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

Clonal IgA and IgG autoantibodies from individuals at risk for rheumatoid arthritis identify an arthritogenic strain of Subdoligranulum

The mucosal origins hypothesis of rheumatoid arthritis (RA) proposes a central role for mucosal immune responses in the initiation or perpetuation of the systemic autoimmunity that occurs with disease. However, the connection between the mucosa and systemic autoimmunity in RA remains unclear. Using dual immunoglobulin A (IgA) and IgG family plasmablast-derived monoclonal autoantibodies obtained from peripheral blood of individuals at risk for RA, we identified cross-reactivity between RA-relevant autoantigens and bacterial taxa in the closely related families Lachnospiraceae and Ruminococcaceae. After generating bacterial isolates within the Lachnospiraceae/Ruminococcaceae genus Subdoligranulum from the feces of an individual, we confirmed monoclonal antibody binding and CD4⁺ T cell activation in individuals with RA compared to control individuals. In addition, when Subdoligranulum isolate 7 but not isolate 1 colonized germ-free mice, it stimulated T_H17 cell expansion, serum RA-relevant IgG autoantibodies, and joint swelling reminiscent of early RA, with histopathology characterized by antibody deposition and complement activation. Systemic immune responses were likely due to mucosal invasion along with the generation of colon-isolated lymphoid follicles driving increased fecal and serum IgA by isolate 7, because B and CD4⁺ T cell depletion not only halted intestinal immune responses but also eliminated detectable clinical disease. In aggregate, these findings demonstrate a mechanism of RA pathogenesis through which a specific intestinal strain of bacteria can drive systemic autoantibody generation and joint-centered antibody deposition and immune activation.

Clonal IgA and IgG autoantibodies from individuals at risk for rheumatoid arthritis identify an arthritogenic strain of Subdoligranulum

The mucosal origins hypothesis of rheumatoid arthritis (RA) proposes a central role for mucosal immune responses in the initiation or perpetuation of the systemic autoimmunity that occurs with disease. However, the connection between the mucosa and systemic autoimmunity in RA remains unclear. Using dual immunoglobulin A (IgA) and IgG family plasmablast-derived monoclonal autoantibodies obtained from peripheral blood of individuals at risk for RA, we identified cross-reactivity between RA-relevant autoantigens and bacterial taxa in the closely related families Lachnospiraceae and Ruminococcaceae. After generating bacterial isolates within the Lachnospiraceae/Ruminococcaceae genus Subdoligranulum from the feces of an individual, we confirmed monoclonal antibody binding and CD4⁺ T cell activation in individuals with RA compared to control individuals. In addition, when Subdoligranulum isolate 7 but not isolate 1 colonized germ-free mice, it stimulated T_H17 cell expansion, serum RA-relevant IgG autoantibodies, and joint swelling reminiscent of early RA, with histopathology characterized by antibody deposition and complement activation. Systemic immune responses were likely due to mucosal invasion along with the generation of colon-isolated lymphoid follicles driving increased fecal and serum IgA by isolate 7, because B and CD4⁺ T cell depletion not only halted intestinal immune responses but also eliminated detectable clinical disease. In aggregate, these findings demonstrate a mechanism of RA pathogenesis through which a specific intestinal strain of bacteria can drive systemic autoantibody generation and joint-centered antibody deposition and immune activation.

Ileocolonic Lymphonodular Hyperplasia in Children Related to Etiologies Ranging from Food Hypersensitivity to Familial Mediterranean Fever

OBJECTIVE

We aimed to share our observations on the demographics, clinical characteristics, and outcomes of lymphonodular hyperplasia (LNH) in children.

SUBJECTS AND METHODS

The study included children on whom colonoscopy was performed between January 2015 and May 2018 (n = 361). Demographics, treatment modalities, and outcomes of the patients with LNH were recorded.

