Flow-based basophil activation test in immediate drug hypersensitivity. An EAACI task force position paper.

Diagnosing immediate drug hypersensitivity reactions (IDHRs) can pose a significant challenge and there is an urgent need for safe and reliable tests. Evidence has emerged that the basophil activation test (BAT), an in vitro assay that mirrors the in vivo response, can be a complementary test for many drugs. In this position paper, members of Task Force (TF) "Basophil activation test in the evaluation of Drug Hypersensitivity Reactions" from the European Academy of Allergy and Clinical Immunology (EAACI) present the data from a survey about the use and utility of BAT in IDHRs in Europe. The survey results indicate that there is a great interest for using BAT especially for diagnosing IDHRs. However, there are still main needs, mainly in the standardization of the protocols. Subsequently consensus-based recommendations were formulated for: (i) Technical aspects of BAT in IDHRs including type of sample, management of drugs, flow cytometry protocols, interpretation of the results; and (ii) Drug-specific aspects that should be taken into account when performing BAT in relation to betalactams, neuromuscular blocking agents, fluoroquinolones, chlorhexidine, opioids, radio contrast media, chemotherapeutics, biological agents, nonsteroidal anti-inflammatory drugs, COVID vaccine, and excipients. Moreover, aspects in the evaluation of pediatric population have also been considered. All this indicates that BAT offers the clinician and laboratory a complementary tool for a safe diagnostic for IDHRs, although its place in the diagnostic algorithm depends on the drug class and patient population (phenotype, geography, and age). The standardization of BAT is important for generalizing this method beyond the individual laboratory.

Polymorphisms in eicosanoid-related biosynthesis enzymes associated with acute urticaria/angioedema induced by nonsteroidal anti-inflammatory drug hypersensitivity.

BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs) are the main triggers of drug hypersensitivity, with NSAID-induced acute urticaria/angioedema (NIUA) the most frequent phenotype. NSAID hypersensitivity is caused by cyclooxygenase 1 inhibition, which leads to an imbalance in prostaglandin (PG) and cysteinyl leukotriene (CysLT) synthesis. As only susceptible individuals develop NSAID hypersensitivity, genetic factors are believed to be involved; however, no study has assessed the overall genetic variability of key enzymes in PG and CysLT synthesis in NSAID hypersensitivity. OBJECTIVES: To evaluate simultaneously variants in the main genes involved in PG and CysLT biosynthesis in NIUA. METHODS: Two independent cohorts of patients were recruited in Spain, alongside NSAID-tolerant controls. The discovery cohort included only patients with NIUA; the replication cohort included patients with NSAID-exacerbated respiratory disease (NERD). A set of tagging single-nucleotide polymorphisms (tagSNPs) in PTGS1, PTGS2, ALOX5 and LTC4S was genotyped using mass spectrometry coupled with endpoint polymerase chain reaction. RESULTS: The study included 1272 individuals. Thirty-five tagSNPs were successfully genotyped in the discovery cohort, with three being significantly associated after Bonferroni correction (rs10306194 and rs1330344 in PTGS1; rs28395868 in ALOX5). These polymorphisms were genotyped in the replication cohort: rs10306194 and rs28395868 remained associated with NIUA, and rs28395868 was marginally associated with NERD. Odds ratios (ORs) in the combined analysis (discovery and replication NIUA populations) were 1·7 for rs10306194 [95% confidence interval (CI) 1·34-2·14; Pcorrected = 2·83 × 10-4 ) and 2·19 for rs28395868 (95% CI 1·43-3·36; Pcorrected = 0·002). CONCLUSIONS: Variants of PTGS1 and ALOX5 may play a role in NIUA and NERD, supporting the proposed mechanisms of NSAID-hypersensitivity and shedding light on their genetic basis.

Clinical Approach to Mast Cell Activation Syndrome: A Practical Overview.

The diagnosis of mast cell activation syndrome (MCAS) is defined by 3 criteria: (1) typical clinical signs and symptoms of acute, recurrent (episodic), and systemic mast cell activation (MCA); (2) increase in tryptase level to >20% + 2 ng/mL within 1-4 hours after onset of the acute crisis; and (3) response of MCA symptoms to antimediator therapy. Classification of MCAS requires highly sensitive and specific methodological approaches for the assessment of clonal bone marrow mast cells at low frequencies. The Spanish Network on Mastocytosis score has been used successfully as a predictive model for selecting MCAS candidates for bone marrow studies based on a high probability of an underlying clonal mast cell disorder. In this article, we propose a diagnostic algorithm and focus on the practical evaluation and management of patients with suspected MCAS.

