Lactate Dehydrogenase Research Articles

7426 Tamoxifen-Induced Ovarian Hyperstimulation in a Pre-Menopausal Patient with Breast Cancer History: Spontaneous Resolution with Conservative Management

Abstract Disclosure: S. Gondi: None. M. Contento: None. A. Leiter: None. Background: Tamoxifen is a selective estrogen receptor modulator (SERM) that competitively binds to estrogen receptors (ER) on tumors and inhibits the effect of estrogen, which is used in the treatment and prevention of ER-positive breast cancer. Tamoxifen therapy has been reported to increase serum estrogens and cause ovarian hyperstimulation in premenopausal women, but knowledge on how to manage these conditions is limited. Clinical Case: A 36-year-old pre-menopausal female with history of malignant neoplasm of the right breast (ER positive) who completed neoadjuvant chemotherapy, lumpectomy, and radiation, on tamoxifen for seven years presented with new-onset oligomenorrhea. Laboratory testing done by the patient’s gynecologist revealed total estrogen 2,723 pg/mL (reference range [RR] 34-501), testosterone 132 ng/dL (RR 8-60), anti-Mullerian hormone 12.7 ng/mL (RR for age 0.66-8.75), ovulation-phase follicle stimulating hormone 11.5 mIU/mL (RR 4.7-21.5) and luteinizing hormone (LH) 63.3 mIU/mL (RR 14-95.6). Further workup revealed that ovarian tumor markers alpha-fetoprotein and serum human chorionic gonadotropin and other labs including dehydroepiandrosterone sulfate, progesterone 17-OH, lactate dehydrogenase, prolactin, and thyroid stimulating hormone were normal. Transvaginal ultrasound (TVUS) showed a new 2.8 x 1.9 x 2.3 cm complex left ovarian cyst, which, along with the elevated estrogen level, was concerning for ovarian hyperstimulation. Treatment with LH-releasing hormone (LHRH) agonists, surgical consultation, and discontinuation of tamoxifen were offered as potential management strategies, but the patient opted for observation and continued tamoxifen. Two months later, estradiol was 989 pg/mL (RR 85-498), and then three months later decreased to 152 pg/mL with repeat TVUS showing resolution of the left ovarian cyst. The patient’s oligomenorrhea resolved with resumption of regular menstrual cycles. Conclusion: While it is well-known that tamoxifen causes elevated serum estrogen levels and can lead to ovarian hyperstimulation, there is limited research on the management of these side effects. Treatment strategies in past cases have included oophorectomy or medical management with LHRH agonists or gonadotropin-RH agonists. However, this case demonstrates that a tamoxifen-induced ovarian cyst and high estrogen levels can resolve on its own with continued tamoxifen treatment. Conservative management with monitoring via imaging and repeat estrogen levels may be sufficient in management of pre-menopausal women with tamoxifen-induced ovarian hyperstimulation. Presentation: 6/1/2024

Investigate the association between genetic polymorphisms of ACE and ACE-2 with some biomarkers in Iraqi patients with COVID-19.

BackgroundThe angiotensin-converting enzyme 2 (ACE2) receptor plays a critical role in mediating SARS-CoV-2 infection. Understanding the genetic factors influencing COVID-19 severity is crucial for developing effective treatment strategies. This study aimed to investigate the association between genetic polymorphism of the ACE gene, specifically the insertion/deletion (I/D) polymorphism in the promoter region, and clinical parameters in COVID-19 patients. MethodsA case-control study was conducted with 225 participants from an Iraqi population. Blood samples were collected for hematological analysis and ACE genotyping. The association between ACE genotypes (DD, ID, II), demographic factors, and clinical parameters, including D-dimer, ferritin, lactate dehydrogenase (LDH), C-reactive protein (CRP), white blood cell (WBC) count, lymphocyte count, packed cell volume (PCV), red blood cell (RBC) count, hemoglobin (HB), and platelet count, was assessed. ResultsCOVID-19 patients exhibited significant differences compared to controls regarding D-dimer, ferritin, LDH, CRP, WBC, lymphocytes, PCV, and RBC (P < 0.05), while no significant differences were found for HB and platelet counts. The DD genotype was predominant (43.11 %), followed by ID (39.56 %) and II (17.33 %). Notably, a significant association was observed between D-dimer levels and ACE genotype (P < 0.0001), with higher levels observed in individuals with the DD genotype. Additionally, a significant correlation was found between ACE genotype and sex (P = 0.0163). No significant association was observed between genotype and ICU admission or lung CT severity. ConclusionOur findings suggest a potential link between the ACE D/D genotype and elevated D-dimer levels in COVID-19 patients, indicating a potential role for ACE gene polymorphism in influencing disease severity. Further research is warranted to elucidate the underlying mechanisms and explore the potential for personalized treatment approaches based on ACE genotype.