RESULTS

LNH was found in 66 patients (18.3%; mean age 8.6 ± 5.96 years, 59.1% male). We found that the etiologic factors were food hypersensitivity (FH) in 25 (37.8%), nonspecific colitis in 12 (18.2%), irritable bowel syndrome in 10 (15.2%), familial Mediter-ranean fever in 7 (10.6%), primary immunodeficiency in 4 (6.1%), and intestinal dysmotility, oxyuriasis, Crohn's disease, and giardiasis in 1 (1.5%) patient. Additionally, in the genetic analysis of patients with idiopathic LNH (n = 4), we detected heterozygote MEFV mutations in all. Cow's milk and egg (25%) were the most common allergens in patients with FH. Symptoms of all patients (n = 25) improved after an elimination diet.

CONCLUSIONS

LNH is a common finding in pediatric colonoscopies with a variety of etiologies ranging from FH and familial Mediterranean fever to immunodeficiency.

Isolated Lymphoid Follicles are Dynamic Reservoirs for the Induction of Intestinal IgA

IgA is one of the most important molecules in the regulation of intestinal homeostasis. Peyer's patches have been traditionally recognized as sites for the induction of intestinal IgA responses, however more recent studies demonstrate that isolated lymphoid follicles (ILFs) can perform this function as well. ILF development is dynamic, changing in response to the luminal microbial burden, suggesting that ILFs play an important role providing an expandable reservoir of compensatory IgA inductive sites. However, in situations of immune dysfunction, ILFs can over-develop in response to uncontrollable enteric flora, resulting in ILF hyperplasia. The ability of ILFs to expand and respond to help control the enteric flora makes this dynamic reservoir an important arm of IgA inductive sites in intestinal immunity.

Review article: intestinal lymphoid nodular hyperplasia in children--the relationship to food hypersensitivity

BACKGROUND

Lymphoid aggregates are normally found throughout the small and large intestine. Known as lymphoid nodular hyperplasia (LNH), these aggregates are observed especially in young children and are not associated with clinical symptoms being considered 'physiological'. In children presenting with gastrointestinal symptoms the number and size of the lymphoid follicles are increased. Patients suffering from gastrointestinal symptoms (i.e. recurrent abdominal pain) should systematically undergo gastroduodenoscopy and colonoscopy. With these indications LNH, especially of the upper but also of the lower gastrointestinal tract has been diagnosed, and in some children it may reflect a food hypersensitivity (FH) condition.

AIM

To review the literature about the relationship between LNH and FH, particularly focusing on the diagnostic work-up for LNH related to FH.

METHODS

We reviewed literature using Pubmed and Medline, with the search terms 'lymphoid nodular hyperplasia', 'food hypersensitivity', 'food allergy' and 'food intolerance'. We overall examined 10 studies in detail, selecting articles about the prevalence of LNH in FH patients and of FH in LNH patients.

RESULTS

Collected data showed a median of 49% (range 32-67%) LNH in FH patients and a median of 66% (range 42-90%) FH in LNH patients. Literature review pointed out that the most important symptom connected with LNH and/or FH was recurrent abdominal pain, followed by diarrhoea and growth retardation. Both LNH and FH are associated with an increase in lamina propria γ/δ+ T cells, but the mechanisms by which enhanced local immune responses causing gastrointestinal symptoms still remain obscure.

CONCLUSIONS

When assessing FH, we rely on clinical evaluation, including elimination diet and challenge tests, and endoscopic and immunohistochemical findings. Considering the possible co-existence of duodenal and ileo-colonic LNH, upper endoscopy can be recommended in children with suspected FH, especially in those presenting with additional upper abdominal symptoms (i.e. vomiting). Likewise, lower endoscopy might be additionally performed in patients with suspected FH and LNH of the duodenal bulb, also presenting with lower abdominal symptoms (i.e. recurrent abdominal pain).

Patients suffering from non-IgE-mediated cow's milk protein intolerance cannot be diagnosed based on IgG subclass or IgA responses to milk allergens

BACKGROUND

Cow's milk is one of the most common causes of food allergy. In two-thirds of patients, adverse symptoms following milk ingestion are caused by IgE-mediated allergic reactions, whereas for one-third, the mechanisms are unknown. Aim of this study was to investigate whether patients suffering from non-IgE-mediated cow's milk protein intolerance can be distinguished from persons without cow's milk protein intolerance based on serological measurement of IgG and IgA specific for purified cow's milk antigens.