ARADyAL: The Spanish Multidisciplinary Research Network for Allergic Diseases.

Thematic cooperative health research networks (RETICS) are organizational structures promoted by the Instituto de Salud Carlos III of the Spanish Ministry of Science with the objective of carrying out cooperative research projects addressing challenges of general interest for society as a whole in the field of health care. The RETICS of Asthma, Adverse Drug Reactions, and Allergy (ARADyAL) received funding in 2016 for a 5-year program (2017-2021). ARADyAL integrates basic and clinical research in the areas of allergy, immunology, genetics, nanomedicine, pharmacology, and chemistry, with special interest in research on new biomarkers and the design and evaluation of new interventions for allergic patients with severe phenotypes. The consortium comprises 28 groups across Spain, including 171 clinical and basic researchers, 17 clinical groups that cover more than 10 000 000 patients of all ages from urban and rural areas and 11 basic groups active mostly at universities and research institutes. ARADyAL has proposed a research program organized into 3 different areas focusing on precision medicine, as follows: Program 1, Mechanisms and prediction of adverse drug reactions and allergic diseases; Program 2, Toward a precise diagnosis of allergic diseases; and Program 3, Predicting interventions in allergic diseases. There is also 1 common program dedicated to training. The network has a Steering Committee and an External Advisory Scientific Committee, which advise the global network coordinator, who has recognized expertise in the field. ARADyAL is a unique meeting point for clinicians and basic scientists who are already working in allergy.

Local allergic rhinitis: Implications for management.

A significant proportion of rhinitis patients without systemic IgE-sensitisation tested by skin prick test and serum allergen-specific IgE (sIgE) display nasal reactivity upon nasal allergen provocation test (NAPT). This disease phenotype has been termed local allergic rhinitis (LAR). LAR is an underdiagnosed entity affecting children and adults from different parts of the world, with moderate-to-severe symptoms, impairment of quality of life and rapid progression to symptom worsening. LAR is a stable phenotype and not merely an initial state of AR. Allergic rhinitis and LAR share many clinical features including a positive NAPT response, markers of type 2 nasal inflammation including sIgE in nasal secretions and a significant rate of asthma development. LAR should be considered as a differential diagnosis in those subjects of any age with symptoms suggestive of AR but no evidence of systemic atopy. Although LAR pathophysiology is partially unknown, in some patients sIgE can be demonstrated directly in the nasal secretions and/or indirectly via positive responses in basophil activation test (BAT). LAR can coexist with other rhinitis phenotypes, especially AR. The diagnosis currently relies on the positivity of NAPT to a single or multiple allergens. NAPT has high sensitivity, specificity and reproducibility, and it is considered the gold standard. BAT and the measurement of nasal sIgE can also contribute to LAR diagnosis. LAR patients benefit from the same therapeutic strategies than AR individuals, including the avoidance of allergen exposure and the pharmacotherapy. Moreover, several recent studies support the effectiveness and safety of allergen immunotherapy for LAR, which opens a window of treatment opportunity in these patients.

Accuracy of the Diagnosis of Allergic Reactions in the Emergency Department.

BACKGROUND AND OBJECTIVE: Suspicion of an acute allergic reaction is a common reason for attending the emergency department (ED). However, there are few comparisons between the initial diagnosis of suspected allergic reaction made in the ED with the definitive diagnosis made subsequently in the allergy department (AD). Objective: To compare details of the initial diagnosis made in the ED relating to allergy with the final diagnosis made in the AD. METHODS: Patients attending the ED of 2 hospitals with suspected allergic reactions were prospectively enrolled based on key words. A certified allergy specialist reviewed the ED records of these patients and, if these were suggestive of an allergic reaction, the patients were scheduled for further evaluation at the allergy clinic. RESULTS: In total, 2000 patients were enrolled between April 2013 and October 2015. Of these, 1333 passed the initial assessment and underwent further evaluation. Of the 1333 patients, 528 underwent an allergological study, and 206 were confirmed as being allergic. With respect to drug allergy, nonsteroidal anti-inflammatory drugs were the most common triggers, followed by ß-lactams; in food allergy, plant-based foods were the most common. Only 16.4% of patients confirmed as having anaphylaxis in the AD were initially diagnosed with the condition in the ED. CONCLUSION: Of the 528 patients who finally underwent the full allergological study, fewer than half were confirmed as allergic. Moreover, anaphylaxis appears to be underdiagnosed in the ED. Better communication between the ED and the AD is necessary to improve the diagnosis and management of these patients.

