Prevalence of chromosomally integrated HHV-6 in patients with malignant disease and healthy donors in the Czech Republic
Abstract
During the prospective surveillance, we tested 812 patients treated for malignant disease. HHV-6 DNA was detected in 86 obtained screening blood samples.
High HHV-6 DNA positivity was detected in nine samples from three children and six adults (median 93,827 NVCs; range 27,530-271,064 NVCs), while in the rest of the patients, we detected lower HHV-6 DNA levels (median 12.9 NVCs; range 1.1-1,430 NVCs). Low-level HHV-6 DNA positivity was observed in 51 children and 26 adults.
In all nine patients with high HHV-6 DNA positivity, we subsequently confirmed Ci-HHV-6 by detection of HHV-6 DNA in the nails (median 59,636 NVCs; range 35,789-130,133 NVCs). In seven of them, we detected HHV-6 A, while in the rest HHV-6 B.
During the surveillance two patients with acute myeloid leukaemia (AML) deceased due to progression of the primary disease, one underwent allogeneic haematopoietic stem cell transplantation (HSCT) for AML and the rest of the patients with Ci-HHV-6 successfully finished the chemotherapy and is at the remission of the malignant disease. From seven patients with Ci-HHV-6, we collected additional 41 peripheral whole blood samples.
The median of detected quantity in the samples obtained from the individuals without/before HSCT was 59,676 NVCs (range 10,199-271,064 NVCs). After the HSCT, we detected similar decrease (see Fig. 1) of the HHV-6 DNA as in our previous case with the median of HHV-6 quantity of 140.7 NVCs (range 47 - 84,000 NVCs).
Because the patient has integrated HHV-6 A, we also tested presence of HHV-6 B in the post-transplant samples; HHV-6 B was not detected. We did not observe clinical symptoms attributable to HHV-6 infection in any of the patients.