Characterization of adult patients with X-linked hypophosphatemia at a specialized center in Buenos Aires, Argentina.

OBJECTIVE

The study objectives were to characterize adult patients with XLH treated at a referral center, assess their physical function and the impact of X-linked hypophosphatemia (XLH) on their quality of life, and estimate their adherence to conventional treatment.

SUBJECTS AND METHODS

Observational, retrospective study of patients with XLH from a referral center in Argentina, based on demographic and clinical data, complementary methods, and validated questionnaires (WOMAC, PROMIS, and SF-36).

RESULTS

Sixteen patients (age: 40.3 ± 13.2 years; female: 87.2%) were included. All patients had clinical and/or radiological skeletal manifestations (lower limb malformations and/or pseudofractures). The prevalence of clinical fractures was 60%. Hearing loss was the most frequent extra skeletal finding (67%). The WOMAC score was 47.8 ± 26 (62.5% of patients had ≥ 40 points). The PROMIS score was 23-33 (43% of patients) and ≥ 34 in 14% of patients. Except for emotional function, the median scores of the SF-36 domains were below 50 points. Only 20% of patients had good adherence to conventional treatment.

CONCLUSIONS

Adult patients with XLH have numerous unmet needs, with frequent bone and extraskeletal complications. Physical function and quality of life scores were poor. Adherence to conventional treatment was unsatisfactory. Long-term studies are required to characterize these patients and confirm the efficacy and safety of continuous treatment, such as anti-fibroblast growth factor-23 monoclonal antibodies.