Mixed connective tissue disorder

Associate Editor:

Histopathological Findings
There are no specific histologic findings that aid in the diagnosis of Mixed Connective Tissue Disorder as a separate autoimmune disease. For example, nephritis in MCTD is usually indistinguishable from lupus nephritis.

Common symptoms

 * Raynaud’s phenomenon


 * Swollen fingers or hands

Mixed Connective Tissue Disorder Findings
A.Systemic lupus erythematosus–like findings


 * Polyarthritis


 * Lymphadenopathy


 * Facial erythema


 * Pericarditis or pleuritis


 * Leukopenia (<4,000/mm3) or thrombocytopenia (<100,000/mm3)

B.Progressive Systemic Sclerosis–like findings


 * Sclerodactyly


 * Pulmonary fibrosis, restrictive changes of the lung (forced vital capacity <80% of predicted), or reduced carbon monoxide diffusing capacity (<70% of predicted)


 * Hypomotility or dilatation of esophagus

C.Polymyositis-like findings


 * Muscle weakness


 * Elevated serum level of muscle enzymes (creatine kinase)


 * Myogenic pattern on electromyogram

Cardiac Involvement in MCTD
Cardiovascular abnormalities associated with mixed connective tissue disease are rare. Presence of any of the complications listed below indicates unfavorable prognosis;


 * Acute pericarditis and/or pericardial effusion,


 * Mitral valve prolapse,


 * Intimal hyperplasia of coronary arteries,


 * Perivascular and myocardial leukocytic infiltrates,


 * Pulmonary hypertension.


 * Coronary Artery Disease (although it is rarer, ACS may occur secondary to vascular changes and underlying CAD. The youngest patient with MCTD and ACS in literature was 18 years old)