Stored Plasma Research Articles

Small extracellular vesicles are released ex vivo from platelets into serum and from residual blood cells into stored plasma

AbstractSmall extracellular vesicles (sEV) purified from blood have great potential clinically as biomarkers for systemic disease; however interpretation is complicated by release of sEV ex vivo after blood taking. To quantify the problem and devise ways to minimise it, we characterised sEV in paired serum, plasma and platelet poor plasma (PPP) samples from healthy donors. Immunoblotting showed twofold greater abundance of CD9 in sEV fractions from fresh serum than from fresh plasma or PPP. MACSPlex confirmed this, and showed that proteins expressed on platelet sEV, either exclusively (CD41b, CD42a and CD62P) or more widely (HLA‐ABC, CD24, CD29 and CD31) were also twofold more abundant; by contrast non‐platelet proteins (including CD81) were no different. Storage of plasma (but not serum) increased abundance of platelet and selected leukocyte sEV proteins to at least that of serum, and this could be recapitulated by activating cells in fresh plasma by Ca2+, an effect abrogated in PPP. This suggests that a substantial proportion of sEV in serum and stored plasma were generated ex vivo, which is not the case for fresh plasma or PPP. Thus we provide strategies to minimise ex vivo sEV generation and criteria for identifying those that were present in vivo.

Brief Report: Impact of Methamphetamine Use and Rectal STIs on Systemic and Rectal Mucosal Inflammation.

Methamphetamine (MA) use is associated with sexual risk behavior as well as systemic and mucosal inflammation, suggesting parallel biological and behavioral mechanisms of HIV transmission among men who have sex with men (MSM) who use MA. Data evaluating the combined biological effects of MA use with concomitant rectal gonococcal and/or chlamydial (GC/CT) infection on inflammation are limited. Secondary analysis of stored rectal and plasma specimens from 100 MSM participating in an NIDA-funded longitudinal cohort in Los Angeles, CA. This cross-sectional analysis evaluated systemic and rectal inflammatory markers under 2 conditions: (1) recent MA use (by urine drug screen) and (2) rectal GC/CT infection. We evaluated 50 participants with recent MA use (25 with and 25 without rectal GC/CT) and 50 MSM without MA use (25 with and 25 without rectal GC/CT). Log-transformed plasma and rectal immune markers were regressed on MA exposure and rectal GC/CT, controlling for HIV status and age. Median age was 32 (range 19-45) years, and 58% of participants were living with HIV. Plasma tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-8, IL-1ß, and rectal IL-6 were associated with rectal GC/CT and MA use, independent of HIV status. Higher levels of rectal TNF-α, IL-1ß, and IL-17a were associated with rectal GC/CT. Systemic and rectal inflammation was positively associated with rectal GC/CT and MA use. Condomless sex in the setting of GC/CT- and MA-induced immune activation may provide a basis for synergistic biobehavioral mechanisms that promote HIV/STI transmission among MSM who use MA.

Blood biomarkers in mild cognitive impairment patients: Relationship between analytes and progression to Alzheimer disease dementia.

Blood-based biomarkers are promising tools for the diagnosis of Alzheimer disease (AD) at prodromal stages (mild cognitive impairment [MCI]) and are hoped to be implemented as screening tools for patients with cognitive complaints. In this work, we evaluated the potential of peripheral neurological biomarkers to predict progression to AD dementia and the relation between blood and cerebrospinal fluid (CSF) AD markers in MCI patients referred from a general neurological department. A group of 106 MCI patients followed at the Neurology Department of Coimbra University Hospital was included. Data regarding baseline neuropsychological evaluation, CSF levels of amyloid β 42 (Aβ42), Aβ40, total tau (t-Tau), and phosphorylated tau 181 (p-Tau181) were available for all the patients. Aβ42, Aβ40, t-Tau, p-Tau181, glial fibrillary acidic protein (GFAP), and neurofilament light chain (NfL) levels were determined in baseline stored serum and plasma samples by commercial SiMoA (Single Molecule Array) assays. Progression from MCI to AD dementia was assessed at follow-up (mean=5.8± 3.4 years). At baseline, blood markers NfL, GFAP, and p-Tau181 were significantly increased in patients who progressed to AD at follow-up (p< 0.001). In contrast, plasma Aβ42/40 ratio and t-Tau showed no significant differences between groups. NfL, GFAP, and p-Tau181 demonstrated good diagnostic accuracy to identify progression to AD dementia (area under the curve [AUC]=0.81, 0.80, and 0.76, respectively), which improved when combined (AUC=0.89). GFAP and p-Tau181 were correlated with CSF Aβ42. Association of p-Tau181 with NfL was mediated by GFAP, with a significant indirect association of 88% of the total effect. Our findings highlight the potential of combining blood-based GFAP, NfL, and p-Tau181 to be applied as a prognostic tool in MCI.

