RESUMO
The involvement of ß-amyloid (Aß) in the pathogenesis of amyotrophic lateral sclerosis (ALS) has been widely discussed and its role in the disease is still a matter of debate. Aß accumulates in the cortex and the anterior horn neurons of ALS patients and seems to affect their survival. To clarify the role of cerebrospinal fluid (CSF) Aß 1-42 and Aß 42/40 ratios as a potential prognostic biomarker for ALS, we performed a retrospective observational study on a cohort of ALS patients who underwent a lumbar puncture at the time of the diagnosis. CSF Aß 1-40 and Aß 1-42 ratios were detected by chemiluminescence immunoassay and their values were correlated with clinical features. We found a significant correlation of the Aß 42/40 ratio with age at onset and Mini Mental State Examination (MMSE) scores. No significant correlation of Aß 1-42 or Aß 42/40 ratios to the rate of progression of the disease were found. Furthermore, when we stratified patients according to Aß 1-42 concentration and the Aß 42/40 ratio, we found that patients with a lower Aß 42/40 ratio showed a shorter survival. Our results support the hypothesis that Aß 1-42 could be involved in some pathogenic mechanism of ALS and we suggest the Aß 42/40 ratio as a potential prognostic biomarker.