Identifying SARS-CoV-2 'memory' NK cells from COVID-19 convalescent donors for adoptive cell therapy.

COVID-19 disease is the manifestation of syndrome coronavirus 2 (SARS-CoV-2) infection, which is causing a worldwide pandemic. This disease can lead to multiple and different symptoms, being lymphopenia associated with severity one of the most persistent. Natural killer cells (NK cells) are part of the innate immune system, being fighting against virus-infected cells one of their key roles. In this study, we determined the phenotype of NK cells after COVID-19 and the main characteristic of SARS-CoV-2-specific-like NK population in the blood of convalescent donors. CD57+ NKG2C+ phenotype in SARS-CoV-2 convalescent donors indicates the presence of 'memory'/activated NK cells as it has been shown for cytomegalovirus infections. Although the existence of this population is donor dependent, its expression may be crucial for the specific response against SARS-CoV-2, so that, it gives us a tool for selecting the best donors to produce off-the-shelf living drug for cell therapy to treat COVID-19 patients under the RELEASE clinical trial (NCT04578210).

Performance evaluation study of ID CORE XT, a high throughput blood group genotyping platform.

BACKGROUND: Traditionally, red blood cell antigens have been identified using serological methods, but recent advances in molecular biology have made the implementation of methods for genetic testing of most blood group antigens possible. The goal of this study was to validate the performance of the ID CORE XT blood group typing assay. MATERIALS AND METHODS: One thousand independent samples from donors, patients and neonates were collected from three research institutes in Spain and the Netherlands. DNA was extracted from EDTA-anticoagulated blood. The data were processed with the ID CORE XT to obtain the genotypes and the predicted blood group phenotypes, and results were compared to those obtained with well-established serological and molecular methods. All 1,000 samples were typed for major blood group antigens (C, c, E, e, K) and 371-830 samples were typed for other antigens depending on the rarity and availability of serology comparators. RESULTS: The incorrect call rate was 0%. Four "no calls" (rate: 0.014%) were resolved after repetition. The sensitivity of ID CORE XT for all phenotypes was 100% regarding serology. There was one discrepancy in E- antigen and 33 discrepancies in Fyb- antigen. After bidirectional sequencing, all discrepancies were resolved in favour of ID CORE XT (100% specificity). ID CORE XT detected infrequent antigens of Caucasians in the sample as well as rare allelic variants. DISCUSSION: In this evaluation performed in an extensive sample following the European Directive, the ID CORE XT blood genotyping assay performed as a reliable and accurate method for correctly predicting the genotype and phenotype of clinically relevant blood group antigens.

HCV screening in blood donations using RT-PCR in mini-pool: the experience in Spain after routine use for 2 years.

BACKGROUND: The aim of this study is to evaluate the feasibility of implementing a commercial HCV RNA RT-PCR screening method and provide data on the prevalence and incidence rates of hepatitis C in Spain. STUDY DESIGN AND METHODS: Five transfusion centers participated in the study, covering 34.1 percent of the country's total number of donations. All the centers evaluated the sensitivity and characteristics of a commercial RT-PCR reagent kit designed for pool testing (Cobas AmpliScreen HCV v2.0), for which serial dilutions of HCV WHO International Standard 96/790 and preseroconversion samples were used. The data obtained from this technique, employed routinely from May 1999 to June 2001 in 22- to 48-unit mini-pools, are presented in this study. RESULTS: An overall 95-percent detection limit was obtained either at 69 IU per mL when 0.2 mL volume of plasma was extracted (used to analyze individual units), or at 20 IU per mL, when viral particles were pelleted from 1 mL plasma (as used for screening in mini-pool) Three HCV-RNA-positive anti-HCV-negative donations were identified out of 1,015,482 screened donations. One of these had an initially undisclosed risk of HCV sexual transmission and carried a low viral load of 104.2 IU per mL HCV RNA. The analysis of first-time (FT) donations during the period of study (21.3% of the total) indicated an average prevalence rate of 2.05 per 103 FT donors (of which 1.55/103 FT donors were RNA positive); the residual risk calculated on repeat (RPT) donors was 3.91 per 106 donations (serology) or 0.59 per 106 donations (serology + NAT), and the predicted NAT yield estimate was 4.2 per 106 FT + RPT donations. CONCLUSIONS: The commercial RT-PCR reagent kit complies with the current European and FDA recommendations on sensitivity and can be easily implemented on a routine basis. The results obtained by the five transfusion centers on the predicted NAT yield (1/302,000 RPT donations or 1/237,000 FT + RPT donations) are very close to the published estimates corresponding to a larger area of our country (1/237,000 RPT donations) and are somewhat higher than, though in line with, the observed NAT yield (1/338,000 FT + RPT donations).