Case report: hematopoietic stem cell transplantation in an adult patient with X-linked agammaglobulinemia and severe refractory enteropathy

Paula Teresa López-León^1,2Marta Dafne Cabañero-Navalon^1,2*Victor Garcia-Bustos^3,4Francisco Giner⁵Héctor Balastegui Martín^1,2Pedro Asensi Cantó^6,7Juan Montoro Gómez^6,7,8Olga Seguí-Cotano⁹María Argente Pla^10,9Pedro Moral Moral^1,2

• ¹Primary Immunodeficiencies Unit, Department of Internal Medicine, La Fe University and Polytechnic Hospital, Valencia, Spain
• ²Research Group of Chronic Diseases and HIV Infection, Health Research Institute La Fe, Valencia, Spain
• ³Unit of Infectious Diseases, La Fe University and Polytechnic Hospital, Valencia, Spain
• ⁴Severe Infection Research Group, Health Research Institute La Fe, Valencia, Spain
• ⁵Department of Pathology, La Fe University and Polytechnic Hospital, Valencia, Spain
• ⁶Hematology Department, La Fe University and Polytechnic Hospital, Valencia, Spain
• ⁷Hematology Research Group, Health Research Institute La Fe, Valencia, Spain
• ⁸School of Medicine and Dentistry, Catholic University of Valencia, Valencia, Spain
• ⁹Endocrinology and Nutrition Department, La Fe University and Polytechnic Hospital, Valencia, Spain
• ¹⁰Joint Research Unit on Endocrinology, Nutrition and Clinical Dietetics, Health Research Institute La Fe, Valencia, Spain

X-linked agammaglobulinemia (XLA) is a rare primary immunodeficiency characterized by absent B cells and severe hypogammaglobulinemia. While lifelong immunoglobulin replacement therapy (IgRT) effectively prevents severe infections, it does not prevent chronic complications in a subset of patients with immune dysregulation. We report the case of a young adult with genetically confirmed XLA and severe, treatment-refractory enteropathy with persistent Campylobacter jejuni and norovirus infections, who underwent successful allogeneic hematopoietic stem cell transplantation (HSCT) after exhausting all therapeutic options. Post-transplant, the patient achieved complete resolution of chronic diarrhea, clearance of enteric pathogens, and sustained independence from parenteral nutrition, with significant improvement in nutritional status, bone density, and quality of life. This case represents one of the few documented adult XLA transplants and highlights HSCT as a feasible, safe, and potentially curative option in selected patients with severe non-hematologic complications. It underscores the need to consider HSCT earlier in the disease course, especially when organ damage is progressive and irreversible. Further studies are needed to clarify indications, timing, and cost-effectiveness of HSCT in XLA.