Serologic tests and HLA-DQ typing for celiac disease diagnosis

This week's Annals of Internal Medicine investigated the accuracy of serologic tests and HLA-DQ typing for diagnosing celiac disease.

Estimates of the diagnostic performance of serologic testing and HLA-DQ typing for detecting celiac disease have mainly come from case-control studies.

Dr Muhammed Haiti and colleagues from the Netherlands defined the performance of serologic testing and HLA-DQ typing prospectively.

Testing positive for either HLA-DQ type maximized sensitivity

Annals of Internal Medicine

The team conducted a prospective cohort study at the University hospital on patients referred for small-bowel biopsy for the diagnosis of celiac disease.

The team assessed celiac serologic testing, antitransglutaminase antibodies, and antiendomysium antibodies and HLA-DQ typing.

The team compared diagnostic performance of serologic testing and HLA-DQ typing with a reference standard of abnormal histologic findings and clinical resolution after a gluten-free diet.

The researchers found that 16 of 463 participants had celiac disease, a prevalence of 4%.

A positive result on both antitransglutaminase antibodies and antiendomysium antibodies testing had a sensitivity of 81%, and specificity of 99%.

The team noted that the negative predictive value was 99%.

Testing positive for either HLA-DQ type maximized sensitivity, and the negative predictive value.

However, the researchers found that testing negative for both minimized the negative likelihood ratio and posttest probability.

The addition of HLA-DQ typing to antitransglutaminase antibodies and antiendomysium antibodies testing did not change test performance compared with either testing strategy alone.

The team noted that the addition of serologic testing to HLA-DQ typing did not change test performance compared with either testing strategy alone.

Few cases of celiac disease precluded meaningful comparisons of testing strategies.

Dr Hadithi's team concluded, "We assessed a patient population referred for symptoms and signs of celiac disease with a prevalence of celiac disease of 4%."

"We found that antitransglutaminase antibodies and antiendomysium antibodies testing were the most sensitive serum antibody tests and a negative HLA-DQ type excluded the diagnosis."

"However, the addition of HLA-DQ typing to antitransglutaminase antibodies and antiendomysium antibodies testing, and the addition of serologic testing to HLA-DQ typing, provided the same measures of test performance as either testing strategy alone."