Mixed connective tissue disorder

Connective tissue disease is not a specific disorder, it is a syndrome that incorporates several symptoms and clinical observations.  Many connective tissue disorders have specific names.  These include Rheumatoid arthritis, Sjogren syndrome, dermatomyositis, polymyositis, scleroderma and SLE.  When the definitions of these conditions are not respected, the term “mixed connective tissue disorder” is considered.

People with mixed connective tissue disorders may have these symptoms:

Fatigue, hand swelling, fevers, muscle or joint pains, Raynaud phenomenon (color changes in the fingers or toes)

Blood testing is not normal in the setting of mixed connective tissue disorders.  Abnormal antibodies in the blood, such as U1 RNP antibodies, may be found. This was once called the ENA.  Other lab abnormalities may be a positive ANA, speckled ANA pattern, or Anti 68 kD and A’, or C antibodies.

There is a significant overlap in laboratory findings of Mixed connective tissue disorder with systemic lupus erythematosis (SLE).  The conditions are not considered to be the same however.