The effect of flow-derived mechanical cues on the growth and morphology of platelet aggregates under low, medium, and high shear rates.

Platelet aggregation is a dynamic process that can obstruct blood flow, leading to cardiovascular diseases. While many studies have demonstrated clear connections between shear rate and platelet aggregation, the impact of flow-derived mechanical signals on this process is not fully understood. The objective of this work is to investigate the role of flow conditions on platelet aggregation dynamics, including effects on growth, shape, density composition, and their potential correlation with binding processes that are characterised by longer (e.g., via αIIbß3 integrin) and shorter (e.g., via VWF) initial binding times. In vitro blood perfusion experiments were conducted at wall shear rates of 800, 1600 and 4000 s-1. Detailed analysis of two modalities of experimental images was performed to offer insights into the morphology of platelet aggregates. A consistent structural pattern was observed across all samples: a high-density core enveloped by a low-density outer shell. An image-based 3D computational blood flow model was subsequently employed to study the local flow conditions, including binding availability time and flow-derived mechanical signals via shear rate and rate of elongation. The results show substantial dependence of the aggregation dynamics on these flow parameters. We found that the different binding mechanisms that prefer different flow regimes do not have a monotonic cross-over in efficiency as the flow increases. There is a significant dip in the cumulative aggregation potential in-between the preferred regimes. The results suggest that treatments targeting the biomechanical pathways could benefit from creating conditions that exploit these low-efficiency zones of aggregation.

Plasmacytoid dendritic cells control homeostasis of megakaryopoiesis.

Platelet homeostasis is essential for vascular integrity and immune defence1,2. Although the process of platelet formation by fragmenting megakaryocytes (MKs; thrombopoiesis) has been extensively studied, the cellular and molecular mechanisms required to constantly replenish the pool of MKs by their progenitor cells (megakaryopoiesis) remains unclear3,4. Here we use intravital imaging to track the cellular dynamics of megakaryopoiesis over days. We identify plasmacytoid dendritic cells (pDCs) as homeostatic sensors that monitor the bone marrow for apoptotic MKs and deliver IFNα to the MK niche triggering local on-demand proliferation and maturation of MK progenitors. This pDC-dependent feedback loop is crucial for MK and platelet homeostasis at steady state and under stress. pDCs are best known for their ability to function as vigilant detectors of viral infection5. We show that virus-induced activation of pDCs interferes with their function as homeostatic sensors of megakaryopoiesis. Consequently, activation of pDCs by SARS-CoV-2 leads to excessive megakaryopoiesis. Together, we identify a pDC-dependent homeostatic circuit that involves innate immune sensing and demand-adapted release of inflammatory mediators to maintain homeostasis of the megakaryocytic lineage.

Develop Tandem Tension Sensor to Gauge Integrin-Transmitted Molecular Forces.

DNA-based tension sensors have innovated the imaging and calibration of mechanosensitive receptor-transmitted molecular forces, such as integrin tensions. However, these sensors mainly serve as binary reporters, only indicating if molecular forces exceed one predefined threshold. Here, we have developed tandem tension sensor (TTS), which comprises two consecutive force-sensing units, each with unique force detection thresholds and distinct fluorescence spectra, thereby enabling the quantification of molecular forces with dual reference levels. With TTS, we revealed that vinculin is not required for transmitting integrin tensions at approximately 10 pN (piconewtons) but is essential for elevating integrin tensions beyond 20 pN in focal adhesions (FAs). Such high tensions have emerged during the early stage of FA formation. TTS also successfully detected changes in integrin tensions in response to disrupted actin formation, inhibited myosin activity, and tuned substrate elasticity. We also applied TTS to examine integrin tensions in platelets and revealed two force regimes, with integrin tensions surpassing 20 pN at cell central regions and 13-20 pN integrin tensions at the cell edge. Overall, TTS, especially the construct consisting of a hairpin DNA (13 pN opening force) and a shearing DNA (20 pN opening force), stands as a valuable tool for the quantification of receptor-transmitted molecular forces within living cells.

Gelsolin regulates receptor-mediated and fluid-phase endocytosis in platelets.

