Citations

Clear

184 citation(s) found for "Chen, Dong".

Evidence-Based Risk Stratification of TP53-Mutated Myeloid Neoplasms
Hung, Kevin , Price, Zoe, Al‐Kali, Aref , Ladon, Dariusz, Begna, Kebede H. , Rud, Danielle, Litzow, Mark R. , Bardy, Peter, Patnaik, Mrinal M. , Foran, James M. , He, Rong , Gangat, Naseema , Yi, Cecilia Y. Arana , Mangaonkar, Abhishek A. , Tefferi, Ayalew , Hung, Kevin , Shah, Meera , Baranwal, Anmol , Toop, Carla , Greipp, Patricia T. , Brown, Anna , Chen, Dong , Kutyna, Monika , Hogan, William J. , Badar, Talha , Kumar, Sharad , Yeung, David , Scott, Hamish S. , Yi, Cecilia Arana , Alkhateeb, Hassan B. , THOMAS, DANIEL W. , Hahn, Christopher N , Orazi, Attilio , Arber, Daniel A. , Kok, Chung Hoow , Hiwase, Devendra

Mayo Clinic

Blood | December 6, 2024 | Volume: 144 | Issue: Supplement 1 | Pages: 3213-3213

10.1182/blood-2024-198269 Get It

Background: TP53-mutated (TP53mut) myeloid neoplasms (MN) have particularly poor survival. Discrepancies in defining TP53mut MN have impact on diagnostic work up, therapeutic decisions, and clinical trial enrolment. Methods: MN cases harboring TP53mut (variant allele frequency, VAF ≥2%) were classified based on bone marrow (BM) and peripheral blood (PB) blast % using the 4th revision of the WHO classification (WHO-4R). Biallelic loss was defined as (i) ≥2 mutations each with VAF ≥2%; (ii) single TP53mut VAF ≥2% plus 17p loss detected on karyotype, FISH, or SNP; or (iii) single TP53mut VAF ≥50%, whereas monoallelic loss was defined as single TP53mut VAF <50% without 17p loss. Primary endpoint was overall survival (OS) from diagnosis. Conditional Inference Trees (CIT) analysis was used to determine the true effect of a predictor. Results: We identified 580 cases including WHO-4R defined acute myeloid leukemia (AML, BM/PB blasts ≥20%, n=219, 37.8%), myelodysplastic syndrome (MDS) with excess blasts-2 (EB-2, BM 10-19% or PB 5%-19%, n=92, 15.9%), MDS with excess blasts-1 (EB-1, BM 5-9% or PB 2-4%, n=75, 12.9%), and the remaining were MDS with low blasts (-LB, BM <5% and PB ≤1%, n=194, 33.4%). Of the 578 cases evaluable for allelic status, 437 (75.6%) and 141 (24.4%) had biallelic and monoallelic TP53 loss, respectively. Higher frequency of biallelic loss was observed with increasing blasts. 