Safety and immunogenicity of the epicutaneous reactivation of pertussis toxin immunity in healthy adults: a phase I, randomized, double-blind, placebo-controlled trial.

OBJECTIVES: Protection induced by acellular vaccines can be short, requiring novel immunization strategies. Objectives of this study were to evaluate safety and capacity of a recombinant pertussis toxin (PTgen) -coated Viaskin® epicutaneous patch to recall memory responses in healthy adults. METHODS: This double-blind, placebo-controlled randomized trial (Phase I) assessed the safety and immunogenicity of PTgen administered on days 0 and 14 to healthy adults using Viaskin® patches applied directly or after epidermal laser-based skin preparation. Patch administration was followed by Boostrix®dTpa on day 42. Antibodies were assessed at days 0, 14, 28, 42 and 70. RESULTS: Among 102 volunteers enrolled, 80 received Viaskin-PT (Viaskin-PT 25 µg (n = 25), Viaskin-PT 50 µg (n = 25), laser + Viaskin-PT 25 µg (n = 5), laser + Viaskin-PT 50 µg (n = 25)), Viaskin-placebo (n = 10) or laser + Viaskin-placebo (n = 2). Incidence of adverse events was similar across groups (any local event: 21/25 (84.0%), 24/25 (96.0%), 4/5 (80.0%), 24/25 (96.0%), 8/10 (80.0%), 10/12 (83.0%), respectively). Direct application induced no detectable response. On day 42, PT-IgG geometric mean concentrations were significantly higher following laser + Viaskin-PT 25 µg and 50 µg (139.87 (95% CI 87.30-224.10) and 121.76 (95% CI 95.04-156.00), respectively), than laser + Viaskin-placebo (59.49, 95% CI 39.37-89.90). Seroresponse rates were higher following laser + Viaskin-PT 25 µg (4/5 (80.0%), 95% CI 28.4-99.5) and 50 µg (22/25 (88.0%), 95% CI 68.8-97.5) than laser + Viaskin-placebo (0/12 (0.0%), 95% CI 0.0-26.5). CONCLUSIONS: Viaskin-PT applied after laser-based epidermal skin preparation showed encouraging safety and immunogenicity results: anti-PT booster responses were not inferior to those elicited by Boostrix®dTpa. This study is registered at ClinicalTrials.gov (NCT03035370) and was funded by DBV Technologies.

Treatment of gastric eosinophilia by epicutaneous immunotherapy in piglets sensitized to peanuts.

BACKGROUND: Eosinophilic gastrointestinal disorders (EGIDs) are hypersensitivity disorders frequently triggered by food allergy and manifested by mucosal eosinophilic infiltration at any level of the gastrointestinal tract. This study established a model of gastric eosinophilia in peanut-sensitized piglets to evaluate the efficacy of epicutaneous immunotherapy (EPIT) for its treatment. METHODS: Experiments were carried out in piglets first sensitized by three intra-peritoneal injections of peanut protein extract (PPE) with adjuvant, and then given PPE orally for 10 days, a sequence leading to gastric eosinophilia assessed by endoscopy. For 3 months, eight piglets received active EPIT, using Viaskin® loaded with PPE, applied daily on the ear, while eight received placebo EPIT (Placebo). Piglets were exposed to a second 10-day period of PPE orally. Lesions were scored by endoscopy on the last day of PPE exposure. After killing, all parts of the digestive tract were analysed by a pathologist unaware of the piglets' status. IgE response was measured, and mechanistic parameters were analysed in the spleen. RESULTS: After sensitization, a significant increase of total IgE was observed in sensitized compared to naive animals (61.1 ± 13.3 vs 27.8 ± 6 ng/mL, P < .01). Following oral intake of PPE, sensitized piglets developed moderate gastritis compared to naive piglets (1.5 vs 1.0, median score). After 3 months of immunotherapy, median IgE was significantly reduced in EPIT vs placebo piglets (61.4 ± 16.3 vs 105.9 ± 25.6 ng/mL, P < .01). Active EPIT significantly reduced gastric mucosal lesions induced by PPE oral intake (macroscopic score 0 [0-2] vs 2 [1-3], P < .01, respectively, active vs placebo) and gastric mucosa eosinophils counts (239 eosinophils/mm2 [59-645] vs 2554 eosinophils/mm2 [462-8057], P < .01, respectively active vs placebo). GATA-3, IL-5 and eotaxin mRNA expression decreased significantly after EPIT (P < .05). CONCLUSIONS: This study describes a large animal model of gastric eosinophil in peanut-sensitized piglets. Utilizing this model, we demonstrated the efficacy of EPIT in treating peanut-induced EGIDs.