Resveratrol-Induced Suppression of C-type Natriuretic Peptide Associates With Increased Vertebral Bone Density in Postmenopausal Women.

C-type natriuretic peptide (CNP) is a paracrine growth factor essential in driving endochondral bone growth in mammals including humans. Despite evidence from animal experiments and tissues that CNP signaling stimulates osteoblast proliferation and osteoclast activity, whether CNP participates in bone remodeling in the mature skeleton is unknown. Using stored plasma samples from a previous randomized controlled clinical trial (RESHAW) of resveratrol supplementation in postmenopausal women exhibiting mild osteopenia, we have studied changes in plasma aminoterminal proCNP (NTproCNP) and concurrent change in bone turnover markers of formation (osteocalcin [OC] and alkaline phosphatase [ALP]) and resorption (C-terminal telopeptide type 1 collagen [CTX]) with bone mineral density (BMD) over a 2-year period of study in 125 subjects. In year one, subjects received placebo or resveratrol, switching to resveratrol or placebo, respectively, in year two. Across all time points, there were no significant associations of NTproCNP with CTX, ALP, or OC. During year one, plasma NTproCNP declined significantly in both groups. In the crossover comparison, analysis of change within individuals showed that, compared with placebo, NTproCNP declined after resveratrol (p=0.011) and ALP increased (p=0.008), whereas CTX and OC were unchanged. Inverse association of NTproCNP (r=-0.31; p=0.025) and positive association of OC (r=0.32, p=0.022) with BMD at the lumbar spine were identified after resveratrol but not found after placebo. Decline in NTproCNP was independently associated with resveratrol treatment. This is the first evidence that CNP is modulated during a period of increasing BMD in postmenopausal women. Further study of NTproCNP and associations with drivers of bone formation or resorption can be expected to clarify CNP's role during other interventions directed to bone health in adults. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Abstract 37: Proteomic Signatures of Obesity-Related Heart Failure in the Atherosclerosis Risk in Communities (ARIC) Study

Background: Obesity is a strong risk factor for cardiovascular disease. The excess heart failure (HF) risk associated with obesity is uniquely unexplained by traditional risk mediators. We sought to identify proteomic signatures that reflect mechanistic pathways associated with obesity-related HF. Methods: We quantified 4955 plasma proteins in stored plasma samples of ARIC Visit 2 (1990-1992) participants without HF using an aptamer-based platform (SOMAScan v4.0). We used Cox regression to identify the proteins associated with incident HF, stratified by obesity (BMI≥30 kg/m 2 ). We used Bonferroni-corrected p-values to assess statistical significance in 2/3 discovery and 1/3 validation subsets. We assessed the biological pathways overexpressed by these proteins using a canonical pathway analysis. Results: We included 9940 participants (28% with obesity, mean age 57 years, 55% female, 22% Black adults). Over a median 21-year follow-up, 2,345 HF events (886 in obesity) occurred. In the discovery subset with obesity, we identified 110 proteins associated with incident HF after demographic adjustment, 19 proteins (7 specific to obesity, Figure B) had robust HF associations after additional adjustment for lifestyle and cardiometabolic risk factors (p&lt;10 -5 ) (Figure A). Of 19 proteins, 12 were also linked to prevalent obesity status. Angiopoietin-2 was associated with higher risk of HF and higher odds of obesity. Conversely, ephrin type-A receptor 4 and seizure 6-like protein were linked to lower HF risk and lower odds of obesity. Lipid and bile acid metabolism (inhibited), cytokine signaling and wound healing pathways (activated) were overexpressed by HF-associated proteins in those with obesity. Conclusion: We identified established and novel proteins associated with HF risk in obesity. Many proteins linked to incident HF in obesity are also strongly associated with prevalent obesity. Formal mediation analysis can help elucidate the potential role of these proteins in the development of obesity-related HF.

