Testing lupus anticoagulants in a real-life scenario - a retrospective cohort study

Introduction: Lupus anticoagulant (LAC) testing is challenging. Most data are derived from a well-controlled study environment with potential alterations to daily routines. The aim of this retrospective cohort study was to assess the capacity of various LAC screening tests and derived mixing tests to predict a positive result in subsequent confirmation tests in a large cohort of patients. Materials and methods: In 5832 individuals, we retrospectively evaluated the accuracy of the aPTT-A, aPTT-LAscreen, aPTT-FS and dRVVTscreen and of their derived mixing tests in detecting a positive confirmation test result within the same blood specimen. The group differences, degree of correlation and the predictive accuracy of LAC coagulation tests were analysed using the Mann-Whitney U test, the Spearman-rank-correlation and by area under the receiver operating characteristic curve (ROC-AUC) analysis. ROC-AUCs were compared with the Venkatraman´s permutation test. Results: The pre-test probability of patients with clinically suspected LAC was 36% in patients without factor deficiency or anticoagulation therapy. The aPTT-LAscreen showed the best diagnostic accuracy with a ROC-AUC of 0.84 (95% CI: 0.82 – 0.86). No clear advantage of the dRVVT-derived mixing test was detectable when compared to the dRVVTscreen (P = 0.829). Usage of the index of circulating anticoagulant (ICA) did not improve the diagnostic power of respective mixing tests. Conclusions: Among the parameters evaluated, aPTT-LAscreen and derived mixing test parameters were the most accurate tests. In our study cohort, neither other mixing test nor the ICA presented any further advantage in LAC diagnostics

The diagnostic and prognostic value of IgG and IgA anti-citrullinated protein antibodies in patients with early rheumatoid arthritis

ObjectivesAnti-citrullinated peptide antibodies (ACPA) are specific markers for rheumatoid arthritis (RA) and typically measured by assays employing a cyclic citrullinated peptide (CCP) as antigen. This study was aimed at investigating the diagnostic performance of anti-CCP2 and anti-CCP3 IgG and IgA assays in patients with early RA with a particular focus on the potential prognostic value of IgA ACPA.MethodsThe anti-CCP3.1 assay (Inova Diagnostics) measuring IgG and IgA antibodies simultaneously was compared to anti-CCP2 IgG and IgA assays (Thermo Fisher Scientific) employing sera of 184 early RA patients, 360 disease controls and 98 healthy subjects.ResultsAnti-CCP2 IgG and IgA assays showed high specificity versus disease controls (98.9%; 99.4%). Sensitivity was 52.2% (IgG) and 28.8% (IgA), resulting in positive likelihood ratios (LR+) of 47.5 (IgG) and 48.0 (IgA). The anti-CCP3.1 assay proved slightly more sensitive than the anti-CCP2 IgG assay (56%) but specificity was markedly lower (90.8% versus disease controls). However, when using a threefold higher cut-off specificity of the anti-CCP3.1 assay increased (97.5%) while sensitivity (52.7%) became comparable to the anti-CCP2 IgG assay resulting in a LR+ of 21.5. Anti-CCP2 IgA antibodies did not increase the diagnostic sensitivity of ACPA testing, but IgA positive patients showed diminished responses to treatment with anti-TNF biologicals compared to patients who had only IgG antibodies.ConclusionSpecificity of ACPA assays should be adjusted to reduce the risk of misclassification and a false positive diagnosis. Determination of ACPA IgA might provide important prognostic information concerning therapeutic responses

Thrombomodulin in patients with mild to moderate bleeding tendency.

