Hypophosphatemic osteomalacia induced by intravenous iron therapy: a case report.

OBJECTIVE: Osteomalacia is an uncommon, overlooked and debilitating metabolic bone disease with numerous aetiologies. Herein, we report an atypical cause of osteomalacia - intravenous iron therapy. METHODS: Description of a case report of hypophophatemic osteomalacia induced by ferric carboxymaltose infusions. RESULTS: A 70-year-old male with Rendu-Osler-Weber syndrome requiring repeated infusions of ferric carboxymaltose was admitted for disabling lower limb pain associated with persistent hypophosphatemia (1.6mg/dL) and increased urinary fractional excretion of phosphate (43%, UP04=118.3mg/dL), serum fibroblast growth factor 23 (324UA/mL), intact parathyroid hormone (110pg/mL) and bone alkaline phosphatase (40.1mcg/L). X-ray and CT of the feet showed severe diffuse bone demineralization. Feet MRI displayed a subchondral fracture of the cuneiform-navicular joints. Spine X-ray revealed dorsolumbar vertebral flattening. Somatostatin receptor PET scan excluded an occult tumor. Bone biopsy with histomorphometry confirmed the presence of osteomalacia. After excluding other causes, a diagnosis of hypophosphatemic osteomalacia induced by frequent ferric carboxymaltose infusions was made. The iron formulation was replaced by saccharated ferric oxide infusions and progressive titration of calcitriol up to 1.5mg/day and oral disodium phosphate up to 5740mg/day was started. After 6 months, there was a clear clinical and analytical improvement. CONCLUSION: Osteomalacia may be a consequence of prolonged hypophosphatemia induced by recurrent ferric infusions, which is an uncommon and neglected bone adverse event of this therapy. Phosphate levels and bone symptoms should be monitored during repetitive iron infusions, maintaining a high level of suspicion for osteomalacia as it is important to identify and treat it in a timely manner, minimizing its severe morbidity.

Characteristics associated with poor COVID-19 outcomes in people with psoriasis, psoriatic arthritis and axial spondyloarthritis: data from the COVID-19 PsoProtect and Global Rheumatology Alliance physician-reported registries.

OBJECTIVES: To investigate factors associated with severe COVID-19 in people with psoriasis (PsO), psoriatic arthritis (PsA) and axial spondyloarthritis (axSpA). METHODS: Demographic data, clinical characteristics and COVID-19 outcome severity of adults with PsO, PsA and axSpA were obtained from two international physician-reported registries. A three-point ordinal COVID-19 severity scale was defined: no hospitalisation, hospitalisation (and no death) and death. ORs were estimated using multivariable ordinal logistic regression. RESULTS: Of 5045 cases, 18.3% had PsO, 45.5% PsA and 36.3% axSpA. Most (83.6%) were not hospitalised, 14.6% were hospitalised and 1.8% died. Older age was non-linearly associated with COVID-19 severity. Male sex (OR 1.54, 95% CI 1.30 to 1.83), cardiovascular, respiratory, renal, metabolic and cancer comorbidities (ORs 1.25-2.89), moderate/high disease activity and/or glucocorticoid use (ORs 1.39-2.23, vs remission/low disease activity and no glucocorticoids) were associated with increased odds of severe COVID-19. Later pandemic time periods (ORs 0.42-0.52, vs until 15 June 2020), PsO (OR 0.49, 95% CI 0.37 to 0.65, vs PsA) and baseline exposure to TNFi, IL17i and IL-23i/IL-12+23i (OR 0.57, 95% CI 0.44 to 0.73; OR 0.62, 95% CI 0.45 to 0.87; OR 0.67, 95% CI 0.45 to 0.98; respectively; vs no disease-modifying antirheumatic drug) were associated with reduced odds of severe COVID-19. CONCLUSION: Older age, male sex, comorbidity burden, higher disease activity and glucocorticoid intake were associated with more severe COVID-19. Later pandemic time periods, PsO and exposure to TNFi, IL17i and IL-23i/IL-12+23i were associated with less severe COVID-19. These findings will enable risk stratification and inform management decisions for patients with PsO, PsA and axSpA during COVID-19 waves or similar future respiratory pandemics.