Introduction Systemic Lupus Erythematosus (SLE) is a systemic connective disease which can have threatening complications. It can be associated to various other auto immune diseases. Our objective is to know whether the prognosis of SLE is more severe in isolated or in associated SLE.

Patients and methods It’s a retrospective study conducted in an internal medicine department. Patients with systemic lupus erythematosus (ACR revised criteria) were included. We compared 2 groups: patients with isolated SLE (ISLE) and patients with associated SLE to another autoimmune disease (ASLE). Variables with a p inferior or equal to 0.05 were considered to be statistically significant.

Results A total of 89 SLE patients were included: 80 females (89.9%) and 9 males (10.1%) (sex ratio F/M was 8.9). Mean age was 35.3 years (14 to 72 years). SLE was isolated in 50 patients (56.1%) and associated to another autoimmune disease in 39 cases (43.9%) as following: sjogren syndrome in 13 patients (14.6%), rheumatoid arthritis in 6 patients (6.7%), Hashimoto in 5 patients (5.6%), Basedow in 2 cases (2.2%) and SLE was associated to more than an autoimmune disease in 13 cases (11.6%). Comparative study between ISLE and ASLE showed no significant difference between age onset or sex ratio. Comparing clinical manifestations, patients with ISLE seem to have more cutaneous manifestations and more photosensitivity but without significant difference (p=0.076, p=0.082 respectively). Immunological findings showed that anti SSA and anti SSB antibodies were significantly associated to ISLE (p=0.007 and p=0.013 respectively). We found no difference in biological findings or SLEDAI score.

Conclusion ASLE seems to develop less specific cutaneous manifestations and to show more frequently positive anti SSA and anti SSB antibodies. When associated to other auto immune diseases SLE doesn’t seem to be more severe.