White blood cells could predict AMD

An increased level of white blood cells can predict the risk of developing early age-related macular degeneration (AMD), according to findings published recently in the American Journal of Epidemiology.

The Blue Mountains Eye Study, carried out by Anoop Shankar, MD and colleagues, looked at the association between markers of systemic inflammation and the development of AMD. The baseline white blood cell level was measured in 3,654 subjects aged between 49 and 97, who were then followed for up to 10 years for the development of both early and late AMD.

The results showed that subjects in the highest white blood cell count tertile (>6.7 billion cells/L) were 85% more likely to develop AMD than those in the lowest tertile (no greater than 5.5 billion cells/L). This was seen in all types of early AMD lesions, including soft indistinct or reticular drusen and incident pigmentary abnormalities, and also in gender and smoking subgroup analyses.

The study concluded that an increased white blood cell count can be used to identify individuals who are at greater risk of developing AMD, independent of possible confounding factors such as smoking and gender. The researchers claim that the findings provide important evidence of a link between inflammation, thought to play a key role in the pathogenesis of AMD and AMD development.