Table 1. Overview of autoantibodies discussed in this study

Autoantibody and subtypes		Autoantigens	Related clinical phenotypes
RA antibodies	Rheumatoid factor (RF)	Fc portion of IgG	RA, JIA, SjS, SSc, SLE
RA antibodies	Anti-CCP antibody	Citrullinated proteins	RA (highly specific), JIA
Antinuclear antibodies (ANA)	Anti-dsDNA antibody	ds-DNA	SLE (disease activity)
	Anti-Ro/SSA antibody	RNPs (52 kD, 60 kD)	SjS, SLE, neonatal lupus/CHB
	Anti-La/SSB antibody	RNPs (45 kD)	SjS, SLE, neonatal lupus
	Anti-Smith (Sm) antibody	Spliceosome	SLE (highly specific)
	Anti-U1-RNP antibody	Spliceosome	MCTD, SLE, Raynaud’s
	Anti-Scl-70 antibody	Scl-70 (topoisomerase 1)	Diffuse SSc, SSc/PM overlap
	Anti-centromere antibody	Centromere	Limited SSc (CREST)
	Anti-histone antibody	Histones	SLE, drug-induced LE
	Anti-ribosomal P antibody	Ribosomal P (60S ribosome)	Neuropsychiatric SLE
	Anti-Jo-1 antibodies	Histidyl-tRNA synthase	IIM (e.g., DM/PM)
Anti-neutrophil cytoplasmic antibodies (ANCA)	PR3-ANCA (= c-ANCA)	Granule protein PR3	GPA (disease activity)
Anti-neutrophil cytoplasmic antibodies (ANCA)	MPO-ANCA (= p-ANCA)	Granule protein MPO	MPA, EGPA, other vasculitis
Anti-phospholipid antibodies (aPL)	Anti-CL antibodies	Cardiolipin (CL)	APS (primary and secondary), SLE
Anti-phospholipid antibodies (aPL)	Anti-β2GP1 antibodies	β2GP1	APS (primary and secondary), SLE

RA: Rheumatoid arthritis; Ig: immunoglobulin; JIA: juvenile idiopathic arthritis; SLE: systemic lupus erythematosus; SSc: systemic sclerosis; SjS: Sjögren’s syndrome; IIM: idiopathic inflammatory myopathy; DM/PM: dermatomyositis/polymyositis; APS: antiphospholipid syndrome; dsDNA: double-stranded deoxynucleic acid; SSA: Sjögren’s syndrome-related protein A; SSB: Sjögren’s syndrome-related protein B; RNP(s): ribonucleoprotein(s); CHB: congenital heart block; MCTD: mixed connective tissue disease; SSc/PM: systemic sclerosis/polymyositis; CREST: calcinosis, Raynaud’s phenomenon, esophageal dysmotility, sclerodactyly and telangiectasia; PR3: proteinase 3; MPO: myeloperoxidase; GPA: granulomatosis with polyangiitis; MPA: microscopic polyangiitis; EGPA: eosinophilic granulomatosis with polyangiitis; CL: cardiolipin; β2GP1: β2 glycoprotein 1.