An Extended Flow Cytometry Evaluation of ex Vivo Expanded NK Cells Using K562.Clone1, a Feeder Cell Line Manufactured in Brazil

Natural killer (NK) cells play a crucial role in the immune system's response against cancer. However, the challenge of obtaining the required quantity of NK cells for effective therapeutic response necessitates the development of strategies for their ex vivo expansion. This study aimed to develop a novel feeder cell line, K562.Clone1, capable of promoting the ex vivo expansion of NK cells while preserving their cytotoxic potential. he K562 leukemic cell line was transduced with mbIL-21 and 4-1BBL proteins to generate K562.Clone1 cells. NK cells were then co-cultured with these feeder cells, and their expansion rate was monitored over 14 days. The cytotoxic potential of the expanded NK cells was evaluated against acute myeloid leukemia blasts and tumor cell lines of leukemia and glial origin. Statistical analysis was performed to determine the significance of the results. The K562.Clone1 co-cultured with peripheral NK showed a significant increase in cell count, with an approximate 94-fold expansion over 14 days. Expanded NK cells demonstrated cytotoxicity against the tested tumor cell lines, indicating preservation of their cytotoxic characteristics. Additionally, the CD56, CD16, inhibitory KIRs, and activation receptors were conserved and present in a well-balanced manner. The study successfully developed a feeder cell line, K562.Clone1, that effectively promotes the expansion of NK cells ex vivo while maintaining their cytotoxic potential. This development could significantly contribute to the advancement of NK cell therapy, especially in Brazil.

Nucleated red blood cell: a feasible quality parameter of cord blood units

INTRODUCTION

Umbilical cord blood is an alternative source of hematopoietic progenitor cells for bone marrow transplantation; however, it is associated with a higher graft failure rate. The presence of a high rate of nucleated red blood cells (NRBCs) seems to be related to a greater capacity for engraftment, although is also associated with fetal distress conditions. We analyzed the correlation of the NRBC with quality parameters and its association with the utilization score of a cord blood unit.

STUDY DESIGN AND METHOD

Data of 3346 units collected in a public cord blood bank from May 2010 to December 2017 were analyzed, retrospectively, to identify factors associated with an increased number of nucleated red blood cells and its correlation with the engraftment capacity measured through total nucleated cells (TNCs) and CD34 positive cells. We also evaluated the utilization score of these units and identified an NRBC cutoff associated with a higher score.

RESULTS

The median volume collected was 104 mL (42-255), the pre-processing TNC count was 144.77 × 107 (95.46-477.18), the post-processing TNC count was 119.44 × 107 (42.7-477.18), the CD34 count was 4.67 × 106 (0.31-48.01), the NRBC count was 5 (0-202) and the utilization score was 0.0228 (0.00143-0.9740). The NRBC showed a correlation with the collected volume, TNC and CD34 positive cells and a higher utilization score and the receiver operating characteristic (ROC) curve analysis identified the five NRBC/100 leukocytes cutoff that correlates better with the probability of use. No association with pathological conditions and the NRBC rate was observed.

CONCLUSIONS

The NRBC is a feasible parameter for the screening of the cord blood unit (CBU) and the minimum cutoff of five NRBC/100 leukocytes can be a strategy in conjunction with the TNC to identify better units for cord blood bank sustainability.

Telemedicine pre-screening for blood donor

INTRODUCTION

The COVID-19 pandemic had an important impact on blood bank services. The onset of the pandemic led to a decrease in the number of blood donors. A remote interview would avoid deferred donors from having to travel to the blood bank. We evaluate the feasibility of using telemedicine as an alternative to a face-to-face interview as a first blood donor screening.

METHODS

Our retrospective study included 404 whole blood and platelets donors, who underwent the clinical interview remotely via telemedicine. The deferred donor would not need to go to the blood bank and eligible candidates were required to donate within 7 days. On the day of donation, a mini-interview was held to ensure donor and blood safety.

