Patients with celiac disease, which attacks the small intestine, have been found to have a higher risk for lymphoma, MedPage Today reported.

The population-based cohort study, published Tuesday in Annals of Internal Medicine, found that celiac patients with persistent villous atrophy have a heightened risk for lymphoma (lymphoproliferative malignancies).

According to Benjamin Lebwohl, MD, of Columbia University, the standardized incidence ratio for lymphoma among celiac patients is 2.81 (95% CI 2.10-3.67). That ratio only goes up to 3.78 (95% CI 2.71-5.12) for patients with villous atrophy of the intestinal mucosa.

While previous studies have pointed to this result, a precise reason has eluded many scientists and doctors. Lebwohl and his colleagues believe it may relate to ongoing villous atrophy mainly in patients who do not adhere to strict gluten-free diets.

The team studied biopsy reports from Sweden's pathology department from 1969 to 2008. They analyzed 7,625 patients who had a follow-up biopsy six months to five years after the initial one.

43 percent of the patients were found to have ongoing villous atrophy following the second biopsy. The median time between a second follow-up and a third was nine years, after which 0.7 percent of patients were diagnosed with lymphoma.

For the group in whole, the incidence rate was 67.9 per 100,000 patient-years. Among patients with ongoing villous atrophy, the rate was 102.4 per 100,000.

"Our finding of an association between persistent villous atrophy and risk for [lymphoproliferative malignancy] supports the practice of performing follow-up biopsy as a complement to dietary assessment," Lebwohl and colleagues observed. "The result of the follow-up biopsy may spur the patient to improve dietary adherence, which will eventually diminish the increased risk."

The researchers concluded that celiac patients should set a goal for mucosal healing to lower their risk of lymphoma. The study's limitations included the lack of information about gluten avoidance. However, the FDA's new and more precise definition of "gluten-free" should help celiac patients refine their diets.

"This study shows that the results of the follow-up biopsy matter," Lebwohl told MedPage Today.