63.2%, 73.3%, 78% and 86.3% of cases with MDS-LB, MDS-EB1, MDS-EB2, and AML had bi-allelic TP53 loss (P<0.0001). In a multivariable analysis, WHO-4R categories, VAF ≥10%, and biallelic loss were independent predictors of poor survival. CIT analysis further stratified the cohort into 4 groups with distinct survival: (1) MDS-LB (n=194, 33.4%); (2) MDS-EB1/EB2 and AML with VAF <10% (n=38, 6.6%); (3) MDS-EB1/EB2 with VAF ≥10% (n=149, 25.7%); and (4) AML with VAF ≥10% (n=199, 34.3%). MDS-LB cases could be further stratified based on allelic status and complex karyotype (CK): OS was poor for cases with biallelic TP53 loss and monoallelic TP53mut with CK compared to monoallelic TP53mut without CK, who had the most favorable survival (12.7 vs. 13 vs. 34.8 months, P<0.0001).MDS-EB1/EB2/AML with VAF<10% could also be stratified by CK: MDS-EB1/EB2/AML with VAF<10% cases without CK had the favorable survival compared to their counterparts with CK and MDS-EB1/EB2 with VAF ≥10% cases (26.2 vs. 5.6 vs. 6.3 months, P=0.003).MDS-EB1/EB2 with VAF ≥10% was a homogenous subgroup: Biological characteristics including the proportion of cases with biallelic TP53 loss, CK (P>0.9), monosomal karyotype (MK, P>0.9), del 5q (P=0.6), del 7q (P=0.4), and del 17p (P=0.2) were comparable between MDS-EB1 and -EB2 with VAF ≥10%. Importantly, median OS of MDS-EB1 and EB2 with VAF ≥10% was comparable (9.6 vs. 7.2 months, P=0.12). OS in this group was comparable regardless of the blast %, allelic status, or presence of CK.AML with VAF ≥10% had extremely poor survival: Median OS was 3.9 months. Survival of AML was equally poor irrespective of the mono- or biallelic (3.6 vs. 3.9, P=0.89) and non-CK vs. CK (1.8 vs. 3.9 months, P=0.09). Combined, our model would acknowledge poor survival of 514 (89.1%) cases. In contrast, retrospective application of the 5th edition of the WHO classification (WHO-5) and International Consensus Classification (ICC) would classify only 211 (36.4%) and 468 (80.7%) cases as biallelic/multi-hit TP53mut MN, respectively. Finally, the Harrell's c-index of the proposed model, WHO-5, and ICC was 0.66, 0.571, and 0.617, respectively. Conclusion: We provide evidence for subsequent refinements in classifying MN harboring TP53mut. Our salient findings include: (i) acknowledgement of CK as ‘biallelic equivalent’ in MDS-LB; as well as EB1/EB2/AML with VAF 2 to <10% cases; and (ii) demonstration of poor survival of MDS-EB1 and -EB2 with VAF ≥10% regardless of the allelic status. In conclusion, our proposed model acknowledged poor survival of a higher proportion of cases as TP53mut MN compared to the current models with a higher c- index.
Altered Calcium Signaling Via STIM1 Drives Aberrant Megakaryopoiesis and Myelofibrosis
Brakhane, Molly , Buduo, Christian A. Di , Sadler, Brooke , Ashworth, Katrina , Kong, Tim , Fulbright, Mary C., Pegoraro, Elena , Gollomp, Kandace , Abbonante, Vittorio , Laranjeira, Angelo B. A. , He, Fan , Chen, Dong , Clemens, Regina A. , Lambert, Michele P. , Paola, Jorge Di , Balduini, Alessandra , Oh, Stephen T.

