RESUMO
Using convalescent plasma as immunotherapy is an old method for treatment of infectious diseases. Several countries have recently allowed the use of such therapy for the treatment of COVID-19 patients especially those who are critically ill. A similar program is currently being tested in Egypt. Here, we tested 227 plasma samples from convalescent donors in Egypt for neutralizing antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using a microneutralization (MN) assay. A third of the tested samples did not have antibody titers and 58% had titers between 1:10 and 1:80. Only 12% had titers >1:160. We also compared MN assays using different virus concentrations, plaque reduction neutralization (PRNT) assays, and a chemiluminescence assay that measures immunoglobulin G (IgG) binding to N and S proteins of SARS-CoV-2. Our results indicated that a MN assay using 100 TCID50/ml provides comparable results to PRNT and allows for high throughput testing.
RESUMO
ß-Thalassemia (ß-thal) represents a major health problem worldwide and particularly in Egypt. Its prevention, compared to treatment, is cost-effective, possible and practical. In this study we evaluate a proposed paradigm for detection of the ß-thal carrier state. The present study included 1627 children and adolescents of both sexes, presenting as outpatients to clinics of Ain-Shams University Hospitals, Cairo, Egypt, from November 1 2009 to June 30 2010. In the first phase, after performing a complete blood count (CBC), 280 microcytic hypochromic patients were selected. These cases were further analyzed by iron profile and high performance liquid chromatography (HPLC); in the second phase, hybridization detected 22 common ß-globin mutations in 74.0% of the suspected cases. Thus, by HPLC, the Hb A2 level of >3.5% provided 100.0% sensitivity, 70.0% specificity, 75.0% positive predictive value (PPV), 100.0% negative predictive value (NPV) and accuracy of 70.0% to identify ß-thal trait and at a cut-off of 4.0%, it provided 97.4% sensitivity, 72.7% specificity, 92.6% PPV, 88.8% NPV and a diagnostic accuracy of 92%. High performance liquid chromatography is a reliable and cost effective primary screening tool for ß-thal trait at a Hb A2 level of ≥4.0%, while molecular testing is mandatory only for selected cases with borderline Hb A2 values between 3.5 and 4.0%.
Assuntos
Heterozigoto , Mutação , Globinas beta/genética , Talassemia beta/genética , Adolescente , Criança , Pré-Escolar , Índices de Eritrócitos , Eritrócitos/patologia , Feminino , Frequência do Gene , Testes Genéticos , Humanos , Lactente , Ferro/sangue , Ferro/metabolismo , Masculino , Programas de Rastreamento , Fenótipo , Prevalência , Sensibilidade e Especificidade , Adulto Jovem , Talassemia beta/diagnóstico , Talassemia beta/epidemiologiaRESUMO
BACKGROUND: Screening donated blood for transfusion-transmissible infections is considered an important strategy for maximising the safety of blood transfusions. MATERIALS AND METHODS: A total of 17,118 donors, classified into two groups--family replacement donors and voluntary non-remunerated donors--were investigated for hepatitis B virus (HBV) surface antigen and antibodies against hepatitis C virus (HCV), human immunodeficiency virus (HIV) and Treponema pallidum. In addition cytomegalovirus (CMV) antibodies were searched for in 160 donors (80 from each group). All the laboratory tests were done using enzyme-linked immunosorbent assays. RESULTS: Of the total cohort of donors, 87.7% were family donors and 12.3% were voluntary non-remunerated donors. There was a highly significant difference in age and gender between the two types of donors with voluntary donors being much younger and including a much higher proportion of male donors than female donors. The prevalences of HBV, HCV and CMV IgG were much higher in family donors than in voluntary donors, with the differences being highly statistically significant. There was also a significantly higher prevalence of syphilis among family replacement donors. As regards HIV and CMV IgM, significant differences were not detected between the two groups. DISCUSSION: The results of our study clearly showed that the prevalence of transfusion-transmissible infections is much higher among family replacement donors than among voluntary donors, and that voluntary donors are the best way of achieving safer blood.