Fifteen years of Nucleic Acid Testing in France: Results and lessons

Evaluating the cost-effectiveness of low-level HBV DNA screening in occult hepatitis B infection donors: A study from Shandong Blood Center, China

OBJECTIVE

This study aimed to assess the efficacy of individual-donation nucleic acid testing (ID-NAT) in detecting occult hepatitis B virus infection (OBI) among anti-HBc positive blood donors, compared to minipool nucleic acid testing (MP-NAT).

METHODS

The present study analyzed data from the Shandong Blood Center in China during the period from January 2018 to June 2022, where HBsAg-negative blood donors were screened using the 6-sample minipool nucleic acid testing (6-sample MP NAT) method. NAT-positive samples underwent subsequent anti-HBc and anti-HBs testing. Approximately 5000 samples that passed the nucleic acid mixing test were randomly selected for anti-HBc testing, and over 100 anti-HBc positive samples underwent individual donor nucleic acid testing (ID-NAT). Any HBV DNA positive samples detected by ID-NAT were subsequently confirmed using alternative nucleic acid testing methods.

RESULTS

Among 220,445 HBsAg-negative blood donors, the positivity rate of HBV DNA detection using the 6-sample minipool nucleic acid testing (MP NAT) method was found to be 0.031% (69/220,445). Of the 67 HBV DNA positive samples, 55 (82.09%) and 25 (37.31%) were found to be positive for anti-HBc and anti-HBs, respectively, using the supplementary chemiluminescent microparticle immunoassay (CMIA). Among the 4797 HBsAg-negative/MP NAT-negative samples, 909 (18.95%) tested positive for anti-HBc. Further NAT testing was performed on 164 arbitrarily selected anti-HBc-positive/MP HBV DNA-negative samples, revealing a HBV DNA positivity rate of 1.22% (2/164).

CONCLUSION

Using individual donation nucleic acid testing can significantly increase the detection rate of occult hepatitis B virus infection in anti-HBc-positive blood donors, resulting in a detection rate of 0.22% (1.22 × 0.1895). This rate is 8.10 times higher than the detection rate achieved by mixed testing methods (0.031%) [calculated as (0.22 + 0.031)/0.031]. Therefore, it is recommended to perform single HBV DNA testing on anti-HBc-positive blood donors, discard plasma with weakly positive or negative anti-HBs but positive anti-HBc, or avoid transfusing anti-HBc-positive plasma to recipients with weakly positive or negative anti-HBs to prevent HBV infection.

Transmitted HIV drug resistance and subtype patterns among blood donors in Poland

Surveillance on the HIV molecular variability, risk of drug resistance transmission and evolution of novel viral variants among blood donors remains an understudied aspect of hemovigilance. This nationwide study analyses patterns of HIV diversity and transmitted resistance mutations. Study included 185 samples from the first time and repeat blood donors with HIV infection identified by molecular assay. HIV protease, reverse transcriptase and integrase were sequenced using population methods. Drug resistance mutation (DRM) patterns were analyzed based on the Stanford Interpretation Algorithm and standardized lists of transmitted mutations. Phylogeny was used to investigate subtyping, clustering and recombination patterns. HIV-1 subtype B (89.2%) followed by subtype A6 (7.6%) were predominant, while in three (1.6%) cases, novel recombinant B/A6 variants were identified. Non-B variants were more common among repeat donors (14.5%) compared to the first time ones (1.8%), p = 0.011, with higher frequency (9.9%) of A6 variant in the repeat donor group, p = 0.04. Major NRTI DRMs were observed in 3.8%, NNRTI and PI in 0.6% and INSTI 1.1% of cases. Additionally, E157Q polymorphism was observed in 9.8% and L74I in 11.5% of integrase sequences. Transmission of drug resistance among blood donors remains infrequent. Subtype patters increase in complexity with emergence of novel intersubtype A6B recombinants.

