Milk proteins,cytokines and intestinal epithelial functions in children

This paper discusses the relationship between food antigens, lymphocytes and the epithelial properties of the jejunum in children with cow's milk allergy. Experimental results indicate that increased protein permeability is not the primary cause of cow's milk allergy. Rather, results are interpreted as a secondary effect of an abnormal immunological response leading to mucosal inflammation and impairment of the endocytic process by the intestinal epithelial cells. Stimulation by cow's milk proteins caused the lymphocytes from infants with cow's milk allergy to release more tumor necrosis factor-α TNFα than those from control infants. After appropriate antigenic stimulation, the cytokines released by the activated lymphocytes from these infants perturbed epithelial function, in particular its barrier capacity. Tumor necrosis factor a, together with gamma interferon are involved in these adverse effects. It is thought that bovine β-lactoglobulin present in the intestinal lumen may be responsible for the secretory diarrhea observed in children with cow's milk allergy, as a consequence of stimulation of electrogenic chloride secretion. In addition, luminal foreign protein may stimulate the submucosal cells. As a consequence, the submucosal release of mediators, including lymphokines, might alter the intestinal epithelial barrier. In conclusion, in physiological conditions, the subepithelial tissue that comprises the immune system and many other systemic systems receive information on the antigenic content within the intestinal lumen via the intestinal epithelium.     

Markers of inflammation in the feces of infants with cow's milk allergy

Growing evidence exists that exposure to cow's milk elicits inflammation in the gut of infants with cow's milk allergy, irrespective of symptoms. To demonstrate inflammation and increased protein leakage from the gut during a cow's milk elimination‐challenge test in fecal samples of infants presenting with different symptoms suggestive of cow's milk allergy, we measured the concentrations of α₁‐antitrypsin (AT), eosinophil cationic protein (ECP), immunoglobulin (Ig) A, and cow's milk‐specific IgA antibodies, in fecal samples of 208 infants with a mean age of 7 months. Prechallenge samples were collected after a mean 3‐week elimination period, and post‐challenge samples were obtained 4 days after starting the challenge. Fecal levels of prechallenge total IgA (p = 0.02) and post‐challenge AT (p = 0.001) were higher in infants with a positive challenge. Of these infants, pre‐ and post‐challenge levels of ECP were higher in those reacting after 24 h than in those reacting within 1 h (p = 0.006 and p = 0.045). Prechallenge levels of ECP were higher in those showing intestinal symptoms (p = 0.008), and both pre‐ and post‐challenge levels of total IgA were higher in those with an IgE‐mediated reaction to cow's milk (p = 0.04 and p = 0.008). Regardless of the challenge result, total IgA increased during the challenge (p < 0.001 for both challenge‐positive and ‐negative infants) and was higher in those breast‐fed until the challenge than in those fed formula only (p < 0.01). Hence, in infants reacting to the cow's milk challenge, higher prechallenge levels of fecal IgA indicate increased antigenic stimuli in the gut, and higher post‐challenge levels of AT reflect increased protein loss as a result of intestinal inflammation. In infants with slowly evolving gastrointestinal symptoms, increased fecal ECP may help in distinguishing patients from those who tolerate cow's milk. Individual serial follow‐up of fecal IgA and ECP can be used to estimate the degree of inflammation in the gut and an appropriate time for a challenge test, but are not diagnostic tools for cow's milk allergy.     

Immunomodulating properties of protein hydrolysates for application in cow's milk allergy

Cow's milk proteins cause allergic symptoms in 2–3% of all infants. In these individuals, the tolerogenic state of the intestinal immune system is broken, which can lead to sensitization against antigens and eventually to allergic responses. Although a true treatment for food allergy is not available, symptoms can be avoided by providing the infants with hydrolyzed proteins. Hydrolyzed proteins are proteins that are enzymatically degraded. They lack typical allergenic IgE‐binding epitopes but are also thought to play a pertinent role in other mechanisms inducing hypoallergenic effects. This review discusses the mechanisms and evidence for immunomodulating properties of cow's milk hydrolysates. Hydrolysates are found to strengthen the epithelial barrier, modulate T‐cell differentiation, and decrease inflammation. Some studies suggest a role for hydrolysates in manipulating pathogen recognition receptors signaling as underlying mechanism. Peptides from hydrolysates have been shown to bind to TLR2 and TLR4 and influence cytokine production in epithelial cells and macrophages. Current insight suggests that hydrolysates may actively participate in modulating the immune responses in subjects with cow's milk allergy and those at risk to develop cow's milk allergy. However, more research is required to design effective and reproducible means to develop targeting strategies to modulate the immune response.     

