Serum antibodies to cow's milk proteins in pediatric inflammatory bowel disease. Crohn's disease versus ulcerative colitis

Therapeutic Opportunities in Inflammatory Bowel Disease: Mechanistic Dissection of Host-Microbiome Relationships

The current understanding of inflammatory bowel disease (IBD) pathogenesis implicates a complex interaction between host genetics, host immunity, microbiome, and environmental exposures. Mechanisms gleaned from genetics and molecular pathogenesis offer clues to the critical triggers of mucosal inflammation and guide the development of therapeutic interventions. A complex network of interactions between host genetic factors, microbes, and microbial metabolites governs intestinal homeostasis, making classification and mechanistic dissection of involved pathways challenging. In this Review, we discuss these challenges, areas of active translation, and opportunities for development of next-generation therapies.

Anti-food and anti-microbial IgG subclass antibodies in inflammatory bowel disease

OBJECTIVES

Inflammatory bowel disease (IBD), particularly Crohn's disease (CD), is associated with increased microbial-specific IgG and IgA antibodies, whereas alterations of anti-food antibodies are still disputed. The knowledge about IgG subclass antibodies in IBD is limited. In this study we analysed IgG subclass antibodies specific for nutritional and commensal antigens in IBD patients and controls.

METHODS

Serum IgG1, IgG2, IgG3 and IgG4 specific for wheat and milk extracts, purified ovalbumin, Escherichia coli and Bacteroides fragilis lysates and mannan from Saccharomyces cerevisiae were analysed by ELISA in patients with CD (n = 56), ulcerative colitis (UC; n = 29), acute gastroenteritis/colitis (n = 12) as well as non-inflammatory controls (n = 62).

RESULTS

Anti-Saccharomyces cerevisiae antibodies (ASCA) of all IgG subclasses and anti-B. fragilis IgG1 levels were increased in CD patients compared to UC patients and controls. The discriminant validity of ASCA IgG2 and IgG4 was comparable with that of ASCA pan-IgG and IgA, whereas it was inferior for ASCA IgG1/IgG3 and anti-B. fragilis IgG1. Complicated CD defined by the presence of perianal, stricturing or penetrating disease phenotypes was associated with increased ASCA IgG1/IgG3/IgG4, anti-B. fragilis IgG1 and anti-E. coli IgG1 levels. Anti-food IgG subclass levels were not different between IBD patients and controls and did not correlate with food intolerance. In contrast to anti-microbial Abs, food-specific IgG responses were predominately of the IgG4 isotype and all food-specific IgG subclass levels correlated negatively with age.

CONCLUSION

Our study supports the notion that the adaptive immune recognition of food and commensal antigens are differentially regulated.

Specific IgG and IgA Antibodies and Related Subclasses in the Diagnosis of Gastrointestinal Disorders or Atopic Dermatitis Due to Cow's Milk and Egg

Today the only investigation considered valid for the diagnosis of reactions to food is the oral stimulation test following a period of diet during which the suspected food item has been withdrawn. This test is, however, not without a certain risk, due to the possibility of the onset of an unexpected anaphylactic reaction. Researchers are therefore focusing attention on new, more reliable and less risky diagnostic techniques. The aim of this investigation was to evaluate, by means of ELISA, the serum levels of specific IgG and IgA antibodies and of their subclasses for casein, alpha lactalbumin, bovine beta-lactoglobulin and ovalbumin in 72 children with gastointestinal disorders or atopic dermatitis due to food. The diagnosis of food intolerance was made following a double blind oral stimulation test: 16 healthy age-matched children were used as controls. The results of the investigation demonstrated that specific IgA levels for all the food antigens were statistically higher compared with those of controls, irrespective of the clinical features, whereas the IgG class antibodies were statistically higher only for casein in the children with atopic dermatitis. Studies on the antibody subclasses, showed a statistically significant increase particulary of IgG, but also of IgA1, especially in children with gastointestinal disorders. In conclusion, the results show that total specific IgA may play a role, although modest, in the diagnosis of food intolerance. The IgG subclasses, and to a lesser extent the IgA subclasses, appear to be useful in the diagnostic work-up, particularly in children with gastrointestinal symptoms.

