Transaminase Levels Infrequently Elevated in Celiac Disease

By Will Boggs MD

NEW YORK (Reuters Health) May 27 - In patients with celiac disease, liver enzyme elevations are unusual, often subclinical, and likely to respond to a gluten-free diet, researchers from Finland say.

Contrary to some earlier studies, only a small minority of celiac disease patients had elevated transaminase levels in the new study, reported online April 19th in the American Journal of Gastroenterology.

"We do not routinely check the transaminase levels in newly diagnosed celiac disease patients," Dr. Markku Maki from University of Tampere told Reuters Health in an email.

Even so, he and his colleagues investigated the prevalence and gluten dependency of hypertransaminasemia in 313 untreated and 339 treated adult celiac disease patients and in 237 nonceliac controls.

They also measured transaminase levels at diagnosis and after a year on a gluten-free diet in 130 celiac patients, and before and after gluten challenge in 25 treated celiac patients in clinical remission.

In the cross-sectional study, aspartate transaminase (AST) levels were elevated in a similar proportion of untreated celiac patients (11%), treated celiac patients (8%), and nonceliac controls (9%).

Earlier studies had reported that as many as half of celiac disease patients may have elevated serum liver enzyme levels at diagnosis.

In the celiac patients, hypertransaminasemia was significantly more common in the presence of severe or moderate symptoms than when symptoms were mild or nonexistent (23% vs 9%; P=0.03).

The findings suggest that "routine investigation of liver enzymes in celiac disease patients would give the same yield as in the population in general-at least in populations with high clinical prevalence of celiac disease," the researchers note. "Strategies for routine investigation of liver enzymes in celiac disease patients should be reevaluated carefully."

In the prospective gluten-free diet trial, serum AST levels decreased significantly (even within the normal range) in parallel with the disappearance of clinical symptoms after a year on the diet.

In the gluten-challenge study, nine of the 25 celiac patients in clinical remission had reappearance of gluten antibodies in their blood and 18 developed gastrointestinal symptoms. AST and alanine transaminase (ALT) levels rose in 11 patients.

When the patients resumed their gluten-free diets, their symptoms resolved, serum endomysial antibodies were again undetectable, and serum transaminase levels returned to baseline levels.

"Gluten may induce liver disease in celiac disease patients," Dr. Maki said. "Even if the liver manifestation is infrequent and mostly mild, awareness of its potential existence is important."

"Daily ingested wheat, rye, and barley gluten, the environmental insult in celiac disease, seem to trigger an autoimmune loop in genetically susceptible persons where formed autoantibodies target the autoantigen, transglutaminase 2, also in the liver," Dr. Maki explained. "This may have biological implications and can be studied further."

In the meantime, he doesn't recommend routine screening with liver function tests when patients are first diagnosed. "We have no evidence that this should be done," he said. "However, if case finding for celiac has been performed on elevated liver enzymes and a diagnosis was made, the normalization of the liver values in the patients should be checked when on gluten-free diet treatment."

SOURCE: http://bit.ly/mfJiKQ

Am J Gastroenterol 2011.