‘Agglutination and flocculation’ of stem cells collected by apheresis due to cryofibrinogen

Collection and processing of hematopoietic progenitor cell products at risk of presenting with cold agglutination

BACKGROUND AIMS

Cold agglutinins are commonly identified in transfusion laboratories and are defined by their ability to agglutinate erythrocytes at 3-4°C, with most demonstrating a titer >64. Similarly, cryoglobulins can precipitate from plasma when temperatures drop below central body temperature, resulting in erythrocyte agglutination. Thankfully, disease associated from these autoantibodies is rare, but unfortunately, such temperature ranges are routinely encountered outside of the body's circulation, as in an extracorporeal circuit during hematopoietic progenitor cell (HPC) collection or human cell therapy laboratory processing. When agglutination occurs ex vivo, complications with the collection and product may be encountered, resulting in adverse events or product loss. Here, we endeavor to share our experience in preventing and responding to known cases at risk of or spontaneous HPC agglutination in our human cell therapy laboratory.

CASE REPORTS

Four cases of HPC products at risk for, or spontaneously, agglutinating were seen at our institution from 2018 to 2020. Planned modifications occurred, including ambient room temperature increases, tandem draw and return blood warmers, warm product transport and extended post-thaw warming occurred. In addition, unplanned modifications were undertaken, including warm HPC product processing and plasma replacement of the product when spontaneous agglutination of the product was identified. All recipients successfully engrafted after infusion.

CONCLUSIONS

While uncommon, cold agglutination of HPC products can disrupt standard processes of collection and processing. Protocol modifications can circumvent adverse events for the donor and minimize product loss. Such process modifications should be considered in individuals with known risks for agglutination going to HPC donation/collection.

Clotting during autologous hematopoietic progenitor cells collection

Autologous hematopoietic progenitor cell (HPC) transplant through peripheral blood mobilization and leukapheresis is a standard treatment for many patients with hematopoietic malignancies. Although leukapheresis is usually completed with no complications, we present a case in which the hematopoietic progenitor cells clotted during collection. The patient had no history of hypercoagulopathy. It was identified that the anticoagulant infusion line was partially constricted by a blood warmer clamp. The machine did not alarm. Most of the multiple Food and Drug Administration reports of clotting occurring during apheresis procedures were due to the patients' preexisting hypercoagulopathy or insufficient anticoagulant solution being used. The machine alarmed in most of these cases. Our case demonstrates that inadequate anticoagulation can occur during an HPC collection procedure without activation of an alarm.

Postthaw clotting of peripheral blood stem cell products due to insufficient anticoagulant

The amount of acid citrate dextrose formula A (ACD-A), which is a commonly used anticoagulant in leukopheresis, has to ensure both the safety of the donor and guarantee the integrity of the peripheral blood stem cell (PBSC) product until its transplant. Two recent consecutive cases of postthaw PBSC product clotting initiated a look-back investigation of the ACD-A percentage in leukopheresis products collected in our facility. The data indicated a significant difference between the average amount of ACD-A in prefreezing products collected during 2006 (11.4%) and in products collected during 2007 and 2008 (8.8% and 8.7%, respectively). These findings and the fact that the two clotted products had less than 7% ACD-A indicated that insufficient amount of anticoagulant might contribute to their clotting. This investigation prompted us to modify our collection and thawing procedures to prevent similar events in the future.

Peripheral blood hematopoietic stem cells: Biology, apheresis collection and cryopreservation

Introduction Hematopoiesis is a continuous, dynamic and highly complex process resulting in production of various mature blood cells from a small population of pluripotent stem and progenitor cells through diverse proliferative and differentiative events. Numerous studies have demonstrated that a complex network of interactive cytokines regulates the survival, maturation, and proliferation of hematopoietic stem and progenitor cells (HSPCs). Application of cell-mediated therapy Massive application of different cell-mediated therapeutic methods has resulted in an increased need for both specific HSPCs and operating procedures providing minimal cell damage during collection, processing and storage in a liquid or frozen state. Therefore, the basic aim of cell harvesting, selection, as well as cryopreservation is to minimize cell damage during these procedures. HSPCs are cells which exhibit extensive self-renewal and proliferative capacity, associated with the capacity to differentiate into all blood cells and other cell lineages (plasticity of HSPC). Thanks to these properties, stem cells can provide complete and permanent restoration of hematopoiesis, which is the basis for clinical employment of HSPC transplantation. In addition, totipotent stem cells can be used for the so called "cell-therapy" in different clinical settings (e.g. myocardial regeneration after acute infarction). Conclusion Despite the fact that HSPC transplantation is already in routine use, some questions related to the optimal blood progenitor/cell collection, selection, storage and clinical use are still unresolved. Therefore, this review only briefly discusses the therapeutic use of HSPCs in different clinical areas and focuses on the recommendations, as well as the specific transfusion policies related to HSPC collection, processing, and cryopreservation with an emphasis on quality control.

Clinical proteomics: study of a cryogel

Cryoproteins are proteins precipitating at low temperature. Usually, the precipitate contains immunoglobulins (Igs), and are therefore called cryoglobulins. Very rarely, Igs do not precipitate, but, upon cooling, form a gel. Here, we report a case of cryogel observed in a patient presenting with Waldenström's disease. Using proteomic tools, a monoclonal IgM was identified as being the cause of the gel formation. Furthermore, addition of H(2)O before incubation at 4 degrees C demonstrated that the monoclonal IgM was precipitable as a type I cryoglobulin (hypocryoglobulin).

Recent advances in blood-related proteomics

Blood is divided in two compartments, namely, plasma and cells. The latter contain red blood cells, leukocytes, and platelets. From a descriptive medical discipline, hematology has evolved towards a pioneering discipline where molecular biology has permitted the development of prognostic and diagnostic indicators for disease. The recent advance in MS and protein separation now allows similar progress in the analysis of proteins. Proteomics offers great promise for the study of proteins in plasma/serum, indeed a number of proteomics databases for plasma/serum have been established. This is a very complex body fluid containing lipids, carbohydrates, amino acids, vitamins, nucleic acids, hormones, and proteins. About 1500 different proteins have recently been identified, and a number of potential new markers of diseases have been characterized. Here, examples of the enormous promise of plasma/serum proteomic analysis for diagnostic/prognostic markers and information on disease mechanism are given. Within the blood are also a large number of different blood cell types that potentially hold similar information. Proteomics of red blood cells, until now, has not improved our knowledge of these cells, in contrast to the major progresses achieved while studying platelets and leukocytes. In the future, proteomics will change several aspects of hematology.

Haemovigilance in a general university hospital: need for a more comprehensive classification and a codification of transfusion-related events

BACKGROUND AND OBJECTIVES

The purpose of this study was to analyse the transfusion-related events recorded in a general university hospital.

MATERIALS AND METHODS

The method we used was retrospective analysis of the data collected between 1999 and 2003.

RESULTS

The incidence of transfusion reactions (n = 394) was 4.19 per 1000 blood products distributed: 59% (n = 231) were febrile non-haemolytic transfusion reactions; 22% (n = 88) were caused by allergy; 5% (n = 21) were caused by bacterial infection; and 14% (n = 54) were classified as other reactions. Platelet concentrates gave rise to a significantly greater number of reactions than erythrocyte concentrates and fresh-frozen plasma. Transfusion errors and near-miss events were also observed and were analysed separately. A series of transfusion-related events, such as haemosiderosis, metabolic disturbances or volume overload, were not reported.

CONCLUSIONS

Our experience prompts us to propose a more comprehensive classification and codification of transfusion-related events.