The regulatory T cells induction by epicutaneous immunotherapy is sustained and mediates long-term protection from eosinophilic disorders in peanut-sensitized mice.

BACKGROUND: Allergen-specific immunotherapy favours immune deviation from a Th2 to a Th1 response and increases the number of regulatory T cells (Tregs). Epicutaneous immunotherapy (EPIT) of sensitized mice decreases the clinical and the allergen-specific Th2 responses and increases local and peripheral Foxp3(+) Tregs. OBJECTIVE: To investigate the role of Tregs in EPIT and characterize their phenotype and maintenance following EPIT. METHODS: Tregs were investigated using in vivo depletion or adoptive transfer into BALB/c mice. Tregs were depleted using anti-CD25 antibody injection during EPIT, and allergen-specific responses were compared with Sham, EPIT alone and naïve mice. To demonstrate that Tregs can mediate protection by their own, and to study their maintenance following the end of EPIT, CD25(+) CD4(+) Tregs isolated from mice just after or 8 weeks after EPIT were transferred into peanut-sensitized mice. Foxp3-IRES-mRFP mice were transferred with EPIT-induced Tregs to analyse the induction of host Tregs. RESULTS: The anti-CD25 antibody injection to EPIT mice abrogated the induction of Tregs in spleen and the expression of Foxp3 in oesophagus. This resulted in levels of peanut-induced eosinophilic infiltration in oesophagus similar to Sham and significantly higher than EPIT. Whereas the transfer of Tregs from Sham-treated mice demonstrated no effect, the transfer of Tregs isolated just after EPIT prevented peanut-induced eosinophil infiltration and eotaxin expression and induced Foxp3 in oesophagus. The transfer of Tregs isolated 8 weeks after EPIT suppressed allergen-specific responses as efficiently as did Tregs isolated just after EPIT and increased spleen Foxp3(+) CD25(+) CD4(+) cells similarly. The use of reporter mice demonstrated an increase in host Tregs. CONCLUSIONS: These results confirm the Tregs-mediated mechanism of EPIT and demonstrate the persistence of efficient Tregs during a long period of time after treatment cessation. This suggests that EPIT induces long-term tolerance in peanut-sensitized mice.

Epicutaneous immunotherapy on intact skin using a new delivery system in a murine model of allergy.

BACKGROUND: Allergen-specific immunotherapy, subcutaneous immunotherapy (SCIT) or oral, has been used for almost a century to redirect inappropriate immune responses in atopic patients. A new mode of administration through the intact skin [epicutaneous immunotherapy (EPIT)], using an original epicutaneous delivery system, may represent an alternative to these classical methods. OBJECTIVE: Proof of concept of efficacy of EPIT on intact skin in mice sensitized to aeroallergens or food allergens. METHODS: Mice were sensitized to pollen (n=18), house dust mite (HDM, n=24), ovalbumin (OVA, n=18) or peanut (n=18), and allocated to four groups: EPIT, SCIT, not treated (NT) and control. Specific Ig (sIg)E, sIgG1 and sIgG2a were monitored. After 8 weeks of treatment, plethysmography was performed after aerosol provocation with appropriate allergens. RESULTS: At the highest doses of methacholine, pause enhancement (Penh) values were significantly decreased in the EPIT group vs. the sensitized NT groups (7.5 vs. 12.3 - pollen, 7.6 vs. 8.9 - HDM, 11.5 vs. 14.5 - OVA, 7.6 vs. 12.8 - peanut, respectively) (P<0.05). With all the allergens tested, Penh values were similar in SCIT, EPIT and control. IgG2a for pollen, HDM, OVA and peanuts were significantly increased in the EPIT group vs. NT: 0.97 vs. 0.42 microg/mL, 2.5 vs. 0.46 microg/mL, 0.39 vs. 0.05 microg/mL and 15.0 vs. 5.5 microg/mL, respectively (P<0.05). There were no significant differences between EPIT and SCIT groups. The IgE/IgG2a ratio decreased significantly in the EPIT group for the four allergens from 70 to 58 (pollen), 175 to 26 (HDM), 5433 to 120 (OVA) and 49 to 6 (peanut), respectively (P<0.05). CONCLUSION: In mice sensitized to the four allergens tested, EPIT was as efficacious as SCIT, considered as the reference immunotherapy. These first results have to be confirmed by clinical studies.