Local allergic rhinitis is an independent rhinitis phenotype: The results of a 10-year follow-up study.

BACKGROUND: The knowledge about the natural history of local allergic rhinitis (LAR) is limited. One unmet question is to demonstrate whether LAR should be considered the first step in the development of allergic rhinitis (AR) or an independent phenotype. The aim of this study was to prospectively evaluate the natural history of a population with LAR, the potential conversion to AR with systemic atopy and the development of asthma during 10 years. METHODS: This is the second phase of a 10-year follow-up study of a cohort of 176 patients with LAR of recent onset and 115 age- and sex-matched healthy controls prospectively evaluated from 2005 to 2016. Clinical-demographic questionnaire, spirometry, skin prick test and specific IgE were evaluated yearly. Nasal allergen provocation tests (NAPT) with Dermatophagoides pteronyssinus, Alternaria alternata, Olea europaea and grass pollen were performed at baseline, and after 5 and 10 years. RESULTS: After 10-year LAR, patients experienced a significant and clinically relevant worsening of the rhinitis, with increase in emergency assistance, development of asthma, loss of allergen tolerance and impairment of the quality of life. This worsening became significant after 5 years and progressed throughout 10 years. A similar rate of development of AR with systemic atopy was detected in patients and controls (9.7% vs 7.8%, log-rank P=.623). In 5 patients, conversion to systemic atopy occurred >10 years (3%). CONCLUSIONS: LAR is a well-differentiated clinical entity with a low rate of development of systemic atopy, a natural evolution towards worsening and a risk factor for suffering asthma.

Specific immunotherapy in local allergic rhinitis: A randomized, double-blind placebo-controlled trial with Phleum pratense subcutaneous allergen immunotherapy.

BACKGROUND: Allergen immunotherapy has been shown to be an effective treatment for local allergic rhinitis (LAR) to house dust mites. Studies with pollen allergen immunotherapy are limited to observational studies. The aim of this study was to evaluate the clinical efficacy and safety of Phleum pratense subcutaneous immunotherapy (Phl-SCIT) in LAR. METHODS: In a randomized double-blind placebo-controlled study, 56 patients with moderate-severe LAR to grass pollen received Phl-SCIT with a depigmented polymerized pollen vaccine or placebo for the first year, and Phl-SCIT the second one. The blind was maintained throughout the study. Primary outcome was combined symptom medication score (CSMS) during grass pollen season (GPS). Secondary clinical outcomes included organ-specific symptoms, medication-free days, rhinitis severity and asthma control. Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ), nasal allergen provocation test (NAPT), skin testing, serum levels of specific IgG4 and specific IgE and safety were also evaluated. RESULTS: Subcutaneous immunotherapy (SCIT) had a short-term and sustained effect with significant improvements of all primary and secondary clinical outcomes and RQLQ score. SCIT significantly increased serum sIgG4 levels and allergen tolerance, from the 6th to 24th months of treatment. At the end of the study, 83% of patients treated with ≥6 months of SCIT tolerated a concentration of P. pratense over 50 times higher than baseline, and 56% gave a negative NAPT. SCIT was well tolerated; six mild local reactions occurred, and there were no serious adverse events related to the study medication. CONCLUSIONS: Subcutaneous immunotherapy with depigmented polymerized allergen extracts is a safe and clinically effective treatment for LAR to P. pratense.

Practical Guidelines for Perioperative Hypersensitivity Reactions.

Perioperative hypersensitivity reactions constitute a first-line problem for anesthesiologists and allergists. Therefore, hospitals should have a consensus protocol for the diagnosis and management of these reactions. However, this kind of protocol is not present in many hospitals, leading to problems with treatment, reporting of incidents, and subsequent etiological diagnosis. In this document, we present a systematic review of the available scientific evidence and provide general guidelines for the management of acute episodes and for referral of patients with perioperative hypersensitivity reactions to allergy units. Members of the Drug Allergy Committee of the Spanish Society of Allergy and Clinical Immunology (SEAIC) have created this document in collaboration with members of the Spanish Anesthesia Society (SEDAR). A practical algorithm is proposed for the etiologic diagnosis, and recommendations are provided for the management of hypersensitive patients.