Food antigen-induced immune responses in Crohn's disease patients and experimental colitis mice

BACKGROUND

In Crohn's disease (CD), the involvement of food antigens in immune responses remains unclear. The objective of this study was to detect immune responses against food antigens in CD patients and examine the mechanism in a mouse model of colitis.

METHODS

We enrolled 98 CD patients, 50 ulcerative colitis patients, and 52 healthy controls (HCs) to compare the levels of serum immunoglobulin (Ig)Gs against 88 foods. The presence of serum IgGs against foods was also examined in interleukin (IL)-10 knockout (KO) mice in which CD4(+) T cell activation by antigenic food protein was assessed. Mice transferred with IL-10 KO cells received diets with or without food antigens, and the development of colitis was evaluated.

RESULTS

The prevalence of IgGs against various foods, especially vegetables, grains, and nuts, was significantly higher in CD patients than in HCs. Similarly, the prevalence of IgGs against food proteins was higher in IL-10 KO mice than in BALB/c mice. Beta-conglycinin, identified as an antigenic food proteins in IL-10 KO mice, induced CD4(+) T cell production of interferon-γ and IL-17 through dendritic cell antigen presentation. Elimination of the food antigens ameliorated the development of colitis in mice without altering the composition of their intestinal microbiota.

CONCLUSIONS

In CD colitis mice, intestinal inflammation via CD4(+) T cell hyperactivation was induced by food antigens associated with high serum IgG levels and was ameliorated by the elimination of food antigens. This disrupted immunological tolerance to food antigen, which might act as an exacerbating factor, remains to be elucidated in CD patients.

Distinct patterns of IgG and IgA against food and microbial antigens in serum and feces of patients with inflammatory bowel diseases

Background

Inflammatory bowel disease (IBD) is associated with a defective intestinal barrier and enhanced adaptive immune responses against commensal microbiota. Immune responses against food antigens in IBD patients remain poorly defined.

Methods

IgG and IgA specific for food and microfloral antigens (wheat and milk extracts; purified ovalbumin; Escherichia coli and Bacteroides fragilis lysates; mannan from Saccharomyces cerevisiae) were analyzed by ELISA in the serum and feces of patients with Crohn's disease (CD; n = 52 for serum and n = 20 for feces), ulcerative colitis (UC; n = 29; n = 17), acute gastroenteritis/colitis (AGE; n = 12; n = 9) as well as non-inflammatory controls (n = 61; n = 39).

Results

Serum anti-Saccharomyces cerevisiae antibodies (ASCA) and anti-B. fragilis IgG and IgA levels were increased in CD patients whereas antibody (Ab) levels against E. coli and food antigens were not significantly different within the patient groups and controls. Subgroup analysis revealed that CD patients with severe diseases defined by stricturing and penetrating lesions have slightly higher anti-food and anti-microbial IgA levels whereas CD and UC patients with arthropathy have decreased anti-food IgG levels. Treatment with anti-TNF-α Abs in CD patients was associated with significantly decreased ASCA IgG and IgA and anti-E. coli IgG. In the feces specific IgG levels against all antigens were higher in CD and AGE patients while specific IgA levels were higher in non-IBD patients. Anti-food IgG and IgA levels did not correlate with food intolerance.

Summary

In contrast to anti-microbial Abs, we found only minor changes in serum anti-food Ab levels in specific subgroups of IBD patients. Fecal Ab levels towards microbial and food antigens show distinct patterns in controls, CD and UC patients.

Serology with ML Flow test in health professionals from three different states of Brazil

BACKGROUND

In highly endemic countries, transmission and sub-clinical infection of leprosy are likely and the disease manifests itself in individuals without any known close contact with a leprosy patient. Health workers are social contacts belonging to the same network (the Health System) and some of them share the same social environment (nursing assistants) as patients with known patients and / or carriers.

OBJECTIVE

To identify ML Flow seropositivity among health professionals.

METHODS

We conducted a cross-sectional study using a serological survey with the ML Flow test in 450 health professionals (doctors, nurses and nursing assistants), in order to detect seropositivity in areas of high and low endemicity in municipalities from three Brazilian states (RJ, MS and RS).

