Purpose Rhupus is defined as an overlapping syndrome that combines the clinical and immunological features of systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) simultaneously. The aim of our study was to characterize the clinical and immunological profiles of rhupus patients and to look for a possible association between the presence of autoantibodies and joint destruction.

Methods Eighteen (18) rhupus patients were included in our work. A clinical and a paraclinical examination were carried out. A serum assay of anti-cyclic citrullinated peptide antibodies (ACPA), rheumatoid factor (RA) and antinuclear antibodies (AAN) was performed.

Results Our series of rhupus patients was exclusively female with an average age of 39.4 ± 11.4 years. ACPA and anti-DNA antibodies were positive in 72.22% and 77.8% of cases, respectively. Joint manifestations were present in 94.44% of patients; all of them presented sonographic synovitis in the wrists and hands, accompanied by bone erosions in 72.22% of cases. Interestingly, our results demonstrated a significant association of ACPA positivity with the presence of arthralgia, synovitis and bone erosion (p=0.017, p<10–3, p=0.05, respectively). Also, RF positivity was associated with the presence of synovitis in our patients (p<10–3). Also, our analysis demonstrated the existence of a significant association between the presence of ACPA and RF at initial diagnosis with the onset of RA in patients initially diagnosed with lupus (p=0.001). In addition, a significant link was demonstrated between the presence of anti-DNA at initial diagnosis and the appearance of SLE-specific manifestations in patients initially diagnosed with RA (p=0.003).

Conclusion A better characterization of the rhupus syndrome on the clinical and immunological levels will allow an earlier and faster diagnosis of this entity; therefore, the choice of therapies and the prognosis of joint damage would be better.