The clinical and immunological effects of Pru p 3 sublingual immunotherapy on peach and peanut allergy in patients with systemic reactions.

BACKGROUND: The peach non-specific lipid transfer protein, Pru p 3, is the primary sensitizer in fruits and responsible for severe reactions in the Mediterranean area. Peach allergy is frequently associated with other allergies such as peanut. Therefore, it is important to assess how specific immunotherapy to Pru p 3 could affect both peach and peanut tolerance. OBJECTIVES: To evaluate peach and peanut desensitization and immunological changes after 1 year of Pru p 3 sublingual immunotherapy (SLIT) in patients with systemic allergic reactions to peach and/or peanut. METHODS: Forty-eight peach allergic patients, 36 treated with SLIT and 12 non-treated, were monitored for 12 months. Treated patients were subclassified as peanut allergic (Group A), sensitized (Group B) or tolerant (Group C). SLIT effect was evaluated by skin prick test (SPT) reactivity and food challenge. Immunological changes were evaluated by monitoring sIgE and sIgG4 levels and basophil reactivity. RESULTS: After 1 year of SLIT, the weal area in SPT significantly decreased and a significant increase in peach threshold in treated patients was observed (P < 0.001). Patients in Group A showed a significant decrease in peanut SPT weal area and an increase in peanut threshold (P < 0.001). Immunological changes were observed in treated patients only, with a significant decrease in sIgE and a parallel increase in sIgG4, sIgG4/sIgE and basophil reactivity for both Pru p 3 and Ara h 9. CONCLUSIONS AND CLINICAL RELEVANCE: After 1 year, Pru p 3 SLIT induces both desensitization and immunological changes not only for peach but also for other food allergens relevant in the induction of severe reactions such as peanut.

Basophil Histamine Release Induced by Amoxicilloyl-poly-L-lysine Compared With Amoxicillin in Patients With IgE-Mediated Allergic Reactions to Amoxicillin.

BACKGROUND: Amoxicillin (AX) is the ß-lactam most often involved in IgE-mediated reactions. Diagnosis is based mainly on skin testing, although sensitivity is not optimal. We produced a new AX derivative, amoxicilloyl-poly-L-lysine (APL), and analyzed its recognition of IgE using the passive histamine release test (pHRT). METHODS: The study population comprised patients (n=19) with confirmed AX allergy and specific IgE to AX and controls (n=10) with good tolerance to AX. pHRT was performed using "IgE-stripped" blood from a single donor that was sensitized in vitro by patient sera and incubated with AX or APL. Histamine release was determined and expressed as nanograms of histamine released per milliliter of blood. RESULTS: The clinical symptoms were anaphylaxis (n=9), urticaria (n=7), erythema (n=2), and nondefined immediate reactions (n=1). The median (IQR) time interval between reaction and study was 90 (60-240) days and between drug intake and development of symptoms 24 (10-60) minutes. The median sIgE level was 3.37 (0.95-5.89) kUA/L. The sensitivity of pHRT to APL was 79% and the specificity 100%, which were higher than data obtained with pHRT to AX (63% sensitivity and 90% specificity). There was a positive correlation between maximal histamine release levels obtained with AX and APL (r=0.63). CONCLUSIONS: In patients with immediate hypersensitivity reactions to AX, APL showed higher sensitivity and specificity than the culprit drug, AX, when tested in vitro by pHRT. This indicates that APL can improve the in vitro diagnostic accuracy of allergic reactions to AX. Further assessment of skin testing is necessary.

The role of IgE recognition in allergic reactions to amoxicillin and clavulanic acid.

