A common variant close to the "tripwire" linker region of NLRP1 contributes to severe COVID-19.

OBJECTIVE AND DESIGN: The heterogeneity of response to SARS-CoV-2 infection is directly linked to the individual genetic background. Genetic variants of inflammasome-related genes have been pointed as risk factors for several inflammatory sterile and infectious disease. In the group of inflammasome receptors, NLRP1 stands out as a good novel candidate as severity factor for COVID-19 disease. METHODS: To address this question, we performed an association study of NLRP1, DPP9, CARD8, IL1B, and IL18 single nucleotide variants (SNVs) in a cohort of 945 COVID-19 patients. RESULTS: The NLRP1 p.Leu155His in the linker region, target of viral protease, was significantly associated to COVID-19 severity, which could contribute to the excessive cytokine release reported in severe cases. CONCLUSION: Inflammasome genetic background contributes to individual response to SARS-CoV-2.

Evaluation of platelet concentrates prepared from whole blood donations with collection times between 12 and 15 min: The BEST Collaborative study.

BACKGROUND AND OBJECTIVES: In many countries, whole blood (WB) donations with collection times between 12 and 15 min are not allowed to be used for platelet concentrates (PC). Since the development of guidelines, many process-related changes have been introduced. We aimed to determine the effect of WB with long collection times on PC quality. MATERIALS AND METHODS: Five participating centres tested buffy coat (BC)-derived PC in platelet additive solution type E prepared from only WB collections lasting <12 min (control) versus similar PC including one BC from a collection lasting >12 min (study group, n = 8). One centre produced platelet-rich plasma (PRP)-derived PC from single donations (<10 or >12 min). All PC were stored at 22 ± 2°C and sampled on Days 1, 6 and 8 post-collection for in vitro quality determination. RESULTS: Average collection time was significantly longer in the study group compared to controls (8.9 ± 2.6 vs. 7.3 ± 1.3 min, p < 0.001). There were no differences in volume, platelet concentration, basal CD62P expression, soluble-CD62P and CCL5 levels, or nucleotide content between the groups. Stimulation with TRAP-6 resulted in comparable levels of cell surface CD62P. On Day 8, all PC fulfilled requirements for pH. The findings from single PRP-derived PC centre were similar. CONCLUSION: PC with one BC and single PRP derived from collections lasting >12 min had equivalent in vitro quality to controls during storage. This study provides evidence that 12-15 min donations should not be excluded for PC preparation and justifies to readdress the guidelines to <15 min instead of <12 min of collection in line with current practice in some countries.

Duffy phenotyping and FY*B-67T/C genotyping as screening test for benign constitutional neutropenia

ABSTRACT Objective: Low levels of neutrophils can be an intrinsic condition, with no clinical consequences or immunity impairment. This condition is the benign constitutional neutropenia (BCN), defined as an absolute neutrophils count (ANC) ≤2000 cells/mm. Diagnosis of BCN is of exclusion where patients are submitted to blood tests and possibly to invasive diagnostic search until secondary causes of neutropenia are ruled out. The natural history of the disease suggests benign evolution and Brazilian study showed an overall frequency of 2.59%. The main mechanisms include reduced neutrophil production, increased marginalization, extravasation to the tissues and immune destruction. Genetic studies showed strong association between the single nucleotide variant rs2814778 located on chromosome 1q23.2 in the promoter region of the atypical chemokine receptor 1 (Duffy blood group system) gene (ACKR1, also termed DARC) and BCN. The aim of this study is to evaluate FY phenotypes and genotypes including the analysis of the rs2814778 SNP in Brazilian patients with BCN in order to determine an effective diagnostic tool, allowing reassurance of the patient and cost reduction in their care. Methods: Case control study, with 94 individuals (18 patients and 76 controls). Phenotyping was performed by gel test and genotyping was performed by PCR-RFLP. Results: White blood cell (WBC) and absolute neutrophils (AN) counts showed lower levels in patients compared to controls. In the patient group 83.3% were genotyped as FY*B/FY*B. The SNP rs2814778 (-67T > C) was identified in 77.8% of the patients genotyped as FY*B-67C/FY*B-67C. In the control group, 72.7% were homozygous for the wild type and 23.3% were heterozygous. Conclusion: This study reinforces that FY phenotyping and genotyping can be used to detect most people with BCN, avoiding excessive diagnostic investigation. Besides, this procedure may reduce health costs and be reproductible in clinical practice.

COVID-19 convalescent plasma cohort study: Evaluation of the association between both donor and recipient neutralizing antibody titers and patient outcomes.