BACKGROUND: Endocytosis is the process by which platelets incorporate extracellular molecules into their secretory granules. Endocytosis is mediated by the actin cytoskeleton in nucleated cells; however, the endocytic mechanisms in platelets are undefined. OBJECTIVES: To better understand platelet endocytosis, we studied gelsolin (Gsn), an actin-severing protein that promotes actin assembly. METHODS: Mouse platelets from Gsn-null (Gsn-/-) and wild-type (WT) controls were used. The uptake of fluorescent cargo molecules was compared as a measure of their endocytic efficiency. Receptor-mediated endocytosis was measured by the uptake of fibrinogen and transferrin; fluid-phase endocytosis was monitored by the uptake of fluorescent dextrans. RESULTS: Adenosine diphosphate (ADP)-stimulated WT platelets readily internalized both receptor-mediated and fluid-phase cargoes. In contrast, Gsn-/- platelets showed a severe defect in the endocytosis of both types of cargo. The treatment of WT platelets with the actin-disrupting drugs cytochalasin D and jasplakinolide also reduced endocytosis. Notably, the individual and combined effects of Gsn deletion and drug treatment were similar for both receptor-mediated and fluid-phase endocytosis, indicating that Gsn mediates endocytosis via its action on the actin cytoskeleton. CONCLUSION: Our study demonstrates that Gsn plays a key role in the uptake of bioactive mediators by platelets.

Temporal dynamics of in vitro hemostatic function in platelets cryopreserved using a novel approach for rapid issuance.

BACKGROUND: Current procedures for thawing and issuing of cryopreserved platelets (CPPs) are laborious and have remained challenging in emergency settings such as blood banks and military operations. In this prospective study, a novel processing method designed to facilitate the rapid issuance of CPPs with no postthaw handling required was developed and functionally characterized in parallel with standard CPPs manufactured. STUDY DESIGN AND METHODS: Double-dose plateletpheresis units (n = 42) were cryopreserved at -80°C in 5%-6% dimethyl sulfoxide to produce matched pairs thawed successively over a 27-month period for comparison between two processing arms. In contrast to the standard CPPs manufactured as standalone units, platelets were frozen in tandem with resuspending plasma in a distinct partition as a single unit in the novel method, herein referred to as tandem CPPs. Postthaw (PT) CPPs from both arms were assessed at PT0-, 12-, and 24-h to measure platelet recovery, R-time (time to clot initiation; min), and maximum amplitude (MA; clot strength; mm) using thromboelastography. RESULTS: In the overall dataset, mean platelet recovery was higher (p < .0005) for tandem CPPs (83.9%) compared with standard CPPs (73.3%) at PT0; mean R-times were faster (p < .0005) for tandem CPPs (2.5-3.6 min) compared with standard CPPs (3.0-3.8 min); mean MA was higher for tandem CPPs (57.8-59.5 mm) compared with standard CPPs (52.1-55.8 mm) at each postthaw time point (p < .05). CONCLUSION: Robust temporal dynamics of superior hemostatic functionality were established for tandem CPPs over extended cryopreservation up to 27 months and 24 h of postthaw storage.

Isohemagglutinin titration in pooled and apheresis platelets.

BACKGROUND: Platelet inventory constraints necessitate ABO-incompatible platelet transfusion. Many minimize the hemolytic impact by confirming low titre (LT) donor isohemagglutinins. This process is costly. Pathogen-reduced platelets (PRP) in platelet additive solutions (PAS) will dilute plasma and decrease high-titre isohemagglutinins (HT). We determined the proportion of HT platelets and incompatible transfusions for units suspended in plasma to reassess the need for titres following introduction of PRP/PAS. STUDY DESIGN AND METHODS: Our titre method is manual tube (1:50) dilution of platelet supernatant from apheresis or whole blood derived buffy coat pools suspended in plasma, tested with A1/B red cells. Testing included 49,058 pooled and 11,738 apheresis platelets over 4 years. The HT proportion, rate of out-of-group transfusions, and hemolytic reactions were determined. The impact of PAS dilution was estimated. RESULTS: Totally 60,796 platelet units were tested. Group O pooled and group B apheresis platelets had HT in 6.6% and 5.7%, respectively. Group A pooled and apheresis platelets included 2% with HT. Approximately 25% of platelets transfused were ABO-incompatible and no hemolytic reactions were reported. Based on the proportions of PAS-E and plasma for PRP platelets, plasma from each donor comprises 11 mL (6% of total volume) vs 20-257 mL in untreated pools. PAS-E will replace and dilute residual plasma by at least 50%. DISCUSSION: Rare platelet pools may demonstrate HT. PRP platelets with PAS will reduce titres and may abrogate the need for titration. A strategy of group specific transfusion or transfusion of group A PRP platelet transfusions may be a safe alternative.

