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. 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. 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). 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.

Summary: Primary immunodeficiency disorders (PID) are a group of heterogeneous disorders characterized by recurrent infections, autoimmunity, increased lymphoproliferative disorders and other malignancies. PID is classified into cellular or humoral disorders or a combination of both. We evaluated the clinical differences among adult patients with three variants of PID: common variable immunodeficiency (CVID), idiopathic CD4 lymphopenia (ICL) and combined immunodeficiency (CID). We retrospectively compared demographics, immunological characteristics, clinical presentations and outcomes of CVID, CID and ICL patients followed from 2012 to 2018. In our cohort, we identified 44 adult patients diagnosed with CVID (22), CID (11) and ICL (11). Malignancy was associated with CID, as seven of 11 patients in this group were diagnosed with malignancy compared to CVID (three of 22) or ICL (two of 11) (P = 0·002 and 0·03, respectively). Malignancies were also linked to male gender [odds ratio (OR) = 5, 95% confidence interval (CI) = 1·12–22·18) P = 0·0342] and a low ratio of CD4/CD8 < 0·8 (OR = 5·1, 95% CI = 1·22–21·28, P = 0·025). Among CID and ICL, two of 11 patients died in each group, while no death was documented among CVID group (P = 0·04). Autoimmune manifestations did not differ between groups. Similarly, the rate of infections was similar between groups, although infectious agents vary. CID is associated with a high risk of malignancy compare to CVID or ICL. Among adults with PID, male gender, low CD4 and a CD4/CD8 ratio of < 0·8 may serve as risk factors of concomitant malignancy. Surveillance of lymphocyte subpopulations should be considered for all adults.

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. 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. 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. 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. 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.

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.

Background: Eosinophilia, defined as peripheral blood eosinophil counts > 0.5 K/μL, is associated with various clinical conditions, including allergic, infectious, and malignant diseases. Emerging evidence suggests that eosinophils may contribute to thrombo-inflammatory processes, but their association with thromboembolic events and mortality remains insufficiently characterized. This study aimed to evaluate whether eosinophilia is independently associated with increased risk of thromboembolic events and mortality in hospitalized patients. Methods: We conducted a retrospective cohort study using electronic medical records from Sheba Medical Center (2011–2020). Eosinophilia was classified as mild (0.5–1.5 K/μL) or hypereosinophilia (HE, >1.5 K/μL). Patients with eosinophilia were matched 1:1 to controls with normal eosinophil counts based on age, sex, and follow-up duration. Results: Among 93,320 patients (46,660 with eosinophilia and 46,660 controls), thromboembolic events occurred in 20.9% of eosinophilic patients vs. 9.8% of controls. Eosinophilia was independently associated with thrombosis (OR = 1.33; 95% CI, 1.28–1.38; p < 0.0001), with increased risk from counts ≥ 0.7 K/μL. Mortality was also higher among eosinophilic patients (HR = 1.17; 95% CI, 1.13–1.20; p < 0.0001). Conclusions: Eosinophilia is associated with increased thromboembolic and mortality risk, highlighting the importance of eosinophil monitoring in clinical practice.