Sharp described diagnostic criteria for mixed connective tissue disease (MCTD). The author is from the University of Missouri at Columbia.
Parameters:
(1) major criteria
(2) minor criteria
(3) serologic findings (ENA = extractable nuclear antigen, Sm = Smith), RNP = ribonucleoprotein)
Major criteria:
(1) severe myositis
(2) pulmonary involvement - one or more of the following:
(2a) carbon monoxide diffusion capacity < 70% of predicted normal
(2b) pulmonary hypertension
(2c) proliferative vascular lesions on lung biopsy
(3) one or both of the following
(3a) Raynaud's phenomenon
(3b) esophageal hypomotility
(4) one or both of the following
(4a) swollen hands observed
(4b) sclerodactyly
(5) all of the following:
(5a) highest observed anti-ENA titer >= 1:10,000
(5b) anti-U1 RNP positive
(5c) anti-Sm negative
Minor criteria:
(1) alopecia
(2) leukopenia (WBC count < 4,000 per µL)
(3) anemia (<= 10 g/dL for female; <= 12.0 g/dL for male)
(4) thrombocytopenia (< 100,000 per µL)
(5) pleuritis
(6) pericarditis
(7) arthritis
(8) trigeminal neuropathy
(9) malar rash
(10) mild myositis
(11) swollen hands by history (observed swelling a major criteria)
Definite diagnosis:
(1) 4 or 5 major criteria
(2) anti-U1 RNP positive
(3) anti-ENA positive with titer >= 1:4,000
(4) anti-Sm negative (anti-Sm positive excludes a definite diagnosis)
Probable diagnosis - all of the following:
(1) 3 or more major criteria
(2) anti-U1 RNP positive
(3) anti-ENA positive with titer >= 1:1,000
Probable diagnosis - all of the following:
(1) 2 or more major criteria (include >= 1 from first 3 major criteria) AND 2 minor criteria
(2) anti-U1 RNP positive
(3) anti-ENA positive with titer >= 1:1,000
Possible diagnosis:
(1) 3 or more major criteria
Possible diagnosis - all of the following:
(1) 2 or more major criteria
(2) anti-U1 RNP positive
(3) anti-ENA positive with titer >= 1:100
Possible diagnosis - all of the following:
(1) 1 or more major criteria
(2) 3 minor criteria
(3) anti-U1 RNP positive
(4) anti-ENA positive with titer >= 1:100
