Sensitization and tolerance

Beta-lactam hypersensitivity in children with cystic fibrosis: a study in a specialized pediatric center for cystic fibrosis and drug allergy

BACKGROUND

Beta-lactam hypersensitivity (HS) is suspected in 5-12% of the children, but proven in only 10-15% of those children, based on skin and challenge tests results. In contrast, 30-60% of patients with cystic fibrosis (CF) are diagnosed allergic to beta-lactams, based mainly on the clinical history of the patients.

OBJECTIVES

To confirm or rule out a suspected beta-lactam HS in CF children and to determine the prevalences of suspected and confirmed beta-lactam HS in those children.

PATIENTS AND METHODS

Children with CF and suspected beta-lactam HS were explored by means of skin and challenge tests with the suspected and alternate beta-lactams. The results in CF children were compared with those reported in the literature in non- CF children.

RESULTS

Eight of the 701 CF children followed in our center between 1990 and 2011 (1.14%), and 11 other children from other centers were explored for suspected beta-lactam HS. Beta-lactam HS was diagnosed in nine of these children (47.3%). Based on the results in the children followed in our center, the prevalence of beta-lactam HS was 0.71% (5/701) in CF children vs. a mean estimated prevalence of 1-1.5% in the general pediatric population.

CONCLUSION

Our results contrast with those of most previous studies. Although half of the CF children with suspected beta-lactam HS were truly allergic to beta-lactams, the general prevalence of beta-lactam HS in CF children was very low. This may result from tolerance induced by frequent and/or prolonged treatments with beta-lactams.

Early fish introduction is associated with less eczema, but not sensitization, in infants

OBJECTIVE

To investigate if the development of allergic diseases during the child's first 18 months of life is influenced by the time at which different food items were introduced into the child's diet.

METHOD

A birth cohort of 184 children was followed to 18 months of age. Diaries were used to document feeding practices, and parental interviews were performed at 6 and 12 months of age, probing for symptoms suggesting allergic disease, general health-related issues and food introduction regimes. Symptoms promoted prompt clinical examination, and all children were examined clinically, and tested for sensitization to common airborne and food allergens at 18 months of age.

RESULTS

The earlier the fish was introduced into the child's diet the lower was the frequency of eczema. This association remained after control for confounding factors. The timing of fish introduction and asthma development showed a similar pattern, but did not reach statistical significance. Sensitization was not influenced by the timing of fish introduction. Other food items or feeding practices did not seem to influence allergy development.

CONCLUSION

  Early introduction of fish into the child's diet was associated with less eczema development, and a tendency to less asthma. Sensitization was not associated with the timing of fish introduction.

Effect of oral tolerance in a mouse model of allergic rhinitis

OBJECTIVE

Induction of oral tolerance (OT) is known to prevent allergic inflammation in models of asthma. This study investigated the preventive effect of OT and airway remodeling in a mouse model of allergic rhinitis (AR).

STUDY DESIGN

An in vivo study using an animal model.

SETTING

Catholic Research Institutes of Medical Science.

METHODS

Forty six-week-old, female BALB/c mice were divided into four groups: control, AR, low-dose OT, and high-dose OT. To induce OT, mice were fed ovalbumin (OVA) before sensitization with OVA/aluminum hydroxide, 1 mg for six days in the low-dose OT group and a 25 mg single dose in the high-dose OT group. Mice in the AR group were fed phosphate-buffered saline. After sensitization followed by challenges with OVA during six weeks, nasal behaviors, interleukin (IL)-13 and interferon gamma (IFN-gamma) levels in nasal lavage (NAL) fluids, as well as OVA-specific IgE levels in serum, were measured. The degree of goblet cell hyperplasia and thickness of lamina propria were observed in nasal tissues by periodic acid-Schiff and Masson's trichrome stain. A P value < 0.05 was accepted as statistically significant.

RESULTS

Both OT groups showed a significant decrease in inflammatory cells, IL-13 and IFN-gamma in NAL fluids, as well as OVA-specific IgE levels in serum compared with the AR group. In addition, the degree of goblet cell hyperplasia and thickness of lamina propria were attenuated in both OT groups compared with the AR group. Further, these alterations did not differ significantly between the two OT groups.

CONCLUSION

These results suggest that OT may effectively reduce allergic inflammation as well as airway remodeling in a mouse model of AR.

An exploration of Glo-3A antibody levels in children at increased risk for type 1 diabetes mellitus

AIMS

To determine whether Glo-3A, (formerly referred to as homologue of Glb1 or Glb1) antibodies are associated with islet autoimmunity (IA) in children at increased risk for type 1 diabetes (T1D) and to investigate their relation with environmental correlates of T1D.

METHODS

We selected a sample from the Diabetes Autoimmunity Study in the Young (DAISY), a prospective study of children at increased risk for T1D. Cases were positive for insulin, glutamic acid decarboxylase (GAD), or insulinoma-associated antigen-2 (IA-2) autoantibodies on two consecutive visits and either diagnosed with diabetes mellitus or still autoantibody positive when selected. Controls were from the same increased risk group, of similar age as the cases but negative for autoantibodies. Sera from 91 IA cases and 82 controls were analyzed in a blinded manner for immunoglobulin G (IgG) antibodies to Glo-3A by ELISA.

