Evaluation of a pre-co-seasonal and a perennial schedule of a single multiallergen depigmented-polymerized subcutaneous immunotherapy in paediatric patients.

AIM: Compare a pre-co-seasonal with a perennial schedule using an undiluted mixture of a depigmented-polymerized grass/Olea europaea immunotherapy (2,000 DPP/mL) in pediatric patients with rhinitis/rhinoconjunctivitis with or without controlled asthma. MATERIAL AND METHODS: Primary objective was to determine the non-superiority of a perennial compared to a pre-co-seasonal schedule by means of Paediatric/Adolescent Rhinoconjunctivitis Quality of Life Questionnaire (PRQLQ/AdolRQLQ). Secondary objectives were Paediatric Asthma/Caregiver´s Quality of Life Questionnaire (PAQLQ/PACQLQ) Asthma Control Test (ACT), Visual Analogue Scale global assessment of allergic disease (VAS), use of resources and immunological response. All variables were compared during the pollen season (April-June) without (2015) and with (2016) immunotherapy. RESULTS: Forty patients were included in the study of which 29 patients were assigned to the perennial and 11 to the pre-co-seasonal schedule. During 2016 pollen season a significant improvement in the PRQLQ/AdolRQLQ, PAQLQ/AdolAQLQ, ACT and VAS score were observed both in perennial and pre-co-seasonal schedule group. No significant differences were seen between treatment schedules for PRQLQ/AdolRQLQ, PAQLQ/AdolAQLQ and ACT scores comparing both pollen seasons. A significant increase in sIgG4 and reduction in the number of rescue medications used and number of patients who needed visit to any specialist was observed in both treatment schedules during 2016 pollen season. No relevant differences were found in the safety profile of any treatment schedule. DISCUSSION: Treatment with undiluted mixture of a depigmented-polymerized Grass/Olea europaea allergen immunotherapy has proven to be effective both using a perennial and a pre-co-seasonal schedule and therefore suitable for polyallergic patients.

Molecular sensitization patterns and influence of molecular diagnosis in immunotherapy prescription in children sensitized to both grass and olive pollen.

BACKGROUND: The overlapping grass and olive pollen seasons in Spain and the phenomenon of cross-reactivity can make it difficult to determine the true causative agent of seasonal allergic rhinitis when only skin prick tests with whole extracts are used. The aim of the GRAMOLE study was to determine sensitization patterns to the major grass and olive pollen allergens detected using specific recombinant IgE and to explore how this knowledge affected physicians' choice of allergen-specific immunotherapy. METHODS: Epidemiological, observational, multicenter, cross-sectional study. Results from children under 18 years of age diagnosed with seasonal allergic rhinitis by positive skin prick tests to olive and grass pollen were analyzed. Specific IgE to Phl p 1+5, Ole e 1, and Phl p 7+12 was determined. Investigators specified the optimal composition of allergen immunotherapy before and after knowing the results of the molecular diagnosis. RESULTS: A total of 281 patients with a mean age of 13.4 years were included. Double sensitization to both major allergens was found in vitro in 76% of children for an IgE cutoff point of 0.35 kU/L. When the molecular diagnosis results were known, specialists changed the composition of the prescribed immunotherapy in 52.87% of cases. CONCLUSIONS: Double sensitization to grass and olive pollen is common in Spain and also occurs in the pediatric population. Molecular diagnosis using specific IgE may help improve immunotherapy selection in polysensitized patients.

Diagnostic evaluation of hypersensitivity reactions to beta-lactam antibiotics in a large population of children.

INTRODUCTION: Hypersensitivity reactions to beta-lactams (BLs) are often reported in children, with amoxicillin and, to a lesser extent, cephalosporins being the most frequent drugs involved. Although many of these children are considered to be allergic, a careful evaluation only confirms a low percentage. OBJECTIVES: To analyse the clinical data, sensitization profile and diagnostic methods used in a large group of children with a clinical history of hypersensitivity reactions to BLs. METHODS: The study included children aged 1-14 yr with symptoms suggestive of hypersensitivity to BLs from January 2006-December 2012. Diagnosis was confirmed from a clinical history, specific IgE determination, skin testing and, if necessary, a drug provocation test (DPT). RESULTS: Of a total of 783 patients studied, only 62 (7.92%) were confirmed as being allergic, 9 (14.52%) with immediate and 53 (85.48%) with non-immediate reactions. In those with immediate reactions, 2 (22.22%) were diagnosed by in vitro test, 2 (22.22%) by skin testing and 5 (55.56%) by DPT; in those with non-immediate reactions, 2 (3.77%) were diagnosed by skin testing and 51 (96.23%) by DPT. In all cases, DPT was positive to the culprit drug (29 AX-CLV, 26 AX, 1 cefixime and 1 cefaclor), and the most usual symptoms were exanthema in 43 cases, urticaria in 12, urticaria-angio-oedema in 1 and erythema in 1 case. CONCLUSION: After an allergological work-up, over 90% of the children evaluated were finally confirmed as tolerant to BLs. Most reactions were of the non-immediate type, and DPT was an essential tool for diagnosis.

