Platelet Reduction Research Articles

Does Occupational Exposure to Chemicals/Carcinogens Affect the Hematological Parameters of Workers?

Background/Objectives: Chemical and carcinogenic risk in workplace are linked to an increase of the incidence of cancer in exposed workers. The aim of this observational study was to identify an association between exposure to chemical risk and changes in hematochemical parameters of workers exposed. Methods: The study examined blood count parameters performed on 4523 employees of Sapienza University of Rome from September 2019 to February 2020. A total of 1402 workers in research laboratories, exposed to chemical risk and carcinogens, was compared with a cohort of 3121 blood donors, in apparently good health, matched for age, sex, and period of blood collection. Results: Multivariate analysis demonstrated acrylamide is the most frequently associated chemical with significant changes between the groups. It is related to an increase in monocytes and MPV, a reduction of lymphocytes, platelets, and red series values, while MCH remained unchanged. Formaldehyde reveals the same changes as acrylamide, with the exception of the percentage of lymphocytes, red blood cells, and HB, which remain unchanged. Other chemicals and carcinogens show variations for few blood count parameters. Conclusions: The present study found out a significant change in blood count values in workers exposed to acrylamide and formaldehyde. It also showed an increase in the mean monocyte value in employees exposed to carcinogenic risk, compared to non-exposed, with the exception of Trypan Blue. The implementation of efficient health surveillance remains of critical importance. These data should be compared with those from follow-up studies.

Transfusion reaction patterns by blood component

Abstract Introduction/Objective Blood transfusion is becoming safer by continuous improvement of donor screening, patient identification, blood management, and infectious disease screening. This study was conducted to examine the rate and characteristics of transfusion reactions in the setting of universal leukoreduction of cellular products as well as pathogen reduction and/or irradiation of apheresis platelets. Methods/Case Report Data from the blood bank database for a 5-year period from 1/1/2019 to 12/31/2023 was collected. Transfusion reaction data as reported to National Healthcare Safety Network (NHSN) was analyzed. Results (if a Case Study enter NA) A total of 134,552 transfusions and 491 transfusion reactions were reported over the study period, resulting in the overall transfusion reaction rate of 0.36%. Allergic reaction was the most common reaction (38%), followed by febrile non-hemolytic transfusion reaction (FNHTR, 30%), delayed serologic transfusion reaction (DSTR, 14%), transfusion-associated circulatory overload (TACO, 10%), and transfusion-associated dyspnea (TAD, 4%). Platelets had the highest rate of transfusion reaction at 0.61% (n=167 of 27,180), red blood cells (RBC) at 0.35% (n=289 of 82,963), plasma at 0.13% (n=24 of 19,114), and cryoprecipitate at 0.06% (n=3 of 5295). The most common reaction associated with platelet transfusion was allergic reaction (64%, n=107), while FNHTR was the most common reaction associated with RBC transfusion (37%, n=106). By severity, 9 (2%) reactions were life-threatening, 21 (4%) were severe, 374 (75%) were non-severe, and 87 (18%) were not determined. Of life-threatening reactions, allergic reactions were the most common (5 of 9), while TACO was the most common severe reaction (9 of 21). Platelets were the most commonly implicated component in life- threatening reactions (4 allergic and 2 TACO), and RBCs were more commonly implicated in severe reactions. Conclusion Platelet transfusions were associated with a higher rate of transfusion reactions and life-threatening allergic reactions compared to other blood components.

Myeloid deficiency of heparan sulfate 6-O-endosulfatases impairs bone marrow hematopoiesis

The heparan sulfate (HS) 6-O-endosulfatases or the Sulfs (Sulf1 and Sulf2) are the only known enzymes that can modify HS sulfation status extracellularly and have been shown to regulate diverse biological processes. The role of the Sulfs in bone marrow (BM) hematopoiesis is not known. In this study, we generated a novel mouse line with myeloid-specific deletion of the Sulfs by crossing Sulf1/2 double floxed mice with the LysM-cre line. The LysM-Sulf knockout (KO) male mice exhibited age-dependent expansion of hematopoietic stem cells and the granulocyte-monocyte lineages in the BM, whereas common lymphoid progenitors and B lymphocyte populations were significantly reduced. Although megakaryocytic and erythroid progenitors were not reduced in the BM, the LysM-Sulf KO males suffered age-dependent reduction of red blood cells (RBCs) and platelets in the peripheral blood, suggesting that the production of RBCs and platelets was arrested at later stages. In addition, LysM-Sulf KO males displayed progressive splenomegaly with extramedullary hematopoiesis. Compared to males, LysM-Sulf KO females exhibited a much-reduced phenotype, and ovariectomy had little effect. Mechanistically, reduced TGF-β/Smad2 but enhanced p53/p21 signaling were observed in male but not female LysM-Sulf KO mice. Finally, HS disaccharide analysis via LC-MS/MS revealed increased HS 6-O-sulfation in the BM from both male and female LysM-Sulf KO mice, however, the distribution of 6-O-sulfated motifs were different between the sexes with compensatory increase in Sulf1 expression observed only in LysM-Sulf KO females. In conclusion, our study reveals that myeloid deficiency of the Sulfs leads to multilineage abnormalities in BM hematopoiesis in an age- and sex-dependent manner.

