Antibodies to RNP occur in approximately 50% of patients with lupus erythematosus (LE) and in patients with other connective tissue diseases, notably mixed connective tissue disease (MCTD).
Spin
Gold serum separator (SST) tube
Spin and separate
Refrigerated (preferred) - 7 days
Frozen - 21 days
Ambient - NO
Chemiluminescent Immunoassay (CIA)
Negative: < 20 CU
Strong positive: ≥ 20 CU