Ready-to-use house dust mites atopy patch test (HDM-Diallertest), a new screening tool for detection of house dust mites allergy in children.

AIM: to assess the accuracy and safety of a ready-to-use atopy patch test (HDM-Diallertest, DBV Technologies, Paris) in the diagnosis of sensitization to house-dust mite (HDM) allergens in children with or without atopic dermatitis. PATIENTS AND METHODS: prospective analysis of a systematic allergic work-up was carried out in 47 children, age 57.4+42 months (mean + SD, range 7 to 176 mo), presenting with isolated or combined atopic dermatitis (AD, n = 28) or other symptoms without AD (control group, n = 19). Children were routinely tested for specific HDM-IgE [against D. pteronyssinus (DPT) and D. farinae (DF)], and skin testing based on HDM (DPT & DF) skin prick test (SPT) and ready-to-use HDM-ATP (HDM-Diallertest), with a reading at 72 hours. RESULTS: 15 children (31.9%) exhibited specific IgE against both DPT and DF, 16 children (34.04%) exhibited positive SPT against DPT and 17 (36.1%) against DF. HDM-Diallertest was positive in 15 cases (31.9%). Among these, 9 exhibited with an eczematous reaction showed an excellent correlation with both SPT and specific IgE for DPT and DF, respectively 93.3%, 97.77%, 90.47%, and 90.47%. The different diagnostic techniques of HDM sensitization neither differ between groups, nor correlated specifically with the different clinical manifestations. No side effect was observed during and after patch testing, except for a local reaction without diffusion outside the local test area. CONCLUSION: The 3 diagnostic techniques exhibited a comparable level of accuracy for the diagnosis of HDM allergens sensitization. The excellent concordance of the highest class reactions of HDM-Diallertest with the other diagnostic techniques indicates a potential role as a screening tool for the detection of HDM sensitization in infancy.

Anemia impairs small intestinal absorption measured by intestinal permeability in children.

OBJECTIVE: To determine the effect of anemia and iron status on intestinal permeability in children. DESIGN: A routine prospective study was performed in 64 children with symptoms suggesting cow's milk allergy (CMA) (11.8 +/- 16 mo, 2-94 mo). They exhibited a negative cow's milk challenge upon the ESPGHAN criteria. Hemoglobin (Hb), mean corpuscular volume (MCV), blood iron (Fe) and ferritin (Fer) concentrations were studied in all. Permeability was measured as percent of urinary excretion of lactitol (L,%) and mannitol (M,%) (oral absorption, 0.1 g/Kg for each sugar) and determination of the L/M ratio (L/M,%). RESULTS: L/M was significantly higher in anemic children than in non-anemic ones, 2.45, (median), 1.92-3.43 (extremes), n = 29, vs. 1.72, 1.56-2.18, n = 35, p = 0.03. Hb correlated negatively with L/M (p = 0.0001) and L (p = 0.05) and positively with M (p = 0.03). Also, L/M correlated negatively with MCV (p = 0.001) and Fe (p = 0.04). CONCLUSION: IP depends on anemia and iron status. The interpretation of IP should be taken cautiously into account in the diagnosis of CMA in case of anemia or iron deficiency.

[Acquisition of secondary resistance after failure of a first treatment of Helicobacter pylori infection in children]. / Acquisition d'une résistance secondaire après échec d'un premier traitement lors de l'infection à Helicobacter pylori chez l'enfant.

