Prevalence of Severe Acute Respiratory Syndrome Coronavirus 2 Neutralizing Antibodies in Egyptian Convalescent Plasma Donors

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.

The degree of safety of family replacement donors versus voluntary non-remunerated donors in an Egyptian population: a comparative study

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.