Clinical characteristics and risk factors associated with lymphoma in patients with systemic lupus erythematosus: a nationwide cohort study.

OBJECTIVES: To assess the characteristics and risk of lymphoma in a large cohort of patients with SLE. METHODS: A case-cohort analysis was performed within a dynamic cohort of SLE patients from the Spanish Society of Rheumatology Lupus Registry (RELESSER). Clinical and analytical features were compared between the lymphoma SLE group and the control SLE group using an independent-sample Student's t-test or Mann-Whitney test for continuous variables and the χ2 test for categorical variables with Fisher's exact test if necessary. The multivariate analysis was based on a generalized linear model. RESULTS: Twenty-one patients with SLE and lymphoma and 3965 non-lymphoma controls with SLE were studied. Most lymphomas were of B cell origin (n = 15/21), with diffuse large B cell lymphoma being the most frequent histological type (8/21, 38.1%). As in the general population, the risk of lymphoma in SLE was higher in male than in female patients and increased with age. In the lymphoma SLE group, bivariate analysis showed a significantly higher percentage of pericarditis, organic brain syndrome, seizures, vasculitis, haemolytic anaemia, splenomegaly, venous thrombosis and mean modified (excluding lymphoma) SLICC/ACR damage index. In contrast, renal involvement, positive anti-dsDNA, and antimalarials ever were less frequent. CONCLUSIONS: In this large multicentre Spanish cohort, we identified characteristics of SLE that are associated with a higher risk of lymphoma. Antimalarials were significantly negatively associated with risk of lymphoma in SLE patients. Nevertheless, further prospective studies are needed to clarify these findings.