Evaluation of a method to fluorescently label platelets for in-human recovery and survival studies.

BACKGROUND AND OBJECTIVES: Platelets for transfusion are evaluated for in vivo quality using recovery and survival measurements in healthy human subjects. Radiolabelling is the standard for tracing platelets post-transfusion but imposes logistical and technical limitations. This study investigates the in vitro feasibility of labelling platelets with the calcein family of fluorescent dyes as an alternative to radioisotopes or biotin. MATERIALS AND METHODS: Protocols for radiolabelling were adapted for use with calcein acetoxymethyl ester (CAM) and biotin. Labelled platelets were analysed by flow cytometry and evaluated for activation and function. We tested feasibility for labelling without manipulation of platelets and for multiplexing of samples. RESULTS: Labelling at 2 µg CAM/1010 platelets resulted in >99% of CAM+ platelets. There was no significant difference in activation or aggregation between CAM-labelled or biotinylated platelets and vehicle controls although %CD62P+ was significantly lower in platelets that were not processed for labelling. Addition of CAM to the platelet storage bag labelled >95% of platelets. Platelet populations labelled with different dyes could be distinguished by flow cytometry. CONCLUSION: These data provide a rationale for further development of CAM and other fluorescent dyes as tools for measuring post-transfusion kinetics of platelets.

The effect of near-infrared low-level light on the in vitro quality of platelets during storage.

BACKGROUND AND OBJECTIVES: Near-infrared (NIR) light has been successfully applied to improve the quality of mouse platelets during storage. Because it is suspected that the mitochondria contain the primary photon acceptor, we hypothesized that human platelets for transfusion may be affected similarly and could benefit from NIR light treatment. MATERIALS AND METHODS: The optimal light dose was determined using portions of platelet concentrates (PCs) in PAS-E. A pool-and-split design was used to prepare PCs in PAS-E or plasma (n = 6). On day 1, one unit of both pairs was illuminated with 830 nm light (light-emitting diodes, 15 J/cm2). PCs were stored at 22°C and sampled regularly for analysis. Data were compared with their corresponding controls with a paired two-sided t-test. RESULTS: Illuminated platelets in PAS-E were less activated with significantly lower CD62P expression (day 8: 10.8 ± 1.8 vs. 12.2 ± 2.6, p < 0.05) and lower Annexin A5 binding (day 8: 11.8 ± 1.9 vs. 13.1 ± 2.4, ns). They produced significantly less lactate resulting in a higher pH (days 6-10). ATP content and mitochondrial membrane potential were not affected. Although these trends were also observed for PCs in plasma, the differences did not reach statistical significance as compared with the control group. CONCLUSION: Our study demonstrates that the glycolysis rate of human platelets can be modulated through the use of NIR, possibly through mitochondrial aerobic metabolism, but this requires confirmation. If NIR illumination can be further optimized, it may potentially become a useful tool in situations in which glycolysis and platelet activation are exacerbated.

Light microscopic morphology of blood cells of non-descript indigenous Zoar chicken of Mizoram, India.

Identifying and analysing distinct blood cells is crucial for the diagnosis and treatment of diseases in the field of biomedicine. The present study was undertaken to study the cytomorphological and cytochemical characteristics of the blood cells of Zoar, a non-descript indigenous breed of chicken extensively reared under backyard poultry farming in Mizoram, India. For this study, 2 mL of blood samples were aseptically collected from the wings veins of 12 chickens and were processed for light microscopic study under standard protocols. The matured erythrocytes were elliptical, while the immature erythrocytes appeared oval. The heterophils were positive for SBB (SBB), Periodic Acid Schiff (PAS), acid phosphatase, alkaline phosphatase and Arylsulphatase while the eosinophils were positive for SBB, PAS, alkaline phosphatase, cytochrome oxidase and peroxidase. The basophils of were positive for toluidine blue while the thrombocytes were positive for PAS. These cytochemical and cytoenzymatic staining properties plays a very important role in diagnosis, differentiation, and classification of leukaemias.

Why might cord blood be a better source of platelets for transfusion to neonates?

