Malignancy in Adults with Inborn Errors of Immunity: A Retrospective Single-Center Study.

Inborn Errors of Immunity (IEI) often lead to recurrent infections, immune dysregulation, and an increased risk of malignancies. Due to the heterogeneity in IEI presentations, personalized monitoring is essential for early detection of non-infectious complications. This study aims to document the characteristics and prevalence of malignancies in IEI patients. A retrospective review of 355 patients diagnosed with IEI at the Adult Allergy and Immunology Clinic of Ege University was conducted. Data on demographics, clinical presentations, laboratory results, and immunological and genetic profiles of patients with malignancies were analyzed.  RESULTS: A total of 40 patients with neoplasia (F/M: 18/22; median age: 51.58 years, range: 18-91) were evaluated. The median ages at IEI symptom onset, diagnosis, and neoplasm diagnosis were 16.5, 45, and 39.5 years, respectively. Malignancy was diagnosed in 60% of patients before IEI, with referrals for low immunoglobulin levels and/or severe infections, and for a genetic profile suggestive of immunodeficiency. The prevalence of malignancy in the overall cohort was 10.42% (37/355), while it was significantly higher in the common variable immunodeficiency (CVID) subgroup, reaching 20.44% (28/137). Lymphoma was the most common malignancy at 45.9%, primarily non-Hodgkin lymphoma (NHL) at 40.5%, with diffuse large B-cell lymphoma (DLBCL) as a key subtype; carcinomas were the second most common at 35.1%. Hematologic malignancies were significantly more frequent among patients with CVID (90.5%), whereas non-hematologic malignancies predominated in the non-CVID group (77.8%) (p = 0.024). Lymphoproliferation was more common in hematologic malignancies (85.7%) compared to non-hematologic malignancies (25.0%) (p < 0.001). Genetic variants were identified in 61% of cases, with 37% classified as pathogenic or likely pathogenic, including variants in TNFRSF13B/TACI, CCDC40, PLCG2, ATM, CARD11, CHEK2, CNV, COPB1, HPS5, LYST, MAPK8IP1, NBS1, NF1, NFKBIA, PI4KA, POLE, SPI1, and TAP2. Findings confirm that NHL, particularly DLBCL, is the most prevalent malignancy in this cohort. Given the link between malignancies and underlying IEI, immunologic evaluation is recommended, particularly for NHL patients. The observed predominance of hematologic malignancies among CVID patients and the association with lymphoproliferation further emphasize the need for heightened malignancy surveillance and early immunologic workup in this subgroup. Further research on biomarkers for malignancy prediction in IEI is warranted.