RESULTS

The results showed general 16% seropositivity, higher in low endemic areas, regardless of whether there was direct care for leprosy patients. Paradoxically, a statistical association was observed between the area studied and seropositivity, as the place with the lowest endemicity (CA) had the highest seropositivity rate (p = 0.033).

CONCLUSION

The authors suggest these results are associated with a presence of an unspecified link to bovine serum albumin (BSA), carrier of PGL-1 in the ML Flow test, and recommend expanded seroepidemiological research utilizing tests with human and bovine albumin.

Enhanced blood lymphocytes apoptosis in children with inflammatory bowel disease

The aim of this work was to measure peripheral lymphocyte apoptosis during IBD flare and remission. Subjects and Methods. Flow-cytometric assessment of apoptosis of peripheral blood lymphocytes (PBL) was assessed in 30 children with IBD (16 with ulcerative colitis and 14 with Crohn's disease) compared to 22, age and sex matched, healthy children. This was carried out during a flare, whether in newly diagnosed or relapsing patients, and after achievement of remission. Clinical findings, complete blood count, liver transaminases, and kidney functions were assessed. Results. Early apoptotic and late apoptotic/necrotic lymphocytes were significantly higher during IBD flare compared to controls (P ≤ 0.01 and <0.01, resp., in ulcerative colitis and P ≤ 0.01 and <0.01, resp., in Crohn's disease patients). Remission values were significantly decreased but did not come back to the control levels. Early apoptotic values were significantly related to joint involvement in IBD patients (P < 0.0001). Conclusions. We can speculate a systemic nature of IBD as evident by enhanced peripheral lymphocyte apoptosis. This is related, to a great extent, to the disease process as it is more deranged in flare than in remission. Relation of this derangement to extraintestinal manifestations needs a special attention.

Does evidence exist to include dietary therapy in the treatment of Crohn's disease?

Prescription drugs and surgery are two common medical therapies for Crohn's disease (CD), an inflammatory bowel disease that affects the GI tract. Unfortunately, certain drugs can cause serious side effects, and surgeries must often be repeated. No diet has been established to alleviate the pain and suffering of CD patients. This is curious given the fact that a higher prevalence of food sensitivities exist in this population of patients, and enteral nutrition is not only the first-line of therapy in Japan, but a known research method used to place the majority of CD patients into remission. Although not all patients respond equally to diet, many simply remove symptom-provoking foods, such as dairy, wheat, corn and certain fruits and vegetables. We suggest assisting these patients in their self-assessment of irritating and symptom-provoking foods by educating them in the use of a food-symptom diary followed by a customized elimination diet trialed for 2-4 weeks to determine if there is any benefit to the individual patient.

Histamine in food: is there anything to worry about?

Biogenic mono-, di- and poly-amines are widely distributed among living organisms. The amines fulfil many important functions in the human body both in the periphery and brain. Some authors suggest that foods rich in biogenic amines, especially histamine, present high health hazards for consumers. However, this is conditional on a range of other factors. The alimentary tract is well equipped with enzymes that inactivate amines and the blood-brain barrier prevents them entering the brain from the circulation. Oxidative deamination, methylation, acetylation and transglutamylation are the degradation pathways which operate efficiently in the stomach, intestines and liver. Particularly important is oxidative deamination. Food histamine poisoning or cheese reaction, manifested itself in patients treated with drugs that inhibit amine oxidases or in patients showing an enterocytic diamine oxidase deficit. It is rather food allergy, which should worry us more, as endogenous histamine release from mast cells is more dangerous. Preventive measures should be undertaken against increases in food allergies.