Abstract 28: Proteomic Signatures of Adiposity in Middle-Aged Adults: The Atherosclerosis Risk in Communities (ARIC) Study

Background: Excess adiposity is linked to adverse cardiovascular outcomes via direct and indirect effects on metabolic pathways. There is limited large-scale data assessing proteomic signatures of adiposity. Methods: We quantified 4,955 plasma proteins using SomaLogic v4.0 in stored plasma samples of 9,940 ARIC Visit 2 participants (1990-92, mean age: 57±6 years, 55% women, 22% Black adults, 28% with obesity). We used linear regression and Bonferroni-corrected p-values to identify proteins associated with body mass index (BMI) in 2/3 discovery and 1/3 validation samples. We performed additional analyses to assess key pathways associated with obesity. Results: In the discovery sample (28% with obesity), after adjusting for age, sex, race-center, eGFR, 1,312 proteins were significantly associated with BMI. After further adjustments for clinical and lifestyle risk factors (Figure), 975 proteins were significantly associated with BMI (p&lt;10 -5 ). There were 713 proteins confirmed in the validation sample (p&lt;0.05/975). Among the confirmed proteins, there were &gt;500 proteins that did not have previously described BMI associations in population studies (including serine protease HTRA1, seizure 6-like protein) as well as proteins with known BMI associations (including leptin, fatty acid binding proteins, insulin-like growth factor-binding proteins). Acute phase response, atherosclerosis signaling, hepatic fibrosis, pancreatic cancer and lipid metabolism were among the top biological pathways overrepresented by the proteins associated with BMI (Figure). The upstream regulators of these proteins included interleukins (IL-17A, IL-13, IL-4), as well as tumor necrosis factor (TNF), which was activated. Conclusion: We discovered several novel proteins associated with adiposity and confirmed previously identified proteins. Alteration in the plasma proteome related to adiposity is linked to differential regulation of inflammatory and metabolic pathways independent of cardiovascular risk mediators.

INFLAMMATORY BIOMARKERS ASSOCIATED WITH COGNITIVE FUNCTION AND DEMENTIA

Abstract Neuroinflammation is an important contributor to the pathogenesis of dementia, but the role of circulating inflammatory markers is unclear. The aim of the study is to identify circulating inflammatory biomarkers associated with cognitive function in the Framingham Heart Study Offspring cohort. We used OLINK inflammation panel to measure 92 inflammation protein biomarkers using stored plasma samples at Offspring examination 7 (1998-2001) from 879 participants (52% female, mean 61 years range 40 to 88 years, 22% APOE e4 carrier). Cognitive function was assessed with seven tests derived from a neuropsychological (NP) testing battery representing four cognitive domains collected closest to the 7th examination. 68 proteins with at least 50% values above the limit of detection (LOD) were clustered with hierarchical clustering, and data below LOD were replaced with LOD/√2. We identified nine clusters of highly correlated proteins and created cluster composite scores on the first principal component of each. Adjusting for age, sex and education, five of the seven NP tests are nominally associated (p &amp;lt; 0.05) with at least one of the protein clusters, and five of the nine clusters are associated with at least one of the NP tests. The executive function test Trails B–Trails A is nominally associated with three clusters, and the Boston Naming Test 30 items version with two clusters, both sharing one common cluster which includes IFN-γ-inducible chemokines involved in inflammatory conditions. Future analyses will explore individual protein associations with cognitive test performance and incident dementia and will investigate the biological relevance of the identified clusters.

Pretransplantation Plasma ST2 Level as a Prognostic Biomarker of 1-Year Nonrelapse Mortality in Allogeneic Hematopoietic Cell Transplantation