A phase 2/3 study of romiplostim N01 in chemotherapy-induced thrombocytopenia (CIT).

217 Background: CIT causes dose reduction or delay of chemotherapy (chemo), bleeding, and platelet (PLT) transfusion. This phase 2/3 study aimed to assess the efficacy and safety of romiplostim N01 in CIT. Methods: This trial comprising Part A (open-label) and B (randomized double-blinded) recruited patients (pts) with solid tumors or lymphoma and with CIT. In Part A, pts with a PLT count ≤200×10 9 /L before the day of chemo were included. Romiplostim N01 was injected subcutaneously per week (QW) for a 3-week chemo cycle at 1 μg/kg (group 1) or 2 μg/kg (group 2) for pts with a PLT count 100~200×10 9 /L, and at 2 μg/kg (group 3) for pts with a PLT count <100×10 9 /L. Primary endpoint was proportion of responders on the last day of chemo cycle, defined as pts who had an increase in PLT count of ≥30×10 9 /L from baseline for pts with a PLT count 100~200×10 9 /L, and an increase in PLT count of ≥30×10 9 /L or a PLT count ≥100×10 9 /L for pts with a PLT count <100×10 9 /L. In Part B, pts with a PLT count 75~150×10 9 /L were included and randomized 2:1 to receive romiplostim N01 or placebo QW at 2 μg/kg on day 1, and at 1 μg/kg on day 8 and 15 for two chemo cycles. Primary endpoint was proportion of responders, defined as pts resuming two consecutive chemo cycles without thrombocytopenia-induced dose modification (dose reduction by ≥15% or delay by ≥4 days or discontinuation) and without a rescue therapy. Results: In Part A, 50 pts were included between Mar 12, 2021 and Jul 29, 2021. The proportions of responders were 66.7% (10/15) in group 1, 53.3% (8/15) in group 2, and 90.0% (18/20) in group 3. Between Nov 8, 2022 and Jan 15, 2024, 63 pts were randomized in Part B. The proportion of responders in the romiplostim N01 group was significantly higher than that in placebo group (68.3% vs 40.9%). The adjusted rate difference was 27.6% (95% confidence interval [CI]: 2.1%, 50.2%). Treatment-related adverse events (TRAEs) occurred in 17 (41.5%) and 12 (54.5%) pts in the romiplostim N01 and placebo groups, of whom 1 (2.4%) and 0 were ≥grade 3. The most frequent TRAEs were nausea (12.2% vs 0), vomiting (12.2% vs 0), and increased aspartate aminotransferase (9.8% vs 4.5%). No treatment-related hemorrhage or death occurred. In pool analysis, the proportion of responders was 73.3% and 40.9% in pts treated with romiplostim N01 and placebo, respectively. The rate difference was 32.4% (95% CI: 9.2%, 52.9%). Conclusions: Romiplostim N01 showed promising efficacy and manageable safety in patients with CIT. Clinical trial information: PartA:NCT05851027 ; PartB:NCT05554913 . Pool analysis of Part A (pts with PLT count ≥75×10 9 /L) and Part B (all pts). Romiplostim N01 Placebo Rate Difference Part A+B (n=75) Part B (n=22) Romiplostim N01 (Part A+B) vs Placebo Lowest PLT count in Cycle 1, ×10 9 /L 85±41 59±32 / Highest PLT count in Cycle 1, ×10 9 /L 226±101 132±45 / Proportion of responders who completed the first chemo cycle without rescue therapy and without thrombocytopenia-induced dose modification of the second chemo cycle 55 (73.3%) 9 (40.9%) 32.4% 95% CI 61.9~82.9% 20.7~63.6% 9.2~52.9%

Evaluation of riboflavin concentrations and light intensities on bacteria reduction in platelets using visible light

Bacterial contamination in platelets has been a major concern over the years. In this study, we showed that treatment with 420 nm visible light with various concentrations of riboflavin in platelets reduced E. coli and S. aureus by 0–1.56 and 0.3–2.02 logs (50 mW/cm2), 2.24–4.77 and 0.73–3.26 logs (75 mW/cm2), and ≥ 5.14 and ≥ 5.27 logs (100 mW/cm2). Treatment with high-intensity light (100 mW/cm2) and high concentrations of riboflavin (400 µM and 500 µM) effectively reduced both bacteria in platelets by over 4 logs. The study also found a positive correlation between bacterial reduction and light intensity, as well as riboflavin concentration in a dose-dependent manner. These results demonstrate the potential of using riboflavin and visible light to reduce the risk of bacterial contamination in platelets, and support the need for further exploration of pathogen reduction using 420 nm visible light and riboflavin.

