs from ragweed-sensitive atopic subjects and nonatopic subjects were stimulated with ragweed or PHA in the presence or absence of rhIL-16. Supernatant levels of IL-4, IL-5, and IFN-gamma were determined by means of ELISA at different time points between 2 and 6 days. Effects of IL-16 on antigen-induced cellular proliferative responses were determined. RESULTS: No IL-4 protein was detected after antigen stimulation of PBMCs from atopic subjects, whereas significant levels of IL-5 were measured on day 6 (median, 534.9 pg/mL). IL-5 secretion was abolished in PBMC cultures depleted of CD4+ cells. The addition of rhIL-16 in antigen-stimulated PBMC cultures significantly reduced the amount of IL-5 released (median, 99.8 pg/mL; P <.001). Detectable levels of IFN-gamma (median, 53.3 pg/mL) were identified after antigen stimulation. The addition of rhIL-16 in antigen-stimulated PBMC cultures significantly increased IFN-gamma levels (median, 255.6 pg/mL; P <.05). Effects of rhIL-16 appear to be specific for antigen-stimulated PBMCs in atopic subjects because rhIL-16 did not alter IL-5 or IFN-gamma production in response to PHA nor did rhIL-16 alter cytokine production in nonatopic normal subjects. CONCLUSION: These studies suggest that IL-16 can play a role in regulating the production of cytokines seen in allergic states in response to antigen.     

Impact of maternal atopy and probiotic supplementation during pregnancy on infant sensitization: a double-blind placebo-controlled study

Background The effects of breastfeeding and probiotics on infant sensitization still remain discrepant.
Objective To explore probable explanatory factors in infant sensitization and the protective effect of probiotics.
Methods Altogether 171 mother–infant pairs from an ongoing placebo-controlled double-blind study with nutrition modulation by dietary counselling and probiotic supplementation were studied. Skin prick testing was done in infants at 6 and 12 months and in mothers at third trimester of pregnancy. The breast milk concentrations of cytokines TGF-β2, soluble CD14, IFN-γ, TNF-α, IL-10, IL-6, IL-4 and IL-2 were measured.
Results The risk of sensitization increased in infants with allergic mothers breastfeeding over 6 months [odds ratio (OR=4.83, P =0.005)], or exclusively breastfeeding over 2.5 months (OR=3.4, P =0.018). Probiotic supplementation had a protective effect against sensitization in infants with a high hereditary risk due to maternal sensitization (OR=0.3, P =0.023). The concentration of TGF-β2 tended to be higher in the colostrum of the mothers in the probiotic group as compared with those on placebo (probiotic/placebo ratio=1.50, P =0.073). A similar result was obtained in the subgroup of allergic mothers (probiotic/placebo ratio=1.56, P =0.094).
Conclusion Infants of atopic mothers, specifically when breastfed exclusively over 2.5 months or totally over 6 months, had a higher risk of sensitization at the age of 12 months. This risk could be reduced by the use of probiotics during pregnancy and lactation, partly by resulting in a beneficial composition of the breast milk.