Table I.

IFN-α-inducing capacity of sera from SLE patients in the presence or absence of pcDNA3, in relation to serum levels of IFN-α, anti-dsDNA Abs, and total IgG

SerumSerum concentrations ofaInduced IFN-α (U/ml)b
Without pcDNA3With pcDNA3
IFN-α (U/ml)Anti-dsDNA (U/ml)Total IgG (mg/ml)Without primingWith primingWithout primingWith priming
SLE 112112535 ± 12444 ± 752454 ± 1473802 ± 110
SLE 21323925306 ± 1431034 ± 825250 ± 5926310 ± 327
SLE 37232618511 ± 541661 ± 576250 ± 3187600 ± 607
SLE 41935811 ± 5182 ± 14548 ± 1041074 ± 101
SLE 5<17213 ± 7128 ± 21<2254 ± 54
SLE 6<1923<2126 ± 2752 ± 43378 ± 67
SLE 7<112103 ± 454 ± 2418 ± 1877 ± 19
SLE 8<1107<227 ± 5<235 ± 10
SLE 9<11166 ± 6271 ± 53<2242 ± 41
NS 1<176<218 ± 11<222 ± 16
NS 2<157<24 ± 4<220 ± 10
NS 3<136<26 ± 6<231 ± 30
NS 4<158<29 ± 12<219 ± 12
Medium<2<2<2<2
  • a The concentrations of IFN-α, anti-dsDNA Abs, and total IgG were determined in nine SLE sera (SLE 1–9) and four normal sera (NS 1–4) by immunoassays.

  • b PBMC of a normal blood donor were cultured in triplicates for 24 h with indicated sera (12.5%), with and without IFN-α2b (500 U/ml) priming and with and without the immunostimulatory plasmid pcDNA3 (0.5 μg/ml). Concentrations of IFN-α in culture supernatants (mean ± SD) were determined by immunoassays. Data from one of two experiments with similar results are shown.