Fig. 4
Increased endocannabinoid levels in cerebrospinal fluid of young but not old relapsing-remitting MS patients compared to age and sex matched control patients. Comparison of analytes in serum and CSF of relapsing-remitting (RRMS) patients with age and sex matched controls sorted by the median age of 39 years into young and old patient populations. (a) Analyte levels are represented as fold change with the median ratio of analyte levels in samples of RRMS patients divided by analyte levels of age and sex matched control (Ctrl) patients in serum and CSF presented in a heatmap. The color-coding legend of the heatmap is shown at the bottom and reaches from 0.25 (blue, indicative for reduction of MS patient analyte level to a quarter of the analyte level in the Ctrl patients), over 1 (white, comparable analyte levels between MS and Ctrl patients) to 4 (yellow, analyte levels are four times higher in MS compared to Ctrl patients). Significant differences between analytes of RRMS and Ctrl patients are labelled in bold (n.d., not detectable). (b) Example graphs of analytes in CSF of young Ctrl patients (21 females, 7 males), young RRMS patients (21 females, 7 males), old Ctrl patients (21 females, 9 males) and old RRMS patients (21 females, 9 males). Data are presented as box plots with median and the 25–75% percentile as box with the range as whiskers. The mean is additionally depicted as + and the analyte level of each patient is represented as one data point (symbol). The number of patients where an analyte level was lower than the limit of quantification (LOQ) is indicated for each group if applicable. For statistical analysis a Mann-Whitney test was performed. Statistically significant differences are indicated as follows: * p < 0.05 and ** p < 0.01. (c) Example scatterplots of the Spearman correlations between CSF analytes and age of RRMS patients and matched control patients (Ctrl). The Spearman r and the p-values of the correlation are indicated in the top left of the graphs and labelled bold if significant (p < 0.05). Additionally, a simple linear regression is shown with 95% confidence bands of the best-fit line with the coefficient of determination (R2) indicated in the top right and labelled bold in case the slope is significantly non-zero (p < 0.05)