Presence of cytomegalovirus and human herpesvirus 6 in-patients with lymphomas

Abstract

Background: Cytomegalovirus (CMV) and human herpesvirus 6 (HHV-6) remain latent after primary infection and can be reactivated after immunosuppression. Very little is known about the prevalence of these herpes viruses in lymphomas patients following cytotoxic chemotherapy in the absence of allogeneic transplantation. Therefore, this study investigated the frequency of HHV-6, its impact on clinical manifestations and its possible association with the risk of development of CMV infection in Hodgkin's and non-Hodgkin's Lymphoma (HL &NHL). Methods and materials: This study included 62 patients with lymphomas (25 HL and 37 NHL) diagnosed and treated in the hematology department of Farhat Hached Hospital in Sousse (Tunisia) during the period from June 2015 to July 2018. One hundred and twenty-four healthy individuals were used as age and sex-matched control group. Herpesviruses DNA (HHV6 and/or CMV) were detected by multiplex polymerase chain reaction (PCR). Nested PCR was used to discern HHV-6 variants A and B for each HHV6 positive sample. Results: Herpesviruses DNA (HHV6 and/or CMV) was present in 12 of the 62 patients with lymphomas (19.35%), a frequency that was significantly higher than that in the control group (4/124, 3.2%) (p < 0.01).There was no significant difference between HL or NHL groups regarding the presence of HHV6 and or CMV (p = 0.74). The CMV DNA was identified in eight patients (1HL, 7NHL) while in 4 both CMV and HHV-6(3HL, 1NHL).CMV infection was associated with a significantly higher rate of HHV6 infection (p < 0.01). Variant B was found in 2 HL patients and variant B in 2 NHL while all the control group individuals showed positive for HHV-6 variant B. Ten out of twelve infected patients were symptomatic with fever and pneumonia (60%), lymphopenia (<500/μL) (30%), diarrhea (20%), hepatitis (10%). The presence of both herpes viruses DNA was not significantly associated with more frequent symptomatic infection (100% vs. 75%, p = 0.5). Conclusion: The detection of CMV and/or HHV6 were more commonly observed in patients with lymphomas and HHV-6 infection was often revealed with CMV infection. In the future, enhanced prospective surveillance may help shed more light on the clinical significance of these herpes virus infections in patients with lymphomas.