s32_ab11

Prevalence of ANCA in mixed cryoglobulinemia and chronic hepatitis C virus infection

P. Lamprecht¹, O. Gutzeit¹, E. Csernok¹, A. Gause¹, G. Longombardo², A.L. Zignego³, W.L. Gross¹, C. Ferri⁴

¹Department of Rheumatology, University of Luebeck, and Rheumaklinik Bad Bramstedt, Luebeck, Germany; ²Rheumatology Unit, Department of Internal Medicine, University of Pisa, Pisa; ³Department of Internal Medicine, University of Florence, Florence; ⁴Rheumatology Unit, Department of Internal Medicine, University of Modena and Reggio Emilia, Modena, Italy.

ABSTRACT
Objective
To determine the prevalence, target antigens and clinical associations of antineutrophil cytoplasmic antibodies (ANCA) in chronic hepatitis C without extrahepatic manifestations and in chronic hepatitis C virus (HCV)-associated mixed cryoglobulinemia (MC) in two European centers.

Methods
50 sera from patients with chronic hepatitis C and 116 sera from HCV-associated MC were tested for cytoplasmic or perinuclear pattern (C-ANCA/P-ANCA) by indirect immunofluorescence test (IFT). ANCA target antigens were determined by enzyme-linked immunosorbent assay (ELISA).

Results
Clinical characteristics of the patients were not different between the two centers. Cryoglobulinemic vasculitis (CV) was biopsy-proven in about 90% of the MC patients. Two patients with HCV-associated MC and 1 patient with chronic hepatitis C had a P-ANCA. A C-ANCA was detected in 1 patient with HCV-associated MC. Eight patients with a HCV-associated MC and 5 patients with chronic hepatitis C had an ANCA either directed against bactericidal/permeability increasing protein (BPI) or cathepsin G (CG). BPI- or CG-ANCA positivity was not associated with a more severe disease course. The C-ANCA titer followed disease activity in one C-ANCA positive HCV-associated MC patient. The subspecifity of the C-ANCA was not determinable in that patient.

Conclusion
Two new target antigens of ANCA have been identified in HCV-associated MC and chronic hepatitis C in this study. BPI-ANCA and GC-ANCA were present in about 10% of patients with HCV-associated MC or chronic hepatitis C. ELISA proved to be more sensitive in the detection of ANCA than IFT. The present study on chronic HCV infection adds to various reports on the induction of CG- and BPI-ANCA in chronic infections.

Key words
ANCA, mixed cryoglo-bulinemia, HCV, chronic hepatitis, vasculitis, BPI-ANCA, CG-ANCA.

Please address correspondence and reprint requests to: Peter Lamprecht, MD, Department of Rheumatology, University of Luebeck, Ratzeburger Allee 160, 23538 Luebeck, Germany.
E-mail: lamprecht@rheuma-zentrum.de