High prevalence of oesophageal involvement in patients with undifferentiated connective tissue disease using radionuclide oesophageal transit scintigraphy

Clinical course, prognosis, and causes of death in mixed connective tissue disease

OBJECTIVE

To study the survival rate and prognostic indicators of mixed connective tissue disease (MCTD) in a Hungarian population.

METHODS

Two hundred eighty patients with MCTD diagnosed between 1979 and 2011 were followed prospectively. Clinical features, autoantibodies, and mortality data were assessed. Prognostic factors for survival were investigated and survival was calculated from the time of the diagnosis by Kaplan-Meier method.

RESULTS

A total of 22 of 280 patients died: the causes of death were pulmonary arterial hypertension (PAH) in 9 patients, thrombotic thrombocytopenic purpura in 3, infections in 3, and cardiovascular events in 7. The 5, 10, and 15-year survival rates after the diagnosis was established were 98%, 96%, and 88%, respectively. The deceased patients were younger at the diagnosis of MCTD compared to patients who survived (35.5 ± 10.4 vs 41.8 ± 10.7 yrs; p < 0.03), while there was no difference in the duration of the disease (p = 0.835). Our cohort study showed that the presence of cardiovascular events (p < 0.0001), esophageal hypomotility (p = 0.04), serositis (p < 0.001), secondary antiphospholipid syndrome (p = 0.039), and malignancy (p < 0.001) was significantly higher in the deceased patients with MCTD. The presence of anticardiolipin (p = 0.019), anti-β2-glycoprotein I (p = 0.002), and antiendothelial cell antibodies (p = 0.002) increased the risk of mortality.

CONCLUSION

Overall, PAH remained the leading cause of death in patients with MCTD. The prevalence of cardiovascular morbidity and mortality, malignancy, and thrombotic events increased during the disease course of MCTD. The presence of antiphospholipid antibodies raised the risk of mortality.

Distinct phenotypes in mixed connective tissue disease: subgroups and survival

The aim of the present study was to assess the autoantibody profile, dominant clinical symptoms and cluster characteristics of different mixed connective tissue disease (MCTD phenotypes. Two-hundred-and-one patients with MCTD were followed-up longitudinally. Five clinical parameters, Raynaud's phenomenon, pulmonary artery hypertension (PAH), myositis, interstitial lung disease (ILD), erosive arthritis and five auto-antibodies besides anti-U1RNP, antiendothelial cell antibodies (AECA), anti-CCP, anti-cardiolipin (anti-CL), anti-SSA/SSB and IgM rheumatoid factor (RF) were selected for cluster analysis. The mean age of patients was 52.9 ± 12.4 years and the mean follow-up of the disease was 12.5 ± 7.2 years. Patients were classified into three cluster groups. Cluster 1 with 77 patients, cluster 2 with 79 patients and cluster 3 with 45 patients. In cluster 1 the prevalence of PAH (55.8%; p < 0.001), Raynaud's phenomenon (92.2%; p < 0.001) and livedo reticularis (24.6%, p < 0.001) was significantly greater than in cluster 2 and 3. In cluster 2, the incidence of ILD (98.7%; p < 0.001), myositis (77.2%; p < 0.001), and esophageal dysmotility (89.8%; p < 0.001) was significantly greater than that in cluster 1 and 3. In cluster 3, anti-CCP antibodies were present in 31 of 45 patients (68.8%) with erosions. Anti-CCP antibodies were present in 37 of 42 patients (88.0%) with erosions. PAH, angina, venous thrombosis was observed in cluster 1 and pulmonary fibrosis in cluster 2, musculosceletal damage, gastrointestinal symptoms and osteoporotic fractures were most frequent in cluster 3. Cumulative survival assessment indicated cluster 1 patients having the worst prognosis. Cluster analysis is valuable to differentiate among various subsets of MCTD and useful prognostic factor regarding the disease course.

[Undifferentiated connective tissue disease]

Evolution of immunopathological diseases is usually slow and progressive. Non-differentiated collagen disease (NDC) or the term "undifferentiated connective tissue disease" (UCTD) represents a stage of disease where clinical symptoms and serological abnormalities suggest autoimmune disease, but they are not sufficient to fulfill the diagnostic criteria of any well-established connective tissue disease (CTD) such as systemic lupus erythematosus (SLE), Sjögren's syndrome, mixed connective tissue disease (MCTD), systemic sclerosis (SSc), polymyositis/ dermatomyositis (PM/DM) or rheumatoid arthritis (RA). 30-40 percent of patients presenting undifferentiated profile develops and reaches the stage of a well defined systemic autoimmune disease during five years follow up, while 60 percent remains in an undifferentiated stage.In the stage of NDC, immunoregulatory abnormalities and endothelial dysfunction are present. In conclusion, NDC represents a dynamic state, and it is important to recognize the possibility of a progression to a definite systemic autoimmune disease.

[When does an autoimmune disease begin? Importance of the early diagnosis]

In autoimmune diseases, such as type I diabetes mellitus, systemic autoimmune diseases and the early phase of rheumatoid arthritis, before the development of a definitive disease, clinical and laboratory alterations can be observed. Being aware of these symptoms is crucial both for family practitioners and specialists, handling autoimmune and early arthritis patients. The early recognition and prognosticating of the disease and sending the patient immediately to a specialist will lead to the exponential improvement of the patient's life expectancies and will also help to avoid complications. The need for special diagnostics, care and treatment made the development of national immunological and rheumatological centers imperative, where sufficient experience and professional knowledge helps the proper medical attendance.