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.

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.