Two year follow-up of immunological response in mite-allergic children treated with sublingual immunotherapy. Comparison with subcutaneous administration.

Although the efficacy of allergen-specific sublingual immunotherapy (SLIT) is now accepted, the underlying mechanisms remain elusive. Such mechanisms are better documented in the case of subcutaneous immunotherapy (SCIT). In order to understand the T-lymphocyte response in patients receiving SLIT, we compared children with respiratory disease monosensitized to Dermatophagoides pteronyssinus receiving SLIT or SCIT over a 2-yr period. Peripheral blood was obtained before beginning immunotherapy, and after 3 months, 1 yr and 2 yr. Total IgE, specific IgE and IgG4 to D. pteronyssinus were determined in serum. T-cell markers (CD3, CD4, CD8, CD25) and intracellular cytokine production (TNF-alpha, IL-2, IL-4 and IFN-gamma) were determined in peripheral blood mononuclear cells (PBMC) by flow cytometry. No differences between SCIT and SLIT were detected in the clinical variables or in the subjective evaluation. Although an increase in specific IgE and IgG4 was only detected in SCIT, a significant decrease in the specific IgE/IgG4 ratio was found in both groups. SCIT and SLIT experienced an increase in the CD4/CD8 ratio over time, but an increase in the CD4(+)CD25(+) and a decrease in the CD8(+)CD25(+) subsets were only found with SCIT. A slight shift from a Th2 to a Th1 pattern, measured by the IFN-gamma/IL-4 ratio, was only detected in the CD4 T cells with SCIT. A decrease in both groups was found in TNF-alpha and IL-2 production over time. Children with respiratory allergic diseases receiving SCIT or SLIT had a different immunologic response in peripheral blood during treatment, though the clinical improvement was similar. Whether SLIT induces a mucosal protective response should be studied.

Improvement of toxic epidermal necrolysis after the early administration of a single high dose of intravenous immunoglobulin.

BACKGROUND: Toxic epidermal necrolysis (TEN) is a severe disease often induced by drugs. Treatment is controversial, although intravenous immunoglobulins (IVIGs) have been effective. OBJECTIVE: To report the case of a child with TEN after lamotrigine treatment, who improved 24 hours after IVIG administration. METHODS: Sequential blood and blister fluid samples were obtained for flow cytometry and reverse transcriptase-polymerase chain reaction analyses. RESULTS: The first blood sample, taken before IVIG administration, showed normal levels of lymphocyte subsets and CLA (4.0%) but high levels of activated lymphocytes (CD69) (18.0%). After treatment, the CLA+, CD69+, and memory cells increased until day 7, decreasing to normal values at days 15 and 30. In the blister fluid samples, taken on day 1, there were high levels of CD8+ (70.2%; CD4/CD8 ratio, 1:5), CLA+ (18.8%), and CD69+ (70%) cells, decreasing 24 hours after IVIG administration. In the blood samples, there was a Th1 cytokine pattern initially, tending to Th0 with time. Perforin, granzyme B, and Fas ligand were only observed before IVIG administration. CONCLUSIONS: A single high dose of IVIG interrupted the progression of skin disease and reduced the expression of the apoptotic markers. The immunologic changes, first seen in blister fluid and remaining several days in peripheral blood, indicate that T cells were first recruited to the skin and then recirculated to blood.

Immediate allergy to tetanus toxoid vaccine: determination of immunoglobulin E and immunoglobulin G antibodies to allergenic proteins.

BACKGROUND: Adverse reactions to tetanus toxoid (TT) vaccine are mostly mild and limited to the injection site. However, immunoglobulin (Ig)E-mediated reactions may occur, and the incidence of anaphylactic responses to TT immunization is 0.001%. When TT induces an allergic reaction, the potential causative agents can be TT antigens, thimerosal or aluminum phosphate. OBJECTIVE: We studied four children who developed immediate urticaria after TT vaccine, soon after the reaction and 5 years later. METHODS: Skin tests were performed separately with TT vaccine and two vaccine components, thimerosal and aluminum phosphate, and the diagnosis was confirmed by provocation test. IgE and IgG antibodies to TT and their specificities were determined. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting were performed to characterize the antigenic proteins. RESULTS: All four children were immediate skin test-positive to TT, but negative to thimerosal and aluminum phosphate; 3 developed a reaction after intramuscular provocation using increasing doses of TT vaccine; and 1 refused to be tested. All these tests were negative in five controls, all of whom received TT vaccine and developed only local swelling at the site of application 24 hours after vaccine administration. After 5 years the IgG antibodies were still high in all cases and the IgE antibody values fell by 50%. Patients allergic to TT vaccine produced IgE and IgG antibodies, which decreased at different rates but remained for at least 5 years. The pattern of antibody decrease was confirmed by radioallergosorbent test, enzyme-linked immunoadsorbent assay, or immunoblotting assay. IgE and IgG antibodies recognized two proteins derived from TT, of 150 and 50 kDa, corresponding to the intracellular form and to a chain of the extracellular form of the tetanus neurotoxin. CONCLUSIONS: In children with immediate allergic reactions to TT vaccine, antibodies may persist for at least 5 years, requiring evaluation by skin and/or in vitro tests before subsequent treatment.