Phantom cytomegalovirus infection in vasculitis patients: what it means and what to do.

We report our experience and hypothesis on the diagnosis and treatment of patients with vasculitis who are simultaneously diagnosed with serum-positive cytomegalovirus (CMV) immunoglobulin (Ig)M antibodies and negative CMV DNA polymerase chain reaction (PCR). It remains unknown how to treat this kind of "phantom" CMV infection. In a patient diagnosed with Henoch-Schönlein vasculitis, CMV IgM titers were increased while angiitis and renal function deteriorated. Empiric treatment of phantom CMV infection with ganciclovir in this CMV IgM-positive and PCR-negative patient resulted in complete vasculitis remission, serum CMV antibody seroconversion, and renal function improvement. These results imply something more than coincidence.