Mixed connective tissue disease

Mixed connective tissue disease (MCTD) is a type of connective tissue disease. With regards to clinical and imaging features, it can have significant overlap with other connective tissue disease such as systemic lupus erythematosus and scleroderma 1. It therefore classified as a type of overlap syndrome and at times it even comes under debate as to whether MCTD should exist a distinct entity 7.


It occurs from an autoimmune abnormality and often is defined by the presence of a ribonuclease-sensitive extractable nuclear antigen.


A prerequisite for the diagnosis of mixed connective tissue disease is the presence, in the serum, of high titers of antibodies against uridine-rich RNA-small nuclear ribonucleoprotein (snRNP) - anti-U1-RNP antibodies 10

The presence of anti-U1-70 kd is considered a characteristic feature.

Organ spectrum

MCTD can affect various organ systems where pulmonary 6 and musculoskeletal 4-5 are some of the two key systems to get affected. As such these are best discussed under separate headings


It was thought to have been first described by Sharp and colleagues in 1972.

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Article information

rID: 16931
Tag: cases
Synonyms or Alternate Spellings:
  • Mixed connective tissue disease (MCTD)
  • MCTD
  • Sharp syndrome
  • Sharp's syndrome

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