The role of oxidative stress in bone tissue in the pathogenesis of osteopenia in patients with chronic lymphocytic leukemia

Introduction. A decrease in bone mineral density (BMD), the development of osteopenia and osteoporosis is observed in patients with chronic lymphocytic leukemia (CLL). Patients with CLL are at a higher risk of developing fractures due to osteoporosis compared to healthy age-matched individuals. The pathogenesis of the osteodestructive process in CLL has been poorly studied and may be associated with excessive generation of reactive oxygen species and/or inhibition of antioxidant defense.Aim: to investigate the relationship between indicators of oxidative stress in bone tissue and indicators of osteopenia in patients with CLL.Materials and methods. The study included 48 male patients with CLL aged 50–70 years, divided into group 1 (n = 34) without signs of osteopenia and group 2 (n = 14) with signs of osteopenia based on osteodensitometry (T-score from –1.0 SD to –2.5 SD). BMD, T- and Z-scores were assessed in the lumbar spine, proximal femoral neck (PFC), and proximal femur. In the bone tissue homogenate, the content of products of oxidative modification of proteins (OMP) was determined spectrophotometrically in spontaneous and metal-catalyzed modes, reserve-adaptation potential, and general antioxidant status.Results. Osteopenia was detected in 30 % of patients with CLL according to osteodensitometry in the neck of the proximal femur. In patients with CLL and osteopenia, signs of oxidative stress were observed in the bone tissue: early OMP products of a neutral and basic nature, late products of a neutral nature accumulated in the spontaneous detection mode; early and late OMP products of a neutral and basic nature accumulated in the induced mode; reserve-adaptive potential, the general antioxidant status decreased. Signs of osteopenia in the PFC in patients with CLL in the femoral neck increased as the content of early and late OMP products in the bone tissue increased in spontaneous and metal-induced detection modes, and the general antioxidant status in the bone tissue decreased.Conclusion. Based on the data obtained, it is possible to modernize diagnostic criteria and therapeutic approaches.