serology
Last reviewed 01/2018
Autoantibodies:
- antibodies to double stranded DNA and the antinuclear antibody anti-Sm, are highly specific for SLE but are poor "markers" because of their low prevalences, 50-70% and 7-30%
- anti-Ro and anti-La antinuclear antibodies occur in both SLE and Sjogren's syndrome
- anti-Ro is important in pregnancy since it is associated with babies born with congenital heart block
- anti U1 ribonucleoprotein, formerly, anti-RNP, is not specific for SLE
- anti-histone antibodies indicate drug induced SLE
- anti-cardiolipin is associated with thrombosis (arterial or venous), chorea, and livedo reticularis
Lupus anticoagulant in 30% of cases - with prolonged PTT and false-positive VDRL test for syphilis.