RESULTS

Adjusting for family history of T1D and human leukocyte antigen (HLA)-DR4 positivity, Glo-3A antibodies were not associated with IA case status (OR: 1.01, 95% CI: 0.99-1.03). Adjusting for age, family history of T1D, and HLA-DR4 positivity, Glo-3A antibody levels were inversely associated with breast-feeding duration (beta = -0.08, p = 0.001) and directly associated with current intake of foods containing gluten (beta = 0.24, p = 0.007) in IA cases but not in controls. Zonulin, a biomarker of gut permeability, was directly associated with Glo-3A antibody levels in cases (beta = 0.73, p = 0.003) but not in controls.

CONCLUSION

Differing correlates of Glo-3A antibodies in IA cases and controls suggest an underlying difference in mucosal immune response.

The biocompatible polysaccharide chitosan enhances the oral tolerance to type II collagen

Chitosan is a mucoadhesive polysaccharide that promotes the transmucosal absorption of peptides and proteins. At mucosal sites chitosan exhibits immunomodulatory activities and stimulates the release of regulatory cytokines. Herein we evaluated the effect of the co-administration of chitosan in the tolerance to type II collagen (CII) using an experimental model of arthritis. Rats were fed diluent (acetic acid), 1 mg CII, 1 mg chitosan or 1 mg CII + 1 mg chitosan during 5 days before immunization with CII in Freund's complete adjuvant. Systemic effects were evaluated in draining lymph nodes after antigenic challenge or during the clinical evolution of arthritis. Specific antibodies, proliferation against CII and the production of interferon (IFN)-gamma and interleukin-10 were assessed. Clinical signs were observed 13-15 days after primary immunization. The CII : chitosan group presented the lowest incidence and developed moderate arthritis, with reduced levels of immunoglobulin (Ig)G2a anti-CII, a limited proliferation in draining lymph nodes and a lower release of IFN-gamma after restimulation with CII. Our results demonstrate that chitosan enhances the tolerance to an articular antigen with a decrease in the inflammatory responses and, as a consequence, an improvement in clinical signs.

Persistent protective effect of heat-killed Escherichia coli producing "engineered," recombinant peanut proteins in a murine model of peanut allergy

BACKGROUND

Peanut allergy (PNA) is a life-threatening food allergy for which there is no definitive treatment.

OBJECTIVE

We investigated the long-term immunomodulatory effect of heat-killed Escherichia coli producing engineered (mutated) Ara h1, 2, and 3 (HKE-MP123) administered rectally (pr) in a murine model of PNA.

METHODS

Peanut-allergic C3H/HeJ mice received 0.9 (low dose), 9 (medium dose), or 90 (high dose) microg HKE-MP123 pr, HKE-containing vector (HKE-V) alone, or vehicle alone (sham) weekly for 3 weeks. Mice were challenged 2 weeks later. A second and third challenge were performed at 4-week intervals.

RESULTS

After the first challenge, all 3 HKE-MP123 and HKE-V-treated groups exhibited reduced symptom scores (P <.01,.01,.05,.05, respectively) compared with the sham-treated group. Interestingly, only the medium- and high-dose HKE-MP123-treated mice remained protected for up to 10 weeks after treatment accompanied by a significant reduction of plasma histamine levels compared with sham-treated mice (P <.05 and.01, respectively). IgE levels were significantly lower in all HKE-MP123-treated groups (P <.001), being most reduced in the high-dose HKE-MP123-treated group at the time of each challenge. IL-4, IL-13, IL-5, and IL-10 production by splenocytes of high-dose HKE-MP123-treated mice were significantly decreased (P <.01;.001,.001, and.001, respectively), and IFN-gamma and TGF-beta production were significantly increased (P <.001 and.01, respectively) compared with sham-treated mice at the time of the last challenge.

CONCLUSIONS

Treatment with pr HKE-MP123 can induce long-term "downregulation" of peanut hypersensitivity, which might be secondary to decreased antigen-specific T(H)2 and increased T(H)1 and T regulatory cytokine production.

Is there scientific evidence that suppression of acute diseases in childhood induce chronic diseases in the future?

Seeking to understand the individual in his symptomatic totality has been an aim of homeopathy since its beginning. Throughout its history, homeopaths have been concerned that inadequate treatment of acute diseases in childhood may lead to future chronic diseases. Hahnemann cautioned that by treating acute diseases with allopathic medicine, with strong doses of drugs, or suppressing local symptoms of those diseases, would increase the risk of future chronic diseases. Burnett proposed the theory of vaccinosis and warned of chronic manifestations subsequent to smallpox vaccination. French homeopaths, seeking the physiopathological origin of chronic diseases, correlated it to the abnormal reaction of the reticuloendothelial system (RES). Through the study of experimental pathology, Maffei attributed symptomatic manifestations to the imbalance between the immunological phenomena of allergy and immunity. He termed the sensitizing and pathogenic effects of medications and vaccines, 'metallergy' and 'parallergy', respectively. The hygiene hypothesis is based on evidence that the imbalance of immunological response in childhood, specifically among the Th1 and Th2 lymphocyte subpopulations, is responsible for the development of some allergic and chronic diseases in the future. The deranging factor for the predisposition to future allergic response (Th2) is the obstruction of natural manifestations of infectious diseases (Th1 response) in young children. Homeopathic treatment aims to equilibrate vital reaction, corresponding to an integrative physiological response, it may regulate Th1/Th2 imbalance. However, clinical trials to support this hypothesis are lacking.