Ethylene oxide-type hypersensitivity reactions in G-CSF mobilized, peripheral blood hematopoietic progenitor cell donors and review.

BACKGROUND: Ethylene oxide (EtO) is a volatile, ringed toxic ether used to sterilize heat-labile plastics including apheresis sets. In the 1980s, EtO-associated severe hypersensitivity reactions during hemodialysis led to widespread adoption of alternative sterilization for dialysis kits but not apheresis tubing sets. We now report several cases of EtO-type hypersensitivity reactions in autologous donors undergoing hematopoietic progenitor cell collection (HPCC). MATERIALS AND METHODS: A 10-year retrospective review of allergic EtO-type reactions in adults undergoing HPCC on the COBE Spectra and SPECTRA Optia was performed. Donor medical history and absolute eosinophil counts were compared between cases and 34 HPCC controls. Published EtO reactions during extracorporeal procedures were reviewed with statistical analysis. Graphics and statistics were performed using commercial software. RESULTS: Three autologous HPCC donors experienced EtO-type reactions within 15 min of initiating HPCC, for a 10-year incident rate of 0.08% per procedure and 0.18% per donor. All three reactions occurred using the Spectra Optia and IDL tubing set, for an Optia/IDL specific rate of 0.2% per procedure and 0.5% per donor. There was no correlation between EtO reactions, eosinophil counts, or saline prime dwell times. No patient had classic predisposing risk factors for EtO hypersensitivity. Two patients required medical intervention whereas the third responded by pausing the procedure and slowing the inlet rate. CONCLUSION: EtO-type hypersensitivity reactions can be observed during HPCC, especially with the Optia IDL tubing set. EtO reactions may be missed due to their rarity and staff unfamiliarity with this clinical entity.

A secondary CD34+ acute lymphoblastic leukemia unmasked and mobilized by G-CSF in an autologous stem cell donor with testicular cancer.

BACKGROUND: Late complications of chemotherapy include treatment-related secondary leukemias. We describe an unusual case of a new treatment-related acute lymphoblastic leukemia (t-ALL) that was unmasked and mobilized by G-CSF during autologous hematopoietic progenitor cell collection (HPCC) in a young man with testicular cancer. METHODS: Electronic chart review of the patient medical history and pertinent laboratory findings. Patient CD34 and blast results were compared to 4249 autologous and 437 allogeneic HPCC performed between 2004 and 2022. In autologous donors, the %blast and %CD34 were compared by linear regression and paired t-test using commercial software. RESULTS: The patient was a 21-year-old male with relapsed testicular cancer referred for G-CSF cytokine-only mobilization and autologous HPCC. His pre-mobilization WBC count and differential were normal. On the day of HPCC, his WBC = 37.9 K/mcL with 12% blasts and 9.75% circulating CD34+ cells. The patient was admitted 9 days after HPCC with a normal WBC count and 15% blasts. He was diagnosed with a pro-B t-ALL bearing an t(4:11)(q21:q23) translocation and KMT2A-AF4 rearrangement. Upon review, this patient had the highest %CD34 among 4686 HPCC and was the only donor with %CD34 > 1% after a cytokine-only mobilization. CONCLUSION: We report a case of t-ALL that mimicked CD34+ HPC and was mobilized by high-dose G-CSF. Up to 70% of secondary leukemias bear 11q23/KMT2A rearrangements, which occur at the multipotent stem cell stage and can result in myeloid and lymphoid leukemias. Donors who have received past chemotherapy, especially with topoisomerase II inhibitors, are at increased risk for 11q23/KMT2A leukemias.

Allo-anti-M: Detection peaks around 2 years of age, but may be attenuated by red blood cell transfusion.

BACKGROUND: Anti-M is frequently observed as a naturally occurring antibody of little clinical significance. Naturally occurring anti-M is often found in children although the specific triggers of production, persistence, and evanescence of anti-M have yet to be elucidated. METHODS: In a retrospective, multicenter, nationwide cohort survey conducted from 2001 to 2015, alloantibody screening was performed before and after transfusion in 18,944 recipients younger than 20 years. Recipients were categorized into six cohorts based on their age at transfusion; within and among these cohorts, allo-anti-M was analyzed in regard to its production, persistence, and evanescence. RESULTS: In 44 patients, anti-M detected before and/or after transfusion was an age-related phenomenon, with a median age of 2 years and an interquartile range of 1-3 years; anti-M was most frequently detected in a cohort of children 1 to <5 years (0.77%, 31 of 4035). At least five patients were presumed to have concurrent infections. Among 1575 adolescents/young adults (15 to <20 years), no anti-M was detected. Of 29 patients with anti-M prior to transfusion, the antibody fell to undetectable levels in 17 recipients (89.5%, of whom at least 13 received only M-negative red cells) after anywhere from 5 days to 5.8 years; anti-M persisted in 2, and was not tested in 10. Only 15 recipients (0.08%) produced new anti-M after transfusion. CONCLUSION: Naturally occurring anti-M is a phenomenon of younger ages, predominantly between 1 and 3 years. After transfusion, it often falls to undetectable levels.