RESULTS

The appointments were made from June 2020 to June 2022, including 263 candidates for whole blood (WB) and 141 for platelets (PLTs). At the end of the telemedicine interview, 285 (70.6 %) candidates were considered eligible. Telemedicine was not performed for 60 (14.8 %) candidates due to technical problems (with audio or video) or absences. The deferral rate among candidates who underwent telemedicine pre-screening was 14.6 % and, among eligible donors after telemedicine, only 7 (2.9 %) were unable to donate blood.

CONCLUSION

Telemedicine is a viable alternative and a welcome convenience for potential donors to avoid unnecessary travel.

Quality assessment of red blood cell concentrates from blood donors at the extremes of the age spectrum: The BEST collaborative study

BACKGROUND

Blood donors at the extremes of the age spectrum (16-19 years vs. ≥75 years) are characterized by increased risks of iron deficiency and anemia, and are often underrepresented in studies evaluating the effects of donor characteristics on red blood cells (RBC) transfusion effectiveness. The aim of this study was to conduct quality assessments of RBC concentrates from these unique age groups.

STUDY DESIGN

We characterized 150 leukocyte-reduced (LR)-RBCs units from 75 teenage donors, who were matched by sex, and ethnicity with 75 older donors. LR-RBC units were manufactured at three large blood collection centers in the USA and Canada. Quality assessments included storage hemolysis, osmotic hemolysis, oxidative hemolysis, osmotic gradient ektacytometry, hematological indices, and RBC bioactivity.

RESULTS

RBC concentrates from teenage donors had smaller (9%) mean corpuscular volume and higher (5%) RBC concentration compared with older donors counterparts. Stored RBCs from teenage donors exhibited increased susceptibility to oxidative hemolysis (>2-fold) compared with RBCs from older donors. This was observed at all testing centers independent of sex, storage duration, or the type of additive solution. RBCs from teenage male donors had increased cytoplasmatic viscosity and lower hydration compared with older donor RBCs. Evaluations of RBC supernatant bioactivity suggested that donor age was not associated with altered expression of inflammatory markers (CD31, CD54, and IL-6) on endothelial cells.

CONCLUSIONS

The reported findings are likely intrinsic to RBCs and reflect age-specific changes in RBC antioxidant capacity and physical characteristics that may impact RBC survival during cold storage and after transfusion.

Neutrophil extracellular traps (NETs), transfusion requirements and clinical outcomes in orthotopic liver transplantation

Inflammatory phenomena have a direct impact on the prognosis of orthotopic liver transplantation (OLT). Neutrophil extracellular traps (NETs) contribute to OLT inflammation and hemostasis imbalance in OLT. The association between NETosis, clinical outcomes and transfusion requirements is not determined. To evaluate NETs release during OLT and the effect of NETosis ontransfusion requirements and adverse outcomes in a prospective cohort of patients submitted to OLT. We quantified citrullinated histones (cit-H3) and circulating-free-DNA (cf-DNA) in ninety-three patients submitted to OLT in three periods: pre-transplant, after graft reperfusion and before discharge. NETs markers were compared between these periods using ANOVA test. The association of NETosis and adverse outcomes was evaluated using regression models adjusted for age, sex and corrected MELD. We observed a peak of circulating NETs following reperfusion, evidenced by a 2.4-fold increase in cit-H3 levels in the post-graft reperfusion period (median levels of cit-H3 pre transplant: 0.5 ng/mL, after reperfusion: 1.2 ng/mL and at discharge 0.5 ng/mL, p < 0.0001). We observed an association between increased levels of cit-H3 and in-hospital death (OR = 1.168, 95% CI 1.021-1.336, p = 0.024). No association was found between NETs markers and transfusion requirements. There is a prompt release of NETs after reperfusion that is associated with poorer outcomes and death. Intraoperative NETs release seems to be independent of transfusion requirements. These findings highlight the relevance of inflammation promoted by NETS and its impact on OLT adverse clinical outcomes.

