Infectious diseases research

Session 4

Kenny de Meirleir (Brussels, Belgium) opened this session with an overview of his research looking at herpes virus and parvovirus B-19 DNA in the gastric and intestinal mucosa of patients with CFS. HHV-7 was frequently found in both patients and controls. EBV and HHV-6 were also detected in patients and controls, and HHV-6 was detected significantly in a small subset of patients in duodenum and stomach. Parvovirus B-19 DNA was however significantly higher in patients and B-19 DNA was found in the peripheral blood of those biopsy-positive patients. One case study of a 20-year old female (+ve B19) was treated for 4 months with γ-globulin and there was no residual load of B-19.

Viral gene micro-array was used to detect viral DNA in 40 patients by the team led by Judy Mikovits (Reno, USA). 1608 viral transcripts, microRNA or endogenous viral elements were observed in the subgroups of patients and controls. Adeno- and rhino-viruses were the most commonly detected in the controls. Herpes viruses (particularly HHV-7 and CMV) predominated among the CFS patients. Human endogenous retroviral elements were also differentially expressed. This may be significant in CFS as neuro-degeneration can result. Bombyx mori densovirus was the 5^th most highly expressed virus in CFS patients, and adeno-associated-virus 3,3e,4 and 2 were all in the top 20 expressed in patients but not  in the controls. These viruses require helper viruses such as herpes or adenovirus to replicate. These studies may provide insight into the immuno-pathogenesis in CFS.

Studies by Modra Murovska (Riga, Latvia) concluded that active infection with HHV-6 and HHV-7 is more frequent in CFS patients than in healthy blood donors. B-19 DNA was also found in the plasma of patients but not controls. Reactivation of these viruses may lead to immune dysfunction.

Barbara Cameron (Sydney, Australia) presented further work from the Dubbo Infection Outcomes Study. This study looks at the evolution of CFS following PIFS prospectively. All 20 of the subjects (10 patients and 10 controls) were sero-positive for HHV-6 and 10 were positive for CMV (5 patients and 5 controls) at baseline. Some EBV titres increased over time in patients and controls. Over time there was no correlation between symptom scores and antibody titres. The data do not support the hypothesis of ongoing active EBV, HHV-6 or CMV in the pathogenesis of PIFS or CFS.