Inertial focusing of circulating tumor cells in whole blood at high flow rates using the microfluidic CTCKey™ device for CTC enrichment.

Circulating tumor cells (CTCs) are extremely rare cells shed from tumors into the blood stream. These cells can provide valuable information about their tumor of origin and direct treatment decisions to improve patient outcomes. Current technologies isolate CTCs from a limited blood volume and often require pre-processing that leads to CTC loss, making it difficult to isolate enough CTCs to perform in-depth tumor analysis. Many inertial microfluidic devices have been developed to isolate CTCs at high flow rates, but they typically require either blood dilution, pre-processing to remove red blood cells, or a sheath buffer rather than being able to isolate cells directly from whole blood. To decrease the need for pre-processing while increasing CTC yield, we developed an inertial device, the CTCKey™, to focus CTCs in whole blood at high throughput yielding a concentrated product stream enriched for CTCs. The CTCKey™ consists of two sections to create CTC enriched blood that can be further processed using any CTC isolation device to selectively isolate the CTCs. A thorough analysis was performed using the MCF7 breast cancer cell line spiked into bovine serum albumin (BSA) solutions of varying concentrations, as well as whole blood to characterize the focusing patterns of the CTCKey™. At the optimal flow rate of 2.4 mL min-1, the CTCKey™ reduces the CTC containing blood volume by 78%; the CTCs from 1 mL of blood are now in 0.22 mL of blood. The CTCKey's™ ability to concentrate CTCs from a large original blood volume to a smaller, highly concentrated volume enables a much greater blood volume to be interrogated by downstream isolation and characterization methods despite their low volume input limitations.

An update on the I blood group system.

CONCLUSIONS: This update of the I blood group system (Cooling L. Polylactosamines, there's more than meets the "Ii": a review of the I system. Immunohematology 2010;26:133-55) continues to show the Ii antigens to be increasingly recognized as important posttranslational modifiers regulating cell adhesion, signaling, differentiation, and cancer. Ii antigens can modulate the immune response through the galectin lattice, as well as influence specific protein-protein interactions. Changes in GCNT2 and I expression accompany stem cell differentiation and are associated with tumor progression in melanoma and breast and colon cancer. Regulation of GCNT2 expression varies between cell types and differentiation. In red blood cell differentiation, GCNT2 is regulated by methylation, microRNAs, and mitogen-activated protein kinase signaling pathways. Methylation and microRNAs also play a prominent role in altering GCNT2 expression in several epithelial cancers. In congenital cataracts, GCNT2 mutations may account for 4-6 percent of all cases. GCNT2 may be particularly susceptible to gene deletion and rearrangements due to the density of Alu-repeat elements.

Apheresis red blood cells associated with repeated hemolysis during blood priming of the Cellex Photopheresis System.

Extracorporeal photopheresis (ECP) in young pediatric patients has a risk for procedural hypotension and anemia due to extracorporeal fluid shifts. A standard mitigation policy in these patients is to prime the device with packed red blood cells (RBC) or whole blood. We now report multiple episodes of hemolysis while attempting to prime the Therakos Cellex in a pediatric transplant patient undergoing a course of ECP for severe graft-vs-host-disease. Over the course of 40 ECP treatments, hemolysis was observed on five occasions. An extensive investigation found an association between hemolysis and apheresis RBC (A-RBC). Of 46 RBC units dispensed for blood priming, hemolysis occurred with 22% (4 of 18) of A-RBC and accounted for 80% (4 of 5) of all hemolysis episodes. Hemolysis was significantly higher with A-RBC when compared with RBC collected by whole blood donations (WB-RBC: 3.5% [1 of 28]; P = .049). A comparison of RBC attributes, including unit age, showed that hemolyzed A-RBC units tended to be younger than both nonhemolyzed RBC (6.5 vs 10.3 days, P = .018) and WB-RBC (8.5 days, P = .10). We hypothesize that A-RBC may exhibit "sublethal" RBC damage following prior exposure to centrifugal shear and negative forces at the time of collection, leading to a decrease in RBC deformability and increased susceptibility to hemolysis. This is the first report showing an increased susceptibility to hemolysis with A-RBC during priming of the Cellex.

