Table 3.

Characteristics of follow-up patients with SLE as grouped by variation of anti-DFS70 antibodies at the first and last visits.

	Anti-DFS70 stable, negative group (n = 42)			Anti-DFS70 stable, positive group (n = 7)			Anti-DFS70 changed, decreasing group (n = 8)			Anti-DFS70 changed, increasing group (n = 4)
	First visit	Last visit	p-value	First visit	Last visit	p-value	First visit	Last visit	p-value	First visit	Last visit	p-value
Age (years) a	42.9 ± 13.6	43.9 ± 13.5	N/A	31.0 ± 13.8	35.1 ± 14.2	N/A	42.4 ± 9.2	44.0 ± 9.7	N/A	49.8 ± 13.1	50.8 ± 13.6	N/A
Sex (men/women)	5/37	5/37	N/A	0/7	0/7	N/A	1/7	1/7	N/A	3/1	3/1	N/A
Duration (years) b	4.0 (1.0–8.3)	4.5 (2.4–10.3)	N/A	12.0 (7.0–12.0)	16.4 (8.4–16.7)	N/A	6.5 (1.3–13.3)	7.0 (3.4–17.3)	N/A	2.7 (1.0–4.8)	3.3 (2.1–6.1)	N/A
Follow-up time (months) b	N/A	8.5 (5.8–18.0)	N/A	N/A	55 (46–57)	N/A	N/A	11.0 (4.0–36.3)	N/A	N/A	12.0 (6.5–18.3)	N/A
SLEDAI-2K b , d	5.0 (2.0–8.3)	4.0 (1.5–8.0)	0.104	4.0 (2.0–9.0)	4.0 (2.0–6.0)	0.246	10.0 (6.5–16.0)	10.0 (6.5–15.5)	0.547	2.0 (2.0–5.8)	5.5 (2.8–14.3)	0.109
Anti-dsDNA (IU/ml) b , d	37.3 (26.3–51.7)	37.4 (24.8–63.5)	0.440	199.0 (45.0–548.1)	160.9 (48.0–475.9)	0.612	363.5 (197.5–857.8)	83.5 (75.9–164.7)	0.012	80.6 (42.5–300.3)	193.2 (157.4–284.3)	0.144
Anti-C1q (RU/ml) b , d	5.5 (3.4–10.5)	4.6 (1.6–10.4)	0.120	5.2 (3.5–26.6)	5.8 (4.1–29.9)	0.398	43.1 (6.7–169.7)	50.5 (3.8–86.4)	0.263	29.3 (2.4–110.3)	13.8 (5.0–20.6)	0.465
Prednisone dose (mg) b , d	15.0 (10.0–30.0)	10.0 (10.0–13.1)	0.001	10.0 (10.0–10.0)	7.5 (7.5–10.0)	0.059	35.0 (22.5–87.5.0)	25.0 (16.3–52.5)	0.207	17.5 (5.0–45)	20.0 (8.1–82.5)	0.273
Hydroxychloroquine c , e	31 (73.8)	33 (78.6)	0.608	6 (85.7)	6 (85.7)	1.000	5 (62.5)	4 (50.0)	1.000	2 (50.0)	0 (0.0)	0.429
Mycophenolate mofetil c , e	12 (28.6)	14 (33.3)	0.637	2 (28.6)	1 (14.3)	1.000	2 (25.0)	3 (37.5)	1.000	2 (50.0)	2 (50.0)	1.000
Cyclophosphamide c , e	14 (33.3)	13 (31.0)	0.815	1 (14.3)	0 (0.0)	1.000	0 (0.0)	3 (37.5)	0.200	0 (0.0)	1 (25.0)	1.000
Tacrolimus c , e	3 (7.1)	3 (7.1)	1.000	1 (14.3)	1 (14.3)	1.000	1 (12.5)	1 (12.5)	1.000	0 (0.0)	0 (0.0)	N/A
Cyclosporin A c , e	2 (4.8)	0 (0.0)	0.474	0 (0.0)	0 (0.0)	N/A	0 (0.0)	0 (0.0)	N/A	0 (0.0)	0 (0.0)	N/A
Azathioprine c , e	1 (2.4)	6 (14.3)	0.114	1 (14.3)	2 (28.6)	1.000	1 (12.5)	0 (0.0)	1.000	0 (0.0)	0 (0.0)	N/A
No immunosuppressants used c , e	2 (4.8)	2 (4.8)	1.000	0 (0.0)	1 (14.3)	1.000	0 (0.0)	1 (12.5)	1.000	1 (25.0)	1 (25.0)	1.000

Anti-DFS70 changed represented that the levels of anti-DFS70 significantly changed, including the conversion between positive and negative, and changed one or more levels of positive results within the intensity classification scheme of LIA, and according to the change trend by comparing results of anti-DFS70 by LIA at the last visit to the first visit during the follow-up, and the patients were divided into the decreasing and increasing groups. Anti-DFS70 stable indicated that the levels of anti-DFS70 remained stable during the follow-up, including remaining at the same level or changing between negative and borderline or changing between weak positive and borderline; by the positive and negative results of DFS70 by LIA, those patients were divided into the positive and negative groups, separately. Classification of line intensity by LIA: index 0–0.79, intensity (−), negative; index 0.8–1.14; intensity (o), borderline; index 1.15–2.49, intensity (+), weak positive; index 2.50–3.99, intensity (++), mid-level positive; and index ≥4.00, intensity (+++), strong positive. p-value defines differences between inclusion (first visit) and follow-up (last visit); p < 0.05 is shown in bold.

N/A, not applicable; DFS70, dense fine speckles 70; ds-DNA, double-stranded DNA; SLE, systemic lupus erythematosus; SLEDAI-2K, Systemic Lupus Erythematosus Disease Activity Index 2000.

^aAverage ± standard deviation.

^bMedian (interquartile range).

^cNumbers (%).

^dWilcoxon matched-pairs test.

^eThe two-tailed chi-square (χ²) test or Fisher’s exact test.