Mayo Clinic

Blood | December 6, 2024 | Volume: 144 | Issue: Supplement 1 | Pages: 1169-1169

10.1182/blood-2024-210283 Get It

Activating mutations in the calcium sensor STIM1 underlie Stormorken Syndrome (SS), a rare congenital disorder that causes thrombocytopenia and tubular aggregate myopathy. We recently identified two patients with SS and confirmed mutations in STIM1 (R304W and S88G), who were found to have features consistent with myelofibrosis (MF), as indicated by bone marrow biopsies demonstrating megakaryocyte hyperplasia and atypia in conjunction with marked reticulin fibrosis. The unusual MF findings in these two patients raised the hypothesis that altered calcium signaling represents a shared hallmark of congenital platelet disorders such as Stormorken Syndrome and myeloproliferative neoplasms (MPNs) including MF. Analyzing gene expression data from public datasets, we found increased expression of STIM1 in megakaryocyte progenitors and platelets, as well as CD34+ hematopoietic stem/progenitor cells (HSPCs), from MPN patients (including those with CALR or JAK2 mutations) vs healthy controls. These findings led us to hypothesize that dysregulation of STIM1 and store operated calcium entry (SOCE) signaling may contribute to altered megakaryopoiesis and development of fibrosis in both SS and MPNs. To further delineate these processes, we analyzed samples from our two SS patients, demonstrating constitutive activation of SOCE causing increased calcium flux, as well as decreased aggregation in mature platelets. We also performed transmission electron microscopy (TEM) and identified platelets with abnormal granularity in dense and alpha granules. We also performed single cell RNA-seq on SS patient peripheral blood mononuclear cells, which revealed enhanced NFkB inflammatory signaling, suggesting that altered signaling driven by STIM1 mutations may drive aberrant inflammation to contribute to MF development. To corroborate these initial observations, we identified a separate family cohort of 9 individuals in Italy with SS and confirmed STIM1 mutation (L92V). In ex vivo megakaryocytic differentiation assays, cells derived from these patients demonstrated a defect in thrombopoiesis with significantly decreased pro-platelet formation and adhesion to extracellular matrix. To further characterize the effects of the gain of function STIM1 mutations seen in our patients, we developed a novel, conditional knock-in mouse model of the heterozygous R304W mutation in the coiled coil (CC) domain of Stim1. Induction of hematopoietic-specific expression of mutant Stim1 via Vav-Cre resulted in recapitulation of hematological features of SS, including thrombocytopenia and a mild bleeding tendency, with confirmation of increased SOCE activity and calcium flux. Notably, we confirmed the development of bone marrow fibrosis, as well as findings of severe osteosclerosis, in these mice. TEM imaging confirmed that platelets from Stim1R304W/+Vav-Cre mice exhibit abnormal granularity, similar to what we observed from our SS patients. Noting that we identified increased STIM1 expression in samples from MPN patients harboring either JAK2 or CALR mutations, we further characterized the role of STIM1 in MPN disease development. NSGS mice were engrafted with CALR-mutant CD34+ cells subjected to CRISPR ablation of STIM1. Recipient mice exhibited decreased human CD45+ cell engraftment in conjunction with prolonged survival. In contrast, targeting of STIM1 in JAK2-mutant CD34+ cells led to exacerbated disease phenotypes, as manifested by enhanced human CD45+ cell engraftment, worsened splenomegaly, and early lethality. Taken together, these findings suggest a striking, differential relationship between mutant JAK2 and CALR and STIM1 activity and their relationship to MF development. Altogether, this study represents the first demonstration of MF development in patients with Stormorken Syndrome, and reveals a previously unrecognized hallmark of altered calcium signaling via aberrant STIM1 activation underlying SS and MPNs. We further demonstrate recapitulation of these hematologic features in a novel knock-in Stim1R304W/+Vav-Cre mouse model. These findings implicate an important role for STIM1and SOCE activity in MF development, and further uncover important distinctions between JAK2 vs CALR mutations and their interaction with altered STIM1 activity. These studies may contribute to the development of novel therapeutic approaches for these disorders.
Platelet-Activating Anti-PF4 Antibodies in MGUS Patients with Thrombosis
Pabmanabhan, Anand, Splinter, Noah P., Mauch, Emily, Kanack, Adam J. , Pruthi, Rajiv K. , Kumar, Shaji, Pabmanabhan, Anand, Chen, Dong , Dispenzieri, Angela , Kumar, Shaji , Houghton, Damon E.