Mucosal reactivity to cow's milk protein in coeliac disease

Patients with coeliac disease (CD) on a gluten-free diet may still have gastrointestinal symptoms. On clinical grounds cow's milk (CM) protein sensitivity may be suspected. Here, using rectal protein challenge, we investigated the local inflammatory reaction to gluten and CM protein in adult patients with CD in remission. Rectal challenges with wheat gluten and dried CM powder were performed in 20 patients with CD and 15 healthy controls. Fifteen hours after challenge the mucosal reaction was recorded by the mucosal patch technique with measurements of local release of neutrophil and eosinophil granule constituents; myeloperoxidase (MPO) and eosinophil cationic protein (ECP). We measured the mucosal production of nitric oxide (NO) simultaneously. Six of the patients who reacted to CM were also challenged with alpha-lactalbumin and casein. In 18 of 20 patients gluten challenge induced neutrophil activation defined as increased MPO release and increased NO synthesis. Ten of these 20 patients showed a similarly strong inflammatory reaction to CM challenge. Six of the CM sensitive patients were challenged with specific CM proteins: casein and alpha-lactalbumin. Casein, in contrast to alpha-lactalbumin, induced an inflammatory response similar to that produced by CM. A mucosal inflammatory response similar to that elicited by gluten was produced by CM protein in about 50% of the patients with coeliac disease. Casein, in particular, seems to be involved in this reaction.

Avidity progression of dietary antibodies in healthy and coeliac children

In most individuals minute amounts of food proteins pass undegraded across the intestinal mucosa and trigger antibody formation. Children with coeliac disease have enhanced antibody production against gliadin as well as other dietary antigens, e.g. beta-lactoglobulin, in cow's milk. Antibody avidity, i.e. the binding strength between antibody and antigen, often increases during antibody responses and may be related to the biological effectiveness of antibodies. The aim of the present study was to determine the avidity of serum IgG antibodies against beta-lactoglobulin and gliadin in healthy children during early childhood and compare these avidities to those found in children with coeliac disease. The average antibody avidity was analysed using a thiocyanate elution assay, whereas the antibody activity of the corresponding sera was assayed by ELISA. The avidity of serum IgG antibodies against beta-lactoglobulin as well as gliadin increased with age in healthy children, even in the face of falling antibody titres to the same antigens. Children with untreated coeliac disease had IgG anti-beta-lactoglobulin antibodies of significantly higher avidity than healthy children of the same age, and the same trend was observed for IgG antigliadin antibodies. The present data suggest that the avidities of antibodies against dietary antigens increase progressively during early childhood, and that this process seems to be accelerated during active coeliac disease.

Is nutrition an aetiological factor for inflammatory bowel disease?

Inflammatory bowel disease (IBD) is a chronic inflammatory process, the aetiology of which is complex and probably multi-factorial. Nutrition has been proposed to be an important aetiological factor for IBD. The present review critically examines the relationship between components of the diet (such as sugar, fat, fibre, fruit and vegetables, and protein) and IBD, including ulcerative colitis and Crohn's disease. In addition, it investigates the possible role of infant feeding practices in the development of IBD.

Breastfeeding and chronic disease in childhood and adolescence

A growing body of research suggests that infant feeding practices influence the risk for several chronic diseases of childhood and adolescence. Increased risks for type 1 diabetes, celiac disease, some childhood cancers, and inflammatory bowel disease have been associated with artificial infant feeding and short-term breastfeeding. As genetic susceptibility is understood more completely and gene-environment interactions are elucidated, evidence to either confirm or refute these findings will be forthcoming.

Development of IgG1 and IgG4 antibodies against beta-lactoglobulin and ovalbumin in healthy and atopic children

BACKGROUND

The IgG responses to food antigens are preferentially restricted to the IgG1 and IgG4 subclasses. Increased levels of IgG1 and IgG4 antibodies against food allergens have been reported in girls and adults with current atopic eczema.

OBJECTIVE

To study the relation between the levels of IgG1 and IgG4 antibodies against beta-lactoglobulin and ovalbumin and the development of atopic disease.

MATERIAL AND METHODS

Atopic symptoms were recorded in 36 girls from birth to 7 years of age. Blood samples were taken at 3 and 8 months and at 2, 4, and 7 years. IgG1 and IgG4 antibodies were measured by ELISA.

RESULTS

Anti-beta-lactoglobulin IgG1 was detected at all ages, peaking at 8 months. Anti-beta-lactoglobulin IgG4 antibodies were detected in 18 to 29 girls at different ages and the antibody levels peaked at 2 years. The levels of anti-beta-lactoglobulin IgG1 were lower in atopic, as compared with healthy individuals at 4 and 7 years (P < .01 and P < .05) and lower anti-beta-lactoglobulin IgG4 antibody levels were found in atopic individuals (P < .05) at 4 years. Anti-ovalbumin IgG1 antibodies were detected in 3/35 girls at 3 months and in 16/35 to 26/35 girls later in life. The number of positive samples and antibody levels peaked at 2 years. Anti-ovalbumin IgG4 positive samples increased from 4/33 at 8 months to 30/32 at 7 years. The levels increased up to 2 years and then remained stable. The anti-ovalbumin IgG1 antibody levels were lower in atopic girls at 4 years (P < .05), while the anti-ovalbumin IgG4 antibody levels were similar at all ages.