A temporary indwelling intravascular aphaeretic system for in vivo enrichment of circulating tumor cells.

Circulating tumor cells (CTCs) have become an established biomarker for prognosis in patients with various carcinomas. However, current ex vivo CTC isolation technologies rely on small blood volumes from a single venipuncture limiting the number of captured CTCs. This produces statistical variability and inaccurate reflection of tumor cell heterogeneity. Here, we describe an in vivo indwelling intravascular aphaeretic CTC isolation system to continuously collect CTCs directly from a peripheral vein. The system returns the remaining blood products after CTC enrichment, permitting interrogation of larger blood volumes than classic phlebotomy specimens over a prolonged period of time. The system is validated in canine models showing capability to screen 1-2% of the entire blood over 2 h. Our result shows substantial increase in CTC capture, compared with serial blood draws. This technology could potentially be used to analyze large number of CTCs to facilitate translation of analytical information into future clinical decisions.

Efficacy of therapeutic plasma exchange on angiotensin II type-1 receptor antibodies on two kidney transplant recipients.

BACKGROUND: Angiotensin II type-1 receptor antibody (AT1RAb) has been reported to cause antibody mediated rejection (AMR) in kidney transplant recipients possibly by contraction of renal arteries. We here report 2 kidney transplant recipients with elevated AT1RAbs and negative HLA donor specific antibodies (DSA) and anti-major histocompatibility complex class I chain-related gene A (MICA) Abs who received therapeutic plasma exchange (TPE) treatment followed by IVIG. CASE 1: Thirty-eight-year-old patient received second kidney transplant for end stage renal disease (ESRD) with chronic rejection. Three years post-transplant, she developed AMR with AT1RAb level >40 U/mL. She received 5 TPE and AT1RAb decreased by 20%, and biopsy showed improvement of AMR. She received another 3 TPE and AT1RAb decreased by 60%. Her creatinine (Cr) was stabilized at around 1.4 mg/dL. CASE 2: Twenty-four-year-old patient received kidney transplant for ESRD with unclear etiology. Two weeks post-transplant, her Cr rose with AT1RAb level at 18 U/mL and biopsy showed possible AMR. She received 6 TPE treatments and AT1RAb decreased by 55% and biopsy showed improvement of AMR. She received weekly TPE for subsequently rising AT1RAb but TPE was discontinued because of unsuccessful decrease of AT1RAb. Her Cr was stabilized at around 1.7 mL/dL. CONCLUSION: We reported 2 patients who received TPE treatments to decrease AT1RAbs. A course of TPE treatment successfully decreased AT1RAb. Histological improvement was observed quickly and Cr was also stabilized following the TPE treatment. Further study is necessary to determine the optimal use of TPE in renal transplant recipients with AT1RAbs.

The devil is in the details: retention of recipient group A type 5 years after a successful allogeneic bone marrow transplant from a group O donor.

CONCLUSIONS: ABO-incompatible (ABOi) hematopoietic stem cell transplants (HSCTs) can present challenges in the blood bank. During transplantation, patients receive components that are ABO-compatible with both the donor graft and recipient; this practice can strain group O red blood cell (RBC) inventories.1 In addition, there are risks for acute hemolysis at the time of infusion and in the early post-transplant period.1,2 In ABO major-incompatible bone marrow HSCTs, which contain significant quantities of donor RBCs that are ABOi with recipient plasma, it is common to perform a RBC depletion of the bone marrow in an effort to minimize hemolysis at the time of infusion.2 Furthermore, patients with high-titer ABO antibodies may undergo a prophylactic, pre-transplant plasma exchange to further reduce the risk of acute hemolysis, delayed RBC engraftment, and pure RBC aplasia.2-4 ABO minor-incompatible HSCTs, in which donor plasma is ABOi with the recipient, have less risk for hemolysis at the time of infusion but can result in transient hemolysis approximately 10-21 days post-transplant, especially in patients undergoing nonmyeloablative HSCT and/or patients who have not received methotrexate for graft-versus-host-disease (GVHD) prophylaxis.1-4 In these patients, viable donor B-lymphocytes in the graft may expand and produce ABO antibodies capable of hemolyzing patient RBCs.