Useful biomarkers for assessment of hepatitis C virus infection-associated autoimmune disorders

Table 1 Extrahepatic autoimmune-related signs and symptoms in patients with chronic hepatitis C virus infection

Clinical manifestations	Arthralgia/myalgia
	Arthritis
	Sicca syndrome
	Purpura
	Lymphadenopathy
	Pulmonary fibrosis
	Raynaud’s phenomenon
	Fibromyalgia
	Thyroid dysfunction
Biological manifestations	Cryoglobulinemia
	Autoimmune hemolytic anemia
	Thrombocytopenia
	Hypocomplementemia
Autoantibodies	RF
	ANA
	Anti-SM and Anti-LKM1 antibody
	Anti-thyroglobulin and Anti-TPO antibody
	Anti-CL antibody

RF: Rheumatoid factor; ANA: Anti-nuclear antibody; Anti-SM: Anti-smooth muscle; Anti-LKM1: Anti-liver kidney microsomal type 1; Anti-TPO: Anti-thyroid peroxidase; Anti-CL: Anti-cardiolipin.

Table 2 Organ involvement in mixed cryoglobulinemia related to hepatitis C virus infection

Organ	Manifestations
Skin	Purpura
	Leg ulcers
	Leukocytoclastic vasculitis
Nerve	Mononeuritis multiplex
	Sensory-motor polyneuropathy
	Central nervous system vasculitis
Kidney	Type 1 membranoproliferative glomerulonephritis
	Vasculitis of small renal artery
Gastrointestinal tract	Mesenteric vasculitis
Lung	Interstitial pulmonary fibrosis
Heart	Mitral valvular damage
	Coronary vasculitis
	Pericarditis

Table 3 Immunological manifestations and useful autoantibodies in the patients with chronic hepatitis C virus infection

Clinical symptoms	Useful autoantibodies	Differential diagnosis
Polyarthritis/polyarthralgia	RF, anti-CCP	RA
Sicca (dry eye/dry mouth)	Anti-SSA/SSB	SS
Purpura	Cryoglobulin	Cryoglobulinemic vasculitis
Leg ulcer	ANCA, Cryoglobulin	Systemic vasculitis
Glomerulonephritis	ANCA, Anti-dsDNA	SLE, systemic vasculitis
Cytopenia	Anti-dsDNA	SLE
Hepatitis	Anti-SM, Anti-LKM1	Autoimmune hepatitis
Thrombosis	Anti-CL IgG/M	APS
Depression/fatigue	Anti-thyroglobulin, Anti-TPO	Autoimmune thyroiditis

RF: Rheumatoid factor; Anti-CCP: Anti-cyclic citrullinated peptide; ANCA: Anti-neutrophil cytoplasmic antibody; Anti-dsDNA: Anti-double strand DNA; Anti-SM: Anti-smooth muscle; Anti-LKM1: Anti-liver kidney microsomal type 1; Anti-CL: Anti-cardiolipin; Anti-TPO: Anti-thyroid peroxidase; RA: Rheumatoid arthritis; SS: Sjögren syndrome; SLE: Systemic lupus erythematosus; APS: Antiphospholipid antibody syndrome.