Multiple sclerosis, human herpes virus type 6, and Chlamydophila pneumoniae

Background and objectives: An increasing number of papers are showing a relationship between two infectious agents, human herpes virus 6 (HHV6) and Chlamydophila pneumoniae (Cp), and multiple sclerosis (MS), although these results remain controversial. The objectives was a meta-analysis of clinical series published in literature until now. Material and Methods: An electronic database search (Medline, Excerpta Medica and IME) was performed with MS relapsing remitting and the infectious agents as keywords. A strict selection criteria was applied. 16 studies were selected who complained with the methodological criteria. Results: After statistical analysis, we found that HHV6 was related with MS by detection of DNA in plasma and antibodies in serum and cerebrospinal fluid, but not with DNA in cerebrospinal fluid or peripheral blood white cells. Cp was related with MS by detection of DNA in cerebrospinal fluid, antibodies and the isolation of bacteria of cerebrospinal fluid, but not with serum antibodies. Conclusions: A study with enough number of patients and samples, prospective, controlled with healthy subjects and other neurological diseases, with multiple microbiological techniques in the same sample and, patient, and correlated with clinical and paraclinical activity parameters, are needed.