Читать книгу Blood and Marrow Transplantation Long Term Management - Группа авторов - Страница 153

Hematopoietic HSCT can induce bone loss and osteoporosis via the toxic effects of TBI, chemotherapy, iatrogenic hypogonadism and may be compounded by prolonged inactivity of patients after HSCT [43, 44]. Osteopenia and osteoporosis are characterized by a reduced bone mass and increased susceptibility to bone fracture. These conditions are distinguished by the degree of reduction in bone mass and can be quantified on dual energy X‐ray absorptiometry. The cumulative dose and number of days of glucocorticoid therapy, and the number of days of cyclosporine or tacrolimus therapy showed significant associations with loss of bone mass. Non‐traumatic fractures occurred in 10% of patients. Using WHO criteria, nearly 50% of patients after HSCT have low bone density, one third have osteopenia and approximately 10% have osteoporosis by 12–18 months after HSCT.

Few studies on the safety and efficacy of bisphosphonate for prevention of bone loss after HSCT have been reported. Results of a randomized study in adult allogeneic HSCT recipients showed less bone loss in patients receiving additional pamidronate (60 mg before and 1, 2, 3, 6, and 9 months after HSCT) compared to patients receiving 1000 mg calcium carbonate and 800 IU vitamin D daily, and estrogen (women) or testosterone (men) alone. In a retrospective study of pediatric HSCT recipients, treatment with bisphosphonates was well tolerated and was associated with improvement in BMD [45]. Preventive measures of bone loss after HSCT are indicated. Many experts recommend the use of anti‐resorptive treatments (gonadal hormonal replacement or bisphosphonates) in patients with gonadal failure and with cGVHD requiring treatment with glucocorticoid [46]. Hormone replacement after HCT should be individualized with the pros and cons discussed carefully with each patient before initiation of replacement and reassessed at least yearly if treatment is continued beyond 1–3 years after HCT. Increased risk of breast cancer, coronary heart disease (CHD), stroke, and venous thromboembolism was reported in the Women's Health Initiative (WHI) study (non‐transplanted women older than 50 years) with continuous combined estrogen‐progestin replacement versus placebo, for an average of 5.2 years. Nonetheless, this study also showed a significantly reduced risk of bone fractures and colon cancer [47].