Introducing Polyautoimmunity: Secondary Autoimmune Diseases No Longer Exist

Table 1

Polyautoimmunity in 1,083 patients with four index autoimmune diseases.

	SLE		RA		MS		SSc		chi	df	𝑃	Cramer’s V
	𝑁	%	𝑁	%	𝑁	%	𝑁	%
N	335	30.9	304	28.1	154	14.2	290	26.8
Polyautoimmunity	136	40.6	98	32.2	21	13.6	118	40.7	40.81	3	0.001	0.19
AITD	60	17.9	64	21.1	14	9.1	67	23.1	14.63	3	0.0022	0.11
SS	47	14.0	36	11.8	4	2.6	43	14.8	16.4	3	0.0009	0.12
VIT					2	1.3
APS	48	14.3	8	2.6					25.83	1	0.001*	0.2
Primary biliary cirrosis							15	5.2	—	—	—	—
MAS	39	11.6	16	5.3	3	1.9	28	9.7	17.99	3	0.0004	0.12

SLE: systemic lupus erythematosus; RA: rheumatoid arthritis; MS: multiple sclerosis; SSc: systemic sclerosis; AITD: autoimmune thyroid disease; SS: Sjögren’s syndrome; VIT: vitiligo; APS: antiphospholipid syndrome; MAS: multiple autoimmune syndrome; chi: chi-square test; df: degree freedom; 𝑃: 𝑃 value; *Yates chi-square.