Omalizumab withdrawal outcomes in chronic spontaneous urticaria are linked with baseline IgE and eosinophil levels.

Background: Chronic Spontaneous Urticaria (CSU) is an immune-mediated skin disease that may require prolonged treatments. Currently, there are no recommendations for treatment discontinuation once CSU symptoms are controlled, particularly among patients primarily diagnosed with severe CSU. Objective: In this real-life study we aimed to describe our experience of omalizumab (Oma) treatment withdrawal in CSU and define biomarkers related to these outcomes. Methods: CSU patients followed at our allergy clinic from January 2016 to December 2022 were included. Response to Oma therapy, and Oma-withdrawal outcomes among patients who reached complete remission for >6 months were analyzed. Results: During the study period 192/335(%) CSU patients were categorized as severe-CSU and entitled to receive Oma according to our country's regulations. Of them, 131/192(68%) were considered "Oma-responders", and 95/131(72.5%) patients underwent gradual treatment withdrawal. Successful Oma-withdrawal was documented in 47/95(49.5%) whereas 48/95(50.5%) patients experienced flare and were defined as unsuccessful OMA-withdrawal. The first was associated with shorter disease duration 7.1 ± 7.4 years vs. 10.7 ± 9.4 (P = 0.042), lower baseline-IgE 81.6 ± 84.1IU/ml vs. 324.7 ± 555.9 (P = 0.005), and lower baseline-eosinophils count 131.4 ± 110.5 vs. 195.6 ± 98.4 (P = 0.043) in comparison to failure of Oma-withdrawal group. Conclusion: OMA may be successfully withdrawn in up to 50% of severe CSU patients following complete remission of disease symptoms, utilizing a gradual withdrawal protocol. Oma-withdrawal failure was linked with longer duration of disease as well as high IgE and eosinophil counts prior to initiation of Oma therapy. These parameters may enable the design of a treatment withdrawal algorithm.

Late Hypersensitivity Reactions to the BNT162b2 SARS-CoV-2 Vaccine Are Linked to Delayed Skin Sensitization and Prior Exposure to Hyaluronic Acid.

Background: Late hypersensitivity reactions (HSRs) to the BNT162b2-vaccine have raised concerns regarding its safety, particularly as further immunizations are required. The yield of skin testing with the BNT162b2v is unclear, as well as the risk factors and outcomes of re-immunization after late HSRs. Objective: We studied a series of patients with late HSRs to BNT162b2v. Methods: Patients referred to the Sheba medical center from December 2020 to May 2021 with late HSRs to the first dose of BNT162b2 were included. HSRs were defined as late if they appeared or lasted >24 h after inoculation. We compared late HSRs to immediate HSRs that appeared within minutes−2 h after vaccination. Intradermal testing with PEG-containing medication and BNT162b2v was performed. Results: A total of 17 patients that presented with late HSRs (study group) were compared to 34 patients with immediate HSRs (control group). Delayed sensitivity to intradermal testing of the BNT162b2v was observed in 9/17 (53%) of the study group compared to 4/34 (12%) in the control group (p = 0.01). Former exposure to a dermal filler with hyaluronic acid was documented among 7/17 (41%) vs. 2/34 (6%) in the study and control groups, respectively, (p = 0.0038). All patients who presented with late HSRs were advised to receive subsequent doses of the BNT162b2v vaccine with or without concomitant medication, and all were re-immunized successfully. Conclusions: Late HSRs to BNT162b2v were linked with positive responses to intradermal testing with the vaccine and prior exposure to derma fillers with hyaluronic acid. This may elude to an immune mechanism triggered by former exposures. Although further studies are needed, late HSRs to the BNT162b2-vaccine did not prevent patients from receiving subsequent doses of the vaccines.

A clinical pathway for the diagnosis of sesame allergy in children.

