Lymph node correlation to pathogen driven disease
EBV a Pathogenic Factor in Hodgkin's Disease

WESTPORT, CT (Reuters Health) Jun 11 - The Epstein-Barr virus (EBV) is not an incidental finding in Hodgkin's disease, as some have suggested, according to researchers in Saudi Arabia. They obtained evidence that EBV plays a role in the pathogenesis, and perhaps the biologic behavior, of the disease.

Dr. Walid A. Mourad and colleagues, from King Faisal Specialist Hospital in Riyadh, studied lymph node tissue from 48 patients with nodular sclerosing Hodgkin's disease. Fifty percent of patients had evidence of EBV infection, they report in the June 1st issue of the journal Cancer.

Eleven (23%) of the 48 subjects had grade II Hodgkin's. "All grade II cases showed EBV expression, whereas only 13 (39%) cases of grade I disease were positive," the authors report.

A correlation between EBV infection and lymphocyte response emerged. "EBV-positive cases had a median CD4 to CD8 ratio of 1.62, whereas EBV-negative cases had a ratio of 3.86," the authors write. Patients with grade I disease had a median CD4 to CD8 ratio of 4.58. The median T-lymphocyte to B-lymphocyte ratio was lower in EBV-positive patients compared with EBV-negative patients, and it was significantly lower in grade II patients compared with grade I patients.

Dr. Mourad's team proposes the following pathogenic model for Hodgkin's disease in relation to EBV. In the presence of a competent immune system, they say, EBV infection of B lymphocytes will be neutralized. In patients with a less competent immune system, EBV infection may lead to infectious mononucleosis or Hodgkin's-like lymphoproliferative disorder. In patients with more pronounced immunosuppression, EBV infection may lead to Hodgkin's. "If the immunosuppression and/or the viral insult are severe enough, a more aggressive form of HD manifests itself," the team suggests.