INTRODUCTION: A massive increase of soluble thrombomodulin (sTM) due to variants in the thrombomodulin gene (THBD) has recently been identified as a novel bleeding disorder. AIM: To investigate sTM levels and underlying genetic variants as a cause for haemostatic impairment and bleeding in a large number of patients with a mild to moderate bleeding disorder (MBD), including patients with bleeding of unknown cause (BUC). PATIENTS AND METHODS: In 507 MBD patients, sTM levels, thrombin generation and plasma clot formation were measured and compared to 90 age- and sex-matched healthy controls. In patients, genetic analysis of the THBD gene was performed. RESULTS: No difference in sTM levels between patients and controls was found overall (median ([IQR] 5.0 [3.8-6.3] vs. 5.1 [3.7-6.4] ng/ml, p = .762), and according to specific diagnoses of MBD or BUC, and high sTM levels (≥95th percentile of healthy controls) were not overrepresented in patients. Soluble TM levels had no impact on bleeding severity or global tests of haemostasis, including thrombin generation or plasma clot formation. In the THBD gene, no known pathogenic or novel disease-causing variants affecting sTM plasma levels were identified in our patient cohort. CONCLUSION: TM-associated coagulopathy appears to be rare, as it was not identified in our large cohort of patients with MBD. Soluble TM did not arise as a risk factor for bleeding or altered haemostasis in these patients

Increasing test specificity without impairing sensitivity: lessons learned from SARS-CoV-2 serology

Background: Serological tests are widely used in various medical disciplines for diagnostic and monitoring purposes. Unfortunately, the sensitivity and specificity of test systems are often poor, leaving room for false-positive and false-negative results. However, conventional methods were used to increase specificity and decrease sensitivity and vice versa. Using SARS-CoV-2 serology as an example, we propose here a novel testing strategy: the € sensitivity improved two-test' or € SIT²' algorithm. Methods: SIT² involves confirmatory retesting of samples with results falling in a predefined retesting zone of an initial screening test, with adjusted cut-offs to increase sensitivity. We verified and compared the performance of SIT² to single tests and orthogonal testing (OTA) in an Austrian cohort (1117 negative, 64 post-COVID-positive samples) and validated the algorithm in an independent British cohort (976 negatives and 536 positives). Results: The specificity of SIT² was superior to single tests and non-inferior to OTA. The sensitivity was maintained or even improved using SIT² when compared with single tests or OTA. SIT² allowed correct identification of infected individuals even when a live virus neutralisation assay could not detect antibodies. Compared with single testing or OTA, SIT² significantly reduced total test errors to 0.46% (0.24-0.65) or 1.60% (0.94-2.38) at both 5% or 20% seroprevalence. Conclusion: For SARS-CoV-2 serology, SIT² proved to be the best diagnostic choice at both 5% and 20% seroprevalence in all tested scenarios. It is an easy to apply algorithm and can potentially be helpful for the serology of other infectious diseases

The effect of endurance sports on the validity of blood-born predictors for depression and diabetes in the elderly

