Table 1 Clinical, demographic, and laboratory characteristics of pSS patients with different stages of ILD

Demographic parameters

 Number, no. (%)

10 (14)

25 (36)

15 (22)

19 (28)

 Female, no. (%)

9 (90)

21 (84)

13 (87)

15 (79)

 Male, no. (%)

1 (10)

4 (16)

2 (13)

4 (21)

 Age at diagnosis of pSS, median (IQR), years

49.00 (33.25–53.25)

53.00 (46.50–61.50)

60.00 (48.00–64.00)*

62.00 (55.00–70.00)***

 Disease duration, median (IQR), years

1.00 (0.25–5.00)

1.00 (0.75–4.00)

3.00 (1.00–10.00)

2.00 (0.50–5.00)

Laboratory findings

 IgG, g/l

16.85 (13.75–19.23)

18.30 (14.25–21.50)

21.20 (13.50–26.10)

14.00 (10.04–19.20)

 IgM, g/l

1.16 (0.77–1.47)

1.00 (0.62–2.39)

1.37 (1.06–2.44)

1.58 (1.38–2.98)*

 IgA, g/l

2.75 (2.19–3.92)

3.36 (2.67–4.60)

2.88 (1.67–4.50)

2.60 (2.49–3.82)

 C3, g/l

1.01 (0.80–1.25)

0.86 (0.67–1.08)

1.02 (0.98–1.11)

0.93 (0.92–1.12)

 C4, g/l

0.22 (0.17–0.31)

0.18 (0.11–0.22)

0.15 (0.12–0.22)

0.28 (0.20–0.31)

 CRP, mg/l

0.66 (0.33–5.45)

2.20 (0.40–6.76)

4.9 (1.41–30.00)

9.95 (4.80–22.60)***

 ANA positive, no. (%)

7 (70)

20 (80)

12 (80)

10 (50)

 Anti-SSA/Ro60 positive, no. (%)

6 (60)

14 (56)

8 (53)

4 (20)**

 Anti-SSB/La positive, no. (%)

3 (30)

10 (40)

3 (20)

3 (15)

 Anti-Ro-52 positive, no. (%)

7 (70)

16 (64)

9 (60)

12 (60)