Crosstalk of methylglyoxal and calcium signaling in maize (Zea mays L.) thermotolerance through methylglyoxal-scavenging system

Methylglyoxal (MG) and calcium ion (Ca2+) can increase multiple-stress tolerance including plant thermotolerance. However, whether crosstalk of MG and Ca2+ exists in the formation of maize thermotolerance and underlying mechanism still remain elusive. In this paper, maize seedlings were irrigated with MG and calcium chloride alone or in combination, and then exposed to heat stress (HS). The results manifested that, compared with the survival percentage (SP, 45.3%) of the control seedlings, the SP of MG and Ca2+ alone or in combination was increased to 72.4%, 74.2%, and 83.4% under HS conditions, indicating that Ca2+ and MG alone or in combination could upraise seedling thermotolerance. Also, the MG-upraised SP was separately weakened to 42.2%, 40.3%, 52.1%, and 39.4% by Ca2+ chelator (ethylene glycol tetraacetic acid, EGTA), plasma membrane Ca2+ channel blocker (lanthanum chloride, LaCl3), intracellular Ca2+ channel blocker (neomycin, NEC), and calmodulin (CaM) antagonist (trifluoperazine, TFP). However, significant effect of MG scavengers N-acetylcysteine (NAC) and aminoguanidine (AG) on Ca2+-induced thermotolerance was not observed. Similarly, an endogenous Ca2+ level in seedlings was increased by exogenous MG under non-HS and HS conditions, while exogenous Ca2+ had no significant effect on endogenous MG. These data implied that Ca2+ signaling, at least partly, mediated MG-upraised thermotolerance in maize seedlings. Moreover, the activity and gene expression of glyoxalase system (glyoxalase I, glyoxalase II, and glyoxalase III) and non-glyoxalase system (MG reductase, aldehyde reductase, aldo-keto reductase, and lactate dehydrogenase) were up-regulated to a certain extent by Ca2+ and MG alone in seedlings under non-HS and HS conditions. The up-regulated MG-scavenging system by MG was enhanced by Ca2+, while impaired by EGTA, LaCl3, NEC, or TFP. These data suggest that the crosstalk of MG and Ca2+ signaling in maize thermotolerance through MG-scavenging system. These findings provided a theoretical basis for breeding climate-resilient maize crop and developing smart agriculture.

Characteristics of Myocardial Structure and Central Carbon Metabolism during the Early and Compensatory Stages of Cardiac Hypertrophy.

Cardiac hypertrophy is a classical forerunner of heart failure and myocardial structural and metabolic remodeling are closely associated with cardiac hypertrophy. We aim to investigate the characteristics of myocardial structure and central carbon metabolism of cardiac hypertrophy at different stages. Using echocardiography and pathological staining, early and compensatory cardiac hypertrophy were respectively defined as within 7 days and from 7 to 14 days after transverse aortic constriction (TAC) in mice. Among mass-spectrometry-based metabolomics, we identified 45 central carbon metabolites. Differential metabolite analysis showed that six metabolites, including citrate, cis-aconitate and so on, decreased significantly on day 1 after TAC. Ten metabolites, including l-lactate, (S)-2-hydroxyglutarate and so on, were obviously changed on days 10 and 14. Pathway analysis showed that these metabolites were involved in seven metabolic pathways, including carbohydrates, amino acids and so on. Western blot showed the expression of ATP-citrate lyase, malate dehydrogenase 1 and lactate dehydrogenase A in myocardium changed markedly on day 3, while the phosphorylation level of AMP-activated protein kinase did not show significantly difference. We hope our research will promote deeper understanding and early diagnosis of cardiac hypertrophy in clinical practice. All raw data were deposited in MetaboLights (MTBLS10555).

Phloridzin prevents diabetic cardiomyopathy by reducing inflammation and oxidative stress

Oxidative stress and inflammation significantly contribute to the pathogenesis of diabetic cardiomyopathy (DCM). Persistent inflammatory stimuli drive the progression of myocardial fibrosis and impaired cardiac function. Phloridzin (Phl), a natural compound, demonstrates both anti-inflammatory and antioxidant properties. Nevertheless, its therapeutic potential and underlying mechanisms in DCM remain unclear. This study aimed to elucidate the mechanisms through which Phl inhibited myocardial fibrosis and exerted its antioxidative effects. The impact of Phl on DCM was evaluated using a high-fat/high-sugar diet combined with streptozotocin to induce an animal model and an in vitro H9C2 cell model stimulated by high glucose (HG). Untargeted metabolomics identified potential mechanisms underlying myocardial fibrosis. Phl treatment significantly enhanced left ventricular ejection fraction (EF%) and shortening fraction (FS%), while reducing myocardial injury markers, such as lactate dehydrogenase and creatine phosphokinase-MB, and suppressing myocardial collagen fiber accumulation. Simultaneously, Phl attenuated myocardial inflammation via inhibition of MyD88/NF-κB signaling, modulated the Nrf2/GPX4 axis to counter oxidative stress, and mitigated ferroptosis. In vitro, Phl inhibited high glucose-induced myocardial hypertrophy and fibrosis in H9C2 cells, while also repressing NF-κB activation in cardiomyocytes. Metabolomic profiling revealed that Phl ameliorated DCM through modulation of glycerophospholipid metabolic pathways, linking these metabolic shifts to enhanced antioxidant capacity, thereby reflecting its ability to reduce oxidative stress in the myocardium. Collectively, Phl provides cardioprotective effects by alleviating inflammation and oxidative damage.