Thrombocytopenia (defined as a platelet count <150×109/L) is a common condition in preterm neonates and may occur in 18-35% of all infants admitted to the Neonatal Intensive Care Unit (NICU). Neonatal platelet functionality in terms of reactivity is often described as reduced compared to adults, even in healthy, term neonates. However, this platelet "hyporeactivity" does not correspond to a global functional impairment of the normal delicately balanced neonatal hemostatic system. The extent to which neonatal thrombocytopenia and platelet hyporeactivity contribute to the bleeding risk in preterm neonates remains unknown. Prophylactic platelet transfusions are often administered to them to reduce the risk of bleeding. However, recent literature indicates that adopting a higher platelet transfusion threshold than a lower one results in significantly higher death rates or major bleeding and can be harmful. Although the mechanism by which this occurs is not entirely clear, a mismatch between adult transfused platelets and the neonatal hemostatic system, as well as volume overload, are speculated to be potentially involved. Therefore, future research should consider novel transfusion products that may be more suitable for premature neonates. Blood products derived from umbilical cord blood (UCB) are promising, as they might perfectly match neonatal blood features. Here, we discuss the current knowledge about UCB-derived products, focusing on UCB-derived platelet concentrates and their potential for future clinical application. We will discuss how they may overcome the potential risks of transfusing adult-derived platelets to premature infants while maintaining efficacy.

Aggregates in apheresis-derived platelet concentrates: A 5-year single-centre experience.

BACKGROUND AND OBJECTIVES: The phenomenon of aggregates in apheresis-derived platelet concentrates (APCs) has not yet been fully elucidated. Initially, visible aggregates (IVA) usually dissolve within 24 h after collection, but some persist till the end of the shelf life (persistent aggregates, PA). A study conducted at the Croatian Institute of Transfusion Medicine aimed to identify factors that influence the aggregate occurrence in APCs. MATERIALS AND METHODS: We conducted a cross-sectional study for the 2018-2022 period and collected data on APCs with IVA. We analysed APCs discarded due to PA separately for two apheresis technologies and compared them to the control group. RESULTS: Significantly more donations were discarded in the IVA group compared with the control group and total number of discarded APCs. A total of 205 APCs were discarded due to PA (14.7% of IVA APCs and 1.27% of all APCs collected). Amicus APCs with PA had a significantly lower platelet count and mean platelet volume. They were obtained by procedures with less anticoagulant used. In contrast to Amicus APCs, Haemonetics APCs with PA had a significantly higher platelet count. None of the donor-related factors examined was predictive of PA. CONCLUSION: APCs with IVA are more often discarded, not only due to aggregates, but also for impairment of other quality control parameters. Type of apheresis technology, being one of the most common risk factors for IVA, was not confirmed as the main risk factor for PA. There seem to be some donor-related causal factors.

Characterization of a novel mouse platelet transfusion model.

BACKGROUND AND OBJECTIVES: Platelet transfusions are increasing with medical advances. Based on FDA criteria, platelet units are assessed by in vitro measures; however, it is not known how platelet processing and storage duration affect function in vivo. Our study's aim was to develop a novel platelet transfusion model stored in mouse plasma that meets FDA criteria adapted to mice, and transfused fresh and stored platelets are detectable in clots in vivo. STUDY DESIGN AND METHODS: Platelet units stored in mouse plasma were prepared using a modified platelet-rich plasma (PRP) collection protocol. Characteristics of fresh and stored units, including pH, cell count, in vitro measures of activity, including activation and aggregation, and post-transfusion recovery (PTR), were determined. Lastly, a tail transection assay was conducted using mice transfused with fresh or stored units, and transfused platelets were identified by confocal imaging. RESULTS: Platelet units had acceptable platelet and white cell counts and were negative for bacterial contamination. Fresh and 1-day stored units had acceptable pH; the platelets were activatable by thrombin and adenosine diphosphate, agreeable with thrombin, had acceptable PTR, and were present in vivo in clots of recipients after tail transection. In contrast, 2-day stored units had clinically unacceptable quality. CONCLUSION: We developed mouse platelets for transfusion analogous to human platelet units using a modified PRP collection protocol with maximum storage of 1 day for an 'old' unit. This provides a powerful tool to test how process modifications and storage conditions affect transfused platelet function in vivo.

From Hematopoietic Stem Cells to Platelets: Unifying Differentiation Pathways Identified by Lineage Tracing Mouse Models.

