MAYO CLINIC ANNOUNCES NEW DIAGNOSTIC ROUTINES

Mayo Clinic recently issued a communiqué announcing new standards and new tests for diagnosing celiac disease and monitoring treatment on a gluten-free diet. [PDF]

The guidelines and diagnostic algorithms described in the announcement can be extremely useful in helping doctors figure out whether patients have celiac disease. There is even a set of recommendations for diagnosing patients who are already on gluten-free diets. It's still advisable for patients to be on gluten-inclusive diets for a significant stretch leading up to the diagnostic period ("Serology may be falsely negative in patients who have already reduced the gluten in their diet," says the announcement), but it's good to have access to a backup strategy clearly outlined by Mayo Clinic (which does market its own tests).

The announcement states, "There are no typical celiac disease-specific symptoms; most people with the disease have general complaints such as intermittent diarrhea, abdominal pain, and bloating." But it does list numerous "signs and symptoms of celiac disease."

Gastrointestinal

Anorexia
Chronic diarrhea
Bloating
Vomiting
Constipation
Pale, foul-smelling stool
Lactose intolerance
Abdominal pain
Ulcers

Nongastrointestinal

Failure to thrive in infants
Anemia
Thyroid disorders
Chronic fatigue
Unexplained short stature
Depression
Irritability
Seizures/neuropathy
Recurrent fetal loss/infertility
Delayed menarche
Early menopause
Osteoporosis, osteopenia
Oral sores
Tooth discoloration or loss of enamel
Vitamin deficiencies
Myocarditis
Hyposplenism
Pulmonary hemosiderosis

Also of note:

"Up to 10% of untreated celiac disease patients may also have negative serology. When serology is uninformative or indeterminate, and there is substantial clinical doubt remaining, HLA [genetic] typing should be performed to help discriminate those patients for whom a diagnosis of celiac disease can be excluded."

"Mayo Medical Laboratories no longer recommends reticulin testing for the diagnosis of celiac disease. The sensitivity and specificity of this test for celiac disease are inferior to the other tests previously mentioned."

"Testing for IgA and IgG antibodies to unmodified gliadin proteins is no longer recommended because of the lower sensitivity and specificity of these tests for celiac disease....New tests for deamidated gliadin IgA and IgC antibodies have replaced the older gliadin antibody tests, which have been discontinued at Mayo Clinic. In a recent study conducted at Mayo Clinic, the sensitivity and specificity of deamidated gliadin antibodies for untreated, biopsy-proven celiac disease were comparable to tTG antibodies."

Thanks to Diane Hosek for the lead.