Aquaporin-1 Facilitates Macrophage M1 Polarization by Enhancing Glycolysis Through the Activation of HIF1α in Lipopolysaccharide-Induced Acute Kidney Injury.

This study aimed to investigate how aquaporin 1 (AQP1) modulates hypoxia-inducible factor-1α (HIF1α) to promote glycolysis and drive the M1 polarization of macrophages. Within 12 h post-treatment with LPS to induce acute kidney injury in rats, a significant upregulation of AQP1 and HIF1α protein levels was noted in serum and kidney tissues. This elevation corresponded with a decrease in blood glucose concentrations and an enhancement of glycolytic activity relative to the control group. Furthermore, there was a pronounced reduction in the circulating levels of the anti-inflammatory cytokine IL-10, accompanied by an upregulation in the levels of the pro-inflammatory cytokines IL-6 and TNF-α. The administration of an HIF1α inhibitor reversed these effects, which did not affect the production of AQP1 protein. In cellular assays, AQP1 knockdown mitigated the increase in HIF1α expression induced by LPS. Furthermore, the suppression of HIF1α with PX-478 led to decreased expression levels of Hexokinase 2 (HK2) and Lactate Dehydrogenase A (LDHA), indicating that AQP1 regulates glycolysis through HIF1α. M1 polarization of macrophages was reduced by AQP1 knockdown and was further diminished by the addition of an HIF1α inhibitor. Inhibition of the glycolytic process not only weakened M1 polarization but also promoted M2 polarization, thereby reducing the release of inflammatory cytokines. These findings provide a novel perspective for developing therapeutic strategies that target AQP1 and HIF1α, potentially improving the treatment of sepsis-associated AKI.

Comprehensive stable-isotope tracing of glucose and amino acids identifies metabolic by-products and their sources in CHO cell culture

Mammalian cell culture processes are widely utilized for biotherapeutics production, disease diagnostics, and biosensors, and hence, should be optimized to support robust cell growth and viability. However, toxic by-products accumulate in cultures due to inefficiencies in metabolic activities and nutrient utilization. In this study, we applied comprehensive 13C stable-isotope tracing of amino acids and glucose to two Immunoglobulin G (IgG) producing Chinese Hamster Ovary (CHO) cell lines to identify secreted by-products and trace their origins. CHO cells were cultured in media formulations missing a single amino acid or glucose supplemented with a 13C-tracer of the missing substrate, followed by gas chromatography-mass spectrometry (GC-MS) analysis to track labeled carbon flows and identify by-products. We tracked the sources of all secreted by-products and verified the identity of 45 by-products, majority of which were derived from glucose, leucine, isoleucine, valine, tyrosine, tryptophan, methionine, and phenylalanine. In addition to by-products identified previously, we identified several metabolites including 2-hydroxyisovaleric acid, 2-aminobutyric acid, L-alloisoleucine, ketoisoleucine, 2-hydroxy-3-methylvaleric acid, desmeninol, and 2-aminobutyric acid. When added to CHO cell cultures at different concentrations, certain metabolites inhibited cell growth while others including 2-hydroxy acids, surprisingly, reduced lactate accumulation. In vitro enzymatic analysis indicated that 2-hydroxy acids were metabolized by lactate dehydrogenase suggesting a possible mechanism for lowered lactate accumulation, e.g., competitive substrate inhibition. The 13C-labeling assisted metabolomics pipeline developed and the metabolites identified will serve as a springboard to reduce undesirable by-products accumulation and alleviate inefficient substrate utilization in mammalian cultures used for biomanufacturing and other applications through altered media formulations and pathway engineering strategies.

LncRNA MALAT1 to Enhance Pyroptosis in Viral Myocarditis Through UPF1-Mediated SIRT6 mRNA Decay and Wnt-β-Catenin Signal Pathway.

