In regression analyses, with NfL as response variable, we found that NfL levels increased with increasing CSF concentrations of anti-NR2 antibodies in both SLE (B 1.26, 95% CI 0.83–1.69, p < 0.001) and pSS patients (B 0.54, 95% CI 0.24–0.84, p = 0.001) (Fig. 3). Here, NEFL is linked to systemic lupus erythematosus.