Leucodepletion and Blood Products

Tumor-Infiltrating Lymphocyte Cell Therapy for the Treatment of Advanced Melanoma: From Patient Identification to Posttreatment Management

Adoptive cell therapy with tumor-infiltrating lymphocytes (TILs) was recently approved for patients with advanced melanoma (metastatic or unresectable) previously treated with immune checkpoint inhibitors and BRAF/MEK targeted therapies (where appropriate). Tumor-infiltrating lymphocytes isolated from patient-derived tumor tissues enter the tumor microenvironment and recognize tumor-specific antigens, leading to the destruction of tumor cells. The multistep TIL cell therapy journey is led by a multidisciplinary health care team. Patients selected for TIL cell therapy undergo tumor tissue procurement for TIL generation, followed by preparative lymphodepletion before receiving a single-dose infusion of TIL and a short course of high-dose interleukin-2. Successful implementation of TIL cell therapy requires well-established procedures and workflows to select and screen patients, procure tumor tissue, administer TIL cell therapy, and monitor patients during treatment and after discharge. The advanced practice provider plays a central role in a patient's TIL treatment journey by planning and coordinating care across the health-care system, educating patients and staff, and providing direct and supportive patient care. Here, we review the treatment landscape for advanced melanoma and clinical data supporting TIL cell therapy. We also provide guidance related to patient selection, tumor tissue procurement, TIL cell therapy regimen, safety monitoring, symptom management, and post-discharge follow-up.

Evaluation of two methods for counting residual leukocytes in leukoreduced packed red cells: Flow cytometry and fully automated cell counter

BACKGROUND AND OBJECTIVES

Objective of the study is to explore the possibility of utilization of seven part fully automated hematology analyzer for enumeration of residual leukocytes (residual white blood cells [rWBCs]) in leukoreduced packed red cells (LR-PRCs) prepared from whole blood at a blood center as an alternate to the gold standard method, flow cytometry. In this study, we evaluate the performance characteristic of hematology analyzer against flow cytometry for the estimation of rWBCs in 39 LR-PRC units.

MATERIALS AND METHODS

PRCs prepared from whole blood donations by 39 donors were leukoreduced and their volumes were noted. The samples from these LR-PRCs were processed on HORIBA Yumizen H2500 hematology analyzer and Backman Coulter DxFlex (B5R3V5) Flow Cytometer and compared.

RESULTS

A total of 39 LR-PRCs were analyzed. The average volume of these LR-PRC units was 252 mL ranging from 227 to 285 mL/bag. The average rWBC count for all LR-PRC units as per flowcytometry method was 3.1 × 106/bag. There were 5 LR-PRC units with rWBC count more than 5 × 106/bag which did not fulfill the minimum quality control criteria of LR-PRCs as per the Indian standards (DGHS).

CONCLUSION

The new generation fully automated hematology analyzers could be simple, reliable, economical, and practically best method for assessing the efficacy of leukoreduction in LR-PRCs. They can be adopted by resource-constrained blood centers as an alternative to flow cytometry for this purpose. It can be practically applied to check the quality of leukoreduction in all blood component samples before release from blood center for transfusion to the patients.

A retrospective observational study to estimate the risk of HLA alloimmunization with blood transfusion: Can the risk be reduced by leucodepletion?

BACKGROUND

In this retrospective study, our aim was to find the effect of leucodepleted (LD) blood transfusions on the formation of anti-HLA-antibodies when compared to non-leucodepleted (non-LD) transfusions using Luminex-based method.

METHODS

In this study, Luminex single antigen bead assay (L-SAB) and HLA typing were performed on 310 patients. Test positivity rates (as MFI - Mean florescence intensity) were analyzed according to the different sensitization events and gender.

RESULTS

Of the 310 patients included in the study, 58.06% (180) patients were male and 41.93% (130) were female. The average age of the patients was 42.86 (±12.37) years. In this study, test positivity rates were significantly lower in the patients who received LD RBC units than in those who received non-LD RBC units (28.43% = 29 of 102 Vs 55.22% = 74 of 134, p < 0.05). In our study, transfusion combined with a history of pregnancy had higher number of significant HLA antibodies compared to cases where transfusion was the only sensitization event (81.81% = 18/22 Vs 39.71% = 85/214, p < 0.05). In addition, anti-HLA-antibodies-MFI were significantly (p < 0.01) higher in non-LD patients compared to LD patients.