Viral myocarditis (VMC) is an inflammatory disease of the myocardium caused by cardioviral infection, especially coxsackievirus B3 (CVB3), and is a major contributor to acute heart failure and sudden cardiac death in children and adolescents. LncRNA MALAT1 knockdown reportedly inhibits the differentiation of Th17 cells to attenuate CVB3-induced VMC in mice. Moreover, long non-coding RNAs (lncRNAs) interact with RNA-binding proteins (RBPs) to regulate UPF1-mediated mRNA decay. However, it remains unclear whether MALAT1 can bind to UPF1 to mediate the mRNA decay of its target genes in VMC. Herein, we aimed to explore the effect of lncRNA MALAT1 on UPF1-mediated SIRT6 mRNA decay in VMC using in vivo and in vitro experiments. CVB3-infected BABL/C mice were used as VMC models, and MALAT1 interfering adenovirus was injected to achieve MALAT1 knockdown. The heart function of the VMC mice was assessed using echocardiography. Pathological changes in myocardial tissues were assessed after hematoxylin-eosin staining. Myocardial injury and inflammation were evaluated by measuring creatine kinase isoenzyme B, cardiac troponin T, interleukin (IL)-1β, and IL-18. TUNEL staining was performed to assess apoptosis in myocardial tissues. In vitro experiments were performed using H9c2 cells after transfection and CVB3 infection. The lactic dehydrogenase release, caspase-1 activity, and IL-1β and IL-18 levels in the cellular supernatant were detected. Western blotting was performed to determine the expression of pyroptosis-related proteins (GSDMD-N, NLRP3, ASC, and Cleaved-Caspase-1) and Wnt/β-catenin signal pathway-related proteins (Wnt1, β-catenin, and p-GSK-3β). RNA immunoprecipitation and RNA stability assays assessed the relationship between MALAT1, UPF1, and SIRT6. CVB3-infected mice and H9c2 cells exhibited elevated MALAT1 and reduced SIRT6 expression. MALAT1 knockdown or SIRT6 overexpression suppressed inflammation and pyroptosis and inhibited the activation of the Wnt/β-catenin signal pathway in myocardial tissues and cells. MALAT1 enhanced the enrichment of SIRT6 mRNA by UPF1 and disturbed the stability of SIRT6 mRNA to promote the development of VMC. MALAT1 can bind UPF1 to mediate SIRT6 mRNA decay and activate the Wnt/β-catenin signal pathway in VMC.

Estimation of Periodontal Inflamed Surface Area by Salivary Lactate Dehydrogenase Level Using a Test Kit.

Background: Salivary lactate dehydrogenase (LD) levels are a feasible and useful parameter for screening periodontal diseases. The periodontal inflamed surface area (PISA) is useful to clinically assess periodontal diseases. However, PISA is difficult to calculate and PISA-compatible screening kits are required. We aimed to investigate the association between salivary LD levels, using a test kit, and PISA and PISA-Japanese and determine the feasibility and reliability of the salivary LD test kit for evaluation of periodontal status. Methods: This study included 110 patients (66.4% female, median and 25-75 percentiles of age were 66.5 and 53.0-75.0 years, respectively) who visited the Dental University Clinic in Japan. Resting saliva samples were collected from each participant and LD levels were evaluated in real time using a kit featuring an integer scale ranging from 1 to 10. PISA and PISA-Japanese were calculated using periodontal parameters. Results: The median salivary LD level was 4.0. The medians of PISA and PISA-Japanese were 46.9 and 61.0, respectively. Salivary LD levels were positively correlated with the bleeding on probing rate (r = 0.626, p < 0.001), PISA (r = 0.560, p < 0.001), and PISA-Japanese (r = 0.581, p < 0.001). Conclusions: Our results suggest that salivary LD levels assessed using the salivary LD kit showed a significantly positive correlation with PISA and PISA-Japanese. In addition, we developed the PISA estimation formula using salivary LD levels measured with a test kit, sex, and age.

Effects of Tralokinumab on Clinical and Laboratory Indexes in Atopic Dermatitis: A 24-Week Real-World Study.

Background: Tralokinumab, a monoclonal anti-IL-13 antibody, is approved for treating atopic dermatitis (AD). Real-world data on its effectiveness and safety are limited. Objective: To evaluate the real-world effectiveness and safety of tralokinumab and the transition of laboratory indexes during 24-week treatment for AD patients. Methods: This retrospective study included 104 patients with moderate-to-severe AD treated with tralokinumab 300 mg every 2 weeks after primary 600 mg. Clinical and laboratory indexes were assessed until week 24. Results: At week 24, achievement rates of Eczema Area and Severity Index 75 (EASI 75), EASI 90, and investigator's global assessment 0 out of 1 in systemic therapy-naïve patients, 83.3%, 72.2%, and 44.4%, respectively, were higher than those in systemic therapy-experienced patients, 46.7%, 20.0%, and 6.7%, respectively. Serum levels of immunoglobulin E (IgE), thymus and activation-regulated chemokine (TARC), and lactate dehydrogenase (LDH) significantly decreased at week 24, whereas neutrophil-to-lymphocyte ratio (NLR) and systemic inflammation response index (SIRI) significantly decreased at week 12 from baseline. Twenty-nine patients (27.9%) experienced mild treatment-emergent adverse events. Conclusions: Tralokinumab treatment showed prosperous therapeutic effects and good tolerability in real-world practice for AD, with higher effectiveness in patients without prior systemic therapy compared with those with prior systemic therapy. Tralokinumab treatment significantly decreased clinical and laboratory indexes, EASI, Peak Pruritus-Numerical Rating Scale, IgE, TARC, LDH, NLR, and SIRI.