Soluble ST2 is established as a prognostic biomarker of nonrelapse mortality (NRM) when measured early after allogeneic hematopoietic cell transplantation (HCT). However, less is known about the prognostic value of ST2 measured before transplantation. We hypothesized that pretransplantation plasma ST2 level was associated with 1-year NRM and could add to our current prognostic assessment. Moreover, we aimed to investigate the associations between pretransplantation plasma ST2 levels and patient characteristics and other plasma biomarkers and to reproduce previous associations between post-transplantation plasma ST2 levels and outcomes of HCT. We conducted this cohort study of 374 adults who underwent allogeneic HCT at our center between July 2015 and December 2019 (median age, 59 years; 55% with a nonmyeloablative conditioning regimen). ST2 levels were measured by enzyme-linked immunosorbent assay in stored plasma samples obtained at a median of 23 days before HCT and also in samples obtained on days +7 and +14 post-HCT. A logistic regression model of 1-year NRM was fitted using an a priori defined set of covariates consisting of age, Hematopoietic Cell Transplantation-Specific Comorbidity Index (HCT-CI), and conditioning intensity (myeloablative versus nonmyeloablative), to which the pretransplantation ST2 level was added as a variable to assess its incremental prognostic value. Models also were fitted of 1-year all-cause mortality, relapse, and grade II-IV acute graft-versus-host disease (GVHD) for pretransplantation and post-transplantation ST2 levels. The median pretransplantation plasma ST2 level was 20.4 ng/mL (interquartile range, 15.2 to 27.2 ng/mL). Pretransplantation ST2 levels were higher in males compared with females (median, 22.2 ng/mL versus 18.1 ng/mL; P < .001) and were correlated with HCT-CI (Spearman ρ=.18; P < .001), body mass index (ρ=.10; P=.05), and plasma levels of C-reactive protein (ρ=.34; P < .001), creatinine (ρ=.17; P=.001), and albumin (ρ=-.17; P < .001). Pretransplantation ST2 levels added prognostic information about 1-year NRM to age, HCT-CI, and conditioning intensity (adjusted odds ratio [OR] of 1-year NRM per 10 ng/mL increase in ST2, 1.32; 95% confidence interval [CI], 1.05 to 1.65; P=.02). Although adding pretransplantation ST2 levels did not notably improve model discrimination (.674 to .675, ΔAUC=.001), it increased the diversity of the predicted risks (P=.02, likelihood ratio test). Pretransplantation ST2 levels also were prognostic of 1-year all-cause mortality (adjusted OR per 10-ng/mL increase, 1.23; 95% CI, 1.02 to 1.48; P=.03), but not of relapse (P=.47) or acute GvHD (P=.81). Plasma ST2 levels at day +7 were prognostic of 1-year NRM, all-cause mortality, relapse, and acute GVHD, whereas levels at day +14 were prognostic of 1-year NRM and all-cause mortality. Our results show that pretransplantation plasma ST2 levels added prognostic information about 1-year NRM to age, HCT-CI, and conditioning intensity, and suggest that ST2 has potential as a biomarker of pretransplantation vulnerability and should be considered in future developments of prediction models of NRM after allogeneic HCT.

Longitudinal Associations of Plasma TMAO and Related Metabolites with Cognitive Impairment and Dementia in Older Adults: The Cardiovascular Health Study.

Animal studies suggest that gut microbiome metabolites such as trimethylamine N-oxide (TMAO) may influence cognitive function and dementia risk. However potential health effects of TMAO and related metabolites remain unclear. We examined prospective associations of TMAO, γ-butyrobetaine, crotonobetaine, carnitine, choline, and betaine with risk of cognitive impairment and dementia among older adults aged 65 years and older in the Cardiovascular Health Study (CHS). TMAO and metabolites were measured in stored plasma specimens collected at baseline. Incident cognitive impairment was assessed using the 100-point Modified Mini-Mental State Examination administered serially up to 7 times. Clinical dementia was identified using neuropsychological tests adjudicated by CHS Cognition Study investigators, and by ICD-9 codes from linked Medicare data. Associations of each metabolite with cognitive outcomes were assessed using Cox proportional hazards models. Over a median of 13 years of follow-up, 529 cases of cognitive impairment, and 522 of dementia were identified. After multivariable adjustment for relevant risk factors, no associations were seen with TMAO, carnitine, choline, or betaine. In contrast, higher crotonobetaine was associated with 20-32% higher risk of cognitive impairment and dementia per interquintile range (IQR), while γ-butyrobetaine was associated with ∼25% lower risk of the same cognitive outcomes per IQR.∥Conclusion:These findings suggest that γ-butyrobetaine, crotonobetaine, two gut microbe and host metabolites, are associated with risk of cognitive impairment and dementia. Our results indicate a need for mechanistic studies evaluating potential effects of these metabolites, and their interconversion on brain health, especially later in life.

Biological effects of stored platelet-rich plasma eye-drops in corneal wound healing

Background/aimsThis study aimed to assess the efficacy and sterility of stored platelet-rich plasma (PRP) eye-drops for corneal epithelial wound healing compared with those of autologous serum (AS) eye-drops.MethodsAt our single...