YAP1 regulates thrombopoiesis by binding to MYH9 in immune thrombocytopenia

AbstractImmune thrombocytopenia (ITP) is a complicated bleeding disease characterized by a sharp platelet reduction. As a dominating element involved in ITP, megakaryocytes (MKs) are responsible for thrombopoiesis. However, the mechanism underlying the dysregulation of thrombopoiesis that occurs in ITP remains unidentified. In this study, we examined the role of Yes-associated protein 1 (YAP1) in thrombopoiesis during ITP. We observed reduced YAP1 expression with cytoskeletal actin misalignment in MKs from patients with ITP. Using an experimental ITP mouse model, we showed that reduced YAP1 expression induced aberrant MK distribution, reduced the percentage of late MKs among the total MKs, and caused submaximal platelet recovery. Mechanistically, YAP1 upregulation by binding of GATA-binding protein 1 to its promoter promoted MK maturation. Phosphorylated YAP1 promoted cytoskeletal activation by binding its WW2 domain to myosin heavy chain 9, thereby facilitating thrombopoiesis. Targeting YAP1 with its activator XMU-MP-1 was sufficient to rescue cytoskeletal defects and thrombopoiesis dysregulation in YAP1+/− mice with ITP and patients. Taken together, these results demonstrate the crucial role of YAP1 in thrombopoiesis, providing potential for the development of diagnostic markers and therapeutic options for ITP.

Biomedical application of TiO2NPs can cause arterial thrombotic risks through triggering procoagulant activity, activation and aggregation of platelets.

Titanium dioxide nanoparticles (TiO2NPs) are widely used in medical application. However, the relevant health risk has not been completely assessed, the potential of inducing arterial thrombosis (AT) in particular. Alterations in platelet function and susceptibility to arterial thrombosis induced by TiO2NPs were examined using peripheral blood samples from healthy adult males and an in vivo mouse model, respectively. Here, using human platelets (hPLTs) freshly isolated from health volunteers, we demonstrated TiO2NP treatment triggered the procoagulant activity of hPLTs through phosphatidylserine exposure and microvesicles generation. In addition, TiO2NP treatment increased the levels of glycoprotein IIb/IIIa and P-selectin leading to aggregation and activation of hPLTs, which were exacerbated by providing physiology-mimicking conditions, including introduction of thrombin, collagen, and high shear stress. Interestingly, intracellular calcium levels in hPLTs were increased upon TiO2NP treatment, which were crucial in TiO2NP-induced hPLT procoagulant activity, activation and aggregation. Moreover, using mice in vivo models, we further confirmed that TiO2NP treatment a reduction in mouse platelet (mPLT) counts, disrupted blood flow, and exacerbated carotid arterial thrombosis with enhanced deposition of mPLT. Together, our study provides evidence for an ignored health risk caused by TiO2NPs, specifically TiO2NP treatment augments procoagulant activity, activation and aggregation of PLTs via calcium-dependent mechanism and thus increases the risk of AT.

Stent coating containing a charged silane coupling agent that regulates protein adsorption to confer antithrombotic and cell-adhesion properties

The evolution of endovascular therapies, particularly in the field of intracranial aneurysm treatment, has been truly remarkable and is characterized by the development of various stents. However, ischemic complications related to thrombosis or downstream emboli pose a challenge for the broader clinical application of such stents. Despite advancements in surface modification technologies, an ideal coating that fulfills all the desired requirements, including anti-thrombogenicity and swift endothelialization, has not been available. To address these issues, we investigated a new coating comprising 3-aminopropyltriethoxysilane (APTES) with both anti-thrombogenic and cell-adhesion properties. We assessed the anti-thrombogenic property of the coating using an in vitro blood loop model by evaluating the platelet count and the level of the thrombin–antithrombin (TAT) complex, and investigating thrombus formation on the surface using scanning electron microscopy (SEM). We then assessed endothelial cell adhesion on the metal surfaces. In vitro blood tests revealed that, compared to a bare stent, the coating significantly inhibited platelet reduction and thrombus formation; more human serum albumin spontaneously adhered to the coated surface to block thrombogenic activation in the blood. Cell adhesion tests also indicated a significant increase in the number of cells adhering to the APTES-coated surfaces compared to the numbers adhering to either the bare stent or the stent coated with an anti-fouling phospholipid polymer. Finally, we performed an in vivo safety test by implanting coated stents into the internal thoracic arteries and ascending pharyngeal arteries of minipigs, and subsequently assessing the health status and vessel patency of the arteries by angiography over the course of 1 week. We found that there were no adverse effects on the pigs and the vascular lumens of their vessels were well maintained in the group with APTES-coated stents. Therefore, our new coating exhibited both high anti-thrombogenicity and cell-adhesion properties, which fulfill the requirements of an implantable stent.