Mayo Clinic

Blood | December 5, 2024 | Volume: 144 | Issue: Supplement 1 | Pages: 3996-3996

10.1182/blood-2024-207999 Get It

Introduction. Platelet-activating anti-Platelet factor 4 (PF4) antibodies mediate a number of thrombotic thrombocytopenic syndromes, including heparin-induced thrombocytopenia (HIT), and more recently recognized conditions, vaccine-induced immune thrombotic thrombocytopenia (VITT), adenovirus-associated thrombotic thrombocytopenia, and monoclonal gammopathy of thrombotic significance (MGTS). In MGTS (Blood. 2023 Apr 6;141(14):1772-1776), a monoclonal IgG antibody to PF4 mediates a chronic prothrombotic state characterized by recurrent thrombosis. More recent evidence suggests that MGTS may present with negative results in HIT enzyme-linked immunosorbent assay (ELISA) and serotonin release assay (SRA), and positivity only in PF4-dependent functional assays such as the PF4-dependent P-selectin expression assay (PEA; submitted). The presence of MGUS in patients has long been associated with high risks of thrombotic disease (Blood. 2010 Jun 17;115(24):4991-8), but the mechanism by which they predispose to thrombosis has been relatively unexplored. In this study, we evaluated a cohort of MGUS patients who experience thrombosis for the presence of platelet-activating anti-PF4 antibodies. M ethods. An administrative database search was performed of Mayo Clinic records to identify patients who had a diagnosis of MGUS, and thrombosis. Research samples from 134 MGUS patients with IgG monoclonal protein and thrombosis were obtained from Mayo Clinic's dysproteinemia biobank and subjected to PF4 antigen-based and functional screening. Research studies were approved by the Institutional Review Board of Mayo Clinic. Results. Of the 134 patients, 17 (12.7%) activated platelets in the PEA (≥19%). To exclude non-specific activation (e.g. due to HLA antibodies), secondary PEA testing was performed to assess whether platelet activation was mediated by a HIT-like antibody (i.e., PF4- and IgG-dependent, and inhibitable with high concentrations of heparin). Four patients, hereafter referred to as patients 1-4, were identified as having a HIT-like antibody, as demonstrated by PF4-dependent platelet activation that could be inhibited with high concentrations of heparin (100 U/mL), and blockade of the platelet IgG receptor, FcγRIIa. Patients 1 and 2 had persistent, platelet-activating anti-PF4 antibodies based on PEA testing of multiple samples obtained several years apart. Patient 1 had a recurrent, multi-year history of deep venous thrombosis (DVT), while patient 2 had one DVT episode. Patient 3 demonstrated a HIT antibody-like profile in the PEA in two of three samples available for testing and had a history of thrombotic cerebrovascular accident (CVA). Patient 4 demonstrated a HIT-like platelet-activating antibody in only one of four samples tested, and consistent with this finding, had an MGUS identified on clinical testing at only one time point (“small” IgG lambda, not quantified), 3 months prior to the platelet-activating sample. This patient experienced multiple thrombotic events including DVTs, left atrial thrombus and embolic CVA, pulmonary embolism and acute limb ischemia. All patients tested negative in two FDA-approved antigen-based HIT assays tested (Immucor PF4 IgG and Zymutest HIA IgG), similar to a recent MGTS case (submitted). SRA was negative in both Patients 1 & 2, weakly positive in Patient 3 (33%, with high CV), and positive (72%) in Patient 4. Conclusions. Definitive diagnosis of patients with MGTS provides insight into a mechanism of “unexplained” thrombosis and may offer additional treatment pathways for these patients with recurrent thrombosis (New Eng J of Med, 2024 Aug 8). Serologic testing in two patients correlated strongly with observations of thrombosis, and the study confirmed recent findings that anti-PF4 antibodies may present with unusual serology that is neither HIT- nor VITT-like (with negative results in both ELISA and SRA). The incidence of confirmed/suspected MGTS was 3% (4/134) in this population of MGUS patients with thrombosis. Prospective studies are needed to confirm these observations.
Coagulation Pediatric Reference Interval Study: Procoagulant Proteins Preliminary Findings
Tange, Julie I, Atkinson, Hunter, Al‐Huniti, Ahmad , Pruthi, Rajiv K. , Chen, Dong

