Value of serum autoantibodies in the diagnosis of anti-mitochondrial antibody-negative primary biliary cirrhosis / 中华消化杂志

ABSTRACT

Objective To compare clinical biochemical and pathological characters among antimitochondrial antibody-negative primary biliary cirrhosis (AMA PBC),AMA positive PBC (AMA+ PBC)and autoimmune hepatitis (AIH),and try to find serum biomarkers in the diagnosis of AMA-PBC.Methods From January 2005 to May 2013,23 patients with AMA-PBC,102 patients with AMA+ PBC and 55 patients with AIH were collected.Clinical features of patients were observed.Biochemical indexes (total bilirubin (TBil),direct bilirubin (DBil),alanine aminotransferase (ALT),aspartate transaminase (AST),alkaline phosphatase (ALP),γ-glutamyltransferase (GGT) and globulin) were tested.Immunological indexes immunoglobulin ((Ig)G,IgM and IgA) were also measured.Antinuclear amibody,anti smooth muscle antibody (SMA) and AMA were detected by indirect immunofluorescence.Soluble acidic phosphorylation nucleoprotein antibody and anti-nuclear membrane glycoprotein antibody were detected by Western blotting.Non parameter test was for non normal distributed measurement data and grade data comparison.The cut off value,sensitivity and specificity of IgM in the diagnosis of PBC were calculated with receiver operating characteristic (ROC) curve.The sensitivity and specificity of soluble acidic phosphorylation nucleoprotein antibody and anti-nuclear membrane glycoprotein antibody in the diagnosis of PBC were analyzed with fourfold table.Results The rates of fatigue and jaundice of AMA-PBC group (39.1％,9/23 ; 43.5 ％,10/23) were both higher than those of AIH group (16.4 ％,9/55; 14.5 ％,8/55),and the differences were statistically significant (x2 =4.735 and 7.648,both P＜ 0.05).The levels of ALP and GGT of AMA PBC group were higher than those of AIH group,and the levels of ALT and AST were lower than those of AIH group (Z=-4.577,-4.257,-2.820 and -2.055,all P＜0.05).The level of IgM of AMA PBC group (417(270,610) mg/L) was higher than that of AIH group (97(69,195) mg/L),however lower than that of AMA+ PBC group (546(419,704) mg/L),and the differences were statistically significant (Z=-4.362 and-0.210,both P＜0.05).The level of IgG of AMA PBC group was lower than that of AIH group (Z=-2.202,P＜0.05).The positive rates of antinuclear antibody and SMA of AMA PBC group (95.7％ (22/23),8.7％ (2/23)) were both higher than those of AMA+ PBC group (33.3％(34/102),1.0％(1/102)),and the differences were statistically significant (x2 =29.474 and 4.769,both P＜0.05).The positive rates of soluble acidic phosphorylation nucleoprotein antibody and anti nuclear membrane glycoprotein antibody of AMA PBC group (60.9％,14/23; 30.4％,7/23) were both higher than those of AIH group (2.0％,1/55; 0),and the differences were statistically significant (x2=36.409 and 24.329,both P＜0.05).The karyotype of antinuclear antibody of AMA PBC and AMA+ PBC group mainly was granules pattern (60.9 ％,14/23;75.5％,77/102),however of AIH group was mainly homogeneous pattern (38.2％,21/55).If the cut off value of IgM was 277 mg/L,the sensitivity and specificity of IgM in the diagnosis of PBC was 72.2％ and 94.4 ％.The sensitivity and specificity of soluble acidic phosphorylation nucleoprotein antibody in the diagnosis of PBC was 24.1％ and 97.2％.The sensitivity and specificity of anti-nuclear membrane glycoprotein antibody was 35.2 ％ and 100.0 ％.The sensitivity and specificity of any one of anti-nuclear membrane glycoprotein antibody positive,soluble acidic phosphorylation nucleoprotein antibody positive or IgM＞277 mg/L in the diagnosis of PBC was 88.9％ and 94.4％.Conclusions AMA-PBC and AMA+ PBC have similar clinical manifestations and serum biochemical test results.Antinuclear antibody and/or SMA positive is the feature of AMA-PBC and which should be distinguished with AIH.The sensitivity and specificity of any one of the followiagsanti nuclear membrane glycoprotein antibody positive,soluble acidic phosphorylation nucleoprotein antibody positive or IgM＞277 mg/L is high in the diagnosis of PBC.