Objectives To compare the profile of clinical and serological manifestations of patients with SLE with and without JA followed in a tertiary care hospital of Madrid.

Methods We performed a retrospective observational study of a cohort of patients diagnosed with SLE (4 or more ACR criteria) between June 1977 and December 2015. The variables evaluated included demographics, clinical, analytical and radiological manifestations. The definition of JA was based on the presence of clinical criteria (reversible joint deformities) and absence of radiographic erosions typical of rheumatoid arthritis.

Results We included 108 patients representing a sample of 24% of the total number of patients with SLE treated at our centre during that period. The majority of patients were women (89.8%), mean age at diagnosis was 30±12.29 years (range: 7–75) and duration of disease was 127 months (range: 2–411). Thirteen patients (12.03%) had findings compatible with JA. There were no significant differences in age, sex or race, but the duration of disease was higher in JA patients (190 vs 118.2 months, p=0.0299). There were significant differences in the presence of malar rash (p=0.0009), photosensitivity (p=0.0050), oral ulcers (p=0.0032) and pericarditis (p=0.000001), which were more frequent in patients without JA, but arthritis, nephritis, pleuritis, seizures, psychosis, Raynaud’s phenomenon and antiphospholipid syndrome had a similar distribution between both groups. Among the immunological features, no significant difference was found in relation to hemolytic anaemia, lymphopenia, thrombocytopenia, ANA, anti-ENA, anti-DNA, anticardiolipin, anti-β2 glycoprotein I and lupus anticoagulant, but leukopenia was also more frequent in patients without JA (p=0.0041).

Conclusions In the analysed sample of patients in our centre JA was a relatively frequent finding and was associated with a longer duration of the disease. It was not possible to corroborate other JA associations suggested in previous studies such as a lower frequency of lupus nephritis or major secondary antiphospholipid syndrome, probably due to limited sample size, but there are also other studies that do not demonstrate significant differences in relation to clinical and serological findings in patients with SLE with JA with respect to those who do not present it.