MicroRNA 320a and Membrane Antigens as Tools to Evaluate the Pathophysiology of Platelets Stored in Blood Banks.

Our research group, through the analysis of miRNomes in platelet concentrates (PCs) stored in blood banks, identified and validated the miR-127 and miR-320a miRNAs as biomarkers of platelet storage lesions (PSLs) in PCs. In order to validate the miRNAs 127 and 320a methodologically, as PSL biomarkers in a large number of PC bags, we also evaluated important immunological markers involved in the platelet activation/aggregation process-the CD62P receptor (P-selectin), the surface glycoproteins (GP) IIb/IIIa, and the purinergic P2Y12 receptor-via flow cytometry. The miRNAs miR-127 and miR-320a were quantified by real-time quantitative PCR (RT-qPCR). To carry out this study, 500 collection tubes were used at the upper edge of the PC bags containing platelets. Each tube was divided into seven equal parts (totaling 3500 samples) for platelet analysis from 7 different storage days, where the 1st day represents the high-quality control, and the 7th day corresponds to the low-quality control of the platelets. After analyzing all parameters during storage days, it was concluded that the relative quantification of miR-320a below 0.50 and the CD62P receptor below 27.92% are reliable indicators of the absence of storage lesions in blood banks. We believe that the values found in the expression of the CD62P receptor legitimize the use of the miR-320a and miR-127 miRNAs to build a kit capable of accurately measuring whether the stored platelets are suitable for transfusion.

Prevalence, incidence and residual risk of transfusion-transmitted HBV infection before and after the implementation of HBV-NAT in northern Brazil.

BACKGROUND: Nucleic acid testing (NAT) for virus detection during blood screening has helped to prevent transfusion-transmitted infections worldwide. In northern Brazil, NAT was implemented in 2012 for HIV and HCV and more recently, in January 2015, the screening for HBV was included and currently used concomitant with serological tests (HBsAg and anti-HBc). This study aims to evaluate the prevalence and the incidence of HBV infection among voluntary blood donors at ten regional blood centers of HEMOPA Foundation in Pará state and to compare the residual risk of transfusion-transmitted HBV infection before and after the Brazilian HBV-NAT implementation. METHODS: The prevalence (restricted to first time donors- FT) and seroconversion rate (restricted to repeat donors- RP) of HBV were calculated based on rates of confirmed positive samples. Residual risk was based on the incidence and window period (WP) model described by Schreiber and coauthors. Logistic and Poisson regression were used in the statistical analysis by SPSS v20.0. A p value <0.05 was considered statistically significant. RESULTS: HBV prevalence in the periods before and after the implementation of HBV-NAT were 247 and 251 per 100,000 donations, respectively. Seroconversion rates were 114 and 122 per 100,000 donations in the two periods, respectively. The residual risk (RR) for HBV decreased significantly in the posterior period to the HBV-NAT implementation, when compared to RR before implementation, with a reduction of 1:144,92 to 1:294,11 donations (p <0,001). CONCLUSIONS: The RR to HBV decreased after the implementation of HBV-NAT, increasing significantly the transfusional security in the North region of Brazil at HEMOPA Foundation.

Differential Expression Profile of MicroRNAs During Prolonged Storage of Platelet Concentrates As a Quality Measurement Tool in Blood Banks.

Platelet concentrate (PC) is a key blood component, which even in good storage conditions, susceptible to cellular damage over time. Hence, blood banks discard unused PC bags after 5 days of storage. Biomarkers of PC quality are therefore highly sought after in blood bank governance. We used the data (Gene Expression Omnibus: GSE61856) generated with next-generation sequencing to examine the expression profiles of microRNAs (miRNAs) from PCs that were stored for 6 days in a blood bank, that is, 1 day longer than is normally stored PC. We identified the 14 most differentially expressed miRNAs by comparing a control PC on the first day of storage with the PCs on each of the subsequent 5 days of storage from day 1 to 6. In all, we identified nine miRNAs with the downregulated profile (miR-145-5p, miR-150-5p, miR-183-5p, miR-26a-5p, miR-331-3p, miR-338-5p, miR-451a, miR-501-3p, and miR-99b-5p) and five upregulated miRNAs (miR-1304-3p, miR-411-5p, miR-432-5p, miR-668-3p, and miR-939-5p). These miRNAs were validated by real-time quantitative PCR in 100 PC units. As each PC unit is composed of platelets of five individuals, the validation was thus performed in 500 individuals (250 men and 250 women, comprised 18-40 years old adults). The data were analyzed with hierarchical clustering and principal component analysis, which revealed the variation of mean relative expression and the instability of miRNAs half-life on the fourth day of PC storage, which coincides with time of onset of platelet storage lesions. These new observations can usefully inform future decision-making and governance in blood banks concerning PC quality.

Residual risk of transmission of human immunodeficiency virus and hepatitis C virus infections by blood transfusion in northern Brazil.

BACKGROUND: Nucleic acid test (NAT) blood screening for human immunodeficiency virus (HIV) and hepatitis C virus (HCV) was introduced in northern Brazil in July 2012. There are several Brazilian articles that have evaluated transfusion transmission risks for HIV and HCV. However, to our knowledge, this article is the first to evaluate the impact of HIV and HCV NAT implementation for blood screening in northern Brazil. The aim of this study was to determine the prevalence and incidence rates of HIV and HCV among blood donors and to compare the residual risk of transfusion transmission of these infections, before (2009-2011) and after (2012-2014) NAT implementation. STUDY DESIGN AND METHODS: HIV and HCV prevalence and incidence were calculated based on rates of confirmed positive samples. Residual risk estimates were based on the incidence and window model described previously. Logistic and Poisson regressions were used in the statistical analysis. A p value of not more than 0.05 was considered significant. RESULTS: HIV and HCV prevalence were 209.9 and 66.3 per 100,000 donations, respectively. Residual risk for HIV and HCV decreased significantly throughout the two study periods, mainly for HCV in which the reduction was one in 169,492 to one in 769,231 donations. For HIV, the decrease was one in 107,527 to one in 769,231 donations. HIV and HCV incidence rates were 21.13 and 3.06 per 100,000 persons/year before NAT and 14.03 and 2.65 per 100,000 persons/year after NAT. CONCLUSION: The HIV and HCV NAT implementation significantly increased the transfusion safety in northern Brazil, bringing benefits to recipients due to better quality of blood products produced.

Population stratification effect on cancer susceptibility in an admixed population from Brazilian Amazon.

BACKGROUND/AIM: Many efforts have been made to identify candidate genes involved in cancer susceptibility. The present study aimed to investigate the association between Arg194Trp (XRCC1), Ala222Val (MTHFR) and Arg521Lys (EGFR) polymorphisms (SNPs) and their susceptibility to gastric and breast carcinoma cancer in patients from Brazilian Amazon, controlling population structure interference. MATERIALS AND METHODS: The SNPs were genotyped by TaqMan® SNP Genotyping Assays. Ancestry was estimated by analysis of a panel with 48 ancestry informative markers. RESULTS: Logistic regression analysis showed an inverse association with a 10% increase in African and European ancestry and cancer risk (odds ratio (OR)=1.919 and 0.676, respectively). In a preliminary Chi-square analysis a positive association between Arg521Lys (EGFR) polymorphism and carcinoma susceptibility was found (p=0.037); however, when two different methodologies to control population structure bias were utilized, this association was lost (p=0.064 and p=0.256). CONCLUSION: Genetic ancestry influence gastric and breast cancer risk and highlight the importance of population structure inference in association studies in highly admixed populations, such as those from Brazilian Amazon.