Decrease in platelet count in patients with AKI and its association with major adverse kidney events

Introduction A reduction in platelet count in critically ill patients is a marker of severity of the clinical condition. However, whether this association holds true in acute kidney injury (AKI) is unknown. We analyzed the association between platelet reduction in patients with AKI and major adverse kidney events (MAKE). Methods In this retrospective cohort, we included AKI patients at the Hospital Civil of Guadalajara, in Jalisco, Mexico. Patients were divided according to whether their platelet count fell >21% during the first 10 days. Our objectives were to analyze the associations between a platelet reduction >21% and MAKE at 10 days (MAKE10) or at 30-90 days (MAKE30-90) and death. Results From 2017 to 2023, 400 AKI patients were included, 134 of whom had a > 21% reduction in platelet count. The mean age was 54 years, 60% were male, and 44% had sepsis. The mean baseline platelet count was 194 x 103 cells/µL, and 65% of the KDIGO3 patients met these criteria. Those who underwent hemodialysis (HD) had lower platelet counts. After multiple adjustments, a platelet reduction >21% was associated with MAKE10 (OR 4.2, CI 2.1-8.5) but not with MAKE30-90. The mortality risk increased 3-fold (OR 2.9, CI 1.1-7.7, p = 0.02) with a greater decrease in the platelets (<90 x 103 cells/µL). As the platelets decreased, the incidence of MAKE was more likely to increase. These associations lost significance when accounting for starting HD. Conclusion In our retrospective cohort of patients with AKI, a > 21% reduction in platelet count was associated with MAKE. Our results are useful for generating hypotheses and motivating us to continue studying this association with a more robust design.

Safety and efficacy of PEG-rhG-CSF as primary prophylaxis against neutropenia induced by combination chemotherapy regimens involving oral chemotherapy agents in gastrointestinal cancer patients: A prospective, exploratory, non-randomized controlled study.

e24107 Background: The safety and efficacy of PEGylated recombinant human granulocyte colony-stimulating factor (PEG-rhG-CSF) for prevention of chemotherapy-induced neutropenia (CIN) in patients undergoing oral chemotherapy remain unclear. This study investigated the safety and efficacy of PEG-rhG-CSF as primary prophylaxis against CIN in gastrointestinal (GI) cancer patients receiving combination chemotherapy regimens involving oral chemotherapy agents. Methods: This is a prospective, single-center, open-label, exploratory, non-randomized controlled study. GI cancer patients receiving two consecutive cycles of IV oxaliplatin (150mg/m2 on day 1) combined with oral capecitabine 1000mg/m2 or tegafur gimeracil oteracil potassium capsule 40-60mg twice daily on days 1-14 every 3 weeks. PEG-rhG-CSF (6mg) was administered subcutaneously 24 hours post-oxaliplatin treatment in the PEG-rhG-CSF group, while the control group did not receive it. The primary endpoint was safety, and secondary endpoints included CIN incidence and neutropenic complications. The study was registered with the Chinese Clinical Trial Registry (registration number ChiCTR2100054854). Results: Between March 2022 and January 2023, a total of 49 patients was screened, and 43 patients completed the treatment (26 in PEG-rhG-CSF group and 17 in control group). The average age was 61.4 years, with 90.7% males and 83.7% having gastric cancer. Baseline characteristics were similar between the two groups. The overall adverse events (AE) did not differ statistically (88.5% vs. 88.2%, p = 1.000), with grade £2 fatigue and nausea being the most common AEs. Grade 3 platelet reduction showed no significant difference between the two groups (7.69% vs. 17.65%, p = 0.432). Four cases of bone pain (15.4%) and five cases of injection site reactions below grade 3 (19.2%) were observed in the PEG-rhG-CSF group. Grade ≥2 CIN was significantly lower in the PEG-rhG-CSF group (3.84% vs. 58.82%, p &lt; 0.001). One case in the PEG-rhG-CSF group required antibiotic treatment due to febrile neutropenia. Regarding neutropenic complications, the PEG-rhG-CSF group exhibited lower proportion of chemotherapy delay (3.85% vs. 35.29%, p &lt; 0.001) and dose reduction (1.92% vs. 23.53%, p = 0.002). Rescue treatment with rhG-CSF for grade 3/4 CIN was significantly less frequent in the PEG-rhG-CSF group (1.92% vs. 23.53%, p = 0.002). Conclusions: Primary prophylaxis with PEG-rhG-CSF in GI cancer patients undergoing oral capecitabine/tegafur gimeracil oteracil potassium may be safe, without an increased chemotherapy-related AEs, and is associated with a reduced grade ≥2 CIN. Clinical trial information: ChiCTR2100054854.