Background: Sesame allergy (SA) is a common cause of life-threatening, persistent food allergy, not only in the Middle East and Asia, but increasingly worldwide. Commercially available tests such as extracts for skin testing or specific IgE for sesame or its components in serum, have very limited predictive values. Therefore the diagnosis is dependent on the performance of oral food challenges (OFC), frequently avoided in children, due to time and resource constraints, as well as the risk of anaphylaxis. In the current study we aimed to develop a simple, readily available, clinical tool, able to predict sesame OFC outcomes in children. Methods: Children with a history of SA were evaluated in the outpatient allergy clinic. All children underwent natural sesame OFC, with an additional baked-sesame challenge offered to children with SA. Clinical data were compared between the sesame tolerant (ST) and SA groups. Machine-learning tools were applied, to create a simple, clinically driven, decision tree analysis (DTA), predicting the outcome of sesame OFCs and the diagnosis of SA. Results: One hundred four children, mean age 47.2 months, 58% boys were included, with a high prevalence of additional food allergies, atopic dermatitis, asthma, and rhinitis. Following OFC, 56 (54%) were diagnosed as ST and 48 (46%) SA. Among SA children, 85% were able to consume baked-sesame in equal or higher protein amounts compared to natural sesame paste. Compared to ST, SA children had a tendency towards a higher incidence of allergic rhinitis (5% Vs 17%, p = 0.062), multiple food allergies (3.6% vs 12.5%, p = 0.09) and requiring medical treatment after the initial SA reaction (27% vs 41%, p = 0.022). As a group, skin tests with both commercial and natural tahini paste differed significantly between ST and SA (mean wheal in mm, for extract 4.2 vs 13.4, p < 0.001 and for natural sesame paste 6.7 vs 24.4, p < 0.001), However, the PPV of any individual test was only between 60%-85%. Our exploratory, clinical DTA, predicted OFC outcomes and the presence or absence of Sesame Allergy, with ≥96% positive (PPV) and negative (NPV) predictive values. Conclusion: OFCs remain the gold standard for the diagnosis of Sesame Allergy and are indicated to define ST/SA status even in highly atopic patients with previous immediate allergic reactions to sesame. A decision-tree analysis based on clinical parameters easily available in every allergy clinic, can predict the outcome of sesame OFC in the vast majority of children, increasing the safety and availability of such diagnostic procedures.

Assessment of Immediate Allergic Reactions After Immunization With the Pfizer BNT162b2 Vaccine Using Intradermal Skin Testing With the COVID-19 Vaccines.

BACKGROUND: Allergic reactions to the coronavirus disease 2019 (COVID-19) vaccines have raised concerns, particularly as repeated doses are required. Skin tests with the vaccines excipient were found to be of low value, whereas the utility of skin tests with the whole vaccine is yet to be determined. OBJECTIVE: To evaluate a panel of skin tests and the outcomes of subsequent doses of immunization among subjects who suffered an immediate allergic reaction to the BioNTech (BNT162b2) COVID-19 vaccine. METHODS: Between March and December 2021, patients who experienced symptoms consistent with immediate allergic reactions to the BNT162b2 vaccine and were referred to the Sheba Medical Center underwent skin testing with polyethylene glyol (PEG)-containing medicines, Pfizer-BNT162b2, and Oxford-AstraZeneca vaccine (AZD1222). Further immunization was performed accordingly and under medical observation. RESULTS: A total of 51 patients underwent skin testing for suspected allergy to the COVID vaccines, of which 38 of 51 (74.5%) were nonreactive, 7 of 51(13.7%) had no skin sensitization but suffered a clinical reaction during skin testing (mainly cough), and 6 of 51 (11.7%) exhibited immediate skin sensitization. Both skin sensitization and cough during testing were related to a higher use of adrenaline following immunization (P = .08 and P = .024, respectively). Further immunization with the BNT162b2 vaccine was recommended unless sensitization or severe reaction to previous immunization was evident. The latter were referred to be tested/receive the alternative AZD1222 vaccine. Ten patients underwent skin testing with AZD1222: 2 of 10 (20%) demonstrated skin sensitization to both vaccines; thus, 8 of 10 were immunized with the AZD1222, of which 2 of 8 (25%) had allergic reactions. CONCLUSIONS: Immediate allergic reactions to COVID-19 vaccines are rare but can be severe and reoccur. Intradermal testing with the whole vaccine may discriminate sensitized subjects, detect cross-sensitization between vaccines, and enable estimation of patients at higher risk.

Prevalence of Allergic Reactions After Pfizer-BioNTech COVID-19 Vaccination Among Adults With High Allergy Risk.