Chronische Erkrankungen und deren Komplikationen könnten zu einem beträchtlichen Teil verhindert werden, würden RisikopatientInnen frühzeitig identifiziert werden. Dies käme allen voran älteren Menschen zu Gute, die überdurchschnittlich an nicht-übertragbaren chronischen Erkrankungen wie z.B. Diabetes mellitus oder Depression leiden. Biomarker aus dem peripheren Blut erleichtern die Früherkennung, solange diese verlässliche Ergebnisse liefern. Diese Verlässlichkeit kann jedoch durch viele Störgrößen, welche zumeist in der prä- oder der postanalytischen Phase auftreten, beeinflusst werden. Zu diesen Störgrößen zählen nicht nur technisch bedingte, sondern auch PatientInnen-bezogene Faktoren wie z. B. das Ausmaß sportlicher Betätigung. Die vorliegende Dissertation hat zum Ziel, die vorhandene Evidenz bezüglich des Einflusses der „Störgröße Sport“ um genetische Risikomarker für Depression (rs6265 im brain-derived neurotropic factor, BDNF; rs6295 innerhalb des 5-HT1A Rezeptors) sowie um Vitamin D3 als Diabetesmarker zu erweitern. Falls durch Sport verursachte Veränderungen der Blutzusammensetzung in einer gerichteten, dosisabhängigen Form auftreten, müsste die Möglichkeit bestehen, Trainingsmotivation und -effizienz mittels Blutuntersuchungen vorherzusagen, wofür ein statistisches Modell errechnet werden soll. Zur Beantwortung dieser Fragen wurden 55 über 60-jährige MarathonathletInnen sowie 58 Kontrollpersonen (gleich in Alter, Geschlecht und Ausbildungsdauer) inkludiert. Die eingehende medizinische und psychologische Untersuchung zu Studieneinschluss und nach drei Jahren, beinhaltete eine Ergometrie sowie diverse Blutuntersuchungen. Genetische Varianten in BDNF und 5HT1A sind mittels der 5-Nuklease-Technik bestimmt worden. Das Ausmaß einer etwaigen depressiven Symptomatik wurde mit dem Beck-Depressions-Inventar (BDI) sowie der Geriatric Depression Scale (GDS) abgeschätzt. Ein binär-logistisches Regressionsmodel zur Vorhersage der sportlichen Leistungsentwicklung wurde in zwei unabhängigen TeilnehmerInnengruppen ermittelt. Wie erwartet unterschied sich die Vorhersagekraft beider genetischer Marker zwischen AthletInnen und Kontrollpersonen. Dabei schien Sport die Korrelation zwischen dem [C];[C]-Genotyp in rs6265 und einer depressiven Symptomatik abzuschwächen, was in einem relativen Risiko von 3,5 (95% Konfidenzintervall, CI: 1,3 9,8) für [C];[C]-TrägerInnen aus der Kontrollgruppe resultierte, einen auffälligen BDI-Score zu erzielen. Dementgegen nützte rs6295 im 5HT1A Rezeptor nur bei AthletInnen zur Vorhersage einer mitunter subklinischen Depression, wohingegen sich ein derartiger Effekt für die Kontrollgruppe nicht zeigen ließ. In Bezug auf die Vorhersage eines zukünftigen (prä-)Diabetes mellitus zeigte sich bei den Kontrollen in der Tat eine signifikante Korrelation zwischen Vitamin D3-Konzentrationen bei Studieneinschluss und einem HbA1c über 5,6% bei der Follow-up-Untersuchung. Dieser Zusammenhang war bei den AthletInnen nicht nachweisbar, wobei deren Vitamin D3-Spiegel von der wöchentlichen Trainingszeit abzuhängen schien. Für die Vorhersage zukünftiger Ergometrieergebnisse aus Baseline-Blutwerten wurde ein Modell mit hoher Vorhersagekraft (receiver-operator characteristics area under the curve, ROC AUC = 0.9510.050 bzw. ROC AUC = 0.7860.098) errechnet. Die vorliegende Dissertation konnte darlegen, dass die Vorhersagekraft von genetischen Risikomarkern für Depression (in BDNF und 5HT1A) sowie von Vitamin D3-Spiegeln als Risikomarker für Diabetes mellitus durch patientInnenbezogene Störgrößen wie z. B. das Ausmaß an sportlicher Betätigung beeinflusst werden. Darüber hinaus konnte gezeigt werden, dass sportliche Betätigung einzelne Blutwerte in einer gerichteten Art und Weise zu verändern scheint, was die Abschätzung von Trainingsmotivation und -effizienz aus der Blutzusammensetzung ermöglicht.A considerable proportion of chronic diseases and long-term complications might be preventable if patients under risk are adequately identified. This is especially true for the elderly, who exhibit considerable prevalences of non-communicable diseases, e.g. diabetes mellitus and depression. Biomarkers from the peripheral blood could be helpful, as long as their predictions are reliable. However, a plethora of disturbance factors influence the reliability of a biomarker, and most of them occur not during blood analysis, but in the pre- or the post-analytical phase. The pre-analytical phase is particularly vulnerable to potential influence. As the existing literature reveals, those disturbance variables include not only technical, but also patient-related factors, e.g. the patients level of physical activity. The present thesis aims to extend the existing evidence to include genetic risk markers for depression (rs6265 within the Brain-derived neurotropic factor, BDNF; rs6295 within the 5-HT1A receptor) and circulating vitamin D3 as a predictive marker for diabetes mellitus. Moreover, if exercise-induced changes in blood composition occurred in a directed and dose-dependent manner, they might be exploitable in order to evaluate training efficacy and motivation. Hence the aim was to calculate a statistical model enabling prediction of future declines in fitness. To this end, 55 elderly marathon athletes above the age of 60 and a sedentary control group (N = 58), matched for age, sex and years of education, were enrolled and examined at baseline and after three years follow-up. Participants underwent a thorough medical and psychological check-up, including ergometry and blood examinations. Genetic variants within BDNF and 5-HT1A were determined by means of the 5-nuclease assay. Depressiveness was assessed using the Beck Depression Inventory (BDI) and the Geriatric Depression Scale (GDS). A binary logistic regression model allowing for future fitness prediction was compiled in two independent participant samples. The predictive capability of both genetic risk markers was different in athletes when compared to sedentary controls. In detail, physical activity seemed to ameliorate the correlation between the rs6265 [C];[C] genotype and depressiveness, resulting in a relative risk of 3.5 (95% confidence interval, CI: 1.3 9.8) for [C]; [C] carriers of the control group regarding the presence of a suspicious BDI score. In contrast, within rs6295 in the 5HT1A receptor, the [G];[G] genotype predicted depressiveness only in athletes, but not in controls. Regarding the prediction of future (pre-)diabetic states, a significant correlation between baseline vitamin D3 levels and a HbA1c level 5.6% was registered among controls. However, this relationship was not seen in athletes, where vitamin D3 correlated with weekly training amounts. In order to predict follow-up ergometry results from baseline blood markers, a binary logistic regression model with excellent statistical significance ( = 21.412, df = 5, p = 0.001) could be calculated. The model presented with high discriminatory power in both the model training sample (receiver-operator characteristics area under the curve, ROC AUC = 0.9510.050) and the test sample (ROC AUC = 0.7860.098). The present thesis revealed that the predictive capabilities of the genetic risk markers for depression in BDNF and 5HT1A, as well as the diabetes-associated risk marker vitamin D3, were influenced by individual life-style factors, i.e. engaging in endurance sports. These findings are largely novel and reinforce the need to consider patient-related pre-analytical confounders when interpreting disease markers. Moreover, it was demonstrated that physical activity seemed to influence blood components in a directed manner, thus making it possible to estimate training motivation and efficacy from easily assessable blood parameters.submitted by Helmuth HaslacherAbweichender Titel laut Übersetzung der Verfasserin/des VerfassersMedizinische Universität Wien, Diss., 2018(VLID)274995

