Table 1 Demographic characteristics of the study population

Age at enrolment, years

33.9 (26.7–40.3)

Male sex

109 (94)

Disease duration, years

10.8 (5.3–15.5)

Follow-up duration, years

6.4 (4.5–7.1)

HLA B27 positivity

115 (99.1)

Peripheral joint involvement

52 (44.8)

History of psoriasis

2 (1.7)

History of uveitis

35 (30.2)

mSASSS

9.0 (6.0–25.9)

BASDAI

2.3 ± 0.9

ASDAS-CRP

2.0 ± 0.5

 High ASDAS-CRP (≥ 2.1)

45 (38.8)

ESR, mm/hr. (normal ≤ 20)

3.0 (2.0–6.0)

CRP, mg/dL (normal ≤ 0.3)

0.2 (0.2–0.2)

 Adalimumab

41 (35.3)

 Etanercept

34 (29.3)

 Infliximab

27 (23.3)

 Golimumab

14 (12.1)

Discontinuation of anti-TNF agent during follow up

13 (11.2)

 Lack/loss of efficacy

9 (69.2)

 Clinical remission

3 (23.1)

 Adverse event

1 (7.7)