BETA-2-GLYCOPROTEIN I-DEPENDENT AND I-INDEPENDENT ANTICARDIOLIPIN ANTIBODY IN PATIENTS WITH END-STAGE RENAL-DISEASE

We investigated whether anticardiolipin antibody (aCL), which is common in patients with end-stage renal disease (ESRD), was dependent on beta2-glycoprotein I (GPI), a cofactor of aCL. Lupus anticoagulant (LA) was identified in 13/39 hemodialysis (HD) patients. GPI-independent aCL was positive in 12/39 of this group, five of whom had both GPI-independent aCL and LA. Three of the 20 patients on symptomatic and supportive treatment other than HD had LA, but none of them were aCL positive. When GPI was added to the assay system to allow for GPI-dependent aCL measurement, the optical density (OD) readings of 10/12 HD patients decreased, thus proving that they were negative for aCL. In contrast, the OD readings of 6 control patients with systemic lupus erythematosus (SLE) increased markedly (3/6) or decreased slightly to moderately (3/6), however, within the limits of positive range, indicating GPI-dependent cCL positivity. These results suggested that LA and GPI-independent aCL were produced in ESRD patients, especially those on HD, possibly through mechanisms related to the hemodialysis membrane. However, the significance of GPI-independent aCL in this clinical setting, which may differ from the GPI-dependent aCL detected in SLE patients, as well as the possible participation of serum GPI in the production of aCL remain to be clarified.