AIMS: To assess the frequency of acquisition of secondary Helicobacter pylori resistant-strains after a first course of antimicrobial treatment. PATIENTS AND METHODS: A retrospective study was performed during the 1994-2000 period, in 15 girls and eight boys, mean age 10.9 +/- 4.8 years (1.4-17 years), with Helicobacter pylori gastritis (culture and antimicrobial susceptibility) presenting a failure of first course treatment, with during one week a proton pump inhibitor and amoxicillin together with either clarithromycin (n = 14) or metronidazole (n = 9). Two endoscopies were performed, the first at the time of diagnosis and the second after the failure of bacterial eradication demonstrated by a positive 13C urea breath test six weeks after the end of treatment. Antimicrobial susceptibility of all Helicobacter pylori strains was tested after each endoscopy and before starting a second course of the treatment. RESULTS: Comparison of antimicrobial susceptibility before and after the first course of treatment showed that Helicobacter pylori strains were all sensitive to amoxicillin, clarithromycin-resistant in eight children (34.7%) before treatment vs 12 (52.1%) after treatment, p = 0.42, ns, metronidazole-resistant in 13 (56.5%) vs 12 (52.1%), p = 0.80, ns, and both clarithromycin and metronidazole-resistant in four (17.3%) vs seven (30.4%), p = 0.63, ns. Among the 14 children treated by a triple therapy including clarithromycin, three (21.4%) developed a secondary resistance to clarithromycin and in one metronidazole resistance was no more detected. Among the nine children treated with a triple therapy including metronidazole, none developed a secondary resistance to metronidazole and one developed a secondary resistance to clarithromycin. CONCLUSION: This study shows the absence of amoxicillin-resistant strains, a high initial clarithromycin-resistant strains level (primary resistance), increasing after a first course of treatment, and for metronidazole a high initial level of resistance not influenced by treatment. Secondary clarithromycin-resistance of Helicobacter pylori strains following the first course of treatment could account for failure of bacterial eradication and suggests the importance of antimicrobial susceptibility.

Intestinal permeability in children: variation with age and reliability in the diagnosis of cow's milk allergy.

OBJECTIVE: To analyse to what extent age may alter intestinal permeability (IP) in children and to assess its reliability according to clinical manifestations in cow's milk allergy (CMA). DESIGN: A routine prospective study was performed in 200 children (12.5+/-23 mo, 0.5-168 mo) presenting with clinical manifestations suggesting CMA. Controls (n = 105) were those with a negative cow's milk challenge, whereas CMA children (n = 95) fulfilled ESPGHAN criteria. Permeability was measured as a percentage of urinary excretion of lactitol (L, %) and mannitol (M, %) (0.1 g/kg for each, oral absorption after a 6 h fast, 5 h urine collection, analysis by gas chromatography) and determination of the L/M ratio (L/M, %). RESULTS: In control children, L/M correlated negatively with age (r -0.33, p = 0.0006), whereas in those with CMA no correlation was found. Median L/M was significantly higher in CMA children (n = 95) than in controls (n = 105), 4.35+/-7.57% (95% CI 5.30-8.39%) vs 1.97+/-0.87% (95% CI 1.76-2.09%), (p = 0.0001). With a L/M cut-off value defined as mean + 2 SD of controls, in CMA IP exhibited a 68% sensitivity and a 77% negative predictive value. The highest sensitivity (70%) was seen at ages 6-12 mo and the lowest (58%) at age more than 3 y. An abnormal IP was seen in 80% of CMA children with digestive manifestations, in 43% with extra-digestive, 68% with mixed and 40% with anaphylactic manifestations. CONCLUSION: IP correlates negatively with age in control children and is altered in children with CMA. The test is at its most accurate in the diagnosis of CMA when done at ages 6-12 mo, when there are digestive manifestations.

Clarithromycin resistance and eradication of Helicobacter pylori in children.

Outcome of Helicobacter pylori infection was analyzed in 61 children treated with a triple therapy including clarithromycin. Bacterial eradication was obtained in all children with clarithromycin-susceptible strains but not in children with clarithromycin-resistant ones (P = 0.0001). H. pylori antimicrobial susceptibility is mandatory before choosing a treatment, and clarithromycin should be avoided in case of resistance.

High levels of resistance to metronidazole and clarithromycin in Helicobacter pylori strains in children.

