Both plasma cf-DNA and MPO levels were higher in pSS patients compared with HCs (cf-DNA: 2137.43±586.03 vs 1278.17±755.51, P=0.001; MPO: 26.98±18.12 vs 14.45±8.65, P=0.034, Fig. 1A,B). Here, MPO is linked to peeling skin syndrome.