'Rhupus syndrome', Coexistence of Rheumatoid Arthritis and Systemic Lupus Erythematosus

Yun, Hyung Ran; Jun, Jae Bum; Lee, Myong Ho; Lee, Hye Soon; Lee, Ji Hyun; Kim, Tae Hwan; Jung, Sung Soo; Lee, In Hong; Bae, Sang Cheol; Yoo, Dae Hyun; Kim, Think You; Kim, Seoun Yoon

Abstract

OBJECTIVE
This study was designed to evaluate clinical features of 20 patients with rhupus syndrome and compare its characteristics with systemic lupus erythematosus(SLE) and rheumatoid artiritis(RA).
METHODS
Patients considered to have rhupus who met the American College of Rheumatology(ACR) 1997 and 1987 revised criteria for SLE and RA, respectively and age, sex, and disease duration matched 64 patients with RA and 56 patients with SLE were selected for comparison.
RESULTS
Twenty patients were all female and their mean age was 43.7+/-9.6 years(range 25~68). They had 5.5 ACR criteria for RA and 5 criteria for SLE. The mean age at onset of RA was 35.2+/-10.5 years(19~63) and that of SLE was 38.2+/-10.0 years(20~63), giving a mean interval between the diagnoses of the two diseases of 3.0+/-5.7 years (14~(-6)). There were 2 patients(10%) with rheumatoid nodule, and 18 patients(90%) with rheumatoid factor, and 16 patients(80%) with bone erosions on hand or wrist joints. The criterial for SLE included malar rash(20%), discoid rash(0%), photosensitivity(30%), oral ulcer(45%), arthritis(100%), serositis(35%), renal disorder(15%), neurologic disorder(0%), hematologic disorder(100%), immunologic disorder(90%), and positive antinuclear antibody(100%). Anti-dsDNA was more than 7.0U/ml in 15 patients(75%). The patients with rhupus syndrome showed lower amount of 24 hour urine protein, more severe radiologic involvement, younger age at onset of arthritis, higher titer of rheumatoid factor, lower frequency of low C3, and less complicated clinical course when compared with the patients with SLE(p<0.05). More frequent anemia, Rayanud's phenomenon, and more complicated clinical course in rhupus when compared with the patientw with RA(p<0.05), but the radiologic stage of hand and wrist was similar between rhupus and RA.
CONCLUSION
Rupus syndrome showed somethisg different clinical characteristics and clinical course when compared with SLE and RA.