AUTHOR=Li Borui , Li Guangtao , Yang Xinlei , Song Zhibo , Wang Yu , Zhang Zhuoli 

TITLE=NETosis in Psoriatic Arthritis: Serum MPO–DNA Complex Level Correlates With Its Disease Activity

JOURNAL=Frontiers in Immunology

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2022.911347

DOI=10.3389/fimmu.2022.911347

ISSN=1664-3224

ABSTRACT=Background NETosis has been rarely reported in psoriatic arthritis (PsA). We aimed to explore the involvement of NETosis in the inflammation of PsA.
Methods Serum MPO-DNA complex was detected by a modified enzyme-linked immunosorbent assay (ELISA) and compared among 74 patients with PsA, 58 patients with psoriasis (PsO) and 20 healthy controls. The association of MPO-DNA level with disease activity index at baseline and follow-up was analyzed in PsA patients. Receiver operating characteristic curve was used to evaluate the predictive value of MPO-DNA for treatment response. 
Results MPO-DNA complex level in serum was significantly increased in PsA/PsO patients compared to healthy controls (p<0.001). The level of MPO-DNA was positively associated with DAPSA score and its components (including TJC, SJC, PGA, VAS-pain and CRP, r=0.25-0.409, all p-values<0.05). Serum MPO-DNA level was downregualted at 12-week after treatment compared to baseline (p=0.022). The decrease of MPO-DNA level was more dramatic in PsA patients who achieved both ACR50 and PASI50 response than those achieving neither of them at 12 weeks (p=0.023). ROC analysis revealed that the serum MPO-DNA level predicted both ACR50 and PASI50 achievement at week 12 (p=0.04, 95% CIs 0.56-0.94). Moreover, the baseline MPO-DNA level (p=0.009, 95% CIs 0.748-1) and change of MPO-DNA at week 12 from baseline (p=0.004, 95% CIs 0.802-1) were associated with the achievement of both ACR70 and PASI75 response at week 24.
Conclusions NETosis plays an important role in psoriatic diseases. The level of MPO-DNA complex in serum reflects disease activity. Serum MPO-DNA complex may be a useful biomarker to predict the therapeutic response in PsA.