An earlier study2 also found significant correlations between CRP and sacroiliitis in PsA patients (p = 0.006), but no other disease activity index was significantly associated with sacroiliitis (DAS28-CRP p = 0.358, DAS28-ESR p = 0.251, BASDAI p = 0.389). Here, ESR1 is linked to Sacroiliac arthritis.