Safety, efficacy, pharmacokinetics, and pharmacodynamics of the illudofulvene drug CAP-0121.

e15120 Background: Irofulven is an anticancer agent derived from illudin S initially investigated due to its unique mechanism of action and potential to overcome multi-drug resistance. This study investigates the pharmacokinetics/pharmacodynamics (PK/PD) and efficacy and safety of the second-generation drug, CAP-0121 (Califia Pharma). Methods: 24-hour comprehensive PK was performed at two different intravenous (IV) doses in canines for irofulven (0.2 mg/kg and 1 mg/kg; MTD) and CAP-0121 (1 mg/kg and 3 mg/kg). Plasma concentrations were measured by LC-MS/MS and PK parameters were calculated for both drugs using noncompartmental methods (Phoenix WinNonlin, version 8.4). PK parameters included area under the concentration vs time curve (AUC), maximum observed concentration (Cmax), clearance (CL), volume of distribution (Vd), and elimination half-life (t1/2). Canine chemistry/hematology/coagulation/urine panels, were measured across 28 days to ascertain the maximum tolerated dose (MTD). Both platelet and neutrophil count reversibility was also assessed. Mice xenograft models implanted with a drug resistant human ovarian cancer (A2870), or a drug-resistant human metastatic lung cancer (MV522), were dosed with irofulven (9 mg/kg; MTD) and CAP-0121 (15, 20, and 25 mg/kg) and resulting tumor mass, % change in body weight, and platelet counts were compared relative to vehicle only. Results: Systemic exposure, CL, Vd, and t1/2 were similar between irofulven and CAP-0121 at a 1 mg/kg IV dose. For irofulven, AUC increased approximately proportionally at doses of 0.2 mg/kg and 1 mg/kg. For CAP-0121, exposure also increased proportionally at doses of 1 mg/kg and 3 mg/kg. MTD of CAP-0121 was found to be 3-fold higher in canines compared to irofulven as 3-fold more CAP-0121 was required to match the platelet reduction observed with irofulven; platelet and neutrophil nadir was rapidly reversible for CAP-0121. Canine nadir platelets and neutrophil counts were 3-fold higher for CAP-0121 vs irofulven at the same dose (1 mg/kg). There was no evidence of any canine systemic organ toxicity (gross, histologic, blood and urine analysis) for CAP-0121 at either dose. CAP-0121 was superior to irofulven (p &lt; 0.02) with regards to final tumor weights in mice xenograft models, even though MTD was not reached for CAP-0121; a change in body weight and platelet loss was not observed for CAP-0121 at up 25 mg/kg in mice. With regards to in vitro anticancer cytotoxic activity, the two drug-resistant xenograft models confirm the superiority of CAP-0121 over irofulven. This study demonstrates that CAP-0121 has favorable PK parameters and a wider therapeutic window in humans compared to irofulven, emphasizing the potential anticancer utility of CAP-0121 for solid cancers without prolonged thrombocytopenia. Conclusions: Further investigation in clinical trials is warranted to confirm these preclinical observations.

HLA-DRB5 Overexpression Promotes Platelet Reduction in Immune Thrombocytopenia Mice Model by Facilitating MHC-II-Mediated Antigen Presentation

Introduction: Major histocompatibility complex II (MHC-II)-mediated antigen presentation contributes to the pathogenesis of immune thrombocytopenia (ITP). Human leukocyte antigen (HLA)-DRB5 is an MHC-II molecule and this study aims to investigate its role and mechanisms in ITP development. Methods: Guinea pig anti-mouse platelet (PLT) serum-induced ITP mice received tail vein injection of HLA-DRB5 overexpressing adenoviral vector/immune receptor expressed on myeloid cells-1 (IREM-1) monoclonal antibody (mAb). PLT count changes in mice blood were assessed by a hematology analyzer. MHC-II/CD80/CD86 expression in mice blood was measured by quantitative real-time-PCR and immunofluorescence assay. CD8+ T-cell proportion in mice blood was detected by flow cytometry. Results: HLA-DRB5 overexpression exacerbated PLT reduction since the 5th day of the establishment of ITP mice model and enhanced MHC-II/CD80/CD86 expression upregulation as well as CD8+ T-cell ratio elevation in the blood of ITP mice, while its effects were reversed by IREM-1 mAb. Conclusion: HLA-DRB5 overexpression upregulates MHC-II-mediated antigen presentation to CD8+ T cells, thus lowering PLT count in the ITP mice model.

Thrombocytopenia risks in ARDS COVID-19 patients treated with high-dose linezolid during vvECMO therapy: an observational study.

