The utility of plasma polymerase chain reaction for human herpes virus-6 among pediatric bone marrow transplant recipients: results of a pilot study

Abstract

Summary:We evaluated the utility of plasma polymerase chain reaction (PCR) for surveillance of human herpes virus 6 (HHV-6) infection among pediatric bone marrow transplant (BMT) recipients. We used a prospective, non-interventional design involving a study group and controls. BMT recipients and healthy controls were evaluated. BMT subjects had HHV-6 PCR done biweekly for 12 weeks post transplantation, while a single PCR test was done on controls. For the PCR assay, EDTA blood was collected and DNA extracted from whole blood and cell-free plasma using standard procedures. The PCR was first performed on DNA from whole blood and if a positive result was obtained, the test was repeated on the DNA from the plasma. Thirty BMT recipients (13 autologous and 17 allogeneic) were enrolled, on whom a total of 156 PCR tests were performed, while six tests were done on six healthy controls. The median age of BMT subjects was 6.2 years (range 0.5-17.5 years). The median age of the control subjects was 6.6 years (range 2-10 years). Among asymptomatic BMT patients who had PCR surveillance, the positivity rate was 3.3% (1/30) on whole blood and 0% (0/30) on plasma. None of the six healthy subjects had a positive PCR test on whole blood. During the period of the surveillance study, 14 patients had diagnostic evaluations for HHV-6 disease because of clinical symptoms. Two of these patients were diagnosed with disease associated with HHV-6 (graft failure and encephalitis) and had positive PCR tests on whole blood and plasma and whole blood and cerebrospinal fluid, respectively. We conclude that despite the fact that HHV-6 seropositivity rates are high among children, the frequency of HHV-6 plasma PCR positivity is low in pediatric BMT subjects who are asymptomatic for HHV-6 disease. Given that a positive test on plasma is consistent with active infection, this increases the utility of the PCR test as a

Epstein-Barr Virus in Pediatric Multiple Sclerosis

“…Of greater interest would be the study of HHV-6 replicative/latency status, which would require molecular methods such as polymerase chain reaction techniques. 20 Such analyses are planned. Although many viral agents other than EBV, including Chlamydia pneumoniae, have been studied in MS, strong associations have yet to be documented, owing in part to differences in methodology and patient populations.…”

Human herpesvirus-6 and -7 in pediatric stem cell transplantation

“…Pediatric studies on HHV-6 and -7 have mostly focused on recipients of allogeneic stem cell grafts from both unrelated [20] and related donors [5] or the analysis has been limited to HHV-6 [20,21]. Chan et al and Miyoshi et al [11,22] studied both viruses among pediatric recipients of allogeneic and autologous stem cell grafts.…”

“…Chan et al and Miyoshi et al [11,22] studied both viruses among pediatric recipients of allogeneic and autologous stem cell grafts. The incidence of HHV-6 viremia among pediatric SCT recipients varied from 3% to 68% [5,11,13,[20][21][22] and that of HHV-7 from 42% to 67% [11,22]. Polymerase chain reaction (PCR) was mostly employed in the detection of HHV-6 and -7 [5,11,21,22].…”

“…The incidence of HHV-6 viremia among pediatric SCT recipients varied from 3% to 68% [5,11,13,[20][21][22] and that of HHV-7 from 42% to 67% [11,22]. Polymerase chain reaction (PCR) was mostly employed in the detection of HHV-6 and -7 [5,11,21,22]. Clinical manifestations of HHV-6 infections varied from nonspecific symptoms to organ manifestations such as pneumonia [20,22].…”

Optimization of the Sybr Green real time PCR for the detection of Human Herpes Virus type 6 (HHV-6)

“…Reactivation may occur after primary infection later in life in healthy individuals but mainly in immunodeficient patients leads to acute or even fatal disease 5 . Several conventional PCR techniques have already been described 1,8 but processing time is long, results and number of copies are only shown at the end of the reaction and contamination risks are greater when compared to real time PCR. HHV6 quantification methods are necessary to monitor the different stages of disease such as latency, reactivation or active infection 7 .…”