Prevalence of human herpesvirus-8 (HHV-8) DNA among South American blood donors: lack of association with the genetic ancestry of the population

TORRES OW; HULANIUK ML; BARTOLI S; FORTUNY L; BURGOS PRATX L; FRIAS A; NUÑEX F; CORACH D; CAPUTO M; TRINKS J

Londres

Congreso; 25th Congress of the International Society of Blood Transfusion (ISBT); 2015

International Society of Blood Transfusion (ISBT)

BACKGROUND: HHV-8 has been postulated as a new infectious agent for screening in blood donors. The viral spread among human populations varies widely with a striking geographical and ethnic distribution pattern described by its seroprevalence rates; for example, HHV-8 is 10-fold higher among Native Americans than among non-native populations. Little is known, however, of the prevalence of HHV-8 DNA in South American countries and its association with the highly admixed genetic ancestry of the population. AIMS: To determine -for the first time- the prevalence of HHV-8 DNA among healthy blood donors from different South American populations and its association with the genetic ancestry. METHODS: After signing an informed consent statement upon enrolment, DNA was obtained from 667 unrelated blood donors, whose serum samples were routinely tested for transfusion transmission infections rendering negative results. Volunteers were grouped as Argentines from the metropolitan (n=200) and North-western (n=106) areas, Bolivians (n=187), Paraguayans (n=98) and Peruvians (n=76). The presence of HHV-8 DNA was determined by a nested PCR protocol for partial amplification of ORF26. In 319 randomly-selected samples (107 from the metropolitan region, 48 from North-western Argentina, 57 from Bolivia, 55 from Paraguay and 52 from Peru), ethnicity was assessed in both maternal and paternal lineages by analysis of haplogroups in mitochondrial DNA and Y chromosome polymorphisms using real-time PCR followed by High Resolution Melting. Chi-square and Fisher´s exact tests were used for statistical analysis. A p-value of less than 0.05 was considered as statistically significant. RESULTS: HHV-8 DNA was significantly more prevalent among blood donors from North-western Argentina (24.5%) than among Argentines from the metropolitan area (3.5%), Bolivians (3.2%), Peruvians (6.6%) and Paraguayans (7.1%) (OR 8.45, 95% CI 3.47-20.56, p less than 0.0001). There were no significant differences in the viral prevalence between men and women of the studied populations, although a possible high risk was observed among Bolivian men (p=0.051). HHV-8 infection was more prevalent among metropolitan Argentines under the age of 30 years (p less than 0.05). Interestingly, North-western Argentines older than 30 years old were more commonly infected than blood donors within the same age group from the other populations of this study (p less than 0.03). Significant differences were observed in the ancestry components of the studied populations. When compared with blood donors from North-western Argentina, Bolivia, Peru and Paraguay, the prevalence of Native American maternal and paternal haplogroups was the lowest for metropolitan Argentines (p less than 0.01). However, no statistical significant differences were found when analysing the relationship between HHV-8 DNA prevalence and genetic ancestry. CONCLUSIONS: The results presented herein indicate that HHV-8 infection is highly endemic in North-western Argentina. The variation in the distribution of HHV-8 in South America remains intriguing and may be associated with specific risk factors or behaviours, but not with the genetic ancestry of the population. In the present study, all HHV-8 DNA positive samples were non-reactive to all other infectious agents tested in blood banks and consequently these blood units were available for transfusion. Special caution should be taken with immunosuppressed recipient patients who are prone to acquire infections and develop the HHV-8 associated diseases.