Neuromyositis associated with cytomegalovirus infection in an immunocompetent patient with antineutrophil cytoplasmic antibodies-associated vasculitis.

The role of CMV in ANCA-positive vasculitis is controversial. A 40-year-old man, with an unremarkable medical history, presented with progressive muscle weakness of all four limbs, accompanied by diffuse myalgia, arthralgia, and a 10 kg weight loss 2 months before admission to the Neurology Department of our hospital. Clinical examination revealed a flaccid tetraparesis with absent reflexes on the lower limbs and marked muscle atrophy. Electrophysiological investigations were consistent with a demyelinating motor polyradiculoneuropathy. Laboratory data showed AST=1137 IU/L (normal<37 IU/L), ALT=582 IU/L (normal<41 IU/L), C-reactive protein (CRP)=19 mg/L (normal<8 mg/L), CPK=13779 IU/L (normal<397). and LDH=911 IU/L (normal<192). CMV ELISA (serum) was strongly positive and CMV DNA by polymerase chain reaction (PCR) in blood and CSF also was positive. Immunologic screening revealed positive anti-myeloperoxidase antibodies anti-MPO=56,9 IU/mL (normal <9 IU/mL; ELISA). The inflammatory process involving the vessel walls and muscle fibers was histologically found in biopsy specimen of the muscle, with positive staining for CMV. The patient was treated initially with corticosteroids and intravenous immunoglobulins, but these therapies had very poor effect. Immunosuppressive therapy was instituted, resulting in a progressive partial recovery of all four limb weakness without relapses. We hypothesize that the CMV infection triggered an ANCA-positive vasculitis and its particular severe neurological involvement. An awareness of the association between CMV infection and vasculitis may have important therapeutic consequences.