IgA anti-beta-2 glycoprotein I antibodies in chronic hepatitis C

Background and study aims: Antiphospholipid antibodies (aPL) have been reported not only in various autoimmune conditions but also in other infections, such as chronic hepatitis C (CHC) infection. The aim of this study is to evaluate the frequency of aPL in patients with CHC.

Patients and methods: Ninety-six CHC patients and 90 healthy blood donors (HBD) were studied. Fifty-three of the patients were under treatment, and 43 had not yet received any treatment. IgG, IgA, and IgM antibodies against cardiolipin (aCL) and beta-2 glycoprotein I (aβ2GPI) were detected by ELISA.

Results: We found that the frequency of aPL (aCL and/or aβ2GPI) was significantly higher in CHC patients than in controls (51% vs 11.1%, p <10^-6). The frequencies of aCL and aβ2GPI were significantly higher in patients than in HBD (27.1% vs 5.5%, p < 10^-3, and 44.8% vs 11.1%, p < 10^-6, respectively). The isotype distribution of aCL and aβ2GPI demonstrated that aCL-IgG and aβ2GPI-IgA were more frequent in patients than in healthy subjects (21.9% vs 2.2%, p < 10^-3, and 38.5% vs 7.8%, p < 10^-6, respectively). In CHC patients, the frequency of aβ2GPI was significantly higher than that of aCL (44.8% vs 27.1%, p = 0.01). aβ2GPI-IgA was significantly more frequent than aβ2GPI-IgG (38.5% vs 7.3%, p <10^-6), aβ2GPI-IgM (38.5% vs 9.4%, p <10^-3), and aCL-IgG (38.5% vs 21.9%, p = 0.01). No difference in aPL frequency was observed between the treated and untreated patients.

Conclusion: On the basis of the findings of this study, aPL, particularly aβ2GPI-IgA and aCL-IgG, are frequent in CHC patients.