CONCLUSION

Patients who received LD RBC units had a significantly lower rate of transfusion-associated alloimmunization compared to those who received non-LD RBC units. Multiparous women had a high risk for transfusion-related alloimmunization compared to both nulliparous women and male patient. Furthermore, class I-anti-HLA-antibodies (HLA-B and HLA-A + B) were significantly associated with pregnancy sensitization and/or blood transfusion as a single sensitization.

Recent advances in micro-sized oxygen carriers inspired by red blood cells

Supplementing sufficient oxygen to cells is always challenging in biomedical engineering fields such as tissue engineering. Originating from the concept of a 'blood substitute', nano-sized artificial oxygen carriers (AOCs) have been studied for a long time for the optimization of the oxygen supplementation and improvement of hypoxia environments in vitro and in vivo. When circulating in our bodies, micro-sized human red blood cells (hRBCs) feature a high oxygen capacity, a unique biconcave shape, biomechanical and rheological properties, and low frictional surfaces, making them efficient natural oxygen carriers. Inspired by hRBCs, recent studies have focused on evolving different AOCs into microparticles more feasibly able to achieve desired architectures and morphologies and to obtain the corresponding advantages. Recent micro-sized AOCs have been developed into additional categories based on their principal oxygen-carrying or oxygen-releasing materials. Various biomaterials such as lipids, proteins, and polymers have also been used to prepare oxygen carriers owing to their rapid oxygen transfer, high oxygen capacity, excellent colloidal stability, biocompatibility, suitable biodegradability, and long storage. In this review, we concentrated on the fabrication techniques, applied biomaterials, and design considerations of micro-sized AOCs to illustrate the advances in their performances. We also compared certain recent micro-sized AOCs with hRBCs where applicable and appropriate. Furthermore, we discussed existing and potential applications of different types of micro-sized AOCs.

Comparative study of quality of leukoreduced packed red blood cell units as assessed by nageotte hemocytometry and flow cytometry

PURPOSE

Assessment of residual white blood cell (rWBC) count is vital to ascertain the quality of leukodepleted (LD) blood components. Automated cell analyzers lack the sensitivity for the assessment of very few leukocytes as found in LD blood components. Flow Cytometry (FC) based methods and Nageotte hemocytometer are the most commonly used techniques for this purpose. The objective of this study was to compare the use of Nageotte hemocytometer and FC for quality control of LD red blood cell units.

MATERIALS AND METHODS

A prospective, observational study was conducted in the Department of Immunohematology and Blood Transfusion of a tertiary care center from September 2018 to September 2020. About 303 LD-packed red blood cell units were tested by FC and Nageotte hemocytometer for rWBCs.

RESULTS

The number of rWBC (mean) detected by flow cytometer and Nageotte's hemocytometer was 1.06 ± 0.43 white blood cell (WBC)/μL and 0.67 ± 0.39 WBC/μL, respectively. Coefficient of variation was 58.37% by Nageotte hemocytometer method and 40.46% by FC. Linear regression analysis did not show any correlation (R2= 0.098, P = 0.001) whereas Pearson's correlation coefficient showed a weak relation (r = 0.31) between the two methods.

CONCLUSION

Flow cytometric technique provides a more precise and accurate objective tool compared to Nageotte hemocytometer which is labor intensive, time consuming, and prone to errors arising out of subjectivity along with reported underestimation bias. In the absence of adequate infrastructure, resources, and trained workforce, Nageotte hemocytometer method is a reliable alternative. Nageotte's chamber could be best used in the resource-constrained setup as it offers a relatively inexpensive, simple, and viable means to enumerate rWBCs.

Optimized simple and affordable procedure for differentiation of monocyte-derived dendritic cells from LRF: An accessible and valid alternative biological source

Dendritic cells are one of the most popular immune cells, which plays a remarkable role in both immunotherapy and tolerance induction. Due to unwanted side effects of leukocyte presence in donated blood, the policy of blood service is the pre-storage reduction of leukocytes, which today, filtration is the most common method for this purpose. The filtration method has led to diminished access to Buffy coat as a generally used conventional source of biological cells. We developed a simple, affordable, and reproducible method for dendritic cell differentiation from filter-derived monocytes and, the results of the filter study were compared with differentiated DCs from the conventional buffy coat-derived monocytes. The Monocytes were recovered from leukoreduction filter using an optimized protocol with supplemented PBS buffer. Following the adhesion method, CD14⁺ Monocyte-enriched population with the purity of 94 % was obtained. After cytokine stimulation over a 6-day period and maturation induction by LPS, differentiated DCs were evaluated for morphology, surface markers (CD86, CD40, CD83 and, HLA-DR), antigen uptake potency and IL-12 secretion. Analysis and comparison of the results represented no significant difference between the two groups. Accordingly, we conclude that leukoreduction filters could be introduced as a reliable and research-grade source of monocyte for DC generation in biological research.

