Endocrine Abstracts

Introduction: HIV infection has been associated with bone loss and increased frequency of bone fractures. The main pathogenetic mechanisms involve the direct effect of the virus and the HIV-induced inflammatory cytokines on bone metabolism, the effect of antiretroviral therapy (cART) per se and the frequently coexisting nutritional disorders and hypogonadism, further accelerating bone loss. Bisphosphonates remain the first-line treatment for these patients. Limited data are available for the safety and efficacy of denosumab while the effect of teriparatide is largely unknow in this population with only one case report described in literature.

Aim: To study the effectiveness and safety of teriparatide in osteoporotic patients with HIV infection.

Methods: This is a 36-month follow-up study. Subcutaneous teriparatide 20 mg was administered once daily for 24 months in three patients (two females and one male aged 68, 54 και 33 years, respectively). In two patients teriparatide was administered after vertebral fractures while on bisphosphonates therapy whereas in the third the agent was initiated after completing a 10-year treatment with risedronate. All patients received adequate calcium and vitamin D supplementation. Laboratory and imaging evaluation with DEXA of lumbar spine (L1-L4) and hip were performed before treatment initiation, at 24, and at 36 months. All patients had well controlled HIV infection (CD4 cell count >500 cells/ μl; undetectable viral load) under сART including tenofovir alafenamide.

Results: At 24 months a significant increase in BMD was observed in the lumbar spine (L2-L4) in all three patients: in the two females [percentage increase 9.4 and 18.4, respectively] and in the male [percentage increase 11.4], while a moderate increase was documented in total hip only in one female and the male [percentage increase 2.2 and 3.2, respectively]. At 36 months, thus one year since completing teriparatide treatment, two patients (68-year-old female and the male) showed further increase in bone density, especially in the lumbar spine (L2-L4) [percentage increase 11 and 3.1, respectively] and to a lesser extent in the total hip in the female [percentage increase 6.9]. CD4 cell count and viral load remained unaffected throughout the study. Additionally, none of the patients developed hypercalcemia during the treatment period, nor did they present any other biochemical or hormonal disturbances.

Conclusions: Teriparatide administration in osteoporotic patients with HIV infection, after bisphosphonate failure, seems to have a favorable impact on bone density. Further studies are needed to confirm the long-term effectiveness and safety of teriparatide in this population.