BACKGROUND: Current evidence regarding COVID-19 convalescent plasma (CCP) transfusion practices is limited and heterogeneous. We aimed to determine the impact of the use of CCP transfusion in patients with previous circulating neutralizing antibodies (nAbs) in COVID-19. METHODS: Prospective cohort including 102 patients with COVID-19 transfused with ABO compatible CCP on days 0-2 after enrollment. Clinical status of patients was assessed using the adapted World Health Organization (WHO) ordinal scale on days 0, 5, and 14. The nAbs titration was performed using the cytopathic effect-based virus neutralization test with SARS-CoV-2 (GenBank MT126808.1). The primary outcome was clinical improvement on day 14, defined as a reduction of at least two points on the adapted WHO ordinal scale. Secondary outcomes were the number of intensive care unit (ICU)-free days and the number of invasive mechanical ventilation-free days. RESULTS: Both nAbs of CCP units transfused (p < 0.001) and nAbs of patients before CCP transfusions (p = 0.028) were associated with clinical improvements by day 14. No significant associations between nAbs of patients or CCP units transfused were observed in the number of ICU or mechanical ventilation-free days. Administration of CCP units after 10 days of symptom onset resulted in a decrease in ICU-free days (p < 0.001) and mechanical ventilation-free days (p < 0.001). CONCLUSION: Transfusion of high titer nAbs CCP units may be a determinant in clinical strategies against COVID-19. We consider these data as useful parameters to guide future CCP transfusion practices.

Anti-A and SARS-CoV-2: an intriguing association.

BACKGROUND: Blood groups and anti-A isohemagglutinin may be involved in susceptibility to SARS-CoV-2 infection. MATERIALS AND METHODS: We retrospectively studied 268 COVID-19 convalescent plasma donors and 162 COVID-19 inpatients (total 430 subjects, confirmed by RT-PCR) and 2,212 healthy volunteer first-time blood donors as a control group. These were further divided into two groups: those with anti-A (blood types O and B) and those without it (types A and AB). Titres of nucleoproteins, and neutralizing SARS-CoV-2 antibody were measured in the convalescent plasma donors and inpatients. Multivariate logistic regression and non-parametric tests were applied. RESULTS: Persons having types O or B showed less infection prevalence than those of types A or AB (OR = 0·62, 95% CI 0·50-0·78; P < 0·001), but there was no difference when COVID-19 inpatients were analysed. Immunoglobulins M, G and A were lower in COVID-19 subjects of types O or B group than those of A or AB (0·16 vs. 0·19; P = 0·03, 2·11 vs. 2·55; P = 0·02, 0·23 vs. 0·32; P = 0·03, respectively). CONCLUSION: In this retrospective cohort, COVID-19 individuals were less likely to belong to blood types O and B, and also had lower SARS-CoV-2 antibody titres than A and AB individuals. COVID-19 severity did not associate with the blood groups.

Predictive factors for the development of anemia after hematopoietic stem cell donation.

BACKGROUND: Although Hematopoietic Stem Cells (HSC) donation through bone marrow (BM) and peripheral blood (PB) are usually safe procedures, adverse events are expected. One of the most common events especially among BM donors (BMD) is the development of anemia. To protect the BMD and preserve the hemoglobin levels, many centers collect autologous pre-procedure blood, but the actual benefits of this procedure is controversial. METHODS AND MATERIALS: This study analyzed retrospectively data to observe what factors may influence the occurrence of post-donation anemia and also evaluate the relevance of autologous red blood cell pre procedure donation (PAD). RESULTS: The development of immediately post donation anemia (IP) was higher in BMD than in PB donors (64.2% BMD and 10.7% PBD, P < .001) and also in late post donation (LP) (28.4% BMD and 3.6% PBD, P = .007). The study demonstrated an association between PAD and anemia in IP (72.7% with anemia and 27.3% without anemia, P = .006) and an association between the volume of red blood cells in the donated hematopoietic product and the development of anemia in LP (356.3 mL and 297.8 mL, P = .037). CONCLUSION: In conclusion, collection of HSC through BM is a risk factor for anemia and PAD is a risk factor for IP anemia.

Duffy phenotyping and FY*B-67T/C genotyping as screening test for benign constitutional neutropenia.

