Quantitative demonstration of intrathecal synthesis of high affinity immunoglobulin G in herpes simplex encephalitis using affinity-mediated immunoblotting

Three paired serial samples of CSF and serum (from days 8, 13 and 22) were taken from a patient referred to the National Hospital for Neurology and Neurosurgery with what was duly confirmed as having herpes simplex encephalitis using PCR. The samples were investigated using affinity-mediated immunoblotting followed by incubation with sodium thiocyanate. Digitisation of the blots enabled further analysis. We showed that the clones of antigen-specific IgG, which were produced intrathecally, were of higher relative affinity than polyclonal antigen-specific IgG.