Importance: Allergic reactions among some individuals who received the Pfizer-BioNTech (BNT162b2) COVID-19 vaccine discourage patients with allergic conditions from receiving this vaccine and physicians from recommending the vaccine. Objective: To describe the assessment and immunization of highly allergic individuals with the BNT162b2 vaccine. Design, Setting, and Participants: In a prospective cohort study from December 27, 2020, to February 22, 2021, 8102 patients with allergies who applied to the COVID 19 vaccine referral center at the Sheba Medical Center underwent risk assessment using an algorithm that included a detailed questionnaire. High-risk patients (n = 429) were considered "highly allergic" and were immunized under medical supervision. Exposures: Pfizer-BioNTech (BNT162b2) COVID-19 vaccine. Main Outcomes and Measures: Allergic and anaphylactic reactions after the first and second doses of BNT162b2 vaccine among highly allergic patients. Results: Of the 429 individuals who applied to the COVID-19 referral center and were defined as highly allergic, 304 (70.9%) were women and the mean (SD) age was 52 (16) years. This highly allergic group was referred to receive immunization under medical supervision. After the first dose of the BNT162b2 vaccine, 420 patients (97.9%) had no immediate allergic event, 6 (1.4%) developed minor allergic responses, and 3 (0.7%) had anaphylactic reactions. During the study period, 218 highly allergic patients (50.8%) received the second BNT162b2 vaccine dose, of which 214 (98.2%) had no allergic reactions and 4 patients (1.8%) had minor allergic reactions. Other immediate and late reactions were comparable with those seen in the general population, except for delayed itch and skin eruption, which were more common among allergic patients. Conclusions and Relevance: The rate of allergic reactions to BNT162b2 vaccine, is higher among patients with allergies, particularly among a subgroup with a history of high-risk allergies. This study suggests that most patients with a history of allergic diseases and, particularly, highly allergic patients can be safely immunized by using an algorithm that can be implemented in different medical facilities and includes a referral center, a risk assessment questionnaire, and a setting for immunization under medical supervision of highly allergic patients. Further studies are required to define more specific risk factors for allergic reactions to the BNT162b2 vaccine.

Combination therapy with omalizumab and an immune-suppressive agent for resistant chronic spontaneous rrticaria - A real-life experience.

BACKGROUND: Chronic Spontaneous Urticaria (CSU) is a relatively common immune mediated disease that can be effectively treated nowadays. Nevertheless, for some patients remission cannot be achieved following current treatment recommendations, defined as resistant CSU (r-CSU). Treating r-CSU is challenging, and, currently, there are no recommended interventions. In this real-life study we describe successful therapy of 18 r-CSU patients using an "intensified protocol" of anti-IgE-antibody (omalizumab) concomitantly with an immunosuppressant. We defined the r-CSU phenotype and compared it to omalizumab-responsive CSU (Or-CSU) phenotype. METHODS: Clinical and serological data of 72 CSU patients (ie, 18 r-CSU and 54 age and sex matched Or-CSU) were retrospectively collected and analyzed. All patients were diagnosed with CSU for ≥6 months and treated at the Sheba Medical Center during 2013-2018. RESULTS: Of 289 CSU patients, 18 (6%) were diagnosed with r-CSU and treated with the "intensified protocol" including omalizumab and cyclosporine-A (16p), methotrexate (1p), and azathioprine (1p). Of which, 14/18 (78%) achieved complete remission, 2/18 (11%) partial remission, and 2/18 (11%) no remission. During follow-up no serious adverse events were documented. r-CSU patients received higher doses of antihistamine (p < 0.0001) and omalizumab (425 ± 58 mg/month vs. 283 ± 86 mg/month; p < 0.0001) compared to Or-CSU. The r-CSU phenotype was linked with concomitant autoimmunity (p = 0.0005) and a lower level of IgE prior to initiation of therapy (p = 0.027). CONCLUSION: r-CSU may be a distinct CSU phenotype characterized by severe disease, concomitant autoimmunity, and lower baseline-IgE levels (low "autoallergy"). An "intensified protocol" with omalizumab and an immunosuppressive agent was found to be efficacious and safe for r-CSU. Further larger studies are required to verify these results.