Effects of Sodium Fluoride – Potassium Oxalate on Blood Lipid Profile Results and Lipid Stability when using this Anticoagulant

Some previous studies have shown the effect of K2EDTA, heparin, citrate, kalioxalate on lipid test results [1,2,3], but no studies on sodium fluoride - potassium oxalate. Furthermore, it is also important to ensure sample stability during testing. We performed this study to evaluate the effect of NaF-KOx on lipid results and lipid stability when storing. A cross-sectional study was conducted on the residual of 150 pairs of serum and NaF-KOx plasma samples from the patients at the University Medical Center 2. These patients participated voluntarily after signing the consent form. We divided the samples into groups: serum (group 1), unpreserved plasma (group 2); stored plasma for 24 hours at 2-8°C (group 3), and stored plasma for 48 hours at 2-8°C (group 4). All samples were analyzed on an AU480 system – Beckman Coulter. The data would be processed using Stata 10.0. The results difference between these groups: 2,3,4 compared to group 1 was statistically significant (p &lt; 0.001). Total cholesterol, triglycerides, HDL-C, and LDL-C concentrations in group 2 decreased, respectively: 5.83%; 6.77%; 5.12%; 5.96%. We found the lipid test results of group 3 and group 4 also reduced compared to group 1: cholesterol decreased by 5.25%, 5.77%; triglycerides by 6.7%, 6.49%; HDL-C by 5.8, 7.22%; and LDL-C by 4.79%; 5.05%. After 48 hours, cholesterol, HDL-C, and LDL-C concentration continued to reduce, while the difference in triglycerides concentration was not statistically significant. NaF-KOx anticoagulant reduces lipid test results. We should not use NaF-KOx plasma to measure lipid tests.

Stability of coagulation factors in feline fresh frozen plasma intended for transfusion after 1 year of storage.

The most common use of plasma transfusion is for haemostatic purposes, but coagulation factor activities in stored feline plasma are unknown. The concentration and stability of coagulation factors I (fibrinogen), II, V, VII, VIII, IX, X, XI and XII in feline fresh frozen plasma (fFFP) stored for 1 year were studied. Fifty-five units of fFFP were produced from 55 fresh whole-blood donations obtained from indoor healthy blood donor cats. Twenty-one units were stored for <2 weeks (T0) and 34 were stored for 1 year (T1). After the completion of storage, specific coagulation factor activities for factors II, V, VII, VIII, IX, X, XI and XII were tested using modified one-stage activated partial thromboplastin or prothrombin time assays. Fibrinogen was determined using the Clauss method. Significantly decreased activities were observed for factors II (T0: 101.94% ± 19.06%; T1: 73.23% ± 39.06% [P = 0.001]), VII (T0: 102.78% ± 24.69%; T1: 60.08% ± 38.17% [P <0.001]), VIII (T0: 77.52% ± 30.39%; T1: 50.32% ± 23.8% [P = 0.001]), XI (T0: 88.76% ± 22.73%; T1: 66.28% ± 22.2% [P = 0.001]) and XII (T0: 89.50% ± 21.85%; T1: 55.46% ± 23.18% [P <0.001]) when comparing units at time 0 and after 1 year of storage. No significant difference was observed for factors IX (T0: 84.86% ± 29.35%; T1: 71.37% ± 22.23% [P = 0.064]) and X (T0: 96.24% ± 25.1%; T1: 83.91% ± 49.54% [P = 0.236]). Unexpectedly, a significant increase was observed for factor V (T0: 71.94% ± 24.14%; T1: 97.89% ± 62.33%; P = 0.046). Fibrinogen was 2.76 ± 1.09 g/l at T1. Factors VIII, XII and VII had the lowest mean activities after 1 year. Although a decrease in most coagulation factors activities was noted with storage, 1-year-old fFFP was haemostatically active in vitro. The most suitable factors for quality control assessment of fFFP are factors VII and VIII. Approximately 13-20 ml/kg of fFFP is required to administer a minimum of 10 IU/kg coagulation factor activity.

Thrombin generation as a predictor of outcomes in patients with non-traumatic intracerebral hemorrhage.