METHODS

We determined IgG(1-4) subclass and IgA antibody levels to purified recombinant αS1-casein, αS2-casein, β-casein, κ-casein, α-lactalbumin, and β-lactoglobulin in four patient groups by ELISA: Patients with IgE-mediated cow's milk allergy (CMA, n=25), patients with non-IgE-mediated cow's milk protein intolerance (CMPI, n=19), patients with gastrointestinal symptoms not associated with cow's milk ingestion (GI, n=15) and control persons without gastrointestinal problems (C, n=26). Cow's milk-specific IgE levels were determined by ImmunoCAP.

RESULTS

Only CMA patients had IgE antibodies to cow's milk. Cow's milk allergic patients mounted the highest IgG(1) and IgG(4) antibody levels to αS1-casein, αS2-casein, β-casein, κ-casein, and α-lactalbumin. No elevated levels of IgG(4) , IgA, and complement-binding IgG subclasses (IgG(1) , IgG(2) , IgG(3) ) to purified cow's milk allergens were found within the CMPI patients compared to persons without cow's milk protein intolerance (GI and C groups).

CONCLUSION

Cow's milk protein intolerant patients cannot be distinguished from persons without cow's milk protein intolerance on the basis of IgG subclass or IgA reactivity to cow's milk allergens.

Food hypersensitivity as a cause of rectal bleeding in adults

BACKGROUND & AIMS

Rectal bleeding and lymphonodular hyperplasia (LNH) in children can be caused by food hypersensitivity (FH). Our aim was to verify whether similar clinical and endoscopy presentations in adults can be due to FH.

METHODS

Consecutive adult patients with rectal bleeding were enrolled. All underwent routine assays, colonoscopy, and histology study.

RESULTS

Ten of 64 (15%) patients showed LNH as the unique sign at colonoscopy. An oligoantigenic diet resolved the rectal bleeding in 9 patients, and the reintroduction of several foods caused symptom reappearance. Double-blind placebo-controlled challenges with cow's milk and wheat protein confirmed the FH; symptoms reappeared 1-96 hours after the challenge. None of the patients were positive for IgE-mediated assays. In patients with LNH and FH, histology of the ileum and colon mucosa showed a higher number of lymphoid follicles and intraepithelial and lamina propria eosinophils compared with the other patients with rectal bleeding.

CONCLUSIONS

Recurrent rectal bleeding can be caused by FH in adult patients. Endoscopic evidence of LNH characterizes these cases.

Effects of soybean glycinin on performance and immune function in early weaned pigs

Glycinin, a major storage protein in soybean, has been identified as an important food allergen. The present study was conducted to investigate the effects of soybean glycinin on the local and systemic immune responses using a swine model specific for glycinin allergy. Performance, peripheral blood lymphocyte proliferation and CD4+ and CD8+ subsets in the plasma of naive and sensitised piglets were determined. In addition, the concentrations of IgA, IgG, IgM, interleukin-4 and interleukin-6 in the jejunum mucosa were measured. Our results showed that dietary supplementation of glycinin reduced piglet performance (p < 0.05), while increasing lymphocyte proliferation and CD4+/ CD8+ ratio (p < 0.01). Intestinal mucosal immune responses to glycinin were enhanced with high levels of IgA (p < 0.01) as well as interleukin-4 and interleukin-6 in the jejunum mucosa in glycinin-treated piglets compared with the control (p < 0.01). There were no differences due to treatment in the densities of IgG and IgM. In conclusion, it was found that glycinin stimulated local and systemic immune responses in allergic piglets and had negative effects on piglet performance. The severity of the immune reactions depends on the dose of glycinin with higher doses causing more severe symptoms.