Low frequency of CD4+, but not CD8+, T cells expressing interferon‐γ is related to cow's milk allergy in infancy

Low interferon‐γ (IFN‐γ) and tumor necrosis factor‐α (TNF‐α) production in peripheral blood mononuclear cells (PBMC) from patients with atopic dermatitis and food allergy have been reported previously. However, it remains unclear whether the weak cytokine production is caused by the imbalance of specific T‐cell subsets or by dysregulation of T‐cell function. In the present study we investigated the intracellular expression of these cytokines at a single‐cell level to clarify the background of the disruption. Twelve of 27 breast‐fed infants (0.1–8.8 months of age) had challenge‐proven cow's milk allergy (CMA), and 15 infants were studied as a healthy control group. PBMC were stimulated with phorbol 12‐myristate 13‐acetate (PMA) and ionomycin. The frequencies of the cells expressing intracellular IL‐4, IFN‐γ, and TNF‐α were assessed using flow cytometry. In addition, at this time‐point leucocyte subsets from the milk of mothers of these infants were evaluated using light microscopy. A lower number of CD8⁺ T cells and the defective capability of CD4⁺ T cells to express IFN‐γ in infant's peripheral blood co‐existed with a lower number of macrophages in their mother's milk.     

RESPONSE OF THE JEJUNAL MUCOSA TO COW'S MILK IN THE MALABSORPTION SYNDROME WITH COW'S MILK INTOLERANCE A Light- and Electron-Microscopic Study

Three infants, in whom the malabsorption syndrome, small intestinal. mucosal damage and clinical cow's milk intolerance were found, were challenged with cow's milk after initial treatment with breast milk. The small intestinal mucosa was investigated with light and electron microscopy both before and after provocation. Clinically one patient reacted rapidly in a few hours and showed round cell infiltration in the surface epithelium and lamina propria 20 hours after a single challenge. Electron microscopy showed short microvilli, abnormal nuclei and thickened basement lamina in the surface epithelium. Two patients reacted slowly. One of them showed similar changes 4 days after commencement of the provocations, but the changes were much more evident 38 days later, when symptoms were also apparent. At this time large accumulations of lysosomes in the apical part of the surface epithelial cell and marked thickening of the basal lamina with accumulations of whirly collagen fibres were detected. The third patient reacted in a milder way, both clinically and morphologically. This study indicates that cow's milk, apparently through its protein fraction, may damage the surface epithelium of the small intestinal mucosa. These alterations during provocation periods resemble those found in coe-liac disease during gluten provocation.     

不同孕期母亲免疫水平对婴儿牛奶蛋白过敏的影响

目的 探讨不同孕期母亲Th1/Th2免疫水平与婴儿牛奶蛋白过敏（CMPA）之间的关联。方法 选取2016年7月至2018年12月于山东省潍坊市益都中心医院及青州市中医院就诊的单胎健康孕妇及其子代为研究对象。检测母亲孕中期、孕后期的白细胞介素（IL）-2、干扰素-γ（IFN-γ）、IL-4和IL-10水平,并分别于出生后1年内进行CMPA问卷调查,对临床怀疑CMPA的婴儿进行食物回避及牛奶口服激发试验,将符合CMPA的48例婴儿纳入CMPA组,其余977例正常婴儿纳入对照组。对CMPA婴儿进行单因素分析,并采用泊松回归分析不同孕期母亲各Th1/Th2型细胞因子水平与CMPA之间的关联。结果 CMPA的检出率为4.68%,临床表现包括消化系统症状、皮肤表现、呼吸系统症状及其他表现。单因素分析结果显示,CMPA组母亲食物过敏、母亲过敏性疾病史的发生率均明显高于对照组（P < 0.05）,母乳喂养率明显低于对照组（P < 0.05）。CMPA组的母亲IL-2（孕中期和孕后期）、IFN-γ（孕后期）较对照组明显降低（P < 0.05）。母亲孕后期低IFN-γ及孕中期、孕后期低IL-2与婴儿CMPA存在显著关联（P < 0.05）;校正母乳喂养、母亲食物过敏及母亲过敏性疾病史等因子后发现,母亲孕后期低IL-2、低IFN-γ与婴儿CMPA仍存在显著关联（P < 0.05）。结论 孕后期母体的Th1型细胞因子水平下降,可能会导致胎儿的免疫改变,从而增加其子代出生后罹患CMPA的风险。     

