The physical health and quality of life of patients with X-linked agammaglobulinaemia in England and Wales

Abstract

Background Patients with X-linked agammaglobulinaemia (XLA) have absent peripheral circulating Blymphocytes and agammaglobulinaemia caused by defects in BTK. Treatment consists of life-long immunoglobulin replacement therapy. This only contains the IgG isotype containing little or no IgA or IgM. Patients may still, therefore, experience recurrent infections and complications. Novel therapies are potentially available, most notably gene therapy and newborn screening. I aimed to examine the clinical health outcomes and quality of life for patients with XLA in England and Wales to evaluate current practices and the potential role for novel therapies. Methods This is a retrospective, longitudinal observational study of patients with a definite diagnosis of XLA (BTK mutation or absent BTK expression), in England and Wales. Retrospective clinical data were collected from patients’ records, including conversion of lung function results to Z-scores. Patients and/or their families were invited to complete questionnaires on their health-related quality of life (HRQoL) and psychological health. Results were compared against UK norms and UK patients with cystic fibrosis. Results Fifty-four patients were enrolled in the study (21 children, 33 adults). Median age at diagnosis was 2.59 years with no statistically significant improvement seen since 1990. Twenty-two patients (44%) had evidence of bronchiectasis on high-resolution computerised tomography. Patients with bronchiectasis were diagnosed with XLA significantly later than patients without bronchiectasis. Neither infection incidence nor IgG trough levels were associated with an increased risk of bronchiectasis. In the absence of bronchiectasis, XLA patients had normal HRQoL results. HRQoL was strongly correlated with respiratory symptoms and lung function. Conclusions Recurrent respiratory tract infections and bronchiectasis remain a major burden for this cohort despite modern therapy. In the absence of bronchiectasis, patients have a normal HRQoL. Curative therapy, such as gene therapy or bone marrow transplantation, may provide the only option for improving outcomes in XLA