Study on the clinical characteristics of systemic sclerosis / 대한내과학회지

BACKGROUND: Systemic sclerosis (scleroderma) is a connective tissue disorder of unknown etiology characterized by fibrosis of the skin and internal organs. It is remarkably heterogeneous in initial presentations and internal organ involvement. Limited and diffuse cutaneous subsets of systemic sclerosis (SSc) are known to be different in clinical and laboratory features. The aim of the present study was to determine the clinical characteristics of systemic sclerosis in Koreans. METHODS: Fifty-six patients with systemic sclerosis at the Rheumatology Clinic of Seoul National University Hospital were studied for age, sex, symptoms, signs, and laboratory results. The differences in clinical and laboratory features between limited and diffuse cutaneous subsets were investigated. RESULTS: The mean age at diagnosis of 56 patients (male:female=1:4.6) was 42.4 years (range 11-72 years). The patients consisted of 30 limited and 26 diffuse cutaneous SSc. Cutaneous involvement was as follows: sclerodactyly (100%), Raynaud's phenomenon (94.6%), digital pitting scar (66.1%), subcutaneous calcinosis (1.8%). In musculoskeletal system, 25 cases (46.3%) developed arthralgia/arthritis, 14 cases (25.9%) myalgia. In gastrointestinal system, esophagus was affected in 11 cases (20.7%). Respiratory involvement consisted of interstitial lung disease (24 cases, 43.7%) and pulmonary hypertension (2 cases, 3.6%). Total skin score and functional vital capacity showed significant negative correlation (p<0.05). Cardiovascular involvement consisted of congestive heart failure (3 cases, 5.5%) and pericardial effusion (1 case, 1.8%). Azotemia was found in one patient (1.8%). Antinuclear antibody was positive in 53 cases (94.6%) and anticentromere antibody 2 cases (3.6%). Anti-Scl 70 antibody was positive in 46.4% of all patients, 40.0% of limited scleroderma and 53.8% of diffuse scleroderma. When comparing clinical features between limited and diffuse cutaneous subsets, musculoskeletal involvement was more common in limited scleroderma. CONCLUSION: Systemic sclerosis in Koreans showed various systemic and organ involvement, musculoskeletal system, lung and esophagus being commonly affected. There was no significant difference between limited and diffuse scleroderma in clinical features except musculoskeletal involvement. Investigation of major internal organs, especially lung and esophagus, is needed, regardless of cutaneous subsets in systemic sclerosis.

A Case of Systemic Lupus Erythematosus Associated with Myasthenia Gravis / 대한내과학회지

Myasthenia gravis(MG) is an autoimmune disorder characterized by the presence of anti-acetylcholine receptor antibody and weakness of voluntary muscles. The pathogenesis of MG is decreased numbers of acetylcholine receptors at postsynaptic membranes of neuromuscular junctions. It has been reported that MG often coexists with other autoimmune disorders. This is a case report of systemic lupus erythematosus coexisting with MG in a 23 year old female patient presenting with dysarthria, dysphagia, and limb weakness. We report the case with relevant literature review.

Autoantibody Profile using Double Immunodiffusion, Elisa, Western Blot and Its Clinical Association in Patients with Ssystemi Lupus Erythematosus / 대한류마티스학회지

OBJECTIVE: To investigate the autoantibody profile and its clinical association in patients with systemic lupus erythematosus. METHODS: The frequency and clinical correlation of autoantibodies were studied in 73 patients with systemic lupus erythematosus who have been followed in Seoul National University Hospital. Double immunodiffusion, ELISA and immunoblot were used for the detection of autoantibodies. RESULTS: The frequency of each autoantibody measured by double immunodif fusion was as follows; anti-Ro 53.4%, anti-La 11.0%, anti-Sm 20.5%, anti-U1 RNP 20.5%. The frequency of each autoantibody by ELISA was as follows; anti-Ro 69.9%, anti-La 27.4%, anti-Sm 54.8%, anti-Ul RNP 68.5%, anti-dsDNA 72.6%, anti-cardiolipin 47.2% (IgG 43.1?0, igM 15. 3%). The frequency of each autoantibody by immunoblot was as follows; anti-Ro 15.1?0, anti-La 42. 5%, anti-Sm 46. 6%, anti-U1 RNP 42. 5%. anti-ribosomal P(P0) 27.4%. Anti-Ro was associated with decreased frequency of nephrotic syndrome. Anti-U1 RNP was associated with increased frequency of malar rash, Raynaud phenomenon and decreased frequency of nephritis. Patients with both anti-Ro and anti La had more frequent serositis than those with anti-l~o only. Patients with both anti-Sm and anti-U1 RNP had less frequent thrombocytopenia than those with anti-U1 RNP only. And patients with anti-Sm and anti-dsDNA had more frequent arthritis than those with only one of both antibodies. There was a positive correlation of autoantibody titers between anti-Ro and anti-La, anti-Sm and anti-U1 RNP, anti-dsDNA and anti-cardiolipin(IgG). Taking the result of immunoblot as a standard, both of double immunodiffusion and ELISA showed low sensitivity but high specficity for anti La. As for anti-Sm and anti-U1 RNP, double immunodiffusion showed low sensitivity but high specificity, whereas ELISA showed high sensitivity but low specificity. CONCLUSIONS: In our study, some autoantibodies (anti-Ro, anti-U1 RNP) were associated with certain clinical manifestations while others not. Immunoblot being used as a standard method, ELISA showed higher sensitivity but lower specificity for anti-La, anti-Sm and anti-U1 RNP compared with immunodiffusion. It is recommended that in interpretating the laboratory findings of these autoantibodies these parameters of each method should be considered.