Betalactam (BL) antibiotics are the drugs most frequently involved in IgE-mediated reactions. The culprit BL varies according to consumption patterns, with amoxicillin (AX) more prevalent in Southern Europe and penicillin V in Scandinavian countries. Nowadays, the combination of AX and clavulanic acid (CLV) is the most highly consumed BL containing medicine worldwide. Both BLs, AX and CLV, can independently be involved in reactions, which poses a diagnostic challenge. In patients with immediate allergic reactions to AX, two patterns of responses have been described, those responding to benzylpenicillin (cross-reactors) and those selective to AX. In addition, selective reactions to CLV account for around 30% of allergic reactions to the combination AX-CLV. These patterns of IgE recognition could be related to differences in the haptenation process, in the immunological response, or in the BL involved in the first sensitization. In this regard, patients with selective responses to CLV are generally younger than those allergic to AX or benzylpenicillin. So far, no evidence of cross-reactivity between CLV and other BLs has been reported. This shows the importance of an accurate diagnosis of CLV allergy, as patients with selective reactions to CLV could take other BLs including AX. Diagnosis can be performed in vivo and in vitro, although no immunoassay currently exists. Research regarding the CLV antigenic determinants and protein conjugates is essential to improve diagnosis. BLs need to covalently bind to a carrier protein to be immunogenic. The antigenic determinant of AX is the amoxicilloyl amide, but CLV leads to unstable structures, many of which are unknown. Moreover, the nature of the BL-protein conjugates plays an important role in IgE recognition. This review aims to summarize current knowledge on the immunochemistry, diagnostic approaches as well as chemical and proteomic studies for both AX and CLV.

Efficacy and safety of D. pteronyssinus immunotherapy in local allergic rhinitis: a double-blind placebo-controlled clinical trial.

The effects of allergen immunotherapy (AIT) on local allergic rhinitis (LAR) are largely unknown. We conducted the first randomized, double-blind, placebo-controlled (DBPC), phase II trial of D. pteronyssinus (DP) subcutaneous AIT (DP-AIT) on LAR (clinicaltrials.gov identifier: NCT02123316). Thirty-six LAR patients received Pangramin PLUS DP or placebo for 24 months. The primary endpoints were symptoms, medication scores, and medication-free days. The secondary included skin test, serum specific IgE and IgG4, nasal allergen provocation test (NAPT), and adverse events. AIT-DP produced significant improvements in both primary and secondary endpoints vs placebo. After 12 months of AIT-DP, we detected a significant and marked increase in allergen tolerance with negative NAPT in 50% of patients, and significant increases of serum sIgG4. Immunotherapy was well tolerated; no systemic reactions were reported. This study demonstrated that AIT-DP is a safe and clinically effective treatment for LAR, confirming that LAR is a new indication for AIT.

Genetic variants associated with drugs-induced immediate hypersensitivity reactions: a PRISMA-compliant systematic review.

Drug hypersensitivity includes allergic (AR) and nonallergic reactions (NARs) influenced by genetic predisposition. We performed a systematic review of genetic predictors of IgE-mediated AR and NAR with MEDLINE and PubMed search engine between January 1966 and December 2014. Among 3110 citations, the search selected 53 studies, 42 of which remained eligible. These eligible studies have evaluated genetic determinants of immediate reactions (IR) to beta-lactams (n = 19), NAR against aspirin (n = 12) and other nonsteroidal anti-inflammatory drugs (NSAIDs) (n = 8), and IR to biologics (n = 3). We reported two genomewide association studies and four case-control studies on candidate genes validated by replication. Genes involved in IR to beta-lactams belonged to HLA type 2 antigen processing, IgE production, atopy, and inflammation, including 4 genes validated by replications, HLA-DRA, ILR4, NOD2, and LGALS3. Genes involved in NAR to aspirin belonged to arachidonic acid pathway, membrane-spanning 4A gene family, histamine production pathway, and pro-inflammatory cytokines, while those involved in NAR to all NSAIDs belonged to arachidonic acid pathway and HLA antigen processing pathway. ALOX5 was a common predictor of studies on NAR to both aspirin and NSAIDs. Although these first conclusions could be drawn, this review highlights also the lack of reliable data and the need for replicating studies in contrasted populations, taking into account worldwide allele frequencies, gene-gene interactions, and contrasted situations of environmental exposure.

In vitro tests for drug hypersensitivity reactions: an ENDA/EAACI Drug Allergy Interest Group position paper.