Senescence State in Mesenchymal Stem Cells at Low Passages: Implications in Clinical Use

Mesenchymal stem cells (MSCs) are multipotent cells found in various tissues and are easily cultivated. For use in clinical protocols, MSCs must be expanded to obtain an adequate number of cells, but a senescence state may be instituted after some passages, reducing their replicative potential. In this study, we report a case where MSC derived from an elderly donor acquired a senescence state after three passages. The bone marrow was aspirated from a female patient submitted to a cell therapy for the incontinency urinary protocol; MSCs were cultivated with DMEM low glucose, supplemented with 10% autologous serum (AS) plus 1% L-glutamine and 1% antibiotic/antimycotic. Senescence analysis was performed by β-galactosidase staining after 24 and 48 h. Controls were established using BM-MSC from healthy donors and used for senescence and gene expression assays. Gene expression was performed using RT-PCR for pluripotency genes, such as SOX2, POU5F1, NANOG, and KLF4. MSC telomere length was measured by the Southern blotting technique, and MSCs were also analyzed for their capacity to differentiate into adipocytes, chondrocytes, and osteocytes. The patient’s MSC expansion using AS displayed an early senescence state. In order to understand the role of AS in senescence, MSCs were then submitted to two different culture conditions: 1) with AS or 2) with FBS supplementation. Senescence state was assessed after 24 h, and no statistical differences were observed between the two conditions. However, patients’ cells cultured with AS displayed a higher number of senescence cells than FBS medium after 48 h (p = 0.0018). Gene expression was performed in both conditions; increased expression of KLF4 was observed in the patient’s cells in comparison to healthy controls (p = 0.0016); reduced gene expression was observed for NANOG (p = 0.0016) and SOX2 (p = 0.0014) genes. Telomere length of the patient’s cells was shorter than that of a healthy donor and that of a patient of similar age. Osteocyte differentiation seemed to be more diffuse than that of the healthy donor and that of the patient of similar age. MSCs could enter a senescence state during expansion in early passages and can impact MSC quality for clinical applications, reducing their efficacy when administered.

The first gene therapy for RPE65 biallelic dystrophy with voretigene neparvovec-rzyl in Brazil

PURPOSE

To report the first Brazilian patient with RPE65 deficiency-inherited retinal dystrophy (RPE65-IRD) treated with voretigene neparvovec-rzyl (VN).

METHODS

An adult patient with Leber congenital amaurosis-2 with a homozygous mutation in the RPE65 gene (p.Phe83Leu) was treated bilaterally with VN. The clinical and surgical aspects are described. The baseline and 4-month postoperative ophthalmologic examinations included measurement of the best-corrected visual acuity (BCVA), full-field stimulus threshold (FST) test, Octopus 900 semiautomated kinetic visual fields (VFs), and microperimetry.

RESULTS

No complications developed in this patient. The BCVA remained stable. The full-field stimulus threshold test (FST) and VFs showed clinically significant improvements bilaterally. The patient reported significant improvements in the ability to perform daily activities, mainly for those requiring the VFs and vision in a low-luminescence environment.

CONCLUSIONS

The treatments were beneficial for this patient who was homozygous for RPE65 p.Phe83Leu. The first VN treatments in an adult Brazilian patient in clinical practice showed measurable improvements in visual outcomes that were meaningful for the patient's daily activities.

TRANSLATIONAL RELEVANCE

This case reinforces the clinical trial results and proves that the procedure is feasible in countries such as Brazil.

TRANSFUSÃO DE PLASMA CONVALESCENTE EM COVID19: ASSOCIAÇÃO ENTRE ANTICORPOS NEUTRALIZANTES E REDUÇÃO DE CARGA VIRAL

Introdução

A transfusão de plasma convalescente tem sido utilizada como terapêutica alternativa no tratamento de COVID19 nos últimos meses. Avaliamos o impacto dos anticorpos neutralizantes produzidos pelos pacientes e dos anticorpos presentes nas unidades transfundidas na redução da carga  viral em pacientes em tratamento hospitalar de COVID19.

