Characterization of M2 antibodies in asymptomatic Chinese population

Table 1 Clinical and laboratory data of M2-positive subjects

	M2-positive subjects No.
	1	2	3	4	5	6	7	8
Age (y)	52	42	40	62	47	67	53	74
Sex	F	F	F	F	F	F	F	M
Laboratory parameters
AMA titer	1:160	1:640	Negative	1:1000	1:640	1:100	1:640	Negative
M2 (O.D.)	0.544	0.578	0.583	0.602	0.655	0.673	0.987	2.157
M2 reactivity	P	B, P	B	B	B, O	B, O	P	B, P
Other autoantibodies	Negative	ANA	Negative	Negative	ANA, SMA	Negative	Negative	ANA
IgG (g/l)	12.12	13.73	22.95	10.57	19.30	11.65	16.35	15.66
IgM (g/l)	2.37	4.32	4.17	4.78	3.98	2.80	2.73	9.52
IgA (g/l)	3.5	1.7	3.3	2.6	3.7	14.2	1.4	9.3
ALP (U/l)	86	110	81	465	302	125	97	796
γ-GT (U/l)	43	48	20	237	211	150	42	494
T-Bil (umol/l)	12	8	13	25	8	15	14	62
ALT (U/l)	24	36	24	55	56	61	33	65
AST (U/l)	28	35	30	22	42	35	37	47
Ultrasonography	Normal	Normal	Normal	Normal	Normal	Normal	Normal	Normal
ERCP	ND	ND	ND	ND	Normal	Normal	ND	Normal
Liver histology	ND	ND	ND	ND	Compatible	Compatible	ND	ND
Accorded with the	No	No	No	Yes	Yes	Yes	No	No
AASLD’s guideline

Upper limits of normal for IgG < 15.5 g/L, IgM < 2.8 g/L, IgA < 4.0 g/L, ALP < 112 U/L, γ-GT < 54 U/L, T-Bil < 21 umol/L, ALT < 40 U/L, AST < 40 U/L; T-Bil: Total serum cholesterol; ND: Not done.

Table 2 Class and subclass of reactive M2 antibodies

BCOADC-E2	PDC-E2	OGDC-E2
IgM 2/8a	3/8	0/8
IgA 2/8	1/8	0/8
IgG13/8	0/8	2/8
IgG21/8	2/8	0/8
IgG30/8	1/8	0/8
IgG40/8	0/8	0/8

^aPositive samples/total samples.