Chronic enteropathy and feeding in children: an update

Enteropathy defines abnormalities of the small intestinal mucosa of various etiologies in which nutrition has a causal or a therapeutic role. Breast milk is the gold-standard feeding during infancy for optimal nutrition in health and the majority of diseases. Therapeutic formulae have decreased the need for enteral or parenteral support. Gastrointestinal infections are worldwide the most frequent cause of enteropathy by increasing mucosal permeability, local expression of costimulatory molecules allowing antigen penetration in the mucosa, and T-cell activation leading sometimes to disruption of oral tolerance. Concomitant malnutrition impairs not only the immunologic response but also the recovery of damaged mucosa with secondary intestinal and pancreatic enzymatic reductions. Optimal nutritional rehabilitation is the cornerstone of the management of persisting diarrhea. Celiac disease and cow's milk protein allergy are examples of chronic enteropathy. Multiple food allergies, even during breast-feeding, are increasingly reported due to an impaired development of oral tolerance. The dietary approach to allergic disease is currently evolving from passive allergen avoidance to active modulation of the immune system to (re)establish tolerance. The gastrointestinal flora provides maturational signals for the lymphoid tissue, improves balance of inflammatory cytokines, reduces bacterial invasiveness and dietary antigen load, and normalizes gut permeability. The clinical effects of nucleotides and zinc merit further clinical evaluation. Major attention has recently focused on the immune effects of dietary lipids in terms of possible prevention of allergic sensitization by downregulating inflammatory response and protecting the epithelial barrier and host-microbe interactions modifying the adherence of microbes to the mucosa.

Colonic lymphoid nodular hyperplasia in children: relationship to food hypersensitivity

BACKGROUND & AIMS

The clinical significance of lymphoid nodular hyperplasia (LNH) of the lower gastrointestinal tract is unclear. The aim of this study was to define the frequency and clinical significance of LNH in pediatric patients undergoing colonoscopy.

METHODS

Two hundred forty-five children (101 male, 144 female; median age, 8.5 years) for whom colonoscopy had been indicated were evaluated during a 3-year period. Apart from ileocolonoscopy with biopsy, all patients underwent routine biochemistry, serum total and specific IgE, and/or skin prick tests for food allergens. Patients with LNH underwent elimination diet and subsequent food challenges.

RESULTS

LNH was observed in 73 of 245 (30%) consecutive colonoscopies. LNH was the only abnormal finding in 52 of the 73 cases (71%). In 43 of these 52 patients a diagnosis of cow's milk or multiple food hypersensitivity was made. Food allergy was significantly more common than in patients without LNH (83% vs 31%; P < .0001). The patients with LNH and food hypersensitivity presented hematochezia (P < .0001), elevated serum anti-beta-lactoglobulin IgG (P < .0001), anemia (P < .005), and failure to thrive (P < .03) more frequently than those without LNH. In the LNH patients histologic examination showed a higher number of lymphoid follicles throughout the colon and the terminal ileum and an increased number of lamina propria and intraepithelial eosinophils.

CONCLUSIONS

The presence of LNH in the colon and/or terminal ileum is a frequent finding in symptomatic children undergoing colonoscopy. Unless associated with other specific endoscopic or histologic lesions, LNH is related to a condition of delayed-type food hypersensitivity.

Casein-specific immunoglobulins in cow's milk allergic patient subgroups reveal a shift to IgA dominance in tolerant patients

Differences in casein-specific immunoglobulin (Ig) G-subclass and IgA serum levels between reactive and tolerant patients may hint at the immunopathogenesis during tolerance development in cow's milk allergy (CMA). alpha-, beta- and kappa-casein-specific IgG(1), IgG(4), IgE and IgA serum levels were compared in clinically reactive and tolerized IgE-mediated (n = 15) and non-IgE-mediated (n = 14) CMA with delayed gastrointestinal symptoms, using enzyme-linked immunosorbent assay (ELISA) and immunoblot techniques. The median anti-casein IgE levels in clinically reactive IgE-mediated CMA patients (n = 9) were 140- to 180-fold higher than in tolerized patients (n = 6) and 160- to 200-fold higher than in controls (n = 10). Median alpha-, beta- and kappa-casein-specific IgG(1) and IgG(4) levels were nine- to 60-fold higher in reactive patients and five- to 60-fold in tolerized patients. Clinical tolerance in IgE-mediated CMA was thus associated with decreased casein-specific IgE, IgG(4) and IgG(1), whereas serum IgA anti-alpha -, beta- and kappa-casein remained practically unaltered. Tolerized cow's milk protein (CMP)-sensitive atopic dermatitis had, in particular, decreased kappa-casein-specific IgG(1) levels, compared with clinically reactive patients. The ELISA levels to immunoblot correlation profile for the alpha-, beta- and kappa-casein-specific IgE suggested that the IgE-mediated CMA patients predominantly reacted to tertiary alpha- and beta-casein epitopes whereas the IgE in non-IgE-mediated patients reacted to linearized alpha-, beta- and kappa-casein epitopes. Clinical tolerance in non-IgE-mediated CMA patients (n = 9) was associated with a four- to 10-fold decrease in casein-specific IgE levels, accompanied by a five- to eightfold decrease in IgG(1) and five- to 60-fold decrease in IgG(4) levels, whereas casein-specific IgA levels remained unaltered. Thus, tolerance in both patient groups was characterized by a generalized decreased humoral immune response to caseins, which induced a functional shift to IgA dominance.