Detection of dengue, chikungunya, and Zika RNA in blood donors from Southeast Asia

BACKGROUND

Chikungunya (CHIKV), dengue (DENV), and Zika (ZIKV) viruses are of concern due to the potential of transfusion transmission in blood, especially in regions such as Southeast Asia where the viruses are endemic. The recent availability of nucleic acid testing (NAT) to screen blood donations on an automated platform provides the opportunity to detect potentially infectious units in asymptomatic donors.

STUDY DESIGN AND METHODS

Three thousand blood donations from Vietnam and 6000 from Thailand were screened with a real-time polymerase chain reaction (PCR) test (cobas CHIKV/DENV, Roche Diagnostics, Indianapolis, IN) and equal numbers on cobas Zika (Roche Diagnostics). Reactive samples were tested by alternative NAT with resolution of discordant results by heminested PCR. Throughput of simultaneous testing of the two assays on the cobas 8800 system (Roche Diagnostics) was evaluated.

RESULTS

In Vietnam, 9 of 3045 samples were reactive for DENV and all were confirmed, for a prevalence (with 95% confidence interval [CI]) of 0.296% (0.135-0.560). In Thailand, 2 of 6000 samples were reactive for CHIKV, 4 of 6000 for DENV, and 1 of 6005 for ZIKV, and all confirmed. The prevalence of CHIKV is 0.033% (0.004-0.120), DENV 0.067% (0.018-0.171), and ZIKV 0.017% (0.000-0.093). The overall specificity for the cobas CHIKV/DENV and cobas Zika tests was 100% (99.959-100). For the simultaneous assay testing, 960 test results were available in 7 hours and 53 minutes.

CONCLUSION

Detection of CHIKV, DENV, and ZIKV RNA in donor samples in Vietnam and Thailand indicate the presence of the virus in asymptomatic blood donors. The cobas 6800/8800 systems (Roche Molecular Systems, Pleasanton, CA) enable screening blood donations in endemic areas for these viruses together or separately.

Transfusion medicine: Overtime paradigm changes and emerging paradoxes

This essay aims to discuss some aspects of blood transfusion in the perspective of the changes that occurred over time as well as modifications of the paradigms that transformed the activities and the organization of blood transfusion services. Without specific knowledge, pioneers envisioned precision and personalized medicine, rendering transfusion medicine operational. Transfusion medicine is like The Picture of Dorian Grey: always young despite being old and sometimes appearing old-fashioned. Over the years, the transfusion medicine discipline has evolved, and major progress has been achieved, despite some troublesome periods (for example, the tainted blood scandal, and—at the time being—the offending plasma market and the selling of human parts). Transfusion medicine has at all times implemented the rapidly developing biomedical technologies to secure blood components. The safety of blood components has now reached an exceptional level in economically wealthy countries, especially compared to other health care disciplines. Strengthening of the safety has mandated that blood donors and recipients are unrelated, an issue which has eased preservation and fractionation practices; blood is no longer arm-to-arm transfused and neither is whole blood, the commonest component. However, it is interesting to note that a revival is occurring as whole blood is back on stage for certain specific indications, which is one among the many paradoxes encountered while studying this discipline.

A Systematic Review of the Current Hepatitis B Viral Infection and Hepatocellular Carcinoma Situation in Mediterranean Countries

