Antineutrophil cytoplasmic antibody (ANCA)-associated autoimmune diseases induced by antithyroid drugs: comparison with idiopathic ANCA vasculitides

Table 3 Serological parameters in PR3/MPO-ANCA-positive idiopathic vasculitides and antithyroid DIDs

	Patients with idiopathic vasculitides (n = 56)	Patients with antithyroid DIDs (n = 16)
pANCA	28 (50)	15 (94)**
Median (1/titer)	64	256*
Range (1/titer)	32–256	64–512
MPO-ANCA	29 (52)	15 (94)**
MPO-ANCA (U/ml)	64.3 ± 22	55 ± 19
CANCA	28 (50)	1(6)**
Median (1/titer)	64	64
Range (titer)	1:32–1:256	-
PR3-ANCA	27 (48)	1 (6)**
PR3-ANCA (U/ml)	58.8 ± 17	44
ANA	3 (5)	8 (50)***
Median (1/titer)	40	80
Anti-DNA	0	1 (6)
Anti-histone	0	3(19)**
Anti-SSA	0	1(6)
aCL	6 (11)	9 (56)***
IgG	5 (9)	1 (6)
IgM	0	2 (12.5)*
IgG/IgM	1 (2)	6 (37.5)***
Anti-β2 GP I	2 (3.5)	4 (25)*
IgG	1 (2)	1 (6)
IgM	1 (2)	3 (19)*
Cryoglobulinemia	0	3 (19)**
Antimicrosomal Ab	1 (2)	13 (81)***
Antithyroglobulin Ab	1 (2)	3 (19)*
Low C4 (<0.1 g/l)	0	3 (19)**
Low α1 AT (<1.1 g/l)	13 (23)	0
High CR-P (>10 mg/l)	56 (100)	8 (50)***
CR-P mg/l	90 ± 35	46 ± 15**
Leucopenia (<3 × 10⁹/l)	1 (2)	2 (12.5)

All values represent either numbers of patients (%), or mean ± standard deviation, except median and range for p and cANCA titer. *p <0.05, **p < 0.01, ***p < 0.001. α1 AT, alpha-1 antitrypsin; Ab, antibodies; aCL, anticardiolipin antibodies; ANA, antinuclear antibodies; anti-β2 GP I, anti-beta 2 glycoprotein I; cANCA, cytoplasmic antineutrophil cytoplasmic antibodies; CR-P, C reactive protein; DID, drug-induced autoimmune disease; MPO, myeloperoxidase; pANCA, perinuclear antineutrophil cytoplasmic antibodies; PR3, proteinase 3.

ISSN: 1478-6362