Non-traumatic intracerebral hemorrhage (ICH) accounts for 10-15% of all strokes and leads to a higher rate of mortality as compared to ischemic strokes. We aimed to find out whether the thrombin generation assay (TGA) could predict outcomes in patients with ICH. In this prospective, observational study, 87 consecutive patients with ICH and 164 healthy controls were included. Computed tomography (CT), detailed clinical investigation, and laboratory investigations were performed from patients on admission. TGA was performed using stored platelet poor plasma obtained on admission. Lag time, endogen thrombin potential (ETP), peak thrombin, and time to peak parameters were calculated. Short- and long-term outcomes of ICH were defined at 14 days and 3 months post-event according to the NIHSS and the modified Rankin Scale (mRS), respectively. Peak thrombin was significantly higher in patients as compared to controls (397.2 ± 93.9 vs. 306 ± 85.3 nM, p < 0.0001). Lag time, ETP, and time to peak parameters showed a significant positive correlation with CRP in both groups. In patients with worse long-term functional outcomes, peak thrombin was significantly higher as compared to those with favorable outcomes [mRS 2-6 median: 402.5 (IQR:344.8-473.8) vs. mRS 0-1: 326.4 (294.2-416.1) nM, p = 0.0096]. Based on the statistically optimal threshold of 339.1 nM peak thrombin, the sensitivity and specificity of this parameter to determine mRS 2-6 as an outcome were 80.8 and 64.7%, respectively. In a binary logistic regression model including age, sex, BMI, smoking status, NIHSS on admission, D-dimer, and peak thrombin (>339.1 nM), only NIHSS and the peak thrombin parameters remained in the model as significant, independent predictors of poor outcome. Lag time and time to peak showed a modest, significant negative correlation with intracerebral bleeding volume on admission (r = -0.2603, p = 0.0231 and r = -0.3698, p = 0.0010, respectively). During the follow-up of patients, estimated hemorrhage volumes on day 90 showed significant positive association with the ETP and peak thrombin parameters (r = 0.3838, p = 0.0363 and r = 0.5383, p = 0.0021, respectively). In patients with ICH, TG was increased as compared to healthy controls, which might be explained by the presence of higher inflammatory parameters in patients. Peak thrombin measured on admission might be a useful tool to predict outcomes in patients with ICH.

The renal-bone axis in older people living with HIV on stable antiretroviral therapy: A sub-analysis of the GS-US-104-0423 study.

Data on low bone mineral density (BMD) in people living with HIV (PLWH) are mainly derived from younger adults; little is known about how antiretroviral therapy (ART) and alterations in the renal-bone axis relate to BMD in older PLWH. Cross-sectional study of men > 50 years and post-menopausal women with HIV. Antiretroviral therapy exposure was stratified into four groups based on use of tenofovir disoproxil fumarate (TDF) and protease inhibitors (PI): non-TDF/non-PI, non-TDF/PI, TDF/non-PI, and TDF/PI. Bone mineral density was measured by dual X-ray absorptiometry (DXA). Bone turnover/regulatory markers and renal tubular function were analysed in stored plasma and urine samples. The association of ART exposure and bone/renal biomarkers on BMD was explored using logistic regression models. 247 individuals (median [IQR] age 57 [53, 65] years; 47% female; 13% of Black ethnicity; CD4 count 643 [473, 811] cells/mm3; and 98% with HIV RNA < 200 copies/mL) were included. Bone turnover and renal tubular function differed significantly by ART exposure. In analyses adjusted for demographic and traditional renal/bone risk factors, exposure to TDF and PI was associated with a fourfold greater risk of low BMD at the femoral neck and exposure to TDF and/or PI with a threefold greater risk of low BMD at the lumbar spine. The relationship between ART and low BMD was not altered by further adjustment for bone turnover or renal tubular function markers. The associations between low BMD and ART exposure (TDF vs. non-TDF and boosted vs. unboosted third agents) were minimally affected by adjustments for bone and kidney biomarkers.

Plasma E-selectin and kallistatin as predictive markers of histologic chorioamnionitis in women with preterm premature rupture of membranes.

We aimed to assess the predictive potential of 12 plasma biomarkers to predict acute histologic chorioamnionitis (HCA) in women with preterm premature rupture of membranes (PPROM) and to develop multi-biomarker panels based on these biomarkers in combination with widely used conventional laboratory markers. This was a retrospective cohort study involving 81 singleton pregnant women (24-34weeks of gestation) who delivered within 96 h of blood sampling. White blood cell (WBC) count, differential counts, and C-reactive protein (CRP) levels were measured at admission. The levels of DKK-3, Fas, haptoglobin, IGFBP-2, kallistatin, MIP-1α, MMP-2, MMP-8, pentraxin 3, progranulin, E-selectin, and P-selectin were evaluated by ELISA using stored plasma samples. The primary outcome measure was acute HCA. Multivariate analyses showed that low plasma E-selectin and kallistatin levels were independently associated with HCA occurrence after adjusting for gestational age. Using a stepwise regression analysis, a multi-biomarker panel comprising plasma E-selectin, serum CRP, and WBC was developed, which provided a good prediction of acute HCA in women with PPROM (area under the curve [AUC], 0.899), with a significantly higher AUC than that of any single variable included in the panel (P<0.05). The plasma levels of DKK-3, Fas, haptoglobin, IGFBP-2, MIP-1α, MMP-2, MMP-8, pentraxin 3, and P-selectin were not significantly associated with HCA occurrence. This study identified E-selectin and kallistatin as potential plasma biomarkers associated with acute HCA in women with PPROM. Their combined analysis with serum CRP and WBC counts significantly improved acute HCA diagnosis.