CONCLUSION

An early IgG1 response and later appearing IgG4 antibodies to the two food antigens beta-lactoglobulin and ovalbumin are common during the first years of life. The levels were similar in the nonatopic and the atopic girls up to four years; then they tended to be lower in the first group.

Boosted systemic immune and local responsiveness after intestinal inflammation in orally sensitized guinea pigs

BACKGROUND & AIMS

Intestinal inflammation resulting in disruption of the mucosal barrier function has been proposed as a cause of increased incidence of allergic diseases. This study was designed to evaluate whether intestinal inflammation is able to change the immune responsiveness to sensitization and antigen challenge responses.

METHODS

Guinea pigs orally sensitized to cow's milk proteins were either treated or not treated with trinitrobenzenesulfonic acid (TNBS) to induce intestinal inflammation and compared with control animals (not sensitized). Systemic immune and local responsiveness to antigen challenge were assessed by measuring antibody serum titers, colonic fluid secretion, mucosal histamine level, and mucus depletion. Intestinal permeability was evaluated from 51Cr-ethylenediaminetetraacetic acid (EDTA) recovery and beta-lactoglobulin serum level.

RESULTS

Immunoglobulin E titers were higher in TNBS-treated animals than in non-TNBS-treated sensitized animals. Antigen challenge in TNBS-treated animals induced a fourfold increase of colonic secretion and greater histamine and mucus depletion than in non-TNBS-treated animals. Permeability to 51Cr-EDTA increased 5 days after TNBS treatment but was unchanged after antigen challenge. In contrast to controls, beta-lactoglobulin was not detected in the sera of challenged sensitized and TNBS-treated animals.

CONCLUSIONS

Intestinal inflammation increasing gut permeability enhances the sensitization process. Therefore, local anaphylactic reactions are exacerbated after antigen challenge.

IgG subclass distribution in serum and rectal mucosa of monozygotic twins with or without inflammatory bowel disease

Serum samples from 26 monozygotic twin pairs concordant or discordant with regard to inflammatory bowel disease, and rectal biopsies from 42 twins of the same subject group, were examined for IgG subclasses. They were all compared with normal controls. Almost all affected twins were in clinical remission. Paired immunofluorescence staining of the rectal mucosa showed that those with ulcerative colitis had a significantly higher (p < 0.01) proportion of IgG1 producing mucosal immunocytes than normal controls (78.1% v 55.9%). Conversely, the IgG2 cell fraction was significantly reduced (15.9% v 34.6%). Healthy twins from ulcerative colitis pairs tended to show a raised proportion of IgG1 cells and the IgG2 cell fraction was significantly reduced (p < 0.05). In discordant ulcerative colitis twin pairs, no difference appeared in the cellular IgG subclass pattern between healthy and affected twins. Furthermore, the proportion of IgG1 in these healthy and diseased twins showed good correlation (T = 0.867). The results in rectal mucosa of twins with Crohn's disease were widely scattered and affected twins did not differ significantly from normal controls. Healthy twins, however, showed a marginally raised IgG1 cell proportion, but no correlation was seen between the IgG subclass fractions in discordant Crohn's disease twin pairs. The serum concentrations of IgG1 and IgG2 did not differ from normal controls in twins of either category. These results suggested that in ulcerative colitis, the aberrant mucosal production of IgG1 and IgG2 does not depend on active disease, but is apparently at least partially explained by a genetic impact. Conversely, the mucosal IgG subclass pattern in Crohn's disease appears to be determined mainly by exogenous variables.