Malate dehydrogenase: a story of diverse evolutionary radiation.

Malate dehydrogenase (MDH) is a ubiquitous enzyme involved in cellular respiration across all domains of life. MDH's ubiquity allows it to act as an excellent model for considering the history of life and how the rise of aerobic respiration and eukaryogenesis influenced this evolutionary process. Here, we present the diversity of the MDH family of enzymes across bacteria, archaea, and eukarya, the relationship between MDH and lactate dehydrogenase (LDH) in the formation of a protein superfamily, and the connections between MDH and endosymbiosis in the formation of mitochondria and chloroplasts. The development of novel and powerful DNA sequencing techniques has challenged some of the conventional wisdom underlying MDH evolution and suggests a history dominated by gene duplication, horizontal gene transfer, and cryptic endosymbiosis events and adaptation to a diverse range of environments across all domains of life over evolutionary time. The data also suggest a superfamily of proteins that do not share high levels of sequential similarity but yet retain strong conservation of core function via key amino acid residues and secondary structural components. As DNA sequencing and 'big data' analysis techniques continue to improve in the life sciences, it is likely that the story of MDH will continue to refine as more examples of superfamily diversity are recovered from nature and analyzed.

Recombinant lactate-assimilating cyanobacteria reduce high-concentration culture-associated cytotoxicity in mammalian cells.

In the fields of cultured meat, biopharmaceuticals, cell therapy, and tissue engineering, large numbers of mammalian cells are required; thus, highly-concentrated cell cultures are widely adopted. In general, such cultures can lead to cell damage caused by waste product accumulation and nutritional inadequacy. In this study, a novel co-culture system where the recombinant lactate-assimilating cyanobacterial strain, KC0110, derived from euryhaline Picosynechococcus sp. PCC 7002, and mammalian muscle cells cultured across porous membranes been developed. By using the KC0110 strain, the amount of ammonium and lactate excreted from C2C12 mouse muscle cells into the culture significantly decreased. Importantly, pyruvate and some amino acids, including pyruvate-derived amino acids, also increased significantly compared to those in monoculture of C2C12 cells. It is believed that the organic acids secreted by the KC0110 strain enhance the growth of mammalian cells, leading to a reduction in high-concentration culture-induced mammalian cell damage [lactate dehydrogenase (LDH) release] through cyanobacterial co-culture. These results show that, through co-cultivation with cyanobacteria, it is possible to culture mammalian cells, alleviating cell damage, even in highly-concentrated cultures. This study demonstrated an in vitro "symbiotic circular system" that can interchange metabolites produced by phototrophs and mammalian cells.

A random survival forest-based pathomics signature classifies immunotherapy prognosis and profiles TIME and genomics in ES-SCLC patients

BackgroundSmall cell lung cancer (SCLC) is a highly aggressive neuroendocrine tumor with high mortality, and only a limited subset of extensive-stage SCLC (ES-SCLC) patients demonstrate prolonged survival under chemoimmunotherapy, which warrants the exploration of reliable biomarkers. Herein, we built a machine learning-based model using pathomics features extracted from hematoxylin and eosin (H&E)-stained images to classify prognosis and explore its potential association with genomics and TIME.MethodsWe retrospectively recruited ES-SCLC patients receiving first-line chemoimmunotherapy at Nanjing Jinling Hospital between April 2020 and August 2023. Digital H&E-stained whole-slide images were acquired, and targeted next-generation sequencing, programmed death ligand-1 staining, and multiplex immunohistochemical staining for immune cells were performed on a subset of patients. A random survival forest (RSF) model encompassing clinical and pathomics features was established to predict overall survival. The function of putative genes was assessed via single-cell RNA sequencing.Results and conclusionDuring the median follow-up period of 12.12 months, 118 ES-SCLC patients receiving first-line immunotherapy were recruited. The RSF model utilizing three pathomics features and liver metastases, bone metastases, smoking status, and lactate dehydrogenase, could predict the survival of first-line chemoimmunotherapy in patients with ES-SCLC with favorable discrimination and calibration. Underlyingly, the higher RSF-Score potentially indicated more infiltration of CD8+ T cells in the stroma as well as a greater probability of MCL-1 amplification and EP300 mutation. At the single-cell level, MCL-1 was associated with TNFA-NFKB signaling and apoptosis-related processes. Hopefully, this noninvasive model could act as a biomarker for immunotherapy, potentially facilitating precision medicine in the management of ES-SCLC.

