Parameters:
(1) common symptoms (2)
(2) antibody to nRNP
(3) mixed finding groups
(3a) SLE-like findings
(3b) PSS-like findings
(3c) polymyositis (PM) like findings
Criteria for the diagnosis of MCTD:
(1) one or both of the common symptoms
(2) presence of anti-nRNP antibodies
(3) presence of >= 1 findings in >= 2 of the mixed finding groups
Common symptoms:
(1) Raynaud's phenomenon
(2) swollen fingers or hands
SLE-like findings:
(1) polyarthritis
(2) lymphadenopathy
(3) facial erythema
(4) pericarditis OR pleuritis
(5) leukopenia OR thrombocytopenia
PSS-like findings:
(1) sclerodactyly
(2) pulmonary fibrosis OR restrictive pattern OR reduced diffusion capacity
(3) hypomotility OR dilatation of esophagus
PM-like findings:
(1) muscle weakness
(2) increased serum CK concentration
(3) myogenic pattern on EMG
where:
• Leukopenia is a WBC count < 4,000 per µL.
• Thrombocytopenia is a platelet count < 100,000 per µL.
• A restrictive pattern in pulmonary function is indicated by a vital capacity < 80% of predicted.
• A reduced diffusion capacity is indicated by a CO diffusing capacity < 70% of predicted.