OBJECTIVE: Low levels of neutrophils can be an intrinsic condition, with no clinical consequences or immunity impairment. This condition is the benign constitutional neutropenia (BCN), defined as an absolute neutrophils count (ANC) ≤2000 cells/mm. Diagnosis of BCN is of exclusion where patients are submitted to blood tests and possibly to invasive diagnostic search until secondary causes of neutropenia are ruled out. The natural history of the disease suggests benign evolution and Brazilian study showed an overall frequency of 2.59%. The main mechanisms include reduced neutrophil production, increased marginalization, extravasation to the tissues and immune destruction. Genetic studies showed strong association between the single nucleotide variant rs2814778 located on chromosome 1q23.2 in the promoter region of the atypical chemokine receptor 1 (Duffy blood group system) gene (ACKR1, also termed DARC) and BCN. The aim of this study is to evaluate FY phenotypes and genotypes including the analysis of the rs2814778 SNP in Brazilian patients with BCN in order to determine an effective diagnostic tool, allowing reassurance of the patient and cost reduction in their care. METHODS: Case control study, with 94 individuals (18 patients and 76 controls). Phenotyping was performed by gel test and genotyping was performed by PCR-RFLP. RESULTS: White blood cell (WBC) and absolute neutrophils (AN) counts showed lower levels in patients compared to controls. In the patient group 83.3% were genotyped as FY*B/FY*B. The SNP rs2814778 (-67T > C) was identified in 77.8% of the patients genotyped as FY*B-67C/FY*B-67C. In the control group, 72.7% were homozygous for the wild type and 23.3% were heterozygous. CONCLUSION: This study reinforces that FY phenotyping and genotyping can be used to detect most people with BCN, avoiding excessive diagnostic investigation. Besides, this procedure may reduce health costs and be reproductible in clinical practice.

Clinical Translation of Mesenchymal Stromal Cell Therapy for Graft Versus Host Disease.

Graft versus host disease (GVHD) is a common condition in patients subjected to allogeneic hematopoietic stem cell transplantation (HSCT). The immune cells derived from the grafted stem cells attack recipient's tissues, including those from the skin, liver, eyes, mouth, lungs, gastrointestinal tract, neuromuscular system, and genitourinary tract, may lead to severe morbidity and mortality. Acute GVHD can occur within few weeks after the allogeneic cells have engrafted in the recipient while chronic GVHD may occur any time after transplant, typically within months. Although treatable by systemic corticosteroid administration, effective responses are not achieved for a significant proportion of patients, a condition associated with poor prognosis. The use of multipotent mesenchymal stromal cells (MSCs) as an alternative to treat steroid-refractory GVHD had improved last decade, but the results are still controversial. Some studies have shown improvement in the life quality of patients after MSCs treatment, while others have found no significant benefits. In addition to variations in trial design, discrepancies in protocols for MSCs isolation, characterization, and ex vivo manipulation, account for inconsistent clinical results. In this review, we discuss the immunomodulatory properties supporting the therapeutic use of MSCs in GVHD and contextualize the main clinical findings of recent trials using these cells. Critical parameters for the clinical translation of MSCs, including consistent production of MSCs according to Good Manufacturing Practices (GMPs) and informative potency assays for product quality control (QC), are addressed.

Seasonal variability is not observed in the rates of high anti-A and anti-B titers in plasma, apheresis platelet, and whole blood units tested by different methods.

BACKGROUND: ABO-incompatible platelet transfusions are common, and transfusions with ABO-incompatible plasma are increasing with the use of group A plasma and group O whole blood (WB) in emergencies. Many centers screen blood products for anti-A and/or anti-B titers to help prevent hemolysis from ABO-incompatible transfusions, yet titer methods and definition of high titers are not standardized. STUDY DESIGN AND METHODS: This international multicenter study collected data on anti-A and anti-B titer practices for plasma, apheresis platelet (AP), and WB units from January 2015 through December 2017 to determine the prevalence of high-titer units using local definitions. RESULTS: A total of 87,701 plasma, AP and WB units were screened for high-titer anti-A and/or anti-B. High-titer detection rates for group A plasma ranged 0%-13.6%; group A AP 2.7%-9.3%; group O AP 2.3%-65.7%; and group O WB 6.4%-20.7%. At the one center that collected group B AP, the high-titer rate was 10.9%. High-titer rates varied from month to month, as well as between years for a given month. There was no clear pattern of when high-titer units were donated. CONCLUSION: The prevalence of high-titer plasma, AP, and WB units varies by titer method and local definition of high titer. Even at the lowest titer threshold of 50, a significant proportion of units had a high-titer antibody, although the clinical relevance of this finding needs further investigation.

The impact of preapheresis white blood cell count on autologous peripheral blood stem cell collection efficiency and HSC infusion side effect rate.

