Paul Allison

Publications (2)6.43 Total impact

• Article: Herpesvirus prevalence and viral load in healthy blood donors by quantitative real-time polymerase chain reaction.

  S David Hudnall, Tiansheng Chen, Paul Allison, Stephen K Tyring, Ashley Heath
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  ABSTRACT: After primary infection, human herpesviruses (HHVs) maintain long-term latent persistence, often punctuated years later by sporadic episodes of symptomatic lytic activation. Also, blood-borne herpesvirus from healthy persistently infected blood donors can lead to active primary infection of immunocompromised transfusion recipients. Utilizing a set of newly developed real-time polymerase chain reaction assays for detection and quantification of all eight human herpesviruses, the prevalence and viral DNA load of white cell-enriched blood from 100 randomly selected blood donors from the southeast Texas region are reported. Herpes simplex viruses 1 and 2 (HSV-1 and HSV-2), varicella-zoster virus (VZV), and HHV-8 DNA were not detected in any donor sample. In contrast, Epstein-Barr virus (EBV) (72%) and HHV-7 (65%) were commonly detected, HHV-6 (30%) was often detected (Type B only), and cytomegalovirus (CMV; 1%) was rarely detected. Median viral loads of positive samples (per milliliter of blood) ranged from 4278 for HHV-6 to less than 46 for EBV. These results suggest that the potential for transfusion-mediated transmission of herpesviruses from healthy adult blood donors is high for EBV and HHV-7; moderately high for HHV-6; uncommon for CMV; and rare for HSV-1, HSV-2, VZV, and HHV-8. Perhaps the most remarkable finding in this study was the detection of a single donor sample with greater than 6.1 x 10(7) HHV-6 Type B genome equivalents per mL blood. Given that this extraordinarily high level of HHV-6 DNA was obtained from a healthy adult blood donor, this phenomenon is likely unrelated to active infection or immunodeficiency.
  Transfusion 05/2008; 48(6):1180-7. · 3.22 Impact Factor
• Article: Human herpesvirus 8 seroprevalence and viral load in healthy adult blood donors.

  S David Hudnall, Tiansheng Chen, Peter Rady, Stephen Tyring, Paul Allison
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  ABSTRACT: Human herpesvirus 8 (HHV-8) is widely suspected to be a human tumor virus because it is associated with Kaposi's sarcoma and primary effusion B cell lymphoma. Report of a case of HHV-8-positive donor blood in the US has led to concern for the safety of donor blood from HHV-8-seropositive donors. The findings of HHV-8 seroprevalence and virus load from 100 randomly selected blood donors from the Houston, Texas, area are reported. Serology with serial titration was performed using a highly sensitive indirect immunofluorescence assay to lytic and latent HHV-8 antigens. For detection of blood-borne virus, buffy-coat DNA was subjected to two ultrasensitive nested PCR-dot blot assays to HHV-8 orf26 and orf72 regions. At a screening titer of 1 in 10, nearly one-quarter (23%; 95% CI, 15-33) of the blood donors are HHV-8 seropositive with a geometric mean titer of 1 in 53. Seroreactivity to lytic antigens (23%) greatly exceeded that to latent antigens (5%). There was a significant association between seropositivity and older age (p < 0.02), white ethnicity (OR, 3.33; 95% CI, 1.40-7.95) and ABO blood group B (OR, 6.44; 95% CI, 2.46-16.80). No association with sex or CMV seropositivity was demonstrated. No HHV-8 viremia was detected, even though 64 percent of tested donor blood samples were EBV DNA positive. Despite a relatively high HHV-8 seroprevalence in this cohort of Houston area blood donors, HHV-8 DNA was not detected in any sample of donor whole blood using a highly sensitive PCR assay. Thus, at least in the southeast Texas region, large-scale screening of blood donor units for HHV-8 antibody or DNA seems unwarranted.
  Transfusion 01/2003; 43(1):85-90. · 3.22 Impact Factor