In the first of these studies, Swardfager andfellow workers analysed the results of 40 studies and reported a higherinflammatory status, evidenced by elevated levels of interleukin 6 (IL-6), IL-12,tumour necrosis factor-alpha (TNF-α), IL-1β and IL-18, compared with age- andsex-matched healthy controls [37].These results have been confirmed in a more recent meta-analysis of 175 studiesinvolving 13,344 AD patients and 12,912 healthy controls conducted by Lai andothers [70]. Here, TNF is linked to Alzheimer disease.