BACKGROUND: Autologous peripheral blood hematopoietic stem cell (PBSC) collection efficiency (CE) is reportedly affected by the patient's blood properties; however, studies to identify factors correlated with CE have shown inconsistent results. Additionally, variables such as stem cell graft granulocyte content and patient age, sex, and underlying disease, may be associated with hematopietic stem cell (HSC) infusion-related adverse reactions. In this study, we evaluated the correlation of preleukapheresis PB granulocyte count and PBSC harvest variables with CD34+ collection yield and efficiency, and thawed HSC infusion side effect occurrence. PATIENTS AND METHODS: We evaluated data from 361 patients who had undergone autologous PBSC transplant. Large volume leukapheresis was the method for PBSC collection. Complete Blood Count and CD34+ cell enumeration were performed in the preapheresis PB and the apheresis product sample. The PBSC grafts were submitted to non-controlled rate freezing after addition of 5% DMSO plus 6% hidroxyethylstarch as a cryoprotectant solution. The cryopreserved graft was thawed in a 37°C water bath and then infused without further manipulation. RESULTS: The CD34+ yield was associated with preapheresis PB CD34+ count and immature granulocyte count. The PBSC CE was negatively correlated with preapheresis white blood cell (WBC), immature granulocyte and granulocyte count. The leukapheresis product total nucleated cell (TNC) and granulocyte content was correlated with the thawed graft infusion side effect occurrence. CONCLUSION: This study has shown that preapheresis PB WBC and granulocyte counts were associated with leukapheresis CE. Additionally, the leukapheresis product TNC and granulocyte content was correlated with thawed graft infusion side effect occurrence.

The Crossmatch/Issue Ratio: Use of a Novel Quality Indicator and Results of an International Survey on RBC Crossmatching and Issuing Practices.

OBJECTIVES: To understand the worldwide scope of RBC crossmatching and issuing practices and measure efficiency using a novel quality indicator, the crossmatch/issue (C/I) ratio. METHODS: An electronic survey was disseminated to hospital transfusion services collecting details about RBC crossmatching and issuing practices. Respondents were asked to enumerate the number of RBCs crossmatched and issued at their institutions during the 2014 calendar year to calculate the C/I ratio. RESULTS: Fifty-two survey responses were received, mostly from North American transfusion services (28/52, 54%). The electronic crossmatch was the most common technique (n = 29), and most respondents performed the crossmatch at the time that an order for RBCs was received in the transfusion service (even if an order to issue the RBCs was not received). Data to calculate the C/I ratio were supplied by 22 respondents, and the mean ± SD was 1.30 ± 0.34. There was no difference in C/I ratios between services that use the electronic or serologic crossmatch techniques (P = .49). The ratio was the same at the four sites that crossmatch RBCs at the time of issue compared with the time of order receipt (mean ± SD, 1.11 ± 0.09 vs. 1.35 ± 0.36, respectively; P = .19). CONCLUSIONS: Electronic crossmatching is common, and the C/I ratio can be an indicator of efficiency.

Predictors of high-quality cord blood units.

BACKGROUND: Analysis of umbilical cord blood (UCB) transplants shows a correlation between engraftment and total number of infused cells. Thus, it is worth evaluating what maternal and neonatal characteristics and collection techniques may affect the quality of UCB units. STUDY DESIGN AND METHODS: A cross-sectional study was performed with 7897 donors sequentially selected in three health care institutions in Brazil from October 2004 to March 2012, in which both quantitative and qualitative approaches were applied. All donors were considered suitable for cord blood collection. RESULTS: The maternal and neonatal characteristics and techniques of collection that influenced the total number of nucleated cells (TNCs; p < 0.001) were type of delivery, newborn weight and sex, and institution of UCB collection. The TNC count was associated with gestational age (p = 0.008), type of delivery (p < 0.001), newborn sex (p < 0.001), newborn weight (p < 0.001), and UCB collection technique (p = 0.003). Center B presented the largest number of nucleated cells in its results (p < 0.001), followed by Center A (p = 0.001). Other characteristics, such as maternal age, were analyzed but were not relevant for the nucleated cell number. CONCLUSION: This study provides elements for a model that allows an efficient selection of UCB donors, prioritizing candidates who have a better chance to lead to an optimized use of cord blood cells units.

Whole-pulmonary low-dose radiation therapy in agnogenic myeloid metaplasia with diffuse lung involvement.

Agnogenic myeloid metaplasia is a hematologic disorder accompanied by extramedullary hematopoiesis (EMH) affecting various organs. Lung involvement however is rare. We present the case of a 76-year-old woman with myelofibrosis, recurrent pleural effusions, pulmonary hypertension, and serious right cardiac failure. An open lung biopsy confirmed pulmonary EMH. She underwent low-dose (200 cGy) whole-lung radiotherapy in 4 fractions of 50 cGy each. Her clinical and hemodynamic parameters improved. We conclude that low-dose whole-lung radiation may be efficacious for the palliative treatment of pulmonary EMH.