Changes in humoral responses to beta-lactoglobulin in tolerant patients suggest a particular role for IgG4 in delayed, non-IgE-mediated cow's milk allergy

The major cow's milk allergen beta-lactoglobulin (beta-LG) is relatively resistant to enzymatic degradation and may therefore be involved in non-immunoglobulin (Ig)E-mediated cow's milk allergy (CMA) with delayed gastrointestinal symptoms. Serum levels of beta-LG-specific IgG(1), IgG(4), IgE, and IgA were compared in clinically reactive and tolerized IgE-mediated and non-IgE-mediated CMA with delayed gastrointestinal symptoms (n = 29) and controls (n = 10). Tolerance was associated with decreased beta-LG-specific IgE, IgG(1), and IgG(4) levels in both patient groups. However, the significantly increased beta-LG-specific IgG(4) levels in clinically reactive non-IgE-mediated CMA patients, and its median 36-fold reduction in tolerant patients, suggested a possible immunopathological role for IgG(4) in delayed CMA. Similarly, the significantly increased beta-LG-specific IgE levels in IgE-mediated CMA patients were decreased 44-fold in tolerant patients. The tolerant patients had apparently shifted the humoral immune response from a beta-LG-specific IgE- and/or IgG(4)-dominated immune response to an IgA-dominated immune response as the IgA/IgE or IgA/IgG(4) ratios increased 90- and 15-fold in tolerant IgE-mediated-, and non-IgE-mediated CMA patients, respectively. Thus, the marked difference in beta-LG-specific Ig ratios suggested a tolerance-induced inhibition of a Th(2)-type of immune response with significantly increased IgA dominance in both CMA patient groups.

Recurrent abdominal pain in school children revisited: fitting adverse food reactions into the puzzle

The diagnostic work-up of children seeking health care because of recurrent abdominal pain is a clinical challenge. Food hypersensitivity might be one of the aetiologies behind this symptom. Neither the understanding of possible immune mechanisms nor endoscopic or histological findings have yet contributed to reliable diagnostic tests.

CONCLUSION

The possibility of adverse food reactions should be evaluated among other abnormalities behind recurrent abdominal pain in children. Still, the diagnosis of immunemediated food reactions depends on open or blinded food challenge.

Unproved diagnostic and therapeutic approaches to food allergy and intolerance

PURPOSE OF REVIEW

Alternative and complementary medicine approaches to allergic disorders are commonly used by patients. Not all have been subjected to experimental analysis to support or refute their validity in the armamentarium of a practitioner. This review covers some of the most common unproved alternative or complementary approaches to diagnosis and therapy that we see in use by patients. These include the use of specific IgG to foods accompanied by rotary diets, provocation-neutralization testing and therapy, applied kinesiology followed by acupressure or acupuncture, and changes in cell size upon in-vitro exposure of leukocytes to food extract (using automated assays going under various trade names) followed by elimination diets or rotary diets.

RECENT FINDINGS

There continues to be a dearth of well performed studies investigating these approaches in the literature, but many testimonials have been posted on websites of practitioners using these methods attesting to their effectiveness. Several recent studies have refuted the use of applied kinesiology and provocation-neutralization in diagnosis. The placebo effect must not be overlooked as a potentially important factor in some approaches.

SUMMARY

There have been no studies supporting the use of these techniques, and several have refuted their utility. A beneficial placebo effect may be responsible for the perceived clinical effectiveness in many cases of food intolerance.