Complement-mediated hemolytic uremic syndrome associated with postpartum hemorrhage: case series and systematic review of individual participant data

BackgroundPostpartum hemorrhage is considered a risk factor for pregnancy-associated complement-mediated hemolytic uremic syndrome (CM-HUS; previously known as atypical hemolytic uremic syndrome) but has not been systematically studied. MethodsA systematic review of individual participant data from case series and reports in addition to a case series from our institution. Search terms were “thrombotic microangiopathy,” “atypical hemolytic uremic syndrome,” and “complement mediated” combined with “pregnancy,” “postpartum,” and/or postpartum hemorrhage. Cases of thrombotic microangiopathy other than CM-HUS were excluded. Outcomes were clinical and laboratory characteristics of postpartum hemorrhage-associated CM-HUS, treatment, and outcomes. ResultsThirty-three studies including 48 women with postpartum hemorrhage-associated CM-HUS and 3 patients from our institution were included in the study. Most women presented at term (28/45; 62%), delivered by cesarean section (21/41; 51%), and had pregnancy complications, mainly preeclampsia (16/51; 31%) or fetal demise (/51; 18%). Hematological and renal abnormalities usually appeared within the first 24 hours postdelivery. The median platelet count was 46 × 109/L (IQR, 45), and the median maximal lactate dehydrogenase was 2638 U/L (IQR, 1866). Renal function normalized in 20/23 (87%) women treated with C5 inhibitors with or without plasma exchange; in 7/11 (63%) women treated with plasma exchange alone, but only in 3/17 (18%) patients treated with supportive care. Patients treated with C5 inhibitors and/or plasma exchange achieved significantly better renal outcomes compared with supportive care alone (P < .001). ConclusionCM-HUS is a rare complication following postpartum hemorrhage and occurs mainly in women with preeclampsia and/or following cesarean section. Patients treated with C5 inhibitors and/or plasma exchange had a better renal prognosis compared with patients who received supportive treatment alone.

A-097 Body Fluid Validation for 11 Analytes on a Chemistry Analyzer

Abstract Background Most clinical chemistry assays are intended for use in serum, plasma, urine, and/or CSF with no performance characteristics on body fluids. However, testing of body fluids can be medically necessary for certain diagnoses. Such as determining the cause of fluid buildup in peritoneal spaces, pleural effusions, whether effusions are transudates or exudates, and even diagnosing some joint disorders. To provide these medically necessary tests, the burden is on the laboratory to perform regulatory-required validations. Herein is the validation of 11 clinical chemistry analytes in several common body fluids. Methods Mixing and stability studies were performed for the following analytes on the Roche cobas c702 (Roche Diagnostics), using the methods intended for use with serum/plasma samples: Albumin, Amylase, Bilirubin, Urea Nitrogen, Cholesterol, Creatinine, Glucose, Lactate Dehydrogenase, Lipase, Protein, and Triglycerides. Six individual fluid samples were mixed with the intended use matrix in 3 ratios: 1:3, 1:1, and 3:1. The following matrices were evaluated: pleural, peritoneal, JP drainage, synovial, and pancreatic cyst fluids. Stabilities were tested for 7 days at room temperature (RT) and 2-8°C. A maximum dilution study was also performed for Amylase. Results Mixing Study: The results are shown in the table below: Stability: For most body fluids, analytes were stable for 7 days at RT and 2-8 °C. The following analytes displayed shorter stability at RT: Bilirubin (peritoneal: 2 days, pleural: 1 day, JP drainage: 1 day), Urea Nitrogen (JP drain fluid: 2 days), Lipase (peritoneal fluid 5 days), and Triglycerides (peritoneal fluid: 5 days). Lactate dehydrogenase in pleural fluid showed a stability of 5 days at RT and 2 days at 2-8 °C. Maximum Dilution A 1:505 compounded manual and automated dilution displayed a &amp;lt;7% bias. Conclusions No sample matrix interferences were observed for any of the body fluids-analyte pairs tested allowing for this medically necessary testing.

B-029 Evaluation of the Analytical Performance of Creatine Kinase, Lactate dehydrogenase L-P, Myoglobin Assays on the Atellica CI Analyzer