Type 2 diabetes care: Improvement by standardization at a diabetes rehabilitation clinic. An observational report.

BACKGROUND:Outcome of type 2 diabetes care depends on the acceptance of self-responsibility by informed patients, as treatment goals will otherwise be missed. AIMS AND METHODS:This pre/post-observational report describes the clinical outcome of type 2 diabetes care in patients with type 2 diabetes (N =930) admitted consecutively to a diabetes rehabilitation clinic (DRC) between June 2013, and June 2016, where they were exposed to standardized lifestyle modification with meals low in salt and rich in vegetables and fruits, totaling 1,200 to 1,600 kcal/d, and an add-on exercise load equivalent to 400-600 kcal/d. RESULTS:At admission, patients presented with multiple treatment modes, elevated HbA1c levels (7.6±1.5%, 60±16 mmol/mol), a high prevalence of co-morbidities dominated by obesity (79%), a low rate of influenza and pneumococcal immunization (<9%) and underuse of lipid-lowering drugs (-29%). Analysis of clinical and metabolic outcome after 3 weeks shows that simple standardization of and better adherence to treatment recommendations improved (p<0.0001) glucose (HbA1c -0.4±0.4%) and lipid metabolism (LDL/HDL ratio, -0.58±0.03), permitting a 39% reduction in insulin dosage, omission of insulin in 36/232 patients and omission of oral antidiabetic drugs (OADs) other than metformin and DPP4-inhibitors, while the use of GLP-1 analogs doubled to 5.2%. Improved outcome was independent of treatment strategy and more marked at initially high HbA1c at costs less than 25% of those encountered at a standard hospital. CONCLUSIONS:Our observations support the clinical notion that adherence to basic treatment recommendations is indispensable in type 2 diabetes care if metabolic and clinical treatment goals are to be met, and if inappropriate add-on over-medicalization with OADs and/or insulin is to be avoided. To this end, 'imprinting' patients at a DRC could be of considerable help

