Case Of Hypophosphatemic Osteomalacia Research Articles

Middle Aged Man with Bilateral Lower Limb Weakness and Non-Traumatic Fractures: Case of Hypophosphatemic Osteomalacia

Middle Aged Man with Bilateral Lower Limb Weakness and Non-Traumatic Fractures: Case of Hypophosphatemic Osteomalacia

Two Cases of Hypophosphatemic Osteomalacia After Long-term Low Dose Adefovir Therapy in Chronic Hepatitis B and Literature Review

Adefovir dipivoxil (ADV) is a nucleotide used as long-term therapy of chronic hepatitis B. Many published reports have shown that long-term high-dose therapy with adefovir can be associated with proximal renal tubular dysfunction resulting in significant hypophosphatemia, renal insufficiency and osteomalacia. We have encountered two patients who developed evidence of hypophosphatemic osteomalacia while on long-term low-dose adefovir therapy for chronic hepatitis B. We report on its clinical features and its potential resolution with cessation of the drug and supplementation with phosphate. We also reviewed the other published cases associated with hypophosphatemic osteomalacia after low-dose adefovir therapy. The symptoms and the hypophosphatemia improved after cessation of the drug and supplementation with phosphate in most cases. Patients taking adefovir long-term should receive regular investigation of the phosphate level and renal function.

Low-dose adefovir-induced hypophosphatemic osteomalacia on whole-body bone scintigraphy.

While adefovir dipivoxil (ADV) effectively suppresses the hepatitis B virus, it can cause proximal renal tubular dysfunction leading to phosphate wasting [1, 2]. The safety of low-dose ADV (a dose of 10 mg/day), which does not induce clinically significant nephrotoxicity, is well recognized, but a few cases of hypophosphatemic osteomalacia (HO) caused by low-dose ADV therapy have recently been reported [3–6]. Although HO induced by low-dose ADV therapy is rare, the presence of bone pain in patients treated with ADV should be monitored. Bone scintigraphy can be performed to confirm the occurrence of osteomalacia and to determine the disease extent. Bone scintigraphic and radiological image findings with a brief review of the literature are presented in this article. We report two cases of HO induced by low-dose ADV therapy that showed multifocal increased radiotracer uptakes in the bilateral bony ribs, spines, pelvic bones and lower extremities on whole-body bone scintigraphy (Figs. 1 and ​and2).2). Bone pain gradually improved after phosphate supplementation and by changing the antiviral agent. Fig. 1 A 44-year-old man presented with a 6-month history of diffuse musculoskeletal pain in the chest, back and both knees without antecedent trauma. The patient had a history of chronic hepatitis B infection and had received adefovir dipivoxil (ADV) (10 mg/day) ... Fig. 2 A 42-year-old man who had taken adefovir dipivoxil (ADV) (10 mg/day) for 7 years for treatment of chronic hepatitis B complained of a 2-year history of diffuse musculoskeletal pain in the anterior chest area with absence of antecedent ... Whole-body bone scintigraphy is a highly sensitive imaging tool and can show disease extent at once in the setting of the wide range of the clinical spectrum with nonspecific radiological findings [5]. Furthermore, frequent involvement of the lower extremities, as a result of maximum weight bearing, could be an additional scintigraphic clue for the diagnosis of HO [6, 7]. These cases could be helpful for both clinicians prescribing ADV and nuclear physicians to prevent delayed diagnosis and plan further appropriate treatment.

低リン性骨軟化症の１例

A case of hypophosphatemic osteomalacia was presented. A 48-year-old woman had suffered from back pain and round back deformity about for 10 years. Weakness of muscles had gradually increased. So she was admitted to a hospital because she could not walk. She was diagnosed as hypophosphatemic osteomalacia. The symptoms improved a little in spite of administration of 1α-(OH) D 0.5μg, so she was referred to our hospital in March in 1988. Radiograms showed atrophy of bone and multiple compression fracture in spine and Looser's zone in the rib and pubic bone. Renal function including %TRP were normal. Serum Ca, K and 25 (OH) D were within normal limits. Serum Al-p was higher than the normal limit. Serum P and 1α-25 (OH) D were lower than the normal limit. We considered that it was due to a decreased 1α-hydroxylase activity and treated her with 4.5μ of 1α-(OH) D. This therapy was effective and the symtoms of this case gradually improved.

低リン血症性骨軟化症に仙腸関節炎および骨肥厚を伴った同胞例

Two cases of hypophosphatemic osteomalacia who have not been treated with vitamin D are presented. Case 1. A 27-year-old man was admitted to our hospital because of severe bow leg and bilateral knee pain. From infancy slightly bow leg was noted and his height increased slowly. He had lower leg pain from the age of 12 years. At 21 years old, osteotomy of his right tibia was performed to correct bow log deformity at the other hospital. Roentgenographic study discloses pseudofracture (Looser's zone) in right tibia, hyperostosis of cranial vault, ribs, clavicles, long and short tubular bones and features of sacro-iliitis.Laboratory investigation shows hypophosphatemia, hyperalkaline phosphatasemia and normal calcemia. We perfomed corrective osteotomy of bilateral tibiae. Histological examination of bone shows the accumulation of osteoid. Case 2. is a 31-year-old, elder sister of Case 1. Clinical and roentgenographic features of this case resembles those in Case 1, except that spondyloarthritic features are more prominet than in Case 1.