Mayo Clinic

Blood | December 5, 2024 | Volume: 144 | Issue: Supplement 1 | Pages: 5525-5525

10.1182/blood-2024-212309 Get It

Introduction Establishment of reference intervals (RI) for quantitative assays requires a minimum of 120 qualified normal donor (ND) samples for each partition of an analyte. Based on CLSI EP28 A3C guideline [CLSI. Defining, Establishing, and Verifying Reference Intervals in the Clinical Laboratory; Approved Guideline-Third Edition. CLSI document EP28-A3c. Wayne, PA: Clinical and Laboratory Standards Institute; 2008.], verification of previously established and/or published RI can be performed with a minimum of 20 NDs, especially given complexities of finding qualified NDs. Reagent manufacturers typically provide adult RI, thus facilitating RI verification as a viable option. NDs for the Pediatric (Peds) (<18 years of age) population are difficult to obtain, published RIs are performed with sample cohorts less than the suggested number or only performed with specific instrument/reagent combinations. Herein, we report our experiences with Peds RI. Methods After IRB approval, healthy pediatric outpatients ages 0-18yrs were recruited and consented. Plasma obtained from umbilical cord, finger/heel/ear stick, or venipuncture blood samples (no more than 50 mL or 3 mL per kg) and collected in 3.2% sodium citrate. Assays included Protein (P) C antigen (PCAG) and chromogenic activity (PCFX); P S total (PST), free (PSF) antigen, and functional (SFX); antithrombin antigen (ATAG) and chromogenic activity (ATFX); plasminogen (PLGN) and alpha-2-plasmin inhibitor (A2PI). Assay kits were PCFX - HemosIL® (Werfen, Beford, MA) Protein C, PST - LIATEST® (Diagnostica Stago S.A.S., Asnières sur Seine, France) Protein S, PSF - HemosIL® Free Protein S, SFX - HemosIL® Protein S Activity, ATAG - LIATEST® AT III , ATFX - HemosIL® Liquid Antithrombin, PLGN - HemosIL® Plasminogen, and A2PI - HemosIL® Plasmin Inhibitor performed on the ACL TOP 700 (Werfen) instrument. PCAG - REAADS® Protein C Antigen Test Kit (Corgenix, Inc. Broomfield, CO) was performed on the Janus G3 liquid handler (Revvity, Waltham, MA) and Synergy Neo2 microplate reader (Agilent, Santa Clara, CA). Assay mean and range were calculated. Results Insufficient numbers of patients <1yr were collected. Type of assay, age range in yr and number of samples (n), assay mean in % and range results respectively were as follows: PCAG 1-5 (n=15) 87(46-146); 5-10 (n=82) 81 (45-158); 10-15 (n=169) 84 (44-157); 15-18 (n=107) 91 (57-149). PCFX 1-5 (n=20) 97 (56-140); 5-10 (n=84) 89 (62-135); 10-15 (n=188) 91 (55-140); 15-18 (n=124) 96 (54-138). PST (males): 1-5 (n=10) 120 (96-145); 5-10 (n=46) 108 (75-150); 10-15 (n=91) 111 (80-168); 15-18 (n=63) 113 (72-184). PST (females): 1-5 (n=9) 104 (67-146); 5-10 (n=37) 111 (81-159); Ages 10-15 (n=94) 107 (78-153); 15-18 (n=63) 101 (65-148). PSF (males): 1-5 (n=10) 94 (74-109); 5-10 (n=47) 101 (66-141); 10-15 (n=93) 101 (69-151); 15-18 (n=62) 111 (74-187). PSF (females): 1-5 (n=9) 78 (9-124); 5-10 (n=37) 107 (79-137); 10-15 (n=95) 99 (63-138); 15-18 (n=63) 97 (60-132). SFX (males): 1-5 (n=9) 100 (85-128); 5-10 (n=48) 104 (66-144); 10-15 (n=93) 103 (66-168); 15-18 (n=59) 109 (72-157). SFX (females): 1-5 (n=8) 94 (18-121); 5-10 (n=37) 107 (81-143); 10-15 (n=90) 101 (65-147); 15-18 (n=60) 97 (53-135). ATAG 1-5 (n=19) 104 (80-121); 5-10 (n=83) 104 (78-121); 10-15 (n=188) 104 (66-126); 15-18 (n=126) 101 (67-126). ATFX 1-5 (n=20) 112 (94-135); 5-10 (n=84) 107 (87-123); 10-15 (n=188) 105 (84-138); 15-18 (n=126) 101 (84-129). PLGN 1-5 (n=17) 96 (76-124); 5-10 (n=85) 88 (65-125); 10-15 (n=183) 90 (49-151); 15-18 (n=119) 94 (64-151). A2PI: 1-5 (n=17) 134 (118-151); 5-10 (n=85) 126 (107-139); 10-15 (n=183) 121 (104-140); 15-18 (n=118) 116 (91-143). Conclusions Based on CLSI EP28 A3C criteria for verification, no more than 10% of results should fall outside of established/published RI, for example adult RI. Thus, compared to the SCL adult RI, PLGN assay meets criteria in all age ranges and no additional ND are needed. For the remaining assays, additional ND for ages 1-5 are needed. For ages 5-18 criteria for verification are satisfied for all analytes except PCAG. PCAG has 27, 61, and 19 patients falling below lower RI for ages 5-10, 10-15, and 15-18, respectively.
The Contribution of Corn Trypsin Inhibitor on Thrombin Generation Kinetics in Trauma Patients: A Comparative Analysis
Navarro, Sergio M. , Thompson, Riley J., Spears, Grant M. , Bailey, Kent R. , Dong, Jing-fei, Kozar, Rosemary A. , Pruthi, Rajiv K. , Park, Myung S., Navarro, Sergio Michael , Chen, Dong