THU332 - Concordance of the Xpert hepatitis B viral load test and conventional quantitative PCR in detecting and quantifying viremia using stored plasma and dried blood spot samples in West Africa

THU332 - Concordance of the Xpert hepatitis B viral load test and conventional quantitative PCR in detecting and quantifying viremia using stored plasma and dried blood spot samples in West Africa

Pre-transplantation vitamin E levels and acute graft-versus-host disease after non-myeloablative allogeneic hematopoietic cell transplantation

BackgroundLow pre-transplantation plasma vitamin E levels have been associated with increased risk of acute graft-versus-host disease (GvHD) after myeloablative allogeneic hematopoietic cell transplantation (allo-HCT). We aimed to investigate the association between pre-transplantation plasma vitamin E levels and acute GvHD in patients undergoing allo-HCT with non-myeloablative conditioning. MethodsIn a cohort of 194 adults who underwent non-myeloablative allo-HCT at Rigshospitalet between July 2015 and December 2019, we measured pre-transplantation plasma vitamin E levels by high-performance liquid chromatography in stored plasma samples. Univariable ordinary least squares linear models were used to investigate associations between vitamin E levels and patient characteristics. A multivariable logistic regression model was used to estimate the association between vitamin E levels and grade II–IV acute GvHD, adjusted for recipient age, donor age, female-male donor-recipient pairing, and donor type. ResultsThe median (Q1, Q3) pre-transplantation plasma vitamin E level was 32.3 (26.4, 40.4) μmol/L. No patients had a vitamin E level below the normal reference range. Vitamin E levels were higher in females (mean difference: 8.0 μmol/L, 95% confidence interval [CI]: 4.9, 11.1 μmol/L) and in patients transplanted for acute leukemia (mean difference: 6.2 μmol/L, CI: 3.0, 9.4 μmol/L). Grade II–IV acute GvHD developed in 33 (17%) patients. Patients who developed acute GvHD had similar pre-transplantation vitamin E levels compared with patients who did not develop grade II–IV acute GvHD (mean difference: 0.7 μmol/L, bootstrap CI: −3.3, 4.7 μmol/L). In the adjusted logistic regression model, an increase in the pre-transplantation vitamin E level from 26.4 (Q1) to 40.4 (Q3) μmol/L was associated with an odds ratio of grade II–IV acute GvHD of 1.17 (CI: 0.64, 2.12). ConclusionsContrary to the previously reported association between pre-transplantation vitamin E levels and acute GvHD after myeloablative allo-HCT, we did not find support for an association in patients who received non-myeloablative conditioning. The potential protective effects of vitamin E may not be efficacious in the reduced inflammatory response following non-myeloablative conditioning.

Sustained Effect on Hepatitis C Elimination Among Men Who Have Sex With Men in the Swiss HIV Cohort Study: A Systematic Re-Screening for Hepatitis C RNA Two Years Following a Nation-Wide Elimination Program.

The Swiss HCVree Trial (NCT02785666) was conducted in 2015-2017 with the goal of implementing a population-based systematic hepatitis C virus (HCV) micro-elimination program among men who have sex with men (MSM) with human immunodeficiency virus (HIV) enrolled in the Swiss HIV Cohort Study (SHCS). The trial led to a 91% and 77% decline of HCV prevalence and incidence, respectively. The long-term effect of this HCV micro-elimination program is yet to be explored. All MSM enrolled in the SHCS were screened for HCV RNA using stored plasma samples obtained in 2019, termed "Swiss HCVree Post" screen. The incidence of HCV infection over time was assessed using additional information on HCV testing routinely collected in the SHCS. Characteristics of participants with replicating HCV infection were analyzed. The point-prevalence of "Swiss HCVree Post" (N = 4641) was 0.6%, reflecting a decline of 48% compared to the end of the Swiss HCVree Trial where the prevalence was 1.2%. Further, the incidence of HCV among MSM in the SHCS declined from 0.31/100 person-years (py) (95% confidence interval [CI] [.17, .55]) in 2017 to 0.19/100 py (95% CI [.09, .39]) in 2019. A systematic HCV RNA-based screening among MSM with HIV conducted 2 years after the Swiss HCVree Trial revealed a sustained effect and further decline of the prevalence and incidence of replicating HCV infection. This indicates that the Swiss HCVree Trial was successful in curbing the HCV epidemic among MSM with HIV in Switzerland. NCT02785666.