Patients treated with ECMO are at great risk of nosocomial infections, and around 10% of isolates are gram-positive pathogens. Linezolid (LZD) is effective in the treatment of these infections but appropriate dosing is challenging. The aim was to evaluate the occurrence of thrombocytopenia during ECMO when treated with LZD. An LZD trough concentration of 8mg/L was set as the cutoff value for thrombocytopenia occurrence among critically ill patients who received parenteral LZD therapy at a dose of 600mg every 8h during ECMO. Eleven patients were included in this prospective observational study. Median LZD trough concentrations were 7.85 (interquartile range (IQR), 1.95-11) mg/L. Thrombocytopenia was found in 81.8% of patients. Based on the median LZD trough concentrations cutoff value, patients were divided into two groups, 1.95 (IQR, 0.91-3.6) and 10.3 (IQR, 9.7-11.7) mg/L, respectively. Median platelet values differed significantly between groups on admission, ECMO day 0, ECMO day 1, and LZD sampling day [194 and 152.5, (p < 0.05)], [113 and 214, (p < 0.05)], [76 and 147.5, (p < 0.01)], and [26 and 96.5, (p < 0.01)], respectively. Duration of LZD therapy was similar between the groups. Significant platelet reduction was observed in both groups, emphasizing the need for closer monitoring to prevent LZD-associated thrombocytopenia.

Janus Nanofibrous Patch with In Situ Grown Superlubricated Skin for Soft Tissue Repair with Inhibited Postoperative Adhesion.

The patch with a superlubricated surface shows great potential for the prevention of postoperative adhesion during soft tissue repair. However, the existing patches suffer from the destruction of topography during superlubrication coating and lack of pro-healing capability. Herein, we demonstrate a facile and versatile strategy to develop a Janus nanofibrous patch (J-NFP) with antiadhesion and reactive oxygen species (ROS) scavenging functions. Specifically, sequential electrospinning is performed with initiators and CeO2 nanoparticles (CeNPs) embedded on the different sides, followed by subsurface-initiated atom transfer radical polymerization for grafting zwitterionic polymer brushes, introducing superlubricated skin on the surface of single nanofibers. The poly(sulfobetaine methacrylate) brush-grafted patch retains fibrous topography and shows a coefficient of friction of around 0.12, which is reduced by 77% compared with the pristine fibrous patch. Additionally, a significant reduction in protein, platelet, bacteria, and cell adhesion is observed. More importantly, the CeNPs-embedded patch enables ROS scavenging as well as inhibits pro-inflammatory cytokine secretion and promotes anti-inflammatory cytokine levels. Furthermore, the J-NFP can inhibit tissue adhesion and promote repair of both rat skin wounds and intrauterine injuries. The present strategy for developing the Janus patch exhibits enormous prospects for facilitating soft tissue repair.

Abstract 1142: Effect Of Chronic E-cigarette Nicotine Exposure On A Mouse Model Of Hind-limb Ischemia

Background: The rise of e-cigarette use in the United States has been rapid, yet its impact on peripheral artery disease (PAD) remains largely unexplored. This study investigates the relationship between e-cigarette use and PAD using a mouse ischemic hindlimb model. Method: Mice aged 6-8 weeks were divided into four groups. Three groups inhaled e-cigarette vapor continuously for 14, 20, or 28 days prior, and for 28 days after hindlimb ischemia (HLI) surgery, using an InExpose system (Figure 1). A control group was exposed to room air (RA) before and after HLI. Laser-Doppler perfusion imaging tracked hindlimb blood flow, and functional deficits were assessed using the modified ischemia scale. Figure 1: Methodology Results: Blood perfusion in the ischemic hindlimb of the e-cigarette groups (EC-14, EC-20, EC-28) was significantly lower than the non-vaping group at 21 days post-surgery. In the EC-14 group, perfusion improved after 10 days of vaping cessation (Figure 2). Additionally, there was a reduction in platelet and leukocyte counts in the e-cigarette groups compared to RA, with no difference in red blood cells. Necrosis and claw damage were observed in EC-20 and EC-28 groups but not in non-vaping mice. Figure 2: Representative images of perfusion recovery measured by LDPI. Conclusion: Chronic e-cigarette nicotine exposure impairs blood flow recovery and causes necrosis in mice with hind limb ischemia, potentially due to perturbed angiogenesis and arteriogenesis. This study highlights the detrimental effects of e-cigarette nicotine on vascular health.

Eculizumab administration for myasthenia gravis also stabilizes thrombogenicity of catastrophic antiphospholipid syndrome

AbstractBackgroundThe co‐occurrence of myasthenia gravis and primary antiphospholipid syndrome (APS) is rare. Notably, both the diseases share common complement‐mediated mechanisms.Case PresentationA 36‐year‐old woman, who was previously diagnosed with myasthenia gravis and APS, developed multiple embolisms, involving the brain, kidney and spleen, with severe anemia and platelet reduction. She was diagnosed as catastrophic APS, and intensive immunotherapies, including plasma exchange, high‐dose corticosteroid and rituximab, were introduced. After these therapies, symptoms of both APS and myasthenia gravis worsened, consistent with elevation of immunoglobulin G anti‐beta‐2‐glycoprotein‐I antibody and anti‐acetylcholine receptor antibody. We started eculizumab, which resulted in stabilizing the disease activity of both diseases without notable adverse events.ConclusionsEculizumab can be effective for controlling multiple complement‐mediated pathophysiology.