Mayo Clinic

Blood | December 5, 2024 | Volume: 144 | Issue: Supplement 1 | Pages: 5529-5529

10.1182/blood-2024-201035 Get It

Trauma-induced coagulopathy (TIC) is common after injury and reliable quantification of its severity is lacking. The objective of this study was to evaluate whether thrombin generation would be significantly altered if whole blood samples from trauma patients were collected without (citrate-only) and with corn trypsin inhibitor (CTI+). In a prospective cohort study, 36 trauma pts presenting to a Level I Trauma Center within 12 hours of injury, had whole blood collected simultaneously in citrate-only (3.2%) and citrated plus CTI (CTI+ [final 25 ug/mL]), and processed to platelet free plasma by double centrifugation (3000g, 15 minutes). Samples were stored at -80C with no thawing until analysis. Thrombin generation profiles were measured using the ST Genesia assay (Diagnostica STAGO SAS) and parameters included endogenous thrombin potential (ETP), lag time (LT), peak height, start of tail, velocity index, and time to peak (ttPeak) were analyzed for trauma pts. Data presented as median [IQR] or n (%), with paired t-test and Spearman's correlation analysis were performed between citrated non-CTI and citrated CTI spiked blood samples, with p-value <0.05 statistically significant. Pts presented with significant injury ISS 13 [5, 21], age 45 [29, 59] years, 80.6% male, BMI 26.9 [25.4, 28.3], 94.4% blunt trauma, 22.3% had surgery by day 1 of admission. Significant differences were found between the citrated-only and CTI +tubes in several thrombin generation parameters: ETP (1339 Nm*min [1172.5,1417], 1124.5 [925.4,1285], p<0.001), peak height (222.3 Nm [186.0, 275.6], 160.6 [132.7,208.3], p<0.001), ttPeak (5.64 min [4.86,6.63], 6.19 [5.36, 7.34], p<0.001), start of tail (19.4 min [17.6,21.3], 21.6 [18.9, 23.6], p=0.014), and velocity index (117.6 Nm/min [77.9, 163.1], 71.9 [54.9,106.0], p<0.001). However, LT (3.14 min [2.74, 3.90], 3.08 [2.84, 3.96], p=0.665) did not show a statistically significant difference. Spearman's correlation analysis showed high correlation between citrate-only and CTI+ citrated plasma samples, with Spearman's rank correlation coefficients for LT (0.941), peak height (0.760), ttPeak (0.928), ETP (0.770), start of tail (0.869), and velocity index (0.766) respectively. The results suggest that use of CTI+ decrease thrombin generation kinetics from blood samples obtained from trauma patients. These findings underscore the need for careful consideration of sample collection and processing for use of thrombin generation assays in clinical setting. However, there is very strong correlation of the thrombin parameters obtained from citrated-only plasma to CTI+ plasma samples, suggesting they capture similar information. CTI-spiked citrated tubes appear to reduce contact activation with respect to thrombin generation profiles compared to standard citrated only tubes. This should be a consideration for platform-based lab processing of thrombin generation assays for assessment of coagulopathy after injury; however, given the cost of CTI, citrated-only tubes can be an option for characterization of thrombin generation profile in clinical samples.
Conformation-specific RNA aptamers for phenotypic distinction between normal von Willebrand factor and type 2B von Willebrand disease
Machha, Venkata R. , Moon‐Tasson, Laurie, Tange, Julie I, Santiago-Davis, Annyoceli, Pruthi, Rajiv K. , Chen, Dong , Maher, L. James , Auton, Matthew , Tischer, Alexander , Moon-Tasson, Laurie, Tange, Julie, Chen, Dong , III, Louis James Maher , Auton, Matthew , Tischer, Alexander

