Background

Chronic fatigue is common in psoriasis, and heat shock proteins (HSP) have been postulated to influence fatigue.

Objective

To evaluate gene expression patterns of selected HSPs in psoriasis patients with high versus low fatigue.

Methods

Fatigue was assessed using the fatigue Visual Analoge Scale and disease activity by the Psoriasis Area and Severity Index. Peripheral blood transcriptional profiles (RNA-seq) of HSP genes from 10 patients with high fatigue were compared with 10 patients with low fatigue. HSPB11, HSPBAP1, HSPA14, HSPA9P1, HSP90B1 and HSP90AB1 contributed most to separation of the two groups in a principal component analysis. Four of these genes (HSPB11, HSPA14, HSP90B1, HSP90AB1) were further investigated by reverse transcription quantitative real-time polymerase reaction (RT-qPCR) in 20 patients with high and 20 with low fatigue scores.

Results

Both RNA-seq and RT-qPCR analyses revealed a tendency to higher expression levels of HSPB11 and lower expression of HSP90B1 in the high fatigue group versus the low fatigue group. Psoriasis disease activity had no influence on the expression levels of the studied HSP genes.

Conclusion

Overall, the results suggest that some HSPs are involved in generation of fatigue in psoriasis supporting the hypothesis that downregulatory innate immune responses influence fatigue.