Role of high-volume plasmapheresis in the management of paediatric acute liver failure.

Paediatric acute liver failure (PALF) is a life-threatening disease. Management aims to support hepatic regeneration or to bridge to liver transplantation. High-volume plasmapheresis (HVP) removes protein-bound substances, alleviates inflammation, and improves survival in adult acute liver failure. However, experience with HVP in PALF is limited. Aim of this study is to report on feasibility, safety, efficacy and outcomes of HVP in PALF. Retrospective observational study in children with PALF. HVP was performed upon identification of negative prognostic indicators, in toxic aetiology or multiorgan failure (MOF). Exchanged volume with fresh-frozen plasma corresponded to 1.5-2.0 times the patient's estimated plasma volume. One daily cycle was performed until the patient met criteria for discontinuation, that is, liver regeneration, liver transplantation, or death. Twenty-two children with PALF (body weight 2.5-106 kg) received 1-7 HVP cycles. No bleeding or procedure-related mortality occurred. Alkalosis, hypothermia and reduction in platelets were observed. Haemolysis led to HVP termination in one infant. Seven children (32%) survived with their native livers, 13 patients (59%) underwent liver transplantation. Two infants died due to MOF. Overall survival was 86%. International normalization ratio (INR), alanine aminotransaminases (ALT), bilirubin and inotropic support were reduced significantly (p < 0.05) after the first HVP-cycle (median): INR 2.85 versus 1.5; ALT 1280 versus 434 U/L; bilirubin 12.7 versus 6.7 mg/dL; norepinephrine dosage 0.083 versus 0.009 µg/kg/min. Median soluble-interleukin-2-receptor dropped significantly following HVP (n = 7): 2407 versus 950 U/mL (p < 0.02). HVP in PALF is feasible, safe, improves markers of liver failure and inflammation and is associated with lowering inotropic support. Prospective and controlled studies are required to confirm efficacy of HVP in PALF.

Purified Granulocyte Concentrates from Buffy Coats with Extended Storage Time

Background: Granulocyte concentrates (GCs) are usually prepared by single-donor apheresis after G-CSF pretreatment and have to be transfused within 24 h after cell collection because of the rapid decrease in pH and cell survival due to high lactate production by red blood cell contamination. GCs pooled from buffy coats of whole blood donations could improve the availability of these products. Methods to reduce red blood cell and platelet contamination may improve storability. We developed a manufacturing process for pooled GCs and investigated cell viability and functionality over time. Methods: Six ABO blood group-identical buffy coats were pooled. Subsequently, the red blood cells spontaneously sedimented after the addition of hydroxyethyl starch. The resulting leukocyte-enriched supernatant was washed twice with saline to reduce platelets and was resuspended in ABO-identical donor plasma. The leukocyte concentrate was transferred to a platelet storage bag and stored up to 72 h at 20–24°C w/o agitation. Cell count and viability, pH, blood gases, phagocytosis, and oxidative burst activity were monitored. Results: The number of red blood cells and platelets was reduced to 0.4% and 6.1% of the baseline levels. About 50% of the original present leukocytes could be extracted (n = 76). In the course of 72 h of storage, there were no significant changes in white blood cell counts (p = 0.12). The viability exceeded 98% during the entire period. The rate of granulocytes performing phagocytosis and oxidative burst remained above 95% anytime. Conclusion: GCs prepared from pooled buffy coats provide a precious alternative to granulocytes obtained from apheresis. Reduction of red blood cells and platelets by more than 90% extends the maximum shelf life of GCs from 24 h to 72 h. For a therapeutic dose of at least 1 × 1010 granulocytes, 15–20 buffy coats are required.

Abstract CT067: The anti-BCMA antibody-drug conjugate HDP-101 with a novel amanitin payload shows promising initial first in human results in relapsed multiple myeloma