Mayo Clinic

NAR Molecular Medicine | November 24, 2024 | Volume: 1 | Issue: 4 | Pages: No page available

10.1093/narmme/ugae021 | PMID 39719968 Get It

Abstract The A1 domain in Von Willebrand Factor (VWF) initiates coagulation through binding to platelet glycoprotein GPIbα receptors. Von Willebrand Disease (VWD)-Mutations in A1 that either impair (type 2M) or enhance (type 2B) platelet adhesion to VWF can locally destabilize and even misfold the domain. We leveraged misfolding in the gain-of-function type 2B VWD phenotype as a target, distinct from the normal conformation. Two nuclease-resistant 2′-fluoropyrimidine RNA aptamers were selected to discriminate normal A1 domains from a type 2B V1314D A1 variant in a glycosylated A1A2A3 tri-domain VWF-fragment. Two aptamers, W9 and V1, were isolated that selectively recognize, bind, and inhibit the A1–GPIbα interaction with WT A1A2A3 and V1314D A1A2A3, respectively. These aptamers were tested against their respective recombinant targets, plasma VWF, VWF concentrates, and patient plasma with the heterozygous type 2B VWD R1306W variant using clinical assays, surface plasmon resonance and inhibition assays of platelet adhesion to recombinant A1 and A1A2A3 domains under shear stress. The specificity of W9 and V1 aptamers confirms that pathological conformations of VWD Type 2B proteins are different from normal VWF. The availability of aptamers that distinguish normal plasma-derived VWF from VWD suggests potential applicability in clinical diagnosis of severe gain-of-function phenotypes.
Histological Findings of ETosis in Hermansky-Pudlak Syndrome with Pulmonary Fibrosis: A Follow-Up Case Report
Navarro, Sergio M. , Ashrani, Aneel A. , Park, Myung S. , Chen, Dong , Navarro, Sergio Michael , Ashrani, Aneel , Park, Myung Soo , Chen, Dong

Mayo Clinic

Journal of Chest Surgery | October 22, 2024 | Volume: 58 | Issue: 1 | Pages: 46-49

10.5090/jcs.24.059 | PMID 39434611 Get It

A-144 Liquid chromatography multiple reaction monitoring-based assay for quantitative assessment of fibrinogen levels in clinical samples
Bokka, Ramesh, Venkataraman, Shreyas , Peterson, Jane A., Tange, Julie I, Leger, Rachel, Seheult, Jansen N. , Pruthi, Rajiv K. , Seheult, Jansen N , Chavan, Sandip , Venkataraman, S, Peterson, J, Chen, Dong , Pandey, Akhilesh

Mayo Clinic

Clinical Chemistry | October 2, 2024 | Volume: 70 | Issue: Supplement_1 | Pages: No page available