Non Infectious Complications Related to Blood Transfusion: An 11 year Retrospective Analysis in a Tertiary Care Hospital

In India transmission of transfusion transmissible infections (TTI) has shown a relative decrease as a result of mandatory screening of donated blood for TTI's. However, reducing the incidence of non infectious complications poses a major challenge, mainly due to the fact that a number of adverse reactions go unreported. Blood transfusion reaction, can be categorized based on the time interval between transfusion of blood products and the presentation of adverse reactions as acute i.e. those presenting during or within 24 h and as delayed i.e. those presenting anytime after 24 h. Transfusion reactions can further be classified as immune and non immune or infectious and non infectious based on the pathophysiology. In this retrospective study which was undertaken with an aim to determine the type and frequency of non infectious complications due to transfusion of blood and blood products recorded the incidence of febrile non hemolytic transfusion reactions (FNHTR) 51.40 %, allergic reactions 40.14 %, non immune hemolytic reactions 4.22 %, hypothermia 2.81 %, anaphylaxis 0.70 % and iron overload 0.70 %. FNHTR which was found to be the most common complication in this study can certainly be minimized, if not completely eliminated by adopting a policy of universal leucodepletion, the implementation of which solely depends on the financial and infrastructure resources available. This study also reiterates the importance of hemovigilance as a tool to improve the safety of blood transfusion.

Biochemical storage lesions occurring in nonirradiated and irradiated red blood cells: a brief review

Red blood cells undergo a series of biochemical fluctuations during 35-42-day storage period at 1°C to 6°C. The sodium/potassium pump is immobilised causing a decrease in intracellular potassium with an increase in cytoplasmic sodium levels, glucose levels decline, and acidosis occurs as a result of low pH levels. The frailty of stored erythrocytes triggers the formation of haemoglobin-containing microparticles and the release of cell-free haemoglobin which may add to transfusion difficulties. Lipid peroxidation, oxidative stress to band 3 structures, and other morphological and structural molecular changes also occur leading to spheroechinocytes and osmotic fragility. These changes that transpire in the red cells during the storage period are referred to as "storage lesions." It is well documented that gamma irradiation exacerbates storage lesions and the reports of increased potassium levels leading to adverse reactions observed in neonates and infants have been of particular concern. There are, however, remarkably few systematic studies comparing the in vitro storage lesions of irradiated and nonirradiated red cell concentrates and it has been suggested that the impact of storage lesions on leucocyte reduced red blood cell concentrate (RBCC) is incomplete. The review examines storage lesions in red blood cells and their adverse effects in reference to blood transfusion.

Expert elicitation for the judgment of prion disease risk uncertainties

There is a high level of uncertainty surrounding the potential for iatrogenic prion transmission through transplantation, medical instrument reuse, blood transfusion, and blood product use due to a lack of evidence-based research on this important risk issue. A group of specialists was enlisted to evaluate some of the knowledge gaps in this area using the "Classical Model," a structured elicitation procedure for weighting and pooling expert judgment. The elicitation exercise was undertaken in March 2009 with 11 transmissible spongiform encephalopathy (TSE) experts who were first calibrated using a series of seed questions for which the answers are known; they were then asked to answer a number of target questions that are important for risk assessment purposes, but for which there remains high uncertainty at this time. The target questions focused on variant Creutzfeldt-Jakob disease (vCJD) prevalence, incubation times for vCJD, genetic susceptibility to prion disease, blood infectivity, prion reduction of blood and blood products, surgical instrument risks, and interspecies transmission of TSEs. The experts were also asked to perform pairwise risk rankings for 12 different potential routes of infection. Dura mater transplantation was seen as having the highest risk, while dental tissue grafts were viewed as presenting the lowest risk of iatrogenic transmission. The structured elicitation procedure provides a rational, auditable, and repeatable basis for obtaining useful information on prion disease risk issues, for which data are sparse.