The Role of Cow's Milk Allergy in Pediatric Chronic Constipation: A Randomized Clinical Trial

Objective

Cow''s milk allergy has different presentations in children and can cause functional bowel symptoms such as chronic constipation. The aims of this study were to investigate the role of cow''s milk allergy as a cause of chronic constipation and effect of cow''s milk free diet (CMFD) on its treatment in children.

Methods

We performed a randomized clinical study comparing CMFD with cow''s milk diet (CMD) in two groups each consisting of 70 patients (age range, 1-13 years) with chronic functional constipation (defined as Rome III criteria). All subjects had been referred to a pediatric gastroenterology clinic and had previously been treated with laxatives for at least 3 months without success; also all 140 patients performed skin prick test. The case group received CMFD for 4 weeks. After that they received CMD for 2 extra weeks. The control group received CMD for whole 6 weeks. A response was defined as decreased in signs and symptoms that not fulfilled Rome III criteria after 4 weeks of CMFD and came back to Rome III criteria after 2 weeks of CMD challenge.

Findings

After 4 weeks 56 (80%) patients of the case group responded in comparison to 33 (47.1%) patients in the control group (P=0.0001). In the case group after 2 weeks challenge 24 out of 56 (42.8%) responders developed constipation according to Rome III criteria. With other words, the frequency of cow''s milk allergy among constipated patients was 80%. Only one patient had positive skin prick test.

Conclusion

In children, chronic constipation can be a manifestation of cow''s milk allergy. At present, although several aspects must be further investigated, a therapeutic attempt with elimination diet is advisable in all children with constipation unresponsive to correct laxative treatment.     

Eosinophilic enteritis due to cow's milk allergy: Possible cause of anastomosis failure following repair of focal intestinal perforation

Reports of cow's milk allergy (CMA) after neonatal gastrointestinal surgery have recently increased. In recent years it has been suggested that the development of CMA after gastrointestinal surgery in newborn infants is due to an immune function. In addition, the development of CMA might be synergistically exacerbated by congenital abnormalities of the intestinal mucosa, general conditional changes and local damage to the intestine by invasive surgery, and poor pre‐ or post‐surgical nutrition. CMA manifests as a variety of symptoms, such as mild vomiting and bloody stool, decreased activity, poor oral intake, and ileus. CMA may also rarely cause gastrointestinal perforation. Here, we report the case of a newborn infant who developed CMA following repair of focal small intestinal perforation, in which eosinophilic enteritis was suspected to be a possible cause of anastomosis leakage.     

How to reintroduce cow′s milk?

In a child that is allergic to milk, the natural next step, following the elimination diet, is the reintroduction of cow's milk. Several questions may arise. When feasible, this reintroduction has many benefits for the child and his family. However, the disease needs to be well defined by physicians and explained to parents. They need to understand that there are different types of allergy to cow's milk, specifically IgE‐ and non‐IgE‐mediated, and each of these may exhibit both a variable duration and frequently an incomplete recovery. Deciding where to first reintroduce cow's milk to a child who has previously followed a milk‐free diet, whether it be at home or in a hospital, also frequently presents an issue. Following this first reintroduction, the progressive increase of milk into the diet needs to be managed properly, as not all children will go back to a normal dairy products intake. Recent studies show that most children with milk allergy tolerate products containing baked milk and that their consumption might speed up recovery. Hence, the purpose of the milk challenge in a child on a milk‐free diet is becoming, even in a child still reactive to milk, the first step of gradual and individually adapted reintroduction of milk or dairy products. When reintroduction of cow's milk does not work, immunotherapy becomes an option, and this is carried out in specialized centers.     

