Explain Kashin Beck disease caused by selenium deficiency?

Kashin Beck disease was identified to affect growing children in parts of Siberian Russia and China. It is characterized by osteoarthritis involving degeneration and necrosis of the joints and epiphyseal-plate cartilages of legs and arms. It is possible that apart from selenium deficiency, many other factors may be contributing to the development of Kashin Beck's disease. Suboptimal selenium status may be widespread in human population. It is accompanied by loss of immuno-competence with the impairment of both cell-mediated immunity and β-cell function.

The early preclinical stages of development of human immune deficiency virus (HIV) infection are accompanied by a very marked decline in plasma selenium. Subclinical malnutrition assumes increased significance during the development of acquired immune deficiency syndrome (AIDS). Selenium supplementation in subjects has been shown to mark immuno-stimulant effects including increased proliferation of activated T-cells. In addition, as selenium has well recognized anti-oxidant and anti-inflammatory roles, other oxidative stress or inflammatory conditions such as rheumatoid arthritis, ulcerative colitis, pancreatitis may also benefit from selenium supplementation. , Further, enhancement of the virulence of virus due to selenium deficiency has been reported. There is a growing evidence that suboptimal selenium status may also increase risk of cancer and cardiovascular disease. However, much work is still needed in these aspects.