Antibody (IgG, IgA, and IgM) to baker's yeast (Saccharomyces cerevisiae), yeast mannan, gliadin, ovalbumin and betalactoglobulin in monozygotic twins with inflammatory bowel disease

To assess whether dietary antigens play a role in inflammatory bowel disease, 26 monozygotic twin pairs with inflammatory bowel disease and 52 healthy controls were investigated for serum antibodies (IgA, IgG, IgM) against ovalbumin, betalactoglobulin, gliadin, whole yeast (Saccharomyces cerevisiae) and yeast cell wall mannan. The twins were made up of five pairs concordant and nine pairs discordant for Crohn's disease, and two pairs concordant and 10 pairs discordant for ulcerative colitis. Two patients with Crohn's disease had a slight increase in disease activity, the others were in clinical remission. Two striking observations were made: first, individuals with ulcerative colitis were indistinguishable from healthy twins, and controls except for the response to gliadin. Both healthy and diseased twins had higher IgA levels to gliadin than controls. Second, twins who had developed Crohn's disease displayed higher antibody titres towards yeast cell wall mannan in particular, but also to whole yeast (Saccharomyces cerevisiae) of all antibody types (IgA, IgG, and IgM). In contrast, the response to gliadin, ovalbumin, and betalactoglobulin did not differ from healthy twins and was even lower than in the controls. The results argue against an increased systemic antigen presentation caused by an impaired mucosal barrier in the inflammatory bowel disease. Rather, they suggest that yeast cell wall material--that is, mannan, or some antigen rich in mannose and cross reacting with mannan, may play an aetiological role in Crohn's disease, but not in ulcerative colitis. The increases in IgA and IgM, as well as IgG suggest that local and systemic immune systems are selectively activated by antigen(s) present in the cell wall of baker's yeast.

Acute intestinal injury induced by acetic acid and casein: prevention by intraluminal misoprostol

Acute injury was established in anesthetized rabbits by intraluminal administration of acetic acid with and without bovine casein, into loops of distal small intestine. Damage was quantified after 45 minutes by the blood-to-lumen movement of 51Cr-labeled ethylenediaminetetraacetic acid (EDTA) and fluorescein isothiocyanate-tagged bovine serum albumin as well as luminal fluid histamine levels. The amount of titratable acetic acid used to lower the pH of the treatment solutions to pH 4.0 was increased by the addition of calcium gluconate. Luminal acetic acid caused a 19-fold increase in 51Cr-EDTA accumulation over saline controls; casein did not modify this effect. In saline controls, loop fluid histamine levels bordered on the limits of detection (1 ng/g) but were elevated 19-fold by acetic acid exposure and markedly increased (118-fold) by the combination of acid and casein. Intraluminal misoprostol (3 or 30 micrograms/mL), administered 30 minutes before acetic acid, significantly attenuated the increase in epithelial permeability (luminal 51Cr-EDTA, fluorescein isothiocyanate-bovine serum albumin accumulation) and histamine release (P less than 0.05). Diphenhydramine, alone or in combination with cimetidine, and indomethacin (5 mg/kg IV) were not protective. It is concluded that exposure of the epithelium to acetic acid promotes the transepithelial movement of casein leading to enhanced mast cell activation and mucosal injury. Damage to the epithelial barrier can be prevented by misoprostol.

Non-specific reactions in enzyme linked immunosorbent assays for serum antibody to entamoeba histolytica and Giardia lamblia in non-endemic areas

Serum samples from 20 Indian children with diarrhoea were compared with those from 20 children resident in the United Kingdom who had been diagnosed as having ulcerative colitis, or Crohn's disease, or indeterminate colitis using enzyme linked immunosorbent assays specific for Entamoeba histolytica and Giardia lamblia. More than 50% of the United Kingdom patients had high IgG responses in ELISAs for E histolytica and G lamblia. A confirmatory ELISA showed that the British sera reacted specifically to bovine serum proteins rather than to protozoal antigens. Prior incubation of sera with 5% bovine serum prohibited this reaction. Bovine serum is an integral part of the crude soluble antigen used in most ELISAs for E histolytica and G lamblia and needs to be replaced with purified antigen preparations. The British sera also reacted to other commonly used blocking agents such as bovine serum albumin, casein, and normal sheep serum. These reactions were attributed to uptake of dietary antigens or an enhanced immunological response to these antigens in patients with inflammatory bowel disease.