IL-17 receptor A and adenosine deaminase 2 deficiency in siblings with recurrent infections and chronic inflammation.

BACKGROUND: Data on patients affected by chronic mucocutaneous candidiasis underscore the preponderant role of IL-17 receptor A (IL-17RA) in preserving mucocutaneous immunity. Little is known about the role of adenosine deaminase (ADA) 2 in regulation of immune responses, although recent reports linked ADA2 deficiency with inflammation and vasculitis. OBJECTIVE: We sought to investigate the mechanisms of chronic inflammation and vasculitis in a child lacking IL-17RA and ADA2 to identify therapeutic targets. METHODS: We report a family with 2 siblings who have had recurrent mucocutaneous infections with Candida albicans and Staphylococcus aureus and chronic inflammatory disease and vasculitis since early childhood, which were refractory to classical treatments. Array-based comparative genomic hybridization analysis showed that both siblings are homozygous for a 770-kb deletion on chr22q11.1 encompassing both IL17RA and cat eye critical region 1 (CECR1). Immunologic studies were carried out by means of flow cytometry, ELISA, and RIA. RESULTS: As expected, in the affected child we found a lack of IL-17RA expression, which implies a severe malfunction in the IL-17 signaling pathway, conferring susceptibility to recurrent mucocutaneous infections. Surprisingly, we detected an in vitro and in vivo upregulation of proinflammatory cytokines, notably IL-1ß and TNF-α, which is consistent with the persistent systemic inflammation. CONCLUSIONS: This work emphasizes the utility of whole-genome analyses combined with immunologic investigation in patients with unresolved immunodeficiency. This approach is likely to provide an insight into immunologic pathways and mechanisms of disease. It also provides molecular evidence for more targeted therapies. In addition, our report further corroborates a potential role of ADA2 in modulating immunity and inflammation.

Comparison of two oral probiotic preparations in a randomized crossover trial highlights a potentially beneficial effect of Lactobacillus paracasei NCC2461 in patients with allergic rhinitis.

BACKGROUND: There is promising but conflicting evidence to recommend the addition of probiotics to foods for prevention and treatment of allergy. Based on previous studies with fermented milk containing Lactobacillus paracasei NCC2461, we aimed to compare the effect of a powder form of the latter probiotic with the effect of a blend of Lactobacillus acidophilus ATCC SD5221 and Bifidobacterium lactis ATCC SD5219 in patients with allergic rhinitis. METHODS: A double-blind, randomized, cross-over study, involving 31 adults with allergic rhinitis to grass pollen, was performed outside the grass pollen season (registration number: NCT01233154). Subjects received each product for 4-weeks in two phases separated by a wash-out period of 6 to 8 weeks. A nasal provocation test was performed before and after each 4-week product intake period, and outcome parameters (objective and subjective clinical symptoms; immune parameters) were measured during and/or 24 hours after the test. RESULTS: Out of the 31 subject enrolled, 28 completed the study. While no effect was observed on nasal congestion (primary outcome), treatment with NCC2461 significantly decreased nasal pruritus (determined by VAS), and leukocytes in nasal fluid samples, enhanced IL-5, IL-13 and IL-10 production by peripheral blood mononuclear cells in an allergen specific manner and tended to decrease IL-5 secretion in nasal fluid, in contrast to treatment with the blend of L. acidophilus and B. lactis. CONCLUSIONS: Despite short-term consumption, NCC2461 was able to reduce subjective nasal pruritus while not affecting nasal congestion in adults suffering from grass pollen allergic rhinitis. The associated decrease in nasal fluid leukocytes and IL-5 secretion, and the enhanced IL-10 secretion in an allergen specific manner may partly explain the decrease in nasal pruritus. However, somewhat unexpected systemic immune changes were also noted. These data support the study of NCC2461 consumption in a seasonal clinical trial to further demonstrate its potentially beneficial effect.

Novel birch pollen specific immunotherapy formulation based on contiguous overlapping peptides.

BACKGROUND: Synthetic contiguous overlapping peptides (COPs) may represent an alternative to allergen extracts or recombinant allergens for allergen specific immunotherapy. In combination, COPs encompass the entire allergen sequence, providing all potential T cell epitopes, while preventing IgE conformational epitopes of the native allergen. METHODS: Individual COPs were derived from the sequence of Bet v 1, the major allergen of birch pollen, and its known crystal structure, and designed to avoid IgE binding. Three sets of COPs were tested in vitro in competition ELISA and basophil degranulation assays. Their in vivo reactivity was determined by intraperitoneal challenge in rBet v 1 sensitized mice as well as by skin prick tests in volunteers with allergic rhinoconjunctivitis to birch pollen. RESULTS: The combination, named AllerT, of three COPs selected for undetectable IgE binding in competition assays and for the absence of basophil activation in vitro was unable to induce anaphylaxis in sensitized mice in contrast to rBet v 1. In addition no positive reactivity to AllerT was observed in skin prick tests in human volunteers allergic to birch pollen. In contrast, a second set of COPs, AllerT4-T5 displayed some residual IgE binding in competition ELISA and a weak subliminal reactivity to skin prick testing. CONCLUSIONS: The hypoallergenicity of contiguous overlapping peptides was confirmed by low, if any, IgE binding activity in vitro, by the absence of basophil activation and the absence of in vivo induction of allergic reactions in mouse and human. TRIAL REGISTRATION: ClinicalTrials.gov NCT01719133.

Distal trisomy 14 (q24 --> qter) and aorto-pulmonary window: a case report and review of the literature.

A newborn female with partial trisomy for the distal part of the long arm of the chromosome 14 (14q24 --> qter) resulting from a paternal balanced translocation (3;14) is described. We compare her phenotype with eight other individuals with trisomy 14q24 --> qter.