Distinct phenotypes in mixed connective tissue disease: subgroups and survival

Area of Science:

• Rheumatology
• Immunology
• Internal Medicine

Background:

• Mixed Connective Tissue Disease (MCTD) is an autoimmune disorder with heterogeneous clinical presentations.
• Understanding distinct MCTD phenotypes is crucial for accurate diagnosis and prognosis.
• Autoantibody profiles and clinical symptoms are key indicators of disease characteristics.

Purpose of the Study:

• To analyze autoantibody profiles and dominant clinical symptoms in MCTD patients.
• To identify and characterize distinct clusters of MCTD phenotypes.
• To evaluate the prognostic value of cluster analysis in MCTD.

Main Methods:

• Longitudinal follow-up of 201 patients diagnosed with MCTD.
• Selection of five clinical parameters (Raynaud's phenomenon, PAH, myositis, ILD, erosive arthritis) and five autoantibodies (AECA, anti-CCP, anti-CL, anti-SSA/SSB, IgM RF) for cluster analysis.
• Classification of patients into three distinct cluster groups using statistical analysis.

Main Results:

• Cluster 1 (77 patients) showed high prevalence of Pulmonary Artery Hypertension (PAH) and Raynaud's phenomenon.
• Cluster 2 (79 patients) was characterized by a high incidence of Interstitial Lung Disease (ILD) and myositis.
• Cluster 3 (45 patients) exhibited a higher frequency of anti-CCP antibodies, erosions, and musculoskeletal damage.

Conclusions:

• Cluster analysis effectively differentiates MCTD subsets based on distinct clinical and serological profiles.
• Cluster 1 patients demonstrated the poorest cumulative survival, indicating a worse prognosis.
• This approach provides valuable insights for predicting disease course and guiding patient management in MCTD.