Support for removal of lymphoma as an exclusion criterion in classification criteria for primary Sjögren’ s syndrome

• Objective. Classification criteria for primary Sjögren’s syndrome (pSS) have previously included pre-existing lymphoma as an exclusion criterion for a pSS diagnosis, but the rationale for this exclusion criterion has not been formally studied.We, therefore, aimed to explore if there were differences between pSS patients with and without pre-existing lymphoma.Methods. Patients registered with ICD-7-10 codes for SS (which capture all reasons for sicca symptoms) and a diagnosis of malignant lymphoma before or after the SS diagnosis were identified by linking the Swedish Patient Register 1964-2007 with the Cancer Register 1990-2007 (n=224). Clinical data was collected from medical records and the underlying cause of the SS diagnosis code was investigated. Lymphoma diagnoses were evaluated by tissue review. Patient characteristics in pSS patients with and without pre-existing lymphoma were compared by Mann-Whitney and Fisher’s tests.Results. A total of 207 SS-lymphoma patients remained after lymphoma tissue review. 107 (52%) of these had pSS according to the treating physician. 18 (17%) had a pre-existing lymphoma at pSS diagnosis. The pSS characteristics were similar in patients with and without pre-existing lymphoma, also in analyses restricted to patients fulfilling the 2002 AECG criteria for pSS. Mucosa-associated lymphoid tissue (MALT) lymphoma (50% vs. 22%, p=0.02), and lymphoma in the salivary glands, (61% vs. 26%, p=0.006) were more common in patients with pre-existing lymphoma.Conclusions. Our results support the removal of pre-existing lymphoma as a general exclusion criterion for a pSS diagnosis. The results also suggest that patients with MALT lymphoma or lymphoma in the salivary glands should be investigated for the presence of pSS.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Reumatologi och inflammation (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Rheumatology and Autoimmunity (hsv//eng)

Nyckelord

Sjögren’s syndrome

pre-existing lymphoma

lymphoma

International Classification of Diseases

classification criteria

Medicinsk vetenskap

Medical Science

Publikations- och innehållstyp

vet (ämneskategori)

ovr (ämneskategori)