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.
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
- pulmonary manifestations of mixed connective tissue disease
- musculoskeletal manifestations of mixed connective tissue disease
It was thought to have been first described by Sharp and colleagues in 1972.
- 1. Sliver, Terry M.; Farber, Stephen J.; Bole, Giles G.; Martel, William. Radiology. doi:10.1148/120.2.269
- 2. Bennett RM, O'connell DJ. The arthritis of mixed connective tissue disease. Ann. Rheum. Dis. 1978;37 (5): 397-403. doi:10.1136/ard.37.5.397 - Free text at pubmed - Pubmed citation
- 3. O'connell DJ, Bennett RM. Mixed connective tissue disease--clinical and radiological aspects of 20 cases. Br J Radiol. 1977;50 (597): 620-5. doi:10.1259/0007-1285-50-597-620 - Pubmed citation
- 4. Lawson JP. The joint manifestations of the connective tissue diseases. Semin Roentgenol. 1982;17 (1): 25-38. - Pubmed citation
- 5. Udoff EJ, Genant HK, Kozin F et-al. Mixed connective tissue disease: the spectrum of radiographic manifestations. Radiology. 1977;124 (3): 613-8. doi:10.1148/124.3.613 - Pubmed citation
- 6. Kim EA, Lee KS, Johkoh T et-al. Interstitial lung diseases associated with collagen vascular diseases: radiologic and histopathologic findings. Radiographics. 2002;22 Spec No : S151-65. Radiographics (full text) - Pubmed citation
- 7. Black C, Isenberg DA. Mixed connective tissue disease--goodbye to all that. Br. J. Rheumatol. 1992;31 (10): 695-700. doi:10.1093/rheumatology/31.10.695 - Pubmed citation
- 8. Citera G, Lázaro MA, Maldonado cocco JA. Mixed connective tissue disease: fact or fiction? Lupus. 1995;4 (4): 255-7. - Pubmed citation
- 9. Magro CM, Crowson AN, Regauer S. Mixed connective tissue disease. A clinical, histologic, and immunofluorescence study of eight cases. Am J Dermatopathol. 1997;19 (3): 206-13. Am J Dermatopathol (link) - Pubmed citation
- 10. Prakash UB. Respiratory complications in mixed connective tissue disease. Clin. Chest Med. 1999;19 (4): 733-46, ix. Pubmed citation