Adiposity, metabolomic biomarkers, and risk of nonalcoholic fatty liver disease: a case-cohort study

ABSTRACTBackgroundGlobally, the burden of obesity and associated nonalcoholic fatty liver disease (NAFLD) are rising, but little is known about the role that circulating metabolomic biomarkers play in mediating their association.ObjectivesWe aimed to examine the observational and genetic associations of adiposity with metabolomic biomarkers and the observational associations of metabolomic biomarkers with incident NAFLD.MethodsA case-subcohort study within the prospective China Kadoorie Biobank included 176 NAFLD cases and 180 subcohort individuals and measured 1208 metabolites in stored baseline plasma using a Metabolon assay. In the subcohort the observational and genetic associations of BMI with biomarkers were assessed using linear regression, with adjustment for multiple testing. Cox regression was used to estimate adjusted HRs for NAFLD associated with biomarkers.ResultsIn observational analyses, BMI (kg/m2; mean: 23.9 in the subcohort) was associated with 199 metabolites at a 5% false discovery rate. The effects of genetically elevated BMI with specific metabolites were directionally consistent with the observational associations. Overall, 35 metabolites were associated with NAFLD risk, of which 15 were also associated with BMI, including glutamate (HR per 1-SD higher metabolite: 1.95; 95% CI: 1.48, 2.56), cysteine-glutathione disulfide (0.44; 0.31, 0.62), diaclyglycerol (C32:1) (1.71; 1.24, 2.35), behenoyl dihydrosphingomyelin (C40:0) (1.92; 1.42, 2.59), butyrylcarnitine (C4) (1.91; 1.38, 2.35), 2-hydroxybehenate (1.81; 1.34, 2.45), and 4-cholesten-3-one (1.79; 1.27, 2.54). The discriminatory performance of known risk factors was increased when 28 metabolites were also considered simultaneously in the model (weighted C-statistic: 0.84 to 0.90; P < 0.001).ConclusionsAmong relatively lean Chinese adults, a range of metabolomic biomarkers are associated with NAFLD risk and these biomarkers may lie on the pathway between adiposity and NAFLD.

Circulating proteins and risk of pancreatic cancer: a case-subcohort study among Chinese adults.

BackgroundPancreatic cancer has a very poor prognosis. Biomarkers that may help predict or diagnose pancreatic cancer may lead to earlier diagnosis and improved survival.MethodsThe prospective China Kadoorie Biobank (CKB) recruited 512 891 adults aged 30–79 years during 2004–08, recording 702 incident cases of pancreatic cancer during 9 years of follow-up. We conducted a case-subcohort study measuring 92 proteins in 610 cases and a subcohort of 623 individuals, using the OLINK immuno-oncology panel in stored baseline plasma samples. Cox regression with the Prentice pseudo-partial likelihood was used to estimate adjusted hazard ratios (HRs) for risk of pancreatic cancer by protein levels.ResultsAmong 1233 individuals (including 610 cases), several chemokines, interleukins, growth factors and membrane proteins were associated with risk of pancreatic cancer, with adjusted HRs per 1 standard deviation (SD) of 0.86 to 1.86, including monocyte chemotactic protein 3 (MCP3/CCL7) {1.29 [95% CI (confidence interval) (1.10, 1.51)]}, angiopoietin-2 (ANGPT2) [1.27 (1.10, 1.48)], interleukin-18 (IL18) [1.24 (1.07, 1.43)] and interleukin-6 (IL6) [1.21 (1.06, 1.38)]. Associations between some proteins [e.g. matrix metalloproteinase-7 (MMP7), hepatocyte growth factor (HGF) and tumour necrosis factor receptor superfamily member 9 [TNFRSF9)] and risk of pancreatic cancer were time-varying, with higher levels associated with higher short-term risk. Within the first year, the discriminatory ability of a model with known risk factors (age, age squared, sex, region, smoking, alcohol, education, diabetes and family history of cancer) was increased when several proteins were incorporated (weighted C-statistic changed from 0.85 to 0.99; P for difference = 4.5 × 10–5), although only a small increase in discrimination (0.77 to 0.79, P = 0.04) was achieved for long-term risk.ConclusionsSeveral plasma proteins were associated with subsequent diagnosis of pancreatic cancer. The potential clinical utility of these biomarkers warrants further investigation.