Diagnostic value of anti-MCV antibodies for ankylosing spondylitis / 中华检验医学杂志

ABSTRACT

Objective To investigate the diagnostic value of anti-mutated citrullinated vimentin (anti-MCV) and anti-cyclic citrullinated peptide (anti-CCP) antibodies for ankylosing spondylitis (AS), and to establish a new diagnostic method of AS based on anti-citrullinated protein/peptide antibodies (ACPAs) detection.Methods Totally 121 AS patients(AS group), 97 rheumatoid arthritis(RA) patients (RA group)and 103 healthy people(control group) were enrolled for the detection of serum levels of anti-MCV and anti-CCP antibodies using ELISA method as a diagnostic test .HLA-B27 in AS patients was tested by flow cytometry , and RF-IgM in RA and AS patients was detected by immune rate nephelometry .Receiver operating characteristics ( ROC) curve was used to analyze the diagnostic value and to determine the cut-off value.Anti-MCV and anti-CCP antibodies among each group were compared by Mann-Whitney U test, Chi-square test or Fisher′s exact test was used to compare positive rate .Results The anti-MCV levels in AS group [11.60 ( 12.36-25.83 ) U/ml ] were significantly higher than control group [ 11.60 ( 8.41 -13.54)U/ml ],U=2 413,P <0.001, while the levels of anti-CCP had no difference between the two groups [AS group 6.22 (4.30 -8.07) U/ml], and control group [6.01 (3.77 -7.58) U/ml], respectively;U=5 421,P=0.094.The calculated area under the ROC curve of anti-MCV was 0.806,and 14.67 U/ml was the optimal cut-off value with sensitivity of 0.645 and specificity of 0.942.In both HLA-B27 positive and negative AS patients , anti-MCV antibodies levels and positive rate were significantly higher than control group using new cut-off value above (U =133.5, P =0.001; U =2 279.5,P <0.001). Sensitivity of the combination detection of anti-MCV and anti-CCP ( MCV+CCP-) or RF-IgM ( MCV+RF-) were 60.3%(73/121), 62.8% (76/121) and specificity were 89.7% (87/97), 90.7% (88/97) respectively in differential diagnosis of AS and RA , which were significantly higher than anti-MCV detection alone in specificity (16.5%,16/97).Conclusions Anti-MCV could be a new biomarker for the diagnosis of AS .With high sensitivity and specificity , anti-MCV has an equal diagnostic efficiency in HLA-B27 positive and negative AS patients using our new cut-off value.Additionally, the combination detection of anti-MCV and anti-CCP or RF-IgM could be an effective method for differential diagnosis of AS and RA .