Drug hypersensitivity reactions (DHRs) are a matter of great concern, both for outpatient and in hospital care. The evaluation of these patients is complex, because in vivo tests have a suboptimal sensitivity and can be time-consuming, expensive and potentially risky, especially drug provocation tests. There are several currently available in vitro methods that can be classified into two main groups: those that help to characterize the active phase of the reaction and those that help to identify the culprit drug. The utility of these in vitro methods depends on the mechanisms involved, meaning that they cannot be used for the evaluation of all types of DHRs. Moreover, their effectiveness has not been defined by a consensus agreement between experts in the field. Thus, the European Network on Drug Allergy and Drug Allergy Interest Group of the European Academy of Allergy and Clinical Immunology has organized a task force to provide data and recommendations regarding the available in vitro methods for DHR diagnosis. We have found that although there are many in vitro tests, few of them can be given a recommendation of grade B or above mainly because there is a lack of well-controlled studies, most information comes from small studies with few subjects and results are not always confirmed in later studies. Therefore, it is necessary to validate the currently available in vitro tests in a large series of well-characterized patients with DHR and to develop new tests for diagnosis.

Immunologic responses to the major allergen of Olea europaea in local and systemic allergic rhinitis subjects.

OBJECTIVE: To evaluate the in vivo and in vitro responses to nOle e 1 in allergic rhinitis (AR) and local allergic rhinitis (LAR) patients sensitized to olive tree pollen (OL) confirmed by nasal allergen provocation test (NAPT). METHODS: Twelve subjects with AR, 12 with LAR and 12 subjects as control group (CG) were selected. Skin testing and NAPT with nOle e 1 were performed. Eosinophilic cationic protein (ECP) and tryptase were measured in nasal lavages before and after NAPT. Serum IgE to OL allergens was measured by ELISA. Basophil activation tests (BAT) with OL and nOle e 1 and dendritic cell maturation/proliferation studies were carried out. RESULTS: All AR (12/12) and 10/12 (83%) of LAR had a +NAPT to nOle e 1. ECP levels in nasal lavages were significantly increased after NAPT in both AR and LAR compared with CG at 15 min (P < 0.05). Serum IgE was positive only in AR. All AR had +BAT responses to OL and 10/12 to nOle e 1 (83%); 8/12 LAR (66.6%) had a +BAT to OL and 4/12 (33%) to nOle e 1, with only one subject of the CG with a +BAT to both OL and nOle e 1 (8%). Dendritic cell proliferation to nOle e 1 was increased in AR compared to LAR and CG (P = 0.019 and P = 0.001, respectively). CONCLUSION: Both AR and LAR had a similar in vivo response to nOle e 1 with release of inflammatory mediators. Specific basophil activation with OL and nOle e 1 was observed in LAR confirming previous data obtained with dust mites.

Initial immunological changes as predictors for house dust mite immunotherapy response.

BACKGROUND: Although specific immunotherapy is the only aetiological treatment for allergic disorders, the underlying mechanisms are not fully understood. Specific immunotherapy induces changes in lymphocyte Th subsets from Th2 to Th1/Treg. Whether differences in immunological patterns underlie patient response to immunotherapy has not yet been established. OBJECTIVES: We studied the immunological changes occurring during a 1-year period of Dermatophagoides pteronyssinus (DP) immunotherapy and their relation with clinical outcome. METHODS: We included 34 patients with DP allergy who received subcutaneous specific immunotherapy (SCIT) for 1 year. Following treatment, patients were classified as responders or non-responders. Fourteen allergic subjects who did not receive SCIT were included as controls. Peripheral blood was obtained at 0, 1, 3, 6 and 12 months and cultured with nDer p 1. Phenotypic changes, cytokine production and basophil response were analysed by flow cytometry; transcription factors were measured by mRNA quantification. Serum immunoglobulin levels were also measured. RESULTS: After 1 year of SCIT, 82% of cases showed improved symptoms (responders). Although increases in sIgG4 were observed, BAT reactivity was not modified in these patients. Increases in T-BET/FOXP3 as well as nDer p 1-specific Th1/Treg frequencies were also observed, along with a decrease in Th2, Th9 and Th17. These changes corresponded to changes in cytokine levels. CONCLUSION: Patients who respond well to DP-SCIT show immunological differences compared to non-responders. In responders, basal differences include a lower frequency of Th1 and higher frequencies of Th2, Th9 and Th17 cells. After 1 year of treatment, an increased production of sIgG4 was observed in responders, along with a change in Th2 response towards Th1/Treg.