Platelets are the terminal progeny of megakaryocytes, primarily produced in the bone marrow, and play critical roles in blood homeostasis, clotting, and wound healing. Traditionally, megakaryocytes and platelets are thought to arise from multipotent hematopoietic stem cells (HSCs) via multiple discrete progenitor populations with successive, lineage-restricting differentiation steps. However, this view has recently been challenged by studies suggesting that (1) some HSC clones are biased and/or restricted to the platelet lineage, (2) not all platelet generation follows the "canonical" megakaryocytic differentiation path of hematopoiesis, and (3) platelet output is the default program of steady-state hematopoiesis. Here, we specifically investigate the evidence that in vivo lineage tracing studies provide for the route(s) of platelet generation and investigate the involvement of various intermediate progenitor cell populations. We further identify the challenges that need to be overcome that are required to determine the presence, role, and kinetics of these possible alternate pathways.

Activation of AMPK in platelets promotes the production of offspring.

Platelets are terminally differentiated anucleated cells, but they still have cell-like functions and can even produce progeny platelets. However, the mechanism of platelet sprouting has not been elucidated so far. Here, we show that when platelet-rich plasma(PRP) was cultured at 37°C, platelets showed a spore phenomenon. The number of platelets increased when given a specific shear force. It is found that AMP-related signaling pathways, such as PKA and AMPK are activated in platelets in the spore state. Meanwhile, the mRNA expression levels of genes, such as CNN3, CAPZB, DBNL, KRT19, and ESPN related to PLS1 skeleton proteins also changed. Moreover, when we use the AMPK activator AICAR(AI) to treat washed platelets, cultured platelets can still appear spore phenomenon. We further demonstrate that washed platelets treated with Forskolin, an activator of PKA, not only platelet sprouting after culture but also the AMPK is activated. Taken together, these data demonstrate that AMPK plays a key role in the process of platelet budding and proliferation, suggesting a novel strategy to solve the problem of clinical platelet shortage.

What is new? In this study, we showed that when platelet-rich plasma(PRP) was cultured at 37°C, platelets showed spore phenomenon and increased.It was found that AMP-related signaling pathways, such as PKA and AMPK were activated in platelets in the spore state.In addition, we found that PKA acts as an upstream kinase of AMPK.In the process of platelet sprouting and proliferation, the mRNA expression levels of skeleton protein PLS1 and its related genes, such as CNN3, CAPZB, DBNL, KRT19, andESPN also changed.What is the impact? Our study proposes a new strategy to solve the problem of clinical platelet shortage.

Evaluating thrombosis risk and patient-specific treatment strategy using an atherothrombosis-on-chip model.

Platelets play an essential role in thrombotic processes. Recent studies suggest a direct link between increased plasma glucose, lipids, and inflammatory cytokines with platelet activation and aggregation, resulting in an increased risk of atherothrombotic events in cardiovascular patients. Antiplatelet therapies are commonly used for the primary prevention of atherosclerosis. Transitioning from a population-based strategy to patient-specific care requires a better understanding of the risks and advantages of antiplatelet therapy for individuals. This proof-of-concept study evaluates the potential to assess an individual's risk of forming atherothrombosis using a dual-channel microfluidic model emulating multiple atherogenic factors in vitro, including high glucose, high cholesterol, and inflammatory cytokines along with stenosis vessel geometry. The model shows precise sensitivity toward increased plasma glucose, cholesterol, and tumour necrosis factor-alpha (TNF-α)-treated groups in thrombus formation. An in vivo-like dose-dependent increment in platelet aggregation is observed in different treated groups, benefiting the evaluation of thrombosis risk in the individual condition. Moreover, the model could help decide the effective dosing of aspirin in multi-factorial complexities. In the high glucose-treated group, a 50 µM dose of aspirin could significantly reduce platelet aggregation, while a 100 µM dose of aspirin was required to reduce platelet aggregation in the glucose-TNF-α-treated group, which proves the model's potentiality as a tailored tool for customised therapy.

Platelet and Monocyte Microvesicles as Potential Biomarkers of COVID-19 Severity: A Cross-Sectional Analysis.