Abstract Background The Atellica® CI Analyzer is an automated, mid-throughput, integrated chemistry and immunoassay analyzer utilizing both Atellica® CH and Atellica® IM assays. This study was designed to evaluate the analytical performance of the Atellica® CH Creatine Kinase (CK_L), Lactate dehydrogenase L-P (LDLP), and Atellica IM Myoglobin (MYO) Assays on the Atellica CI Analyzer. Methods The Atellica CI assays use the same reagents and calibrators as the Atellica CH and IM assays. Precision studies were performed according to CLSI EP05-A3 using human serum samples. One aliquot of each sample pool was tested in duplicate in two runs per day &amp;gt;2 hours apart on each analyzer for 20 days. MC studies were performed according to CLSI EP09-A3. Individual human serum samples were analyzed using the Atellica CH, Atellica IM, and Atellica CI Analyzers. LoB, LoD, LoQ were determined according to CLSI EP17-A2. Results Representative precision and MC results across indicated sample ranges are listed for each assay in the table. Over the three assays tested, %CVs for repeatability were &amp;lt;2.6% and %CVs for within-lab were &amp;lt;4.5%. Slopes determined using the Deming linear regression model were approximately equal to 1. LoB, LoD, LoQ were 5, 8, and 15 U/L for CK_L; 2, 4, and 11 U/L for LDLP; and 3,00, 6.00, and 6.00 ng/mL (µg/L) for MYO assays, respectively. Conclusions Atellica CH CK_L and LDLP, and Atellica IM MYO Assays on the Atellica CI Analyzer demonstrated good precision and equivalent performance to the same assays on Atellica IM and CH Analyzers.

B-136 From Result to Response: The Development of Laboratory-Based Scoring Models to Predict COVID-19 Patient Outcomes

Abstract Background Patient characteristics relating to increased risk for COVID-19 severity are well-documented, including older age and pre-existing health concerns; however, methods to accurately predict patients’ acute reaction to SARS-CoV-2 infections remain lacking. Identification of specific laboratory tests informative of patient outcomes could effectively screen incoming patients and better inform physicians regarding optimal treatment plans. The aim of this study was to examine associations between frequently ordered laboratory markers and COVID-19 patient mortality to develop an objective laboratory-based scoring system that estimates patients’ risk of mortality. Methods Study participants included inpatients from 3 hospitals recruited into the GENCOV project based in Ontario, Canada. Participants (n=325) were at least 18 years of age, provided consent, and were hospitalized within 1 month of having a PCR confirmed COVID-19 infection between January 2020 and February 2022. Extensive clinical data including patient demographics, laboratory results, and treatment outcomes were extracted from patient’s electronic medical records (EMR). Results for 32 biochemical and hematological tests including complete blood cell counts, coagulation (activated partial thromboplastin time, D-dimer, fibrinogen, prothrombin time), general chemistry (albumin, blood gases, creatine kinase, electrolytes, glucose, triglycerides), inflammatory (lactate dehydrogenase, ferritin, C-reactive protein), liver (alanine aminotransferase, aspartate aminotransferase, total bilirubin), renal (creatinine, urea) and cardiac (troponin, NT-proBNP, BNP) markers were collected from each chart. Univariable logistic regression with nested likelihood ratio tests were used to determine significant associations between laboratory results and patient outcomes. Significant markers were incorporated into multivariable models and variable risk values were assigned. Total calculated risk scores for each participant were compared using univariable and multivariable risk values. Validation of each scoring method was performed on a 20% subset of inpatients. Receiver operating characteristic (ROC) curves evaluated model performance. Results Six laboratory markers were associated with COVID-19 patient mortality when controlling for age and sex. Univariable regression showed that elevated creatinine, elevated lactate, elevated white blood cell, low base excess, low bicarbonate, or low pH results upon admission were significantly associated with increased odds of mortality, in comparison to test results within the reference range for these same markers. Multivariable regression revealed fewer markers (only low bicarbonate and low base excess) showing significant associations with COVID-19 mortality. Area under the ROC curves (AUC) determined that risk scores derived from univariable values performed similarly to multivariable values in validation (0.800 vs 0.802) and development cohorts (0.821 vs 0.829). Total risk scores calculated from the univariable vs multivariable models suggest higher sensitivity (90% vs 85%) than specificity (58% vs 67%) in the validation cohort, whereas the development cohort had higher sensitivity (88%) than specificity (66%) with univariable scores, and higher specificity (81%) than sensitivity (74%) with multivariable scores. Conclusions Laboratory results associated with COVID-19 mortality following both univariable and multivariable analyses suggest hospitalized patients infected with SARS-CoV-2 may present with acidosis. Total risk scores derived from univariable and multivariable values performed similarly in predicting mortality; however, differences in marker significance between models indicate discrepancies with risk interpretation. Further comparison of the created risk score assessments with equivalent models in other populations is warranted.

Chromofungin mitigates free fatty acids-induced endothelial inflammation via inhibition of NOD-like receptor thermal protein domain-associated protein 3 mediated by adenosine 5'-monophosphate-activated protein kinase.

