HHV-7 in adults with drug-resistant epilepsy: A pathological role in hippocampal sclerosis?

The study sample included 201 male subjects. The mean age was 23.9, SD 6.2 years (range 15-45). HS was the pathology in 69 samples (23%). The HHV-7 protein was detected in 27 (9%) of the 305 samples and in none of the 42 controls. The factors associated with HHV-7 infection were HS (11/69), glial scar (8/58), arachnoid cyst (2/21), focal cortical dysplasia (2/31) and vascular malformation (4/52). HHV-7 antigen was distributed mainly in the cytoplasm of astrocyte and oligodendrocyte in HS samples. HHV-7 DNA was detected in 20 of the 63 nitrogen preserved HS samples. The expression of TGF-β was up-regulated in samples that were positive for the HHV-7 protein and was mainly detected in neurons. This finding suggests a possible association between HHV-7 positivity, activation of TGF-β and drug-resistant epilepsy, especially HS, but these data need to be replicated.