Materiais e métodos

Foram avaliados consecutivamente 29 pacientes admitidos para tratamento hospitalar de COVID19 em um único centro. Doses de 300 a 600 ml de plasma convalescente foram administradas ao longo de 2 dias. Foram coletados swabs nasais a cada 48 h a partir do D0 (dia de transfusão de plasma convalescente) até a alta hospitalar, a fim de determinar a carga viral por digital droplet PCR (ddPCR) dos alvos N1 e N2 do gene N (nucleocapsídeo) para análise de redução de carga viral, sendo considerado o número de cópias virais por 1000 células presente na amostra. Mensuramos os títulos de anticorpos neutralizantes (cytopathic effect-based virus neutralization test  -SARS-CoV-2 GenBank MT126808.1) dos pacientes (NAbsP) antes da transfusão (D0)  e títulos de anticorpos neutralizantes das unidades de plasma transfundidas (NAbsT). Para análise de associação entre NAbsP e redução de carga viral, os pacientes foram divididos em dois grupos de acordo com o status de NAbsP no D0: título de NabsP inferior a 80 e título de NabsP igual ou superior a 80. Para esta análise, foi utilizado o teste de Mann-Whitney . Para verificar a associação entre NAbsT e redução de carga viral, os pacientes foram divididos em três grupos: aqueles que receberam transfusão de plasma convalescente com título de NAbsT até 160, título de NAbsT entre 160-640 e NAbsT superior a 640. Para esta análise, foi utilizado o  teste de Kruskall-Wallis.

Resultados

Pacientes com baixos títulos de neutralizantes à admissão (NAbsP inferior a 80) apresentaram redução de carga viral significativamente maior (p=0,009) que pacientes com NAbsP igual ou superior a 80. Com relação ao impacto da transfusão de plasma, observou-se que quanto maior o título de anticorpos neutralizantes transfundidos maior foi a redução da carga viral; porém, tal achado não apresentou significância estatística (p = 0,528).

Discussão

O combate e eliminação da viremia através dos anticorpos neutralizantes presentes no plasma convalescente compreende uma das justificativas da sua aplicação como terapia alternativa para COVID19. Contudo, estudos prévios demonstraram resultados contraditórios em relação ao seu impacto no clearance viral. Na presente casuística, pacientes com baixos títulos de anticorpos neutralizantes apresentaram maior redução de carga viral após a transfusão de plasma convalescente do que pacientes com altos títulos. Pacientes que já apresentavam títulos elevados de neutralizantes parecem não se beneficiar da transfusão de plasma no que se refere à redução de carga viral. A estratificação dos pacientes de acordo com os níveis basais de anticorpos neutralizantes parece ser um ponto importante a ser discutido no tratamento de COVID19 com plasma convalescente e fornece uma explicação plausível para os resultados controversos previamente observados.

Zika virus RNA detection in blood donors in São Paulo, Brazil

Introduction: The Zika Virus (ZIKV) is a single-stranded RNA genome virus, belonging to the family Flaviviridae, genus Flavivirus. Outbreaks around the world have demonstrated that the presence of asymptomatic viremic blood donors provides an increase in the risk of transfusion transmission (TT) and nucleic acid test (NAT) screening has been proposed to ensure the blood safety. This study implemented an “in-house” method to detect ZIKV RNA in blood sample donations.

Methods: Primary plasma tubes are submitted to nucleic acid extraction on an automated platform. After extraction, the NAT set-up is performed in the robotic pipettor, in which an amplification mixture containing primers and probes for ZIKV and Polio vaccine virus (PV) are added in duplex as an internal control. The real-time polymerase chain reaction is then performed in a thermocycler, using the protocol established by the supplier.

Results: From May 2016 to May 2018, 3,369 samples were collected from 3,221 blood donors (confidence coefficient 95%), of which 31 were considered false positive (0.92%), as they did not confirm initial reactivity when repeated in duplicates and 14 (0.42%) had their results invalid due to repeat failure in the internal control, 4 (0.12%), due to insufficient sample volume and 2 (0.05%), due to automatic pipettor failures. No Zika RNA reactive sample was identified.

Conclusion: The test showed feasible to be incorporated into the blood screening routine. Our data do not indicate the need to screen for ZIKV RNA in São Paulo during the evaluated period. However, a generic NAT system covering a group of flaviviruses which are circulating in the region, such as DENV and YFV, among others, could be a useful tool.

