What does a negative test for anti-tissue transglutaminase in a suspected celiac disease patient suggest?

A negative test for anti-tissue transglutaminase antibodies in a patient suspected of having celiac disease suggests that further testing for HLA typing is necessary. This is because, while the presence of these antibodies is indicative of celiac disease, a negative result does not definitively rule out the condition. Celiac disease has a strong genetic component, and HLA-DQ2 and HLA-DQ8 are the specific genetic markers typically associated with the disease.

In cases where anti-tissue transglutaminase antibodies are negative but clinical suspicion remains high, HLA typing can help assess the risk for celiac disease. If the patient lacks these genetic markers, it is highly unlikely they have celiac disease, providing a clearer direction for diagnosis and management. The presence of these genetic factors can either confirm a predisposition to celiac disease or support the decision to investigate other conditions.

This context makes it clear that while the other options relate to different aspects of autoimmune testing or conditions, the most relevant next step after a negative anti-tissue transglutaminase test in the context of a suspected diagnosis of celiac disease is HLA typing.