A preliminary study about neurofilament light chain and tau protein levels in psoriasis: Correlation with disease severity

BACKGROUND: Studies investigating cognitive dysfunction in psoriatic patients remain inconclusive. OBJECTIVE: To investigate the risk of cognitive decline in plaque‐type psoriasis patients. METHODS: Serum neurofilament light chain (NFL) and tau protein concentrations in 45 patients with plaque‐type psoriasis and forty‐five healthy controls were measured by enzyme‐linked immunosorbent assay (ELISA). RESULTS: Mean homeostasis model assessment (HOMA‐IR) values (6.82 vs 3.25) and serum levels of insulin (28.19 vs 15.71), NFL (5.74 vs 1.98), and tau (348.17 vs 207.30) in patients with psoriasis were found to be significantly higher than those of in healthy controls. There was a significant positive correlation between NFL and tau (r = .257, P = .015). There was significant correlation between NFL, tau and PASI (r = .310, P = .040) and (r = .383, P = .010), respectively. Significant correlations between NFL and insulin, TC, HDL‐C, TG, VLDL‐C, and BMI were found. NFL (9.38 vs 3.08) and tau (439.28 vs 281.58) concentrations and PASI values (23.94 vs 14.18) in patients with disease onset before 40 years were significantly higher than that of the patients with disease onset after 40 years. C‐reactive protein (CRP) was significantly correlated with BMI (r = .449, P < .001), LDL‐C (r = .240, P = .026), TG (r = .244, P = .024), and VLDL‐C (r = .241, P = .025) in patients with psoriasis. CONCLUSIONS: Increased serum NFL and tau protein levels and the presence of positive correlations between NFL, tau protein and PASI score show cognitive decline risk may be higher in moderate‐to‐severe psoriasis.