Detection of cytomegalovirus-matrix protein (pp65) in leukocytes of HIV-infected patients with painful peripheral neuropathy.

Painful peripheral neuropathy (PPN) in HIV-infected patients has been increasingly associated with cytomegalovirus (CMV) infection at other sites. In the last few years, the detection of CMV lower matrix phosphoprotein (pp65) antigen in leukocytes has become a major tool in the diagnosis of CMV systemic infection in immunocompromised patients. In this study, CMV antigen detection was assessed in 13 HIV-infected patients with PPN and, as controls, in 82 HIV seropositive patients without any evidence of peripheral nerve syndromes (10 with CMV retinitis and 72 without CMV end-organ disease). CMV antigenemia was found in 10 (76.9%) patients with PPN, in 5 (6.9%) without CMV disease, and in all 10 patients (100%) with CMV retinitis. Of the 10 PPN patients with CMV antigenemia, only 3 presented with CMV retinitis, while the remaining 7 had no clinical evidence of overt CMV infection at other sites. CMV pp65-positive cells were also found in three of the four cerebrospinal fluid (CSF) samples collected from PPN patients. Ganciclovir was effective in improving neurological symptoms in two of the four treated patients. The findings suggest that active CMV infection may be associated with PPN in HIV infection even in the absence of CMV disease at other sites. The detection of CMV-matrix pp65 antigen in the blood and CSF leukocytes could represent a simple and rapid tool of selecting PPN patients for antiviral therapy.