Association of HHV-6 with Hodgkin and non Hodgkin lymphoma.

BACKGROUND AND OBJECTIVES: Human Herpes 6 virus (HHV-6) could remain latent and chronic in the host cells after primary infection. HHV-6 genome encodes certain transactivation proteins which may results in development of malignant lymphoma. The association of human herpes six virus (HHV-6) infection and Hodgkin and Non-Hodgkin lymphomas is strongly supported by epidemiological studies. The aim of this study was to determine the prevalence of HHV-6 among the patients with Hodgkin, Non-Hodgkin's lymphoma.

MATERIALS AND METHODS: Overall 44 blocks of formalin-fixed, paraffin-embedded of the patients including 22(50%) Hodgkin and 22(50%) Non-Hodgkin Lymphoma were collected. Initially the section of 5μm-thickness were prepared from the formalin-fixed, paraffin-embedded tissue blocks. Then the deparaphinazation was carried out for each sample. The DNA was extracted, followed by nested PCR for detection of HHV-6. Based on PCR product size and sequencing, the HHV-6 A or B subtypes were characterized.

RESULTS: 12/22(54.54%) cases of Hodgkin and 8/22 (36.36%) Non-Hodgkin's lymphoma were shown as positive for HHV-6. Out of 12 positive HHV-6 in Hodgkin lymphoma, 10 patients (45.45%) belonged to variant A while 2 cases (9.09%) were found positive for both HHV-6A and HHV-6B. All the Non Hodgkin samples (n=8, 36.36%) showed positive for HHV-6 variant A.

CONCLUSION: High prevalence of HHV-6 was found among the patients with Hodgkin and Non-Hodgkin's lymphoma. Two patients with Hodgkin lymphoma had mixed HHV-6A and HHV-6B infections. It is recommended patients with Hodgkin and Non-Hodgkin should be screened for HHV-6 detection before chemotherapy.