Mixed Connective Tissue Disorder with Pulmonary Hypertension: A Case Report

Abstract

Background: First identified by Sharp et al. in 1972, Mixed Connective Tissue Disease (MCTD) is an autoimmune overlap syndrome that is typified by anti-U1RNP antibody positivity and symptoms of polymyositis, systemic lupus erythematosus, and systemic sclerosis. Case Presentation: A 39-year-old female presented with fever, limb and small joint pain, exertional dyspnea, bluish discoloration of fingers on cold exposure (Raynaud’s phenomenon), and dysphagia. Examination was unremarkable. Investigations revealed anemia (Hb 8.4 g/dL), thrombocytopenia (0.80 lakhs/cumm), elevated troponin-T (29.11 pg/mL), and CPK (255 IU/L). ECG showed poor R-wave progression with T-wave inversion (V1–V4), and echocardiography revealed dilated right chambers with severe tricuspid regurgitation and pulmonary hypertension. ANA and anti-U1RNP were positive, along with anti-Scl-70; skin biopsy showed sclerosis. Discussion: The patient fulfilled both Alarcón-Segovia and Kasukawa diagnostic criteria for MCTD based on serology and clinical findings. Cardiac and pulmonary involvement underscored the disease’s systemic nature. Conclusion: Early recognition of overlapping autoimmune features and serological markers is vital for timely diagnosis and management of MCTD to prevent life-threatening complications.