Background: Coronavirus disease (COVID-19) induces inflammation, coagulopathy following platelet and monocyte activation, and fibrinolysis, resulting in elevated D-dimer levels. Activated platelets and monocytes produce microvesicles (MVs). We analyzed the differences in platelet and monocyte MV counts in mild, moderate, and severe COVID-19, as well as their correlation with D-dimer levels. Methods: In this cross-sectional study, blood specimens were collected from 90 COVID-19 patients and analyzed for D-dimers using SYSMEX CS-2500. Platelet MVs (PMVs; PMVCD42b+ and PMVCD41a+), monocyte MVs (MMVs; MMVCD14+), and phosphatidylserine-binding annexin V (PS, AnnV+) were analyzed using a BD FACSCalibur instrument. Results: PMV and MMV counts were significantly increased in COVID-19 patients. AnnV+ PMVCD42b+ and AnnV+ PMVCD41a+ cell counts were higher in patients with severe COVID-19 than in those with moderate clinical symptoms. The median (range) of AnnV+ PMVCD42b+ (MV/µL) in mild, moderate, and severe COVID-19 was 1,118.3 (328.1-1,910.5), 937.4 (311.4-2,909.5), and 1,298.8 (458.2-9,703.5), respectively (P =0.009). The median (range) for AnnV+ PMVCD41a+ (MV/µL) in mild, moderate, and severe disease was 885.5 (346.3-1,682.7), 663.5 (233.8-2,081.5), and 1,146.3 (333.3-10,296.6), respectively (P =0.007). D-dimer levels (ng/mL) weak correlated with AnnV+ PMVCD41a+ (P =0.047, r=0.258). Conclusions: PMV PMVCD42b+ and PMVCD41a+ counts were significantly increased in patients with severe clinical symptoms, and PMVCD41a+ counts correlated with D-dimer levels. Therefore, MV counts can be used as a potential biomarker of COVID-19 severity.

Evaluation of platelets componentized with the Reveos Automated Blood Processing System and stored for 7 days at room temperature in a non-Di(2-ethylhexyl) phthalate (DEHP) platelet pooling set.

BACKGROUND: Platelet concentrates (PCs) used for transfusion can be produced by apheresis or derived from whole blood (WB). The Reveos device is the first US Food and Drug Administration-approved automated blood processing system that can produce PCs. In this work, we evaluated the quality and function of Reveos-collected PCs stored for 7 days at room temperature. STUDY DESIGN AND METHODS: WB was collected from healthy donors and componentized on the day of collection (Fresh) or after an overnight hold (Overnight). PCs were produced (n = 7 Fresh; n = 6 Overnight), stored at room temperature in plasma, and evaluated on days 1 and 7 for quality metrics, platelet activation, clot formation, and aggregation response. RESULTS: Platelet count was comparable between Fresh and Overnight PCs. A drop in pH was reported in Fresh day 7 PCs (p < .001, vs. day 1) but not in Overnight. Overnight units displayed the lowest levels of P-selectin expression (p = .0008, vs. day 7 Fresh). Reduced clot strength and increased lysis were observed in both Fresh and Overnight units on day 7 (vs. day 1). Overnight-hold PCs resulted in the highest clot strength on day 7 (p = .0084, vs. Fresh). No differences in aggregation were reported between groups. CONCLUSION: Reveos-processed PCs produced from overnight-hold WB performed better in hemostatic function assays and displayed reduced activation compared to fresh WB-derived PCs, although both PC groups maintained platelet quality throughout storage. Utilization of overnight WB for PC preparation with Reveos holds promise as an alternative method of producing platelets for transfusion purposes.

Platelet-to-lymphocyte ratio and lymphocyte-to-monocyte ratio in glaucoma: a meta-analysis.

Aim: To explore the association between two systemic inflammation markers, platelet-to-lymphocyte ratio (PLR) and lymphocyte-to-monocyte ratio (LMR), and glaucoma. Materials & methods: The authors searched PubMed, Embase and the Cochrane Library for eligible studies comparing PLR and LMR levels in glaucoma patients and healthy controls. Results: Analysis revealed that glaucoma patients exhibited significantly elevated PLR levels and reduced LMR compared with nonglaucoma controls. These findings were consistent across various glaucoma types, with the exception of secondary glaucoma, where the association with PLR was less significant. Conclusion: The authors found PLR and LMR to be potential valuable biomarkers for glaucoma identification and progression monitoring. These findings highlight the role of systemic inflammation in glaucoma pathogenesis.