Cow's Milk Allergy as a Cause of Infantile Colic: Immunofluorescent Studies on Jejunal Mucosa

Fourteen infants and children who had suffered from infantile “colic” and related symptoms were diagnosed as being allergic to cow's milk because of their response to cow's milk exclusion and then to repeated challenge with cow's milk. The parents of these children frequently were allergic themselves and very frequently refused to drink cow's milk. Small bowel biopsy specimens were taken on these children, but only seven had biopsies both while taking cow's milk and when on a milk free diet. The mucosae were all histologically normal with normal disaccharidase levels. However, on immunological study it has been shown that significantly higher numbers of IgE containing plasma cells were present in the mucosal specimens when these infant? were taking cow's milk, than when they were on a milk-free diet.     

Ontogeny of the gut-associated lymphoid system in man

Immunoperoxidase histochemistry using monoclonal antibodies to lymphoid/myeloid cells has been used to study the development of the human mucosal immune system in frozen sections of foetal human intestine at different ages. A steady progression of development was seen between 11 and 19 weeks' gestation. At 11 weeks, Peyer's patches were identifiable only as aggregates of strongly HLA-DR+ cells. By 16 weeks these aggregates became colonized with T and B cells, without distinct cellular zonation. By 19 weeks primary B-cell follicles were seen and T cells occupied the inter-follicular zones. There was also a steady increase in the numbers of lamina propria and epithelial T cells between 11 and 19 weeks' gestation. As in postnatal bowel, CD8+ cells predominated in the epithelium and CD4 + cells predominated in the lamina propria. Thus the important T- and B-cell compartments of the mucosal immune system are well established in the human foetal intestine by mid-gestation.     

Immune response to food antigens: Kinetics of food-specific antibodies in the normal population

The role of food-specific antibodies in the pathogenesis of food allergy is controversial. The first step in solving this controversy may be the assessment of antibody response to food antigens in the normal population. Most of the existing data in this field come from studies that used assays of different standards. This study investigated food-specific antibodies in the normal population using standardized assays. Normal levels of antibody titers were also derived for use as reference. Two hundred and eight individuals from different age groups participated. Immunoglobulin G (IgG) antibodies to cow's milk and its component proteins, and to hen's egg ovalbumin, IgA and IgM antibodies to β-lactoglobulin and ovalbumin were measured by enzyme-linked immunosorbent assay. The sepharose-radioallergosorbent test was used to measure IgE antibodies to cow's milk and ovalbumin. Titers of IgG antibodies to cow's milk and its component proteins revealed an age-related trend, peaking in the 5 months-1 year age group and then decreased to negligible values in adults. A similar trend was observed with IgG anti-ovalbumin antibodies. Temporal association was less evident for antibodies of other classes. Only six subjects had positive IgE antibodies to cow's milk, while none had positive IgE anti-ovalbumin antibody. The prevalences of IgG antibodies to cow's milk, its component proteins, and ovalbumin are influenced by age and feeding habits. Cross-reactivity to related food antigens is common. The presence of IgE antibodies to food antigens is not a physiological phenomenon.     

Comparison of a partially hydrolyzed infant formula with two extensively hydrolyzed formulas for allergy prevention:A prospective, randomized study

