Clinical and serologic characteristics of mixed connective tissue disease in korea / 대한내과학회지

ABSTRACT

The concept that mixed connective tissue disease (MCTD) is a clinically distinct disease entity has been the subject of debate. Some authors regard it as a transitional phase in the development of systemic lupus erythematosus (SLE), systemic sclerosis (SSc), or polymyositis/ dermatomyositis (PM-DM). This study set out to analyze the clinical and serologic characteristics of MCTD in Korean patients and to determine whether the diagnosis of MCTD held up on follow-up. METHODS: Forty-five patients diagnosed as MCTD using the diagnostic criteria of Alarcon-Segovia between October 1989 and February 1998 at Hanyang University Hospital were retrospectively reviewed. RESULTS: All but two patients were female. The average age at diagnosis was 39.3 years and the average diaseae duration was 7.5 years. The most frequent clinical symptoms were Raynauds phenomenon (100%), followed by synovitis (73%), swollen hands (68%), and myositis (48%). Lung involvement was evident in 53% and renal involvement in 15%. After a follow-up period averaging 3.3 years, 3 patients showed evidence of progressing towards SLE (increasing anti-dsDNA, decreased complement level, or disappearance of anti-nRNP and appearance of anti-Sm). One of our patients converted to SSc, but none of our patients converted to PM/DM. CONCLUSION: Only 4 (9%) of our patients showed evidence of developing into a classic connective tissue disease. Although we believe that regular follow-up on our patients would be needed, our findings lead us to conclude that MCTD is a distinct entity in Korean patients.