Lack of association between B19 or V9 erythrovirus infection and ANCA-positive vasculitides: a case-control study

Objectives. To examine the potential association of human B19 or V9 erythrovirus infection and onset of ANCA-positive vasculitides. Methods. We tested the sera of 13 adults with newly diagnosed ANCA-positive vasculitides. Each was age- and sex-matched to three sera obtained from healthy controls. All samples were tested for B19- and V9-specific immunoglobulin (Ig) G and IgM antibodies (Ab) (third-generation ELISA), and B19 or V9 DNA was sought with the polymerase chain reaction. Statistical analysis was performed by conditional logistic regression. Results. Patient diagnoses comprised six cases of Wegener's granulomatosis, six of microscopic polyangiitis and one of Churg-Strauss syndrome. IgG Ab to B19 were detected equally in patient and control sera (77 and 79% respectively) (odds ratio=0.84, P=0.84). All 13 cases and 39 controls were negative for IgM Ab and viral DNA. Conclusion. These results suggest that neither acute nor chronic B19 or V9 infection is an aetiological factor in ANCA-associated vasculitides.