Long-term safety of photobiomodulation therapy for oral mucositis in hematopoietic cell transplantation patients: a 15-year retrospective study

Photobiomodulation therapy (PBMT) has demonstrated efficacy in the prevention and treatment of oral mucositis (OM) in hematopoietic cell transplantation (HCT). However, based on the cell stimulation properties, its long-term safety has been questioned, mainly in relation to risk for secondary malignancies in the oral cavity. The aim of this study was to investigate if different PBMT protocols for OM control have association with immediate and late adverse effects in HCT patients. Data on autologous and allogeneic transplantation, conditioning regimen, PBMT protocols, and OM severity were retrospectively collected from medical and dental records. Presence of secondary malignancies in the oral cavity was surveyed during a 15-year follow-up. Impact of OM on overall survival was also analyzed. Different PBMT protocols for prevention and treatment of OM were recorded over the years. Severe OM (grades 3 and 4) was infrequently observed. When present, we observed a significant decrease of the overall survival. No immediate adverse effect and secondary malignancy was associated to PBMT. In conclusion, the PBMT protocols used in the study were considered safe. The low frequency of severe OM observed encourages the implementation of this technique, with a special emphasis on the dosimetry adjustments focused on the HCT context.

The relevance of a bank with genotyped platelets donors

OBJECTIVE

Describe the clinical and laboratory characteristics and the transfusion strategy of patients at Hospital Israelita Albert Einstein with platelet refractoriness and identify their etiological characteristics. Standardize the platelet immunofluorescence technique by flow cytometry as a test for platelet compatibility in immune platelet refractoriness in transfusion support.

METHODS

Review of medical records of refractory platelet patients followed at HIAE from January 2011 to May 2017. Clinical-demographic data, laboratory data and identification of the use of compatible genotyped platelets for patients in need of transfusion therapy were collected. The analyzed patients were classified according to the etiology of their platelet refractoriness. To standardize the FC-PIFT technique, blood group O platelets were incubated with serum from blood group AB donors and anti-IgG monoclonal antibody to determine the negative control. In order to verify the influence of the ABO system, monoclonal anti-IgG antibodies were incubated with blood group A or B platelets and with blood group O donor serum with isohemagglutinins below and above 1/64.

RESULTS

A total of 47 patients were evaluated, a 51% (24/47) preponderance of associated immune and non-immune factors (NIPR + IPR). The most common causes of NIPR + IPR were splenomegaly (54%) and the development of HLA antibodies (88%), consistent with the literature. For patients who required therapeutic transfusion, only a small portion received compatible genotyped platelets.

CONCLUSION

Although 60% of patients could benefit from the therapeutic transfusion of genotyped platelets, only 10% were actually transfused with this type of blood component. This reaffirms the need for investments in a bank of genotyped platelet donors.

Pediatric resident knowledge of transfusion medicine: Results from the BEST-TEST3 international education needs assessment

BACKGROUND

Transfusions are a common intervention within pediatrics and require unique considerations to optimize patient care. Poor knowledge of evidence-based transfusion practice can lead to misuse of transfusion therapy and harm. While there have been assessments of transfusion medicine knowledge of physicians caring for adult patients, there is little data regarding pediatricians.

STUDY DESIGN AND METHODS

Using a published transfusion medicine knowledge exam for internal medicine physicians as a backbone, pediatric transfusion medicine experts, using an iterative process, developed a pediatric-specific examination. Pilot testing and Rasch analysis, a method used in high-stakes testing, was used to validate the exam. The exam and a previously validated survey on transfusion medicine training, attitudes, and perceived ability were administered to pediatric residents. Analysis consisted of descriptive statistics as well as comparisons of exam scores based on survey responses.

RESULTS

330 pediatric residents from 19 sites in 6 countries participated in the study. The vast majority (91%) of residents had obtained blood product consent. The mean exam score was 37.1% (range 9.5%-71.4%) with no statistical differences based on amount or perceived quality of transfusion medicine education or perceived ability.

