Yazdani S, Mariosa D, Hammar N, et al. - Researchers undertook a prospective cohort analysis, with 20 years of follow-up, to investigate the associations of various blood immune biomarkers with the future risks of amyotrophic lateral sclerosis and Parkinson disease. This longitudinal cohort study—the Swedish Apolipoprotein-Related Mortality Risk study—included 812,073 participants who underwent repeat blood biomarker measurements between 1985 and 1996, and were observed until 2011. The investigators observed a lower risk of Parkinson disease in relation to increasing levels of leukocytes, haptoglobin, and uric acid. There was no statistically significant link between the examined biomarkers and amyotrophic lateral sclerosis. Relative to controls, lower levels of leukocytes and haptoglobin between 20 and 10 years prior to diagnosis and lower levels of uric acid during the 20 years prior to diagnosis seemed to be present in patients with Parkinson disease; however, statistically significant variations were only seen during parts of the respective time intervals following multivariable adjustment. Overall, the researchers’ findings implicate a distinct role of systemic inflammation on the risk of Parkinson disease vs amyotrophic lateral sclerosis, but further study in independent populations is warranted.