Genetic predispositions in children with primary immunodeficiency and lymphoma: Experience from king hussein cancer center

Abstract Introduction: Primary immunodeficiencies (inborn errors of immunity) confer susceptibility to recurrent infections and malignancies—particularly B-cell lymphomas—due to immune surveillance deficits and poor control of oncogenic viruses such as Epstein-Barr virus. Moreover, lymphoma arising in a PID patient complicates management, making treatment challenging and necessitating tailored chemotherapy and vigilant supportive care. Methods: In this retrospective single-center study, we identified 17 pediatric patients with lymphoma and concurrent primary immunodeficiency. All patients met ≥1 criterion of the McGill Interactive Pediatric OncoGenetic Guidelines (MIPOGG) for cancer predisposition and were referred to our Pediatric Cancer Predisposition Clinic. Each patient underwent targeted next-generation sequencing using a primary immunodeficiency gene panel. Lymphoma subtype, specific immunodeficiency diagnosis, and survival status were recorded alongside any treatment modifications (dose reductions, prophylaxis). Clinical data, genetic findings, and outcomes were analyzed descriptively. Results: Seventeen children (10 males, 7 females) with primary immunodeficiency and lymphoma were identified, including 7 Hodgkin lymphoma (HL) and 10 non-Hodgkin lymphoma (NHL) cases. The median age at lymphoma diagnosis was 8 years (range 2–17). Pathogenic or likely pathogenic homozygous variants were identified in four genes—ATM (n=2 patients), DCLRE1C (Artemis, n=3), RASGRP1 (n=1), and STK4 (n=1). The remaining 10 patients carried variants of uncertain significance in the following genes: ITK (n=3), RASGRP1 (n=1), TNFRSF9 (CD137, n=1), DOCK8 (n=1), FOXI3 (n=1), PLCG2 (n=1), IRF8 (n=1), and PIK3CD (n=1). These genetic findings corresponded to a range of primary immunodeficiency disorders, from severe combined immunodeficiencies (e.g., Artemis-SCID) and DNA repair disorders (Ataxia-Telangiectasia) to immune dysregulation syndromes (e.g., activated PI3K-delta syndrome and PLCG2-associated PLAID). Most patients received reduced-intensity chemotherapy protocols due to their immunodeficiency, along with supportive therapy such as monthly intravenous immunoglobulin (IVIG), antimicrobial prophylaxis, and rituximab for Epstein-Barr virus reactivation. Despite these measures, outcomes were poor: at last follow-up, only 7 of 17 patients (41%) were alive in remission (3 of 7 HL and 4 of 10 NHL), while 10 had died (mostly from infections). Conclusion: Survival for children with lymphoma and PID was worse than for immunocompetent patients. Our findings underscore the need to screen newly diagnosed pediatric lymphoma cases for underlying immunodeficiency (especially in consanguineous families or those with recurrent infections). Early identification enables tailored chemotherapy, infection prophylaxis, and timely transplantation to improve outcomes.