Abstract Background: HDP-101 is a new antibody drug conjugatetargeting B-cell maturation antigen (BCMA) that carries a synthetic amanitin payload with a new mode of action. Amanitin inhibits RNA polymerase II, effectively stopping transcription and inducing apoptosis in tumor cells, regardless of their proliferation status. It's shown cytotoxicity in vitro against BCMA-positive myeloma cell lines and non-proliferating primary CD138+ cells from refractory myeloma patients withefficacy even in cells with low BCMA density. Clinical Study: HDP-101-01 is a first-in-human, open label, non-randomized, multicenter, phase 1/2a trial in patients with multiple myeloma whose disease has progressed or is refractory, aiming to determine the Maximum Tolerated Dose and/or the Recommended phase 2 Dose in Phase 1. Dose escalation is guided by an adaptive Bayesian logistic regression model with overdose control. The primary objective in phase 2 is to assess anti-tumor activity. Study Progress: As of November 2023, 18 patients (7 females, 11 males) were enrolled in 5 consecutive dose cohorts of 20, 30, 60, 80, and 100µg/kg. Patients had a median age of 70 years (48-82), were heavily pre-treated and multidrug-resistant, and had a median of 6,5 prior treatments (2-15). Study Results: Preliminary data shows that pharmacokinetics of HDP-101 aligns with expectations, and exposure to HDP-101 is dose proportional. Free payload was not detected in serum at a limit of detection of 30 ng/mL, and no anti-drug antibodiesor immunogenic reactions were noted. 17 of 18 patients were evaluable for dose limiting toxicities (DLT) in the 5 treatment cohorts. Initial cohorts were well tolerated, without any DLTs, including no signs of hepatic and renal toxicities, infusions reactions, or ocular disorders. All patients in Cohort 5 had Grade 1-4 transient thrombocytopeniawith platelet reductions starting on Cycle 1/Day 2 (C1/D2), a nadir on C1D5, and full recovery by C1D15 at the latest without any clinical sequelae or interventions. Notably, subsequent dosing with HDP-101 did not produce similarly deep episodes of thrombocytopenia, supporting the possibility that this event is not due to a direct cytotoxic effect against megakaryocytes. After Cohort 5, mitigation strategies are being considered and further dose and schedule optimization is planned with fractionated dosing and/or with premedication. Efficacy: Cohort3 has a patient with stable disease (SD) after 15 cycles. Cohort 5 has 4 ongoing patients with promising results after 3-4 cycles: 2 patients achieved PR, and 2 have SD. Updated data will be presented at the AACR2024 meeting. Citation Format: Jonathan Kaufman, Marc Raab, Shambavi Richard, Sebastian Grosicki, István Takács, András Strassz, Andreas Pahl, Michael Kulke, Thorsten Michael, Anette Last, Hajnalka Szabóki, Garrit Jentsch, Oliver Schönborn-Kellenberger, Robert Orlowski. The anti-BCMA antibody-drug conjugate HDP-101 with a novel amanitin payload shows promising initial first in human results in relapsed multiple myeloma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT067.

SPECT/CT Image-Derived Absorbed Dose to Red Marrow Correlates with Hematologic Toxicity in Patients Treated with [177Lu]Lu-DOTATATE.

Hematologic toxicity, although often transient, is the most common limiting adverse effect during somatostatin peptide receptor radionuclide therapy. This study investigated the association between Monte Carlo-derived absorbed dose to the red marrow (RM) and hematologic toxicity in patients being treated for their neuroendocrine tumors. Methods: Twenty patients each receiving 4 treatment cycles of [177Lu]Lu-DOTATATE were included. Multiple-time-point 177Lu SPECT/CT imaging-based RM dosimetry was performed using an artificial intelligence-driven workflow to segment vertebral spongiosa within the field of view (FOV). This workflow was coupled with an in-house macroscale/microscale Monte Carlo code that incorporates a spongiosa microstructure model. Absorbed dose estimates to RM in lumbar and thoracic vertebrae within the FOV, considered as representations of the whole-body RM absorbed dose, were correlated with hematologic toxicity markers at about 8 wk after each cycle and at 3- and 6-mo follow-up after completion of all cycles. Results: The median of absorbed dose to RM in lumbar and thoracic vertebrae within the FOV (D median,vertebrae) ranged from 0.019 to 0.11 Gy/GBq. The median of cumulative absorbed dose across all 4 cycles was 1.3 Gy (range, 0.6-2.5 Gy). Hematologic toxicity was generally mild, with no grade 2 or higher toxicity for platelets, neutrophils, or hemoglobin. However, there was a decline in blood counts over time, with a fractional value relative to baseline at 6 mo of 74%, 97%, 57%, and 97%, for platelets, neutrophils, lymphocytes, and hemoglobin, respectively. Statistically significant correlations were found between a subset of hematologic toxicity markers and RM absorbed doses, both during treatment and at 3- and 6-mo follow-up. This included a correlation between the platelet count relative to baseline at 6-mo follow up: D median,vertebrae (r = -0.64, P = 0.015), D median,lumbar (r = -0.72, P = 0.0038), D median,thoracic (r = -0.58, P = 0.029), and D average,vertebrae (r = -0.66, P = 0.010), where D median,lumbar and D median,thoracic are median absorbed dose to the RM in the lumbar and thoracic vertebrae, respectively, within the FOV and D average,vertebrae is the mass-weighted average absorbed dose of all vertebrae. Conclusion: This study found a significant correlation between image-derived absorbed dose to the RM and hematologic toxicity, including a relative reduction of platelets at 6-mo follow up. These findings indicate that absorbed dose to the RM can potentially be used to understand and manage hematologic toxicity in peptide receptor radionuclide therapy.