10.1093/clinchem/hvae106.142 Get It

Abstract Background Fibrinogen plays a critical role in hemostasis and is essential to clot formation. Changes in the quantity or activity of fibrinogen can lead to disorders affecting coagulation. Thus, it is essential to precisely quantify fibrinogen levels to differentiate between hyperfibrinogenemia in hypercoagulable disorders and dysfibrinogenemia, hypo/afibrinogenemia, and irregular bleeding. Current diagnostic tests that use antibodies to detect fibrinogen or activity-based measures are susceptible to interference from heparin contamination, hemolysis, and hyperbilirubinemia. Here, we evaluated the use of targeted proteomics for developing a quantitative assay for fibrinogen in plasma samples. Methods Four peptides each for alpha and gamma chains of fibrinogen were synthesized using FMOC chemistry on a Liberty Blue (CEM Corp) peptide synthesizer. A targeted multiple reaction monitoring (MRM) assay was developed and optimized using Dionex Ultimate 3000 HPLC connected to a TSQ Altis triple quadrupole mass spectrometer (Thermo Scientific). Evaluations were conducted using a range of standards, such as pure protein, WHO plasma and commercially available plasma with known fibrinogen amounts for the accurate quantitation of fibrinogen. Calibration curves were generated using different dilutions in various matrices. The repeatability and precision of the assay were evaluated across five different days. The plasma samples were processed and digested in a 96-well plate and subjected to C18 clean-up using a Bravo automated liquid handler (Agilent). All samples were spiked-in with corresponding heavy-labeled peptides prior to digestion with trypsin. Multiple reaction monitoring assays were performed on tryptic digests of plasma samples. Results Calibration curves using commercial plasma for all peptides showed linearity from 20 mg/dl to 1,308 mg/dl. This covers the entire clinical range including normal (200-350 mg/dl), deficient states (<100 mg/dl) and excess production (>350 mg/dl) that can be used for evaluation of bleeding disorders including consumption coagulopathy and hyperfibrinogenemia. Based on the overall performance in terms of linearity, limit of detection/quantitation, carryover and coefficient of variation (CV) across five different days, two peptides per chain were finally selected for developing the quantitative assay. The intra-assay variability was <5% and intra-day CV was ∼20%. This assay is currently being tested on a variety of clinical samples representing a range of fibrinogen levels. Conclusions Our study focused on assessing whether multiplexed MRM assay could be implemented to measure fibrinogen levels in plasma. Our data indicate the feasibility of MRM-based assays for determining fibrinogen levels as an alternative to existing non-mass spectrometry-based activity or antigen assays.
A-161 Diagnosis of Lupus Anticoagulant Cases using Deep Neural Networks
Leger, Rachel, Heikal, Nahla, Pruthi, Rajiv K. , Wang, J, Chen, Dong , Seheult, Jansen N.

Mayo Clinic

Clinical Chemistry | October 2, 2024 | Volume: 70 | Issue: Supplement_1 | Pages: No page available

10.1093/clinchem/hvae106.159 Get It

Abstract Background Laboratory identification of lupus anticoagulant (LAC) is critical for diagnosing antiphospholipid antibody syndrome, a common cause of unprovoked thromboembolic events and pregnancy morbidity. Commonly used clot-based assays for LAC include the dilute Russell’s viper venom time (DRVVT) and activated partial thromboplastin time (APTT), but these are susceptible to anticoagulant interferences. Despite standardization efforts, LAC interpretation remains challenging due to pre- and post-analytical complexity and limited expertise. This study explored the use of deep neural networks (DNN) to facilitate LAC diagnosis. Methods Retrospective data for LAC profiling with 13 features performed at Mayo Clinic between 2021 and 2022 was collected. The profiles of 7,202 patients were randomly divided into training (n=4608), validation (n=1153), and test cohorts (n=1441). Diagnostic outputs including LAC positivity (determined by DRVVT or APTT) and the presence of warfarin (WAR) and heparin (HEP), were confirmed by expert assessment. Three DNN architectures were developed and evaluated (Figure 1): (1) four single output DNN models with a domain knowledge driven selection of input features, (2) four single output DNN models using the same 13 inputs across all models, and (3) a multi-output DNN model. Model performance was evaluated using the F1 score and the index of balanced accuracy (IBA) for each output label. Results Architecture 1 achieved high diagnostic accuracy with IBA values of 0.989-1.000 for all four outputs and F1 scores of 0.945-0.991. Architecture 2 exhibited F1 scores of 0.902-0.973 and IBA values of 0.935-0.992. Architecture 3 achieved F1 scores of 0.933-0.967 and IBA values of 0.941-0.983. Conclusions All three architectures accurately classify LAC and common anticoagulation effects. The comparable performance of architectures 1 and 2 suggests that manual feature extraction is unnecessary. Given its relative simplicity and versatility, architecture 3 is the preferred choice for implementation in a clinical laboratory to standardize LAC diagnosis.
Neurosurgical bleeding in platelet storage pool disorder: a case report
Alcorn, Kirsten, Fesler, Joanna, Landis, Daniel, Litvack, Zachary, Hegerova, Livia , Pierre, Clifford A. , Chen, Dong , Konkle, Barbara A.

Mayo Clinic

Platelets | July 23, 2024 | Volume: 35 | Issue: 1 | Pages: No page available

10.1080/09537104.2024.2380374 | PMID 39041657 Get It