The aim of this study was to compare the allergy‐preventive effect of a partially hydrolyzed formula with two extensively hydrolyzed formulas, in infants with a high risk for development of allergic disease. High‐risk infants from four Danish centres were included in the period from June 1994 to July 1995. Five‐hundred and ninety‐five high‐risk infants were identified. High‐risk infants were defined as having bi‐parental atopy, or a single atopic first‐degree relative combined with cord blood immunoglobulin E (IgE) ≥ 0.3 kU/l. At birth all infants were randomized to one of three different blinded formulas. All mothers had unrestricted diets during pregnancy and lactation and were encouraged to breast‐feed exclusively. If breast‐feeding was insufficient, one of the three formulas, according to randomization, was given during the first 4 months. It was recommended not to introduce cow's milk, cow's milk products, and solid foods until the age of 4 months. After the age of 4 months a normal unrestricted diet and conventional cow's milk‐based formula were given when needed. All infants were followed‐up prospectively with interview and physical examination at the age of 6, 12, and 18 months, and if any possible atopic symptoms were reported. If food allergy was suspected, controlled elimination/challenge procedures were performed in a hospital setting. Of 550 infants included in the study, 514 were seen at all visits and 36 were excluded owing to non‐compliance. Of 478 infants who completed the study, 232 were exclusively breast‐fed, 79 received an extensively hydrolyzed casein formula (Nutramigen), 82 an extensively hydrolyzed whey formula (Profylac), and 85 a partially hydrolyzed whey formula (Nan HA), during the first 4 months of life. These four groups were identical in regard to atopic predisposition, cord blood IgE, birthplace, and gender. Exclusively breast‐fed children were exposed less to tobacco smoke and pets at home and belonged to higher social classes, whereas the three formula groups were identical concerning environmental factors. The frequency of breast‐feeding was high; only eight (2%) children were not breast‐fed at all. The three formula groups were identical in regard to duration of breast‐feeding and age at introduction of formula and solid foods. No significant differences were found in the three groups of infants receiving formula milk regarding the cumulative incidence of atopic dermatitis or respiratory symptoms. The cumulative incidence of parental‐reported cow's milk allergy was significantly higher in children fed partially hydrolyzed formula (Nan HA) compared with extensively hydrolyzed formula (Nutramigen or Profylac) at 12 and 18 months (NanHA, 7.1%; Nutramigen, 2.5%; Profylac, 0%; p = 0.033). The cumulative incidence of confirmed cow's milk allergy was 1.3% (three of 232) in exclusively breast‐fed infants, 0.6% (one of 161) in infants fed extensively hydrolyzed formula (Nutramigen or Profylac), and 4.7% (four of 85) in infants fed partially hydrolyzed formula (Nan HA). Partially hydrolyzed formula was found to be less effective than extensively hydrolyzed formula in preventing cow's milk allergy, 0.6% vs. 4.7% (p = 0.05), but because of the small number of cases the results should be interpreted with caution. Compared with other similar studies the frequency of atopic symptoms was low, even though the dietetic intervention did not include either maternal diet during lactation or dietary restrictions to the children after the age of 4 months.     

Actualités thérapeutiques dans la prise en charge nutritionnelle de l’allergie aux protéines de lait de vache

Dietary management of cow's milk allergy is based on the elimination of all cow's milk proteins from the diet. For non-breastfed infants, the main dietetic move is the replacement of the standard infant formula with a formula for which the protein fraction has been modified. This formula can be based on hydrolyzed cow's milk proteins, rice proteins or amino acids. Monitoring the growth of these children is essential. The reintroduction of cow's milk, raw or heated, should always be made carefully and gradually. As the child grows and remains allergic, the use of heated (baked) milk substantially eases his/her feeding.     

Serum immunoglobulin E,IgA, and IgG antibodies to different cow's milk proteins in children with cow's milk allergy: Association with prognosis and clinical manifestations