Viral hepatitis B is a global public health problem affecting nearly two billion subjects; 3.3% of whom are from the WHO (World Health Organization) Eastern Mediterranean Region (EMRO). It induces both acute and chronic hepatic disorders with subsequent liver cirrhosis and hepatocellular carcinoma (HCC) in a considerable percentage of patients based on the age of exposure. In this review, hepatitis B virus (HBV) and HCC prevalence, distribution and prevalence of different genotypes, and male/female infection frequencies in relation to the vaccination status in the Mediterranean countries were reported. Study Design. This systematic review describes the prevalence of hepatitis B infection, genotype distribution of hepatitis B virus, and prevalence and incidence of hepatocellular carcinoma in Mediterranean countries belonging to three different continents: Southern Europe (Spain, France, Italy, Croatia, and Greece), North Africa (Morocco, Algeria, Tunisia, Libya, and Egypt), and the Near East region (Syria, Lebanon, Turkey, Israel, and Palestine). We tried to collect new data from electronic databases: PubMed, ScienceDirect, ResearchGate, Google Scholar, and public health reports between 1980 and 2019. For each publication, we recorded reference, publication year, study characteristics (date, locations, sample size, and study population), and participant characteristics (population group, year, age, and sex). No language limitation was imposed, and articles or reports from non-peer-reviewed sources were not considered for this analysis. The main keywords were HBV prevalence, hepatitis B infection, HBV genotype, and HCC. Inclusion and Exclusion Criteria. Healthy population-based studies included the following sample populations: (i) voluntary blood donors, (ii) pregnant women, (iii) community studies, (iv) hemodialysis patients, (v) hospitalized patients, (vi) healthcare workers, (vii) sex workers, (viii) drug abusers, and (ix) prisoners. We excluded studies from the following special groups who were assumed to be at a special high risk: patients from sexually transmitted disease clinics and thalassemia clinics and professional or paid blood donors.

Quality and safety measures in transfusion practice: The experience of eight southern/eastern Mediterranean countries

BACKGROUND AND OBJECTIVES

Blood transfusion is inherently associated with risks, and little is known regarding the available quality and safety measures in developing countries. No studies or census has been carried out, and therefore, no data on this compelling issue are available.

MATERIALS AND METHODS

Data emanating from eight Arabic eastern/southern Mediterranean countries who responded to five surveys were collected and tabulated.

RESULTS

Asepsis during phlebotomy, screening for serological and immuno-haematological parameters and appropriate storage conditions are maintained across all countries. Variations in blood component processing exist. Universal leucoreduction is systematically applied in Lebanon. Nucleic acid testing is only performed in Egypt. Aphaeresis procedure, leucoreduction and quality control for blood components are virtually inexistent in Mauritania. Written donor questionnaire is absent in Algeria and Tunisia. Most donor deferral periods for infectious agents are inconsistent with international standards.

CONCLUSION

Gaps in the processing and in the quality/safety measures applied to the manufacture of blood components are quite evident in most eastern/southern Mediterranean countries. The decision of establishing an effective collaboration network and an independent body - aside from WHO - composed of specialists that oversees all transfusion activities in these countries is certainly a crucial step towards ensuring an optimum level of blood safety.

Effectiveness of blood donor screening by HIV, HCV, HBV-NAT assays, as well as HBsAg and anti-HBc immunoassays in Germany (2008-2015)

BACKGROUND AND OBJECTIVES

In Germany, in addition to standard blood donor screening, further mandatory tests were introduced for HCV-RNA, HIV-1-RNA and for anti-HBc. Screening for HBV-DNA is optional. This study investigates the benefits of these additional tests for the detection of HIV, HCV, and HBV infections among German blood donors.

MATERIALS AND METHODS

From 2008 to 2015 we collected data on blood donations exclusively testing NAT positive (NAT yield) or reactive in only one of the screening assays. Assuming a Poisson distribution, we calculated NAT yield/reactive only rates on a per donation basis (number of yield/reactive only cases divided by the number of donations tested in the period under review) with 95% confidence intervals.

RESULTS

Responding establishments covered 95% of the donations. We identified 20 HIV-1-NAT, 61 HCV-NAT and 29 HBV-NAT yield cases among approximately 46 million blood donations tested corresponding to 0·43 HIV-1 NAT, 1·32 HCV-NAT, and 0·64 HBV-NAT yield cases per million blood donations tested. For one HBsAg reactive only case and 23 anti-HBc reactive only cases in repeat donors, infection was confirmed by ID-NAT which translates into 0·02 and 0·55 cases per million donations tested. During the 8-year-observation period, one HIV-1, no HCV and four HBV transmissions associated with donations in the viremic pre-seroconversion window period were reported.

