[Detection of active varicella-zoster virus (VZV) infection in patients with neurological complications]

Abstract

Objectives: When introduced into routine virological diagnosis of nervous system infections, PCR detection of viral DNA revealed the varicella-zoster virus (VZV) in cerebrospinal fluid (CSF) at much higher rates than expected. The aim of the study was to evaluate the frequency of VZV DNA detection in CSF of patients with neurological symptoms in correlation with their VZV-specific serological findings and clinical symptoms.

Material and methods: A total of 438 patients followed up in the neurology departments of the Motol and Královské Vinohrady University Hospitals and the Department of Infectious Diseases of the Bulovka University Hospital were screened for the presence of VZV-specific antibodies in serum and intrathecal antibodies in CSF. A home-brew nested PCR assay was used for detection of VZV DNA in CSF. Positive results were correlated with clinical findings.

Results: Intrathecal antibodies against VZV were detected in 19.6 % of the studied patients, VZV-specific IgM antibodies were present in serum of 17.3 % of the patients and VZV DNA was recorded in CSF of 9.4 % of the patients. The clinical diagnosis was confirmed in 16 patients positive for VZV DNA in CSF: encephalitis as a complication of neonatal varicella in a 2-week child; encephalitis or meningoencephalitis in 5 adult patients of whom three had a history of herpes zoster, one suffered from severe haemorrhagic focal encephalitis with fatal complications and one had encephalitis and myelitis; neuropathies in 4 patients, two with inflammatory polyneuropathy of unknown origin and two with brachial plexopathy, in one case preceded by herpes zoster; epileptic symptoms in 2 patients; multiple sclerosis in 3 patients and nonspecific symptoms of chronic fatigue in one patient.

Conclusions: 1) PCR proved to be a suitable method for diagnosing VZV-mediated nervous system infections. 2) VZV DNA can be present in CSF of patients with a wide range of neurological symptoms, even with no history of either herpes zoster or varicella. 3) VZV DNA detection in CSF needs to be interpreted with caution and in correlation with case histories, clinical findings and electrophysiological and imaging data, especially in patients with chronic inflammatory disease receiving immunosuppressive therapy.