Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease which
leads to death in a median time of 2–3 years. Inflammation has been claimed important
to the ALS pathogenesis, but its role is still not well-characterized. In the present study, a
panel of five cytokines (IL-2, IL-6, IL-10, IFN-gamma, and TNF-alpha)measured in plasma
has been investigated in ALS. These biomarkers of inflammation were measured in a
population-based cohort of 79 patients with ALS and 79 age- and sex-matched healthy
controls using the Bio-Plex technology (Bio-Rad). All the five cytokines were significantly
increased in plasma samples of patients compared with controls (p < 0.0001), with IL-6
having the highest median concentration (10.11 pg/ml) in the ALS group. Furthermore,
IL-6 was the plasma cytokine with the highest discrimination ability between patients and
controls according to the receiver operating characteristic analysis (area under the curve
= 0.93). At a cut-off point of 5.71 pg/ml, it was able to classify patients and controls with
91% of sensitivity and 87% of specificity. In the ALS group, plasma IL-6 concentration
correlated with demographic (age: rs = 0.25, p = 0.025) and clinical (revised ALS
Functional Rating Scale at evaluation: rs = −0.32, p = 0.007; Manual Muscle Testing: rs
=−0.33, p=0.004; progression: rs=0.29, p=0.0395) parameters. In line with previous
studies, our results confirm that inflammatory cytokines are elevated in ALS, supporting
a possible role of inflammation in disease mechanism and progression. However, the
precise role of inflammation in ALS needs to be further investigated on larger samples
and with more mechanistic studies