Free fatty acids (FFAs) have emerged as significant risk factors for atherosclerosis (AS). Prolonged exposure to FFAs induces vascular endothelial injury, including inflammatory responses and oxidative stress, which are central events in AS. Chromofungin (CHR), a peptide derived from chromogranin A (CGA), has been implicated in various biological functions. However, its physiological roles in endothelial biology and its involvement in the pathological development of AS have not been previously reported. In the present study, we investigated the underlying mechanisms through which CHR exerts its beneficial effects on FFA-challenged human aortic endothelial cells (HAECs). We found that treatment with CHR ameliorated the FFA-induced reduction in cell viability and increase in lactate dehydrogenase (LDH) release. Additionally, CHR mitigated oxidative stress by reducing mitochondrial reactive oxygen species (ROS) levels and increasing superoxide dismutase (SOD) activity. Furthermore, exposure to FFAs increased NADPH oxidase (NOX) 4 expression at both the mRNA and protein levels, which were attenuated by CHR in a dose-dependent manner. Notably, CHR reduced the levels of nucleotide-binding domain and leucine-rich repeat-containing (NLR) family pyrin domain containing 3 (NLRP3), apoptosis-associated speck-like protein containing a CARD (ASC), and cleaved caspase-1 (p10), key components of the NLRP3 inflammasome complex, as well as interleukin 1β (IL-1β) and interleukin-18 (IL-18) expression. Mechanistically, it was demonstrated that FFAs reduced the phosphorylation of AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC), which were rescued by CHR in a dose-dependent manner. Conversely, inhibition of AMPK with its specific inhibitor compound C abolished the protective effects of CHR against FFA-induced activation of the NLRP3 inflammasome in HAECs. Based on these findings, we conclude that CHR may serve as a promising agent for maintaining normal endothelial cell function and treating AS.

Mesoporous Silica Administration as a New Strategy in the Management of Warfarin Toxicity; In Vitro and In Vivo Study

Purpose: Warfarin is one of the most widely used anticoagulants that function by inhibiting vitamin K epoxide reductase. Warfarin overdose, whether intentional or unintentional, can cause life-threatening bleeding. Here, we present a novel warfarin adsorbent based on mesoporous silica that can act as an antidote to warfarin toxicity. Method: Amino-functionalized mesoporous silica (MS-NH2) was synthesized based on co-condensation method through a soft template technique followed by template removal. The prepared structure and functional group were studied by FT-IR, XRD. The morphology was checked by SEM and TEM. The capacity of MS-NH2 in the adsorption of warfarin was evaluated in vitro, at pH=7.4 and pH=1.2. In vivo evaluation was performed in control and warfarin-overdosed animal models. Overdosed animals were treated with MS-NH2 by oral gavage. Biomarkers of organ injury were assessed in animal serum. Results: The MS-NH2 were relatively uniform, spherical with defined diameters (400 nm) and homogeneous structure. synthesized particles had a large surface area (1015 m2 g-1) and mean pore diameter 2.4 nm which leaded considerable adsorption capacity for warfarin 1666 mg/g. In vivo studies revealed that oral administration of MS-NH2 in mice poisoned with warfarin caused a significant difference (p &lt; 0.05) on International Normalized Ratio (INR) and prothrombin time (PT). Moreover, the warfarin with MS-NH2 group demonstrated a notable decrease in biomarkers associated with tissue damage, such as bilirubin, lactate dehydrogenase (LDH), alanine aminotransferase (ALT), and aspartate aminotransferase (AST). Conclusion: The results confirm that MS-NH2 administration can be an effective treatment for warfarin toxicity and could potentially mitigate the adverse effects of warfarin poisoning.

A-084 Performance evaluation of Sentinel Diagnostics’ Ammonia Ultra assay on Beckman Coulter AU/DxC AU Systems

Abstract Background The analytical performances of the Ammonia Ultra assay for in vitro quantitative enzymatic determination of Ammonia in human plasma have been evaluated on Beckman AU/DxC AU Systems. Ammonia, derived from the amino acids catabolism and from the action of intestinal bacteria on dietary proteins, is converted to non-toxic urea by the liver. An excess of ammonia can have toxic effects on the Central Nervous System with possible neurological disturbances. Elevated ammonia levels can also be observed in severe liver failure as may occur in Reye’s syndrome, viral hepatitis or cirrhosis. Methods Ammonia, in the presence of glutamate dehydrogenase (GLDH), combines with alpha-ketoglutarate and NADH to yield glutamate and NAD+. The decrease in 340 nm absorbance (NADH → NAD+) is proportional to the ammonia level in the examined plasma. The reagent contains excess of lactate dehydrogenase (LDH) to rapidly reduce endogenous pyruvate and avoid its interference with the assay system. Performances evaluation have been done following current CLSI guidelines protocols. Results 3 calibrator lots and 2 reagent lots have been used for testing. For each test and among different combinations of reagents and calibrators, worst case has been reported in the table. Conclusions Analytical performances of Ammonia Ultra assay on Beckman AU/DxC AU Systems meet the requirements for its use as quantitative determination of Ammonia in human plasma and make this assay very suitable for the routine measurement of this analyte.