The aim of the study was to evaluate the prevalence of resistance to amoxicillin, metronidazole, and clarithromycin before treatment of Helicobacter pylori infection in children and to assess the evolution of resistance with time. The study was carried out between 1994 and 1999 with 150 H. pylori-positive children through gastric culture (antimicrobial susceptibility) and histology. All cultured H. pylori strains were sensitive to amoxicillin, 64 (43%) were resistant to metronidazole, 32 (21%) were resistant to clarithromycin, and 14 (9%) were resistant to both metronidazole and clarithromycin. The overall prevalence of resistance to metronidazole and clarithromycin did not change significantly with time. The study highlights the generalized high-level and stable metronidazole and clarithromycin resistance of H. pylori strains from children.

[Helicobacter pylori infection in children]. / L'infection à Helicobacter pylori de l'enfant.

Helicobacter pylori infection is frequent in children. Its incidence in Europe, around 6% in children aged 6-16 years, varies with the socio-economic level and nutritional status. It may reach 46% in Africa and up to 75% in some institutions. Clinical manifestations debated. Vomiting, dyspepsia and acute pain related to ulcer disease may undisputedly be linked to H. pylori, whereas its role in chronic abdominal has yielded contradictory reports. Direct isolation of the bacterium is classically done through perendoscopic antral biopsies followed by culture and histology. Non-invasive diagnosis methods get a wider use in children. Serodiagnosis is reproducible and easy only in older children. The 13C-urea breath test is sensitive and specific, and seems perfectly suitable in pediatrics. The H. pylori stool antigen test for the detection of infection seems promising but not yet of current clinical use. Triple therapy using amoxicillin-clarithromycin (or metronidazole or tinidazole) and anti-secretory agents is recognised as the most efficient association.

Risk factors for severe esophageal and gastric lesions in term neonates: a case-control study. Groupe Francophone d'Hépato-Gastroentérologie et Nutrition Pédiatrique.

BACKGROUND: The purpose of this multicenter case-control study was to search for causes and risk factors related to the severe upper digestive tract lesions often seen in neonates. METHODS: Case patients were full-term neonates with endoscopically confirmed severe bleeding or ulcerative lesions of the esophagus and/or stomach. Matched control subjects were the next infant born in the same maternity unit who met the same criteria and had no clinical abnormality (and, for ethical reasons, no endoscopy). The analysis was based on 137 case-control pairs and considered data showing the mothers' medical and obstetric background, the infants' clinical status and laboratory results, feeding details, and the State and Trait Anxiety Inventory (STAI) questionnaire, which was used to assess the anxiety of the mothers. RESULTS: Cases and controls did not differ in any demographic or social factors. Antacid and anti-ulcer drugs were used significantly more frequently during the last month of pregnancy by case mothers than by control mothers (28% and 10%, respectively; P < 0.001). Mode of delivery was similar. Case infants more frequently experienced cardiac deceleration during labor and delivery (28% and 12.9%; P = 0.003). Breastfeeding at birth was less frequent for case infants (36% and 49%; P = 0.05). The mean trait anxiety scores did not differ between the two groups, but the mean state anxiety score was higher in case mothers. Multivariate logistic regression found that three factors were independently and significantly associated with esophageal and gastric lesions: use of antacid and antiulcer treatments (odds ratio [OR], 3.9; P < 0.001), cardiac deceleration (OR, 2.2; P = 0.03), and breast-feeding (OR, 0.5; P = 0.02). CONCLUSIONS: Antacid drug use by mothers during the last month of pregnancy was associated with esophageal and gastric lesions. Breast-feeding may play a protective role against severe lesions in neonates.

[Chronic laryngitis in children: the role of gastroesophageal reflux]. / Laryngite chronique chez l'enfant: place du reflux gastro-oesophagien.

UNLABELLED: Gastro-oesophageal reflux (GOR) is associated with a number of inflammatory ENT disorders in the adult and is correlated with recurrent croup in the child. AIM: To estimate the frequency of GOR in a population of children consulting for chronic laryngotracheal symptoms. METHOD: The study included 17 children, aged between 2 and 14 years (mean: 7 years) all of whom suffered from dysphonia or a chronic cough. After a clinical ENT examination, each child had a fibreoptic laryngoscopy and a long duration pH-study lasting between 18 and 24 hours. RESULTS: Pathological GOR was discovered in 10 children, i.e. 59%. Overall the number of refluxes per study varied from 6 to 816 (mean 156). The vast majority of these refluxes occurred when the child was awake. CONCLUSION: In our series of children with chronic laryngotracheal disorders, at least 59% were shown to suffer from pathological GOR.