Diverse pathogenic mechanisms elicit different clinical manifestations in cow's milk allergy (CMA). Our aim was to determine the concentration of serum immunoglobulin levels to different cow's milk proteins in patients with CMA and to determine how these values were related to clinical symptoms and prognosis. Fifty children (mean age 10.9 months, range: 1–34 months) with previously confirmed CMA were enrolled in this study. All had various clinical manifestations of CMA, including gastrointestinal, skin, and respiratory symptoms. At the diagnosis of CMA the serum total and the milk‐specific immunoglobulin (Ig)E values were measured by enzyme immunoassay and fluoroimmunoassay, respectively, while the relative levels of serum IgA and IgG antibodies against different cow's milk proteins were determined by a sensitive enzyme‐linked immunosorbent assay (ELISA). The results were compared to those of 30 non‐atopic age‐matched control children. On average, after 9.2 months (range 2–31 months) on a milk‐free diet, a repeated challenge was performed in 38 children. At the re‐challenge, 12 patients had clinical symptoms while the remaining 26 children were symptom‐free. The IgG antibody level to bovine serum albumin (BSA) was significantly lower in the patients than in the controls (median: 0.36 vs. 2.94, p < 0.01). There was a close correlation among all individual IgA and IgG antibodies to different cow's milk proteins. The anti‐α‐casein IgG level (of 2.10) in children with a positive reaction at the re‐challenge was significantly higher than in those with a negative reaction (0.89) (p < 0.05). The total IgE serum concentration was also significantly higher in those who had symptoms at the re‐challenge compared to those who did not have any reaction at this time (22.9 vs. 6.8 kU/l, geometric mean, p < 0.02). There was no association between the clinical manifestations and the IgG and IgA antibody levels to the cow's milk proteins studied, except for the anti‐BSA IgA level, which was higher in patients with gastrointestinal symptoms. The serum total IgE and anti‐α‐casein IgG levels could have prognostic values; their increase at the beginning of the disease may indicate the development of tolerance to cow's milk only at a later age and after a longer duration of CMA. However, as there is considerable overlap among the values observed in different groups of patients, there is a limitation of these tests for predicting the prognosis.     

Induktion der oralen Toleranz bei Kindern mit Kuhmilchallergie

Cow's milk allergy (CMA) is the most frequent food allergy in early childhood, occurring during the first months of life. Despite its spontaneous benign evolution, CMA is still problematic, since diagnosis remains unsafe and the prediction of clinical outcome and time of appearance of oral tolerance (OT) is difficult. The acquisition of OT is of 45–56% at 1 year, 60–77% at2 years and about 90–95% after 5 to 10 years. The concept of OT is a mechanism of immunological regulation, which consists of a modulation of the systemic immune response to oral proteins. The main actors of OT are: antigens, digestive mucosal, antigen-presenting cells and T-lymphocytes. The most common food allergens are cow's milk, soy and egg proteins, as well as fish and seafood products and peanuts. Two types of oral tolerance exist: primary, which is the induction of tolerance to a formerly unknown antigen; and secondary, which is a re-induction of OT to an antigen. The role of eviction of antigens and of partially hydrolyzed formulae was largely studied for primary tolerance. For secondary OT, patients must receive a cow's milk-free diet and extensively hydrolyzed formulae until its spontaneous appearance, which, as shown in a recent study, seems to be quicker with the use of oligopeptides rather than amino acids.     

A similar high level of immunoglobulin A and immunoglobulin G class milk antibodies and increment of local lymphoid tissue on the duodenal mucosa in subjects with cow's milk allergy and recurrent abdominal pains

In previous studies, we have reported endoscopic and histological alterations locally on the gastrointestinal (GI) tract associated with a gastrointestinal type of cow's milk allergy. In this study, we sought to further characterize endoscopic, and immunological findings in these children. We also hypothesized that the same type of immune responses might also be found in children with unexplained and recurrent abdominal pains. We did a gastroduodenoscopy for persistent GI symptoms, examined the mucosal histology of the small intestine and measured the antibodies to whole cow's milk and its fractions with an enzyme‐linked immunosorbent assay (ELISA) in a consecutive series of 22 subjects with untreated and 14 with treated cow's milk allergy (CMA) and 44 with recurrent abdominal pains (RAP). The immunological findings of the study subjects were compared with 54 controls. Lymphonodular hyperplasia (LNH) of the duodenum was the main endoscopic finding in 11 subjects (50%) with untreated and 5 (36%) with treated CMA. It was also found in 6 of 44 subjects with RAP. Compared with the controls, the patients with CMA showed significantly higher levels of IgA class antibodies to whole milk (p = 0.003) and βLG (p < 0.0001). Of the IgG class antibodies to βLG (p = 0.032), BSA (p < 0.0001) and αCAS (p < 0.0001) were significantly higher. The patients with LNH of the duodenal bulb as the main endoscopic finding showed significantly higher values of IgG class antibodies to βLG (p = 0.01) and αCAS (p = 0.005). Interestingly, the patients examined for RAP showed a similar increment in the pattern of whole milk and specific milk protein antibodies as the CMA children. In conclusion this study showed that gastrointestinal CMA beyond infancy is significantly associated with high levels of IgG and IgA class antibodies to milk and its fractions. As high levels of these antibodies and LNH of the duodenal bulb were also found in subjects with RAP, the study further suggests that gastrointestinal CMA might be one major reason for RAP.     

