Sjogren's syndrome may increase lymphoma risk

NEW YORK (Reuters Health) - Compared to the general population, patients with Sjogren's syndrome have a sixteen-fold increased risk of developing non-Hodgkin's lymphoma, Swedish researchers report in the Annals of the Rheumatic Diseases.

Sjogren's syndrome is an autoimmune disease that attacks the body's moisture-producing glands, leading to progressively worsening dry mouth, eyes, vagina and skin, as well as fatigue. The syndrome is associated with rheumatic disorders and can also affect the kidneys, blood vessels, lungs, liver, pancreas and brain. It is estimated that as many as 4 million in the United States have this syndrome, with most cases occurring in adults 40 years of age or older and in women (90 percent).

Dr. Elke Theander and colleagues at Malmo University Hospital linked patient information from the Malmo Primary Sjogren's Syndrome Register, the Swedish Cancer Register and the Cause-of-Death Register to calculate the frequency of lymphomas and other malignancies in patients with Sjogren's syndrome.

Theander identified 286 patients who met the clinical criteria for Sjogren's syndrome. Over an average of eight years of follow-up, patients with this syndrome were 15.6-times more likely to develop non-Hodgkin's lymphoma compared with the general population. The subjects also had a 42 percent increased risk of developing any malignancy.

Seven of the 12 patients with non-Hodgkin's lymphomas had diffuse large B cell lymphomas. Patients with skin rash and abnormal white blood cell counts were more likely to develop lymphoma.

In an accompanying editorial, Dr. Stanley R. Pillemer of MedImmune, Inc. in Gaithersburg, Maryland, adds a note of caution regarding the Swedish findings. He points out that the numbers in the study are small and no firm conclusions can be drawn.

However, a low ratio of the white blood cells CD4+ and CD8+ as a lymphoma risk factor is a new finding, Pillemer notes, and this may prove to be important in Sjogren's syndrome.

Also, the increased risk associated with various white blood cell irregularities may shed light on the underlying causes of Sjogren's syndrome and lymphoma, he adds.

SOURCE: Annals of the Rheumatic Diseases, June 2006.