CONCLUSION

Annually, NAT screening alone detected 2·5 HIV-1, 7·6 HCV, and 3·6 HBV infectious donations; anti-HBc screening alone identified 2·9 infectious donations of repeat donors with occult HBV infection. Overall, the survey results support that the currently practiced donor HIV/HCV/HBV screening strategy in Germany does ensure a high standard of blood safety.

The plasma supply in France

Contrary to economically comparable countries, France has had a versatile policy to process and manufacture therapeutic plasma, and to apply safety measures. This has principally affected the origin of plasma (whole blood supernatant versus apheresis), and the application or not of a chemical process. At the time being, the civilian and Army Forces blood establishments produce more than 99% of the plasma issued for patients in need; safety means consist in a large part of quarantine and, to a lesser extent, to a pathogen reduction technology process (Amotosalen-HCl-UVA). The blood establishments ship plasma to the national manufacturer of blood derivatives. Plasma in France is strictly within the Voluntary Non-Remunerated pathway with no breach to this principle to be expected for both labile components and source plasma. The constant hemovigilance allows reflection to make policies evolving, with respect to safety measures particularly to reduce cases of allergy.

Transfusion of HIV-infected blood products despite highly sensitive nucleic acid testing

BACKGROUND

In France, the risk of HIV transmission by transfusion was reduced by implementing pooled nucleic acid testing (NAT) in 2001 and individual NAT in 2010. We report here the first case in France of transfusion of human immunodeficiency virus (HIV)-infected blood donated during HIV pre-ramp-up phase that tested individual NAT negative.

METHODS

Blood donations are screened for HIV antibodies and HIV RNA (ProcleixUltrio, Grifols; limit of detection at 95%, 23 copies/mL). When a repeat donor tests positive for HIV, a repository sample from the previous donation is tested with the Cobas Taqman HIV-1 test (CTM, Roche; limit of detection at 95%, 17 copies/mL).

RESULTS

In August 2017, a 57-year-old male repeat donor was screened positive for HIV antibodies and RNA (plasma viral load, 11,599 copies/mL). The previous donation had tested negative with Ultrio in March 2017 but was positive with an unquantifiable plasma viral load when tested with CTM. Sequencing showed no mismatch between Ultrio primers/probes and the target sequence. HIV transmission was excluded by lookback studies in the recipient of platelets, which had been pathogen reduced, but not in the recipient of RBCs due to premature death.

CONCLUSION

This case demonstrates that the risk of contaminated donations due to the early HIV infection phase going undetected by highly sensitive NAT is real but exceptional. The absence of transmission to the platelets recipient could be due to the very low viral inoculum and/or to the efficacy of the viral inactivation. This case also highlights the additional value of a systematic donation archiving and the importance of donor education and predonation selection.

What can be learned in the snake antivenom field from the developments in human plasma derived products?

Human plasma-derived medicinal products and snake antivenom immunoglobulins are unique and complex therapeutic protein products. Human plasma products are obtained by fractionating large pools of plasma collected from blood plasma donors. They comprise a wide range of protein products, including polyvalent and hyperimmune immunoglobulins, coagulation factors, albumin, and various protease inhibitors that are transfused to patients affected by congenital or acquired protein deficiencies, immunological disorders, or metabolic diseases. Snake antivenoms are manufactured from pools of plasma collected from animals, typically horses, which have been immunized against snake venoms. Transfusing antivenoms is the cornerstone therapy to treat patients affected by snakebite envenoming. Over the last thirty years, much technical and regulatory evolution has been implemented to ensure that this class of biologicals meets modern quality requirements. The purpose of this review is to compare the main developments that took place in plasma production, protein fractionation, pathogen safety, quality control, preclinical and clinical studies, and regulations of these products. We also analyze whether both fields have been influencing and cross-fertilizing each other technically and in regulatory aspects to reach modern safety and efficacy standards at global levels, and how experience in the human plasma fractionation industry can further impact the manufacture of snake antivenom and that of other animal-derived antisera.