Milk Protein Permeability of the Infantile Intestine from the Aspect of Antibody Reaction

1. Cow's milk antibody in the blood of infants was determined using the tannic acid-treated red cell agglutination method. The highest level was found in the infants given completely artificial feeding. 2. Antibody positives were higher in the group in which cow's milk or cow's milk preparations was started before the 15th day after birth compared to those given artificial feeding after the 15th day. 3. Determination of the antibody according to each protein fraction reveals the highest rate for a-casein while the antibody against a-lactalbumin and ß-lactoglobulin was low. 4. When α-casein is given orally in the rat, antibody was found only in the animals given α-casein in the newborn stage and could not be observed when given at later stages.     

Cow's milk protein-specific T-helper type I/II cytokine responses in infants with necrotizing enterocolitis

Enteral feeding, in particular with formula feeds, is associated with necrotizing enterocolitis (NEC). In this study, we have examined, in the systemic and mucosal immune compartments, for evidence of bovine milk antigen sensitization in infants with NEC. Eleven newborns with Bell's staging 2–3 NEC [median post-conceptional age 31 wk (range 27–41 wk)], 21 neonatal controls [33 (28–40) wk] and 15 infants undergoing intestinal resection or mucosal biopsy for non-inflammatory conditions [39 (34–42) wk] were studied. Spontaneous and antigen or mitogen elicited interferon-γ (IFN-γ) [T-helper type I (Th1)], interleukin (IL)-4 and IL-5 [T-helper type II (Th2)] responses were enumerated using single-cell enzyme-linked immunospot (ELISPOT) assay in peripheral blood (PBMC) or lamina propria mononuclear cells. NEC infants, compared with controls, showed a significant elevation in baseline PBMC cytokine secreting cells, vigorous mitogen responses (20- to 120-fold increase) for IFN-γ, IL-4 and IL-5 (p < 0.001), strong responses to beta-lactoglobulin (βlg) (IFN-γ > IL-4/IL-5, p ≤ 0.001), and somewhat smaller casein responses. Similarly, in the lamina propria, a small but significant increase in spontaneous cytokine-secreting cells was detected in NEC infants (p < 0.01), with an IFN-γ/IL-4 predominant phytohemagglutinin (PHA)/concanavalin-A (ConA) response. Three of nine NEC infants (but no controls) also showed a positive ELISPOT response to βlg (IFN-γ only) but none to casein. We have thus demonstrated significant cow's milk protein (CMP) sensitization in NEC, at least in the systemic compartment (mixed Th1/Th2), with minimal mucosal activation in some cases. These novel findings provide a potential mechanism for a direct contributory role of CMP in the pathogenesis of NEC.     

Protocolitis in exclusively breast-fed infants

We present nine exclusively breast-fed, full-term infants with mild rectal bleeding due to proctocolitis. The mean age at the onset of symptoms was 5 weeks (range 1–8 weeks). Rectosigmoidoscopic examination was performed in all the children within 2 days after admission, showing inflammatory changes such as oedematous mucosa with petechial haemorrhages. Rectal mucosal biopsy specimens, were obtained in eight cases and revealed intra-epithelial eosinophilic granulocytes in seven and a diffuse increase of eosinophils in the lamina propria in six. Allergy to cow's milk protein transferred to the infants via the breast milk was believed to be the cause of the inflammation. The intake of cow's milk protein was then restricted in seven mothers. Following this regimen, symptoms were relieved within 4 weeks in the six infants who were seen at follow up. One child recovered spontaneously without dietary restrictions. Considering the beneficial effect of the diet regimen in addition to the histological findings, allergy to cow's milk protein is possibly the aetiology of the proctocolitis seen in these nine exclusively breast-fed babies, although no challenge tests were performed to confirm this suspicion.Conclusion This report shows that proctocolitis occurs in exclusively breast-fed infants. It is speculated that allergy to cow's milk protein may have played a role in the pathogenesis.