Fig 1: Validation of proteome findings in the cerebrospinal fluid (CSF). sVCAM-1, chitotriosidase 1 (CHIT1), and cathepsin C (CTSC) concentration were determined by ELISA in paired (A–F) CSF and (G–L) serum samples from HTLV-1-infected individuals identified according to their clinical status as HTLV-1 asymptomatic carriers (AC) (n=13) and HAM/TSP patients (n=21). The CSF (n=9) and serum samples (n=5) from individuals with non-inflammatory and non-infectious neurological diseases were used as a control. HAM/TSP patients were also subdivided according to the speed of disease progression as very slow (n=6), typical (n=9) and rapid (n=6). The statistical analysis was performed with Kruskal-Wallis test, followed by Dunn’s posthoc test. Unadjusted p-values were used and differences with p < 0.05 were considered significant. (M–O) The association of the HAM/TSP progression index, defined by the speed of neurological deterioration in the IPEC-2 disability scale and the time of disease, and the CSF levels of CHIT1, sVCAM-1, and CTSC was evaluated by Spearman’s rank of correlation analysis, and p-values < 0.05 were considered significant.