DISCUSSION

A rigorously validated exam has now been developed that can be used to assess pediatric transfusion medicine knowledge. A large international group of pediatric residents performed poorly on the exam demonstrating a pressing need for improved transfusion medicine education to ensure safe and appropriate administration of blood components to infants and children.

Frequency of rare, serious donor reactions: International perspective

BACKGROUND

Severe blood donor adverse events are rare, but due to their rarity studying them can be difficult. To get an accurate estimate of their frequency and rate in the donor population it may be necessary to combine donation data across countries.

STUDY DESIGN AND METHODS

International blood collection organizations (BCOs) provided data on rare/severe donor reactions as well as denominator information for their donor populations from 2015 to 2017. Donor reactions were classified using standardized definitions.

RESULTS

BCOs from six countries provided reaction data for more than 22 million donations. A total of 480 rare reactions were reported of which 76.7% were imputed as definite and 11% probable. Rates of rare reactions were higher in females and first-time donors. Systemic rare reactions were the most common reaction type, accounting for over three quarters of reactions reported. Of systemic reactions, vasovagal reactions with loss of consciousness and injury or off-site (n = 350) made up the majority and occurred 1.53 per 100,000 donations. For the 22.3% that were localized reactions, the majority of these were cellulitis (n = 71, 0.31 per 100,000 donations) followed by deep venous thrombosis (n = 21, 0.09 per 100,000 donations).

CONCLUSION

Pulling together data from multiple BCOs across countries allows for a better understanding of rare reactions, such as vasovagal reaction with injury or cellulitis, and for generating a reliable incidence rate for air embolism or compartment syndrome. However, gaps remain due to missing elements such as unknown donor status or location of reaction.

Screening for SARS-CoV-2 antibodies in convalescent plasma in Brazil: Preliminary lessons from a voluntary convalescent donor program

BACKGROUND

Coronavirus disease 2019 (COVID-19) convalescent plasma (CCP) collection began in two Brazilian hospitals for treatment of severe/critical patients.

METHODS AND MATERIALS

Mild/moderate COVID-19 convalescents were selected as CCP donors after reverse transcription polymerase chain reaction (RT-PCR) confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and absence of symptoms for ≥14 days plus (a) age (18-60 years), body weight greater than 55 kg; (b) immunohematological studies; (c) no infectious markers of hepatitis B virus, hepatitis C virus, human immunodeficiency virus, human T-lymphotropic virus-1/2, Chagas and syphilis infection; (d) no HLA antibodies (multiparous); (e) second RT-PCR (nasopharyngeal swab and/or blood) negativity; (f) virus neutralization test (cytopathic effect-based virus neutralization test neutralizing antibody) and anti-nucleocapsid protein SARS-CoV-2 IgM, IgG, and IgA enzyme-linked immunosorbent assays.

RESULTS

Among 271 donors (41 females, 230 males), 250 presented with neutralizing antibodies. Final RT-PCR was negative on swab (77.0%) or blood (88.4%; P = .46). Final definition of RT-PCR was only defined at more than 28 days after full recovery in 59 of 174 (33.9%) RT-PCR -ve, and 25/69 RT-PCR +ve (36.2%; 13 between 35 and 48 days). Neutralizing antibody titers of 160 or greater were found in 63.6%. Correlation between IgG signal/cutoff of 5.0 or greater and neutralizing antibody of 160 or greater was 82.4%. Combination of final RT-PCR -ve with neutralizing antibody ≥160 was 41.3% (112/271). Serial plasma collection showed decline in neutralizing antibody titers and IgA levels (P < .05), probably denoting a "golden period" for CCP collection (≤28 days after joining the program); IgA might have an important role as neutralizing antibody. Donor's weight, days between disease onset and serial plasma collection, and IgG and IgM levels are important predictors for neutralizing antibody titer.

CONCLUSIONS

RT-PCR +ve cases are still detected in 36.2% within 28 to 48 days after recovery. High anti-nucleocapsid protein IgG levels may be used as a surrogate marker to neutralizing antibody.