RESUMO
OBJECTIVE: To evaluate prospectively the efficacy of bisphosphonate treatment in infants with severe forms of osteogenesis imperfecta (OI). STUDY DESIGN: Of 10 children (6 females) with OI type III, 5 (group A) started treatment (2 mg/kg neridronate administered intravenously for 2 consecutive days, every 3 months) just after diagnosis at birth and 5 (group B) after 6 months. Ten untreated children, matched for sex, age, and clinical severity of OI, constituted a historical control group (group C). We measured weight, length, and number of fractures every 3 months and serum and urinary levels of calcium, phosphorus, creatinine, serum alkaline phosphatase, 25-hydroxyvitamin D, insulin-like growth factor I, parathyroid hormone, and osteocalcin, urinary type I collagen N-terminal telopeptide, and lateral radiography of vertebral column every 6 months. RESULTS: Group A had better growth and a lower incidence of fractures than groups B and C in the first 6 months of treatment. In the second 6 months, both groups A and B had lower fracture rates than group C. After 12 months of therapy, osteocalcin and insulin-like growth factor I levels significantly increased only in group A. The urinary Ca/Cr ratio and N-terminal telopeptide/Cr ratio significantly declined only in treated patients. Vertebral body area and the structure of vertebral bodies improved in all treated patients, but especially in group A. CONCLUSIONS: Cyclical neridronate treatment, started just after diagnosis at birth, had positive effects on growth and fracture rate.
