Significance of HBV NAT Among HBs Antigen-Negative Blood Donors in Saudi Arabia.

BACKGROUND: Bloodborne hepatitis B virus (HBV) transmission from asymptomatic donors with acute HBV infections who have undetectable surface antigen of HBV (HBsAg), or from donors with chronic infections in whom serological markers were not detected, could cause residual infections leading to relevant transfusion-transmitted infections (RTTIs). HBV nucleic acid testing (NAT) can detect HBV DNA in the HBsAg-negative and total hepatitis B core antibody (anti-HBc)-negative window period of infection and in chronic cases. OBJECTIVE: To assess the presence or absence of HBV DNA in blood donors with HBsAg negativity. METHODS: We collected 3014 blood specimens from volunteer blood donors at the blood bank of King Khalid University Hospital in Riyadh, Saudia Arabia. Specimens from each donor were tested for HBsAg, anti-HBc, and hepatitis B surface antibody (anti-HBs) by commercial immunoassays and for qualitative assessments of HBV-DNA by HBV-NAT testing. RESULTS: Of the 3014 donors, 7 (0.23%) tested positive for HBsAg and anti-HBc, 1 for HBsAg (0.03%) only, and of those 264 donors (8.8%) for anti-HBc. Of these last, 6.9% also tested positive for anti-HBs and 1.9% tested negative for anti-HBs. HBV-NAT testing was reactive in 75.0% of subjects who tested HBsAg positive, and nonreactive in 100% of subjects who tested anti-HBc positive/HBsAg negative (with or without anti-HBs). Among 2742 donors who tested seronegative, 1 specimen was determined to be reactive via HBV-NAT testing. CONCLUSIONS: The frequency of HBV DNA in blood donors who tested seronegative was low. This finding may indicate the significance of the HBV NAT technique in reducing the residual risk of transfusion-transmitted HBV infection.

PPM1A Methylation Is Associated With Vascular Recurrence in Aspirin-Treated Patients.

BACKGROUND AND PURPOSE: Despite great efforts by pharmacogenetic studies, the causes of aspirin failure to prevent the recurrence of ischemic events remain unclear. Our aim was to study whether epigenetics could be associated with the risk of vascular recurrence in aspirin-treated stroke patients. METHODS: We performed an epigenetic joint analysis study in 327 patients treated with aspirin. In the discovery stage, we performed a nested case-control study in 38 matched ischemic stroke patients in whom 450 000 methylation sites were analyzed. Nineteen patients presented vascular recurrence after stroke, and 19 matched patients did not present vascular recurrence during the first year of follow-up. In a second stage, 289 new patients were analyzed by EpiTYPER. RESULTS: The following 3 differentially methylated candidate CpG sites, were identified in the discovery stage and analyzed in the second stage: cg26039762 (P=9.69×10(-06), RAF1), cg04985020 (P=3.47×10(-03), PPM1A), and cg08419850 (P=3.47×10(-03), KCNQ1). Joint analysis identified an epigenome-wide association for cg04985020 (PPM1A; P=1.78×10(-07)), with vascular recurrence in patients treated with aspirin. CONCLUSIONS: The pattern of differential methylation in PPM1A is associated with vascular recurrence in aspirin-treated stroke patients.

Novel presenilin 1 mutation associated with early-onset Alzheimer`s disease in a Saudi patient.

We report a 60-year-old Saudi patient with the clinical diagnosis of Alzheimer`s disease (AD) and a novel mutation in the presenilin gene. We investigated mutations in the presenilin-1 gene in Saudi patients with AD using polymerase chain reaction and direct DNA sequencing methods. We extracted genomic DNA from the whole blood of both patients and normal control individuals. We sequenced and compared amplicons with the sequences of the respective exons of normal individuals as well as data available in GenBank. We detected a homozygous mutation (g-c) in exon 12, resulting in the missense mutation (Arg377Thr), in the DNA of a 60-year-old patient. We located this mutation in the cytoplasmic loop near the transmembrane domain 7.