ABSTRACT

To study the prevalence of different anticardiolipin antibody isotypes (aCLs), anti-C1q antibodies (anti-C1q), and anti-b2-glycoprotein 1 IgG antibo-dies (anti-b2GP1 IgG) in a group of Turkish SLE patients and their association with lupus nephritis and extra-renal involvement

SLE patients who were evaluated in Ankara Univer-sity Faculty of Medicine, Department of Clinical Immunology and Rheuma-tology between May 2001 and May 2002 were included in the study, unless they were also hemodialysis patients. Disease duration, medications, organ involvement, disease complications and follow-up laboratory results were re-corded. Disease activity was evaluated with SLEDAI; a score of ≥ 4 indicated active disease. Antibody titers were determined using the enzyme immunoas-say method.

A total of 62 patients (51 women, 11 men) were included. The mean age was 37. Average duration of illness was 104 months. Of the patients, 55% had a SLEDAI score of ≥ 4. Renal involvement was present in 76%, with active nephritis in 49%. Thrombosis was present in 11%, 16% had obstetric complications, 37% had neurologic findings, 26% had thrombocytopenia, and 45% had Raynaud’s phenomenon. None of the antibodies were related to re-nal involvement. Patients with SLEDAI ≥ 4 had significantly increased total aCL positivity (p<0.05). There was no relation between disease duration and antibody positivity. Anti-b2GP1 IgG and aCL IgG were significantly related to thrombosis (p<0.05). The negative predictive value of aCL for thrombosis was high, 94%. A significant association between thrombocytopenia and aCL IgG positivity was observed (p=0.026). Anti-b2GP1 IgG positivity showed a significant correlation with all aCL isotypes. None of the antibodies had a significant relationship with obstetric complications, neurologic findings, or Raynaud’s phenomenon.

The findings that aCL IgG positivity was closely associated with thrombotic events and thrombocytopenia, and anti-b2GP1 IgG was closely as-sociated with aCL levels and thrombosis were in accordance with the general literature. No relation between anti-C1q and renal involvement, renal flare, or proliferative nephritis was demonstrated in this group of Turkish patients.