As haematologists and paediatric oncologists, we are frequently the first specialists to evaluate patients presenting with unexplained cytopenias, persistent lymphadenopathy, or treatment-resistant malignancies. Primary care physicians and other specialists rely on us to assess complex haematologic abnormalities, from severe anaemia in young children to recurrent thrombocytopenia in adolescents and aggressive lymphoproliferative disorders. However, these conditions may not always be isolated haematologic disorders or malignancies. There may be more to the patient story.
We now know that immune dysregulation plays a major yet often overlooked role in haematologic disease. Patients with inborn errors of immunity (IEI /primary immunodeficiencies) not only have dysfunctional immune responses but are also at high risk of haematologic malignancies, chronic cytopenias, and therapy-related complications.
These conditions often first present as haematologic/oncological abnormalities, yet their immunologic origins remain undiagnosed for months or even years. This leads to delays in appropriate treatment and missed opportunities for targeted therapies that could dramatically improve patient outcomes.
But beyond that first diagnosis, even when a patient’s immune defect is known, haematologists and oncologists must work closely with immunologists. Many oncology treatments induce profound secondary immunodeficiencies, significantly increasing the risk of infections, autoimmune complications, and treatment-related toxicities. Managing these patients effectively requires a multidisciplinary approach, ensuring that both the malignancy and the immune dysfunction are addressed in parallel.
The Immunodeficiency–Malignancy Link: What Every Haematologist and Oncologist Needs to Know
Recent data from the ESID Registry, which has tracked over 30,000 patients, underscores a crucial fact: immune deficiencies are not just about infections – they are directly linked to bone marrow failure, autoimmune haematologic diseases, and malignancies such as lymphoma and leukaemia. Understanding these connections is essential for haematologists and oncologists because:
- You see these patients first. A child with refractory immune thrombocytopenia (ITP) may not just have an isolated platelet disorder, it could be the first sign of an underlying immune defect like ALPS or CTLA-4 deficiency.
- The underlying genetics matter. Many IEIs involve mutations in key immune regulatory genes, such as STAT3, CTLA4, and GATA2, which not only predispose to immunodeficiency but also dramatically impact blood cell production and cancer risk.
- Treatment choices can be game-changers. Conventional chemotherapy and immunosuppressants may worsen an undiagnosed immunodeficiency, while targeted therapies like JAK inhibitors, CTLA-4 agonists, or HSCT may offer better outcomes, but only if the immune defect is recognized.
- Oncology therapies create new immune challenges. Secondary immunodeficiencies due to chemotherapy, HSCT, or immunotherapy leave patients vulnerable to life-threatening infections, autoimmune complications, and relapse. Collaborating with immunologists is critical to balancing oncologic treatment with immune support.
The challenge for haematologists and oncologists is not just knowing when to suspect an underlying immunodeficiency, but also how to integrate immunology expertise into cancer care.
Could the unexplained cytopenia in your patient be immune-driven? Is the relapsing lymphoma actually linked to a DNA repair defect? Is your chemotherapy protocol worsening an undiagnosed immune deficiency? These are the key questions shaping the future of haematology-oncology.
A Unique Opportunity at ESID EHA SIOPE 2025: Breaking Down Silos in Patient Care
The ESID-EHA-SIOPE 2025 Focused Symposium in Vienna offers haematologists and oncologists a vital platform to collaborate with immunologists on the complex interplay between immunodeficiencies, haematologic disorders, and paediatric oncology. Through multidisciplinary case discussions, targeted sessions, and expert-led panels, the symposium will refine diagnostic strategies, explore emerging therapies, and address the challenges of secondary immunodeficiencies in cancer patients. This cross-specialty learning will improve early recognition of immune-driven haematologic disease and foster new collaborations, shaping the future of integrated, patient-centred care.
Vienna Awaits You
Join us 18-20 November to enhance your understanding and foster essential cross-specialty connections that will shape the future of patient care.