Intrathecal synthesis of specific antibodies as a marker of herpes simplex encephalitis in patients with negative PCR

摘要

Study question Detection of herpes simplex in the cerebrospinal fluid using PCR technology may sometimes be negative for several reasons. The diagnosis may then rely on the detection of intrathecal specific im-munoglobulins. Summary answer The detection of specific immunoglobulins in the CSF is a useful tool when clinical signs, MRI imaging and EEG signs are in favour of herpes simplex encephalitis and the PCR is negative, even if a short delay is required. What is known and what this paper adds PCR is highly sensitive but may be negative for several reasons such as low viral load or a too short time lapse between the onset of the disease and CSF analysis. Intrathecal specific immunoglobulins were widely used before the PCR era but are now forgotten. This technique should be used in parallel to PCR when a doubt exists on the diagnosis.