Table IV.

Induction of IFN-α production in PBMC by apoptotic U937 cells and IgG from different SLE patientsa

Culture SupplementcSLEDAI ScoreddsDNA AbeInduced IFN-αb
Treatment of U937 cellsfControls
NoneUV
SLE-IgG 11011286 ± 401393 ± 38930 ± 15
SLE-IgG 25239173 ± 661670 ± 219142 ± 80
SLE-IgG 342326316 ± 30537 ± 5264 ± 23
SLE-IgG 4223547 ± 28803 ± 10322 ± 15
SLE-IgG 50734 ± 2645 ± 1627 ± 11
SLE-IgG 60929 ± 590 ± 1510 ± 9
SLE-IgG 741299 ± 321012 ± 16654 ± 24
SLE-IgG 80104 ± 516 ± 54 ± 2
SLE-IgG 901132 ± 1893 ± 2218 ± 6
N-IgG 176 ± 411 ± 9<2 ± 0
N-IgG 254 ± 4<2 ± 12 ± 1
N-IgG 338 ± 24 ± 2<2 ± 0
N-IgG 457 ± 610 ± 10<2 ± 0
  • a Normal PBMC were cultured with the combination of U937 cells and IgG from SLE patients (SLE-IgG) and normal individuals (N-IgG) for 24 h.

  • b The figures represent produced IFN-α (U/ml; mean ± SD), measured by immunoassay. Results from one experiment.

  • c IgG was prepared from sera by means of protein G columns and used in a final concentration of 1 mg/ml in the cultures.

  • d Clinical disease activity in individual patients was determined by the SLEDAI score.

  • e Anti-dsDNA Ab concentration (IU/ml) determined by immunoassay of sera used for IgG preparation.

  • f The U937 cells were untreated or UV-treated (60 mJ) and then cultured for 4 h before addition of PBMCs. Controls denote PBMC cultured without U937 cells.