Fig. 5
Distribution of serum levels of soluble Fas in relation to anti-Fas specificities. Serum levels are measured as anti-VEINCTR-N (IgG) activity detected by ELISA in 21 human immunodeficiency virus-type 1 (HIV-1)-infected subjects with definite reactivities to the Fas domain (full symbol) and 67 control patients (empty symbol). Significant titers of the soluble form of the receptor are in linear correlation (R2 = 0.168) with anti-VEINCTR-N levels. In several instances, the amount of sFas was higher than the equivalent value of 2.0 ng/ml of recombinant Fas-Fc (rFas-Fc) used as quantitative control. By contrast, sFas was significantly present in 8 subjects of the control population and exceeded the reference value only in two instances (pts. #57, and #14). Positive values of sFas were detected in control sera from three systemic lupus erythematosus (SLE) patients. Numbers relate to patients from both groups. The shaded area defines the significance limits (M + 3SD) of each parameter obtained from the whole HIV-1+ population; whereas, the black area refers to those from 19 normal donors.