Hypophosphatemic osteomalacia associated with tenofovir: a multidisciplinary approach is required.

• Main Authors: Giuseppe Vittorio De Socio, Gianluigi Fabbriciani, Marco Massarotti, Salvatore Messina, Enisia Cecchini, Bianca Marasini
• Format: Article
• Language: English
• Published: PAGEPress Publications 2012-01-01
• Series: Mediterranean Journal of Hematology and Infectious Diseases
• Subjects: Tenofovir; HIV infection; Hypophosphatemia; Alkaline phosphatase; Pseudofractures.
• Online Access: http://www.mjhid.org/article/view/9950

<p class="MsoNormal" style="margin: 6pt 0cm 0pt; line-height: 200%; mso-layout-grid-align: none;"><span style="mso-ansi-language: EN-GB;" lang="EN-GB"><span style="font-size: small;"><span style="font-family: Times New Roman;">Tenofovir is widely used as first-line treatment of HIV infection, although its use is sometimes complicated by a reversible proximal renal tubulopathy. </span></span></span></p><p class="MsoNormal" style="margin: 6pt 0cm 0pt; line-height: 200%; mso-layout-grid-align: none;"><span style="font-family: Times New Roman;"><span style="font-size: small;"><span style="mso-ansi-language: EN-GB;" lang="EN-GB">We report the case of a 45-year-old woman with chronic HIV infection and personality disorder, who after 12 months of tenofovir, complained of fatigue, diffuse bone pain and gait disturbances. The elevated level of alkaline phosphatase, hypophosphatemia and inappropriate phosphaturia suggested the diagnosis of hypophosphatemic osteomalacia secondary to proximal renal tubulopathy.</span><span style="mso-ansi-language: EN-US;" lang="EN-US"> A dual-energy x-ray absorptiometry showed a bone mineral density below the expected range for age (lumbar spine Z-score -3.3, femoral neck Z-score -2.1).</span></span><span style="mso-ansi-language: EN-GB;" lang="EN-GB"><span style="font-size: small;"> A whole body </span><sup><span style="font-size: x-small;">99m</span></sup><span style="font-size: small;">Tc-methylene diphosphonate bone scan showed multiple areas of increased focal activity in the </span></span><span style="font-size: small;"><strong><span style="font-weight: normal; mso-ansi-language: EN-US; mso-bidi-font-weight: bold;" lang="EN-US">lumbar and thoracic spine and in sacroiliac and hip joints </span></strong><span style="mso-ansi-language: EN-GB;" lang="EN-GB">consistent with pseudo-fractures. Two months after tenofovir discontinuation and administration of vitamin D and phosphate, osteomalacia-related symptoms disappeared. Eleven months later, bone and mineral metabolism data were normal and bone scintigraphy did not show any pathological findings. </span></span></span></p><p class="MsoNormal" style="margin: 6pt 0cm 0pt; line-height: 200%; mso-layout-grid-align: none;"><span style="mso-ansi-language: EN-GB;" lang="EN-GB"><span style="font-size: small;"><span style="font-family: Times New Roman;">This report highlights the importance of considering the diagnosis of osteomalacia in patients treated with tenofovir and emphasizes the need for monitoring alkaline phosphatase, blood and urinary phosphate and creatinine, especially in patients with risk factors for bone disease.</span></span></span></p>