Elevated IL-6 and TNF-alpha levels in patients with ALS: inflammation or hypoxia?

Abnormal levels of interleukin (IL)-6 were described in patients with ALS, related to an inflammatory process. The authors compared IL-6 and tumor necrosis factor alpha (TNF-alpha) levels in CSF and sera from 10 hypoxemics and 10 normoxemics patients with ALS to those of 10 hypoxemics and 10 normoxemics neurologic controls. The same pattern exists in patients with ALS and controls: the highest levels are found in hypoxic conditions and undetectable levels are found in normoxemic conditions. Elevated IL-6 levels in ALS could correspond to a normal response to hypoxemia.