Bases moleculares del reconocimiento de antígenos

Aunque todos los organismos pertenecientes al reino animal poseen una serie de mecanismos inmunitarios que persiguen mantener su integridad y rechazar la invasión de material foráneo, solo los vertebrados cuentan con un sofisticado sistema de reconocimiento específico, capaz de discriminar entre las distintas formas que puede presentar dicho material, en especial los microorganismos. El tipo celular que permitió el surgimiento de un sistema inmune específico es el linfocito, presente en todos los vertebrados, desde los peces más primitivos hasta los mamíferos superiores. Su característica principal es la capacidad de reconocimiento selectivo de los antígenos, a través de proteínas de superficie celular especializadas para tal fin.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto Clodomiro Picado (ICP

Impact of fetal maceration grade on risk of maternal disseminated intravascular coagulation after intrauterine fetal death : A retrospective cohort study

Disseminated intravascular coagulation (DIC) is a life-threatening event that is the endpoint of a pathologically activated cascade leading to excessive consumption of platelets culminating in bleeding. Several diseases are known to be associated with DIC, some of which may also occur during pregnancy or the puerperium. One of the potential risk factors that have been considered as a potential trigger for DIC is the retention of a highly macerated fetus after intrauterine fetal death (IUFD). However, sparse evidence exists on its clinical implication on hemostasis parameters. In this retrospective single-center study, we investigated the role of fetal maceration grades 0-III on the risk of DIC in 91 women following IUFD between gestational weeks (+days) 22+0 and 41+6 between 2003 and 2017. We calculated the Erez DIC-score after consideration of maternal platelet count (PC), prothrombin time (PT) and fibrinogen (Fib) and correlated the findings with fetal maceration grade. Mean (SD) age of women was 32.16.7 years. Neither maternal hemostasis parameters (PC, PT, Fib), nor the Erez score showed a statistically significant difference between maceration grades 0-III with median values of 1 for all four grades (maceration grade I: range 0 to 27; I: 0 to 51; II: 0 to 52; III: 0 to 39). We therefore conclude, that the pathophysiology of DIC in women after singleton IUFD is unrelated to the degree of fetal maceration.(VLID)471848

Evaluation of the Septifast MGrade Test on Standard Care Wards--A Cohort Study.

BACKGROUND:The immediate need for appropriate antimicrobial therapy in septic patients requires the detection of the causative pathogen in a timely and reliable manner. In this study, the real-time PCR Septifast MGrade test was evaluated in adult patients meeting the systemic inflammatory response syndrome (SIRS) criteria that were treated at standard care wards. METHODS:Patients with clinical suspected infection, drawn blood cultures (BC), the Septifast M(Grade) test (SF) and sepsis biomarkers were prospectively screened for fulfillment of SIRS criteria and evaluated using the criteria of the European Centre of Disease Control (ECDC) for infection point prevalence studies. RESULTS:In total, 220 patients with SIRS were prospectively enrolled, including 56 patients with detection of bacteria in the blood (incidence: 25.5%). BC analysis resulted in 75.0% sensitivity (95% confidence interval, CI: 61.6%- 85.6%) with 97.6% specificity (CI: 93.9%- 99.3%) for detecting bacteria in the blood. In comparison to BC, SF presented with 80.4% sensitivity (CI: 67.6%- 89.8%) and with 97.6% specificity (CI: 93.9%- 99.3%). BC and SF analysis yielded comparable ROC-AUCs (0.86, 0.89), which did not differ significantly (p = 0.558). A trend of a shorter time-to-positivity of BC analysis was not seen in bacteremic patients with a positive SF test than those with a negative test result. Sepsis biomarkers, including PCT, IL-6 or CRP, did not help to explain discordant test results for BC and SF. CONCLUSION:Since negative results do not exclude bacteremia, the Septifast M(Grade) test is not suited to replacing BC, but it is a valuable tool with which to complement BC for faster detection of pathogens