Differences in the Composition of Activated Partial Thromboplastin Time (APTT) Reagents Affect Clot Waveform Analysis

Background Clot waveform analysis (CWA) based on activated partial thromboplastin time (APTT) is a useful assay for hemostasis. However, the effects of activators and phospholipid conditions on CWA have not been adequately investigated. Therefore, we characterized CWA using four different APTT reagents. Methods: We used 39 archived plasma samples from patients with hemophilia A (HA), 16 samples from patients with HA under emicizumab treatment, and 10 samples from healthy individuals for CWA with four different types of APTT reagents (reagents A, B, C, and D). We then compared Ad|min1|, Ad|min2|, and Ad|max2| from the CWA, which reflect the maximum velocity, maximum acceleration, and maximum deceleration, respectively, among the four reagents. Results: Similar clot waveform shapes were observed for each reagent in the healthy donor group, HA group, and HA under emicizumab group, and the waveform was different for each target group. Significant changes were found in clotting time (CT) (s), Ad|min1| (%/s), Ad|min2| (%/s2), and Ad|max2| (%/s2). The waveform pattern for the coagulation reaction by reagent D, comprising silica and synthetic phospholipids, was the fastest among the reagents examined. Further, the difference in Ad|min1| (%/s) and Ad|min2| (%/s2) was larger than that in CT depending on the reagent used(s), indicating that the measured value of CWA was affected by the reagent composition. Conclusion: Our results showed a significant difference among reagents with varying composition and concentration; this was found to affect the parameters obtained from CWA. Thus, the differences between reagents hinder standardization of quantitative evaluation using these parameters; further, this highlights the necessity of understanding the characteristics of APTT reagents and determining the reference range in individual facilities

A Randomized Placebo-controlled Trial of an Oral Preparation of High Molecular Weight Fucoidan in Patients with Type 2 Diabetes with Evaluation of Taste Sensitivity

[Background] Fucoidan is derived from seaweed widely used in Japanese cuisine, but little is known about its influence on glucose metabolism. To obtain information about the physiological effects of fucoidan on glucose metabolism, the digestive system, and the gustatory system controlling taste sensation in patients with type 2 diabetes, we conducted a randomized, double-blind, placebo-controlled study. [Methods] Thirty patients with type 2 diabetes on diet therapy were recruited from an outpatient clinic (22 men and 8 women aged 59.10 ± 13.24 years, body mass index: 25.18 ± 3.88, hemoglobin A1c: 7.04 ± 1.24%). They were divided into 2 groups and underwent 2 interventions with a 4-week interval. One group received fucoidan for 12 weeks (a daily 60 mL test beverage containing 1,620 mg of fucoidan) and then placebo (60 mL) for the subsequent 12-week period, while the order was reversed in the other group. Evaluation was performed just before and after each intervention. Taste sensitivity was measured for 5 basic tastes by the filter paper disk method and food intake was evaluated with a validated diet questionnaire. [Results] No adverse events occurred during the study period. Despite no change of the diet, stool frequency increased during fucoidan intake (from 7.78 ± 4.64/week in Week 1 to 9.15 ± 5.03/week in Week 5, P < 0.001), and it increased more in lean subjects. In 11 subjects whose stool frequency exceeded the mean value, the thresholds for sweet, salty, bitter and umami tastes were significantly reduced (enhancement of sensitivity) after fucoidan intake. In 14 subjects with normal HOMA-IR (homeostatic model assessment of insulin resistance, < 2.5), hemoglobin A1c decreased after fucoidan intake (from 6.73 ± 1.00 to 6.59 ± 1.00%, P < 0.05), as did the fasting plasma level of GLP-1 (glucagon-like peptide-1, from 6.42 ± 3.52 to 4.93 ± 1.88 pmol/L, P < 0.05). [Conclusion] Sustained fucoidan intake led to alterations of gastrointestinal function, including increased stool frequency and enhanced taste sensitivity, which could contribute to better control of diabetes

Evaluation of antigen-positive toxin-negative enzyme immunoassay results for the diagnosis of toxigenic Clostridium difficile infection

Clostridium difficile (C. difficile)-associated diarrhea (CDAD) is a challenging nosocomial infectious disease. C. DIFF Quik Chek Complete assay is widely used to detect glutamate dehydrogenase (GDH) antigen and toxin A/B of C. difficile simultaneously. However, the interpretation of GDH positive/toxin negative results is problematic.We performed a retrospective study of patients with GDH positive/toxin negative results to determine the probability of detecting toxigenic C. difficile and its risk factors. Between April 2012 and March 2017, we investigated cultures of fecal specimens followed by toxin detection tests. The clinical histories of patients with and without toxigenic C. difficile were compared using univariate- and multivariate-analyses. In total, 2675 patients were examined using C. Diff Quik Chek Complete assay. Among 356 GDH positive/toxin negative patients, cultures were performed in 220 cases and toxigenic C. difficile was recovered from 139 (63.2%) specimens. Patients with toxigenic C. difficile had significantly lower body mass index than those without. Over half the GDH positive/toxin negative patients were infected with toxigenic C. difficile. Lower BMI was a CDAD risk factor in this patient population. These data can be utilized to initiate isolation and clinical interventions before confirmatory test results are available

Association Between Serum Soluble Low-Density Lipoprotein Receptor Levels and Metabolic Factors in Healthy Japanese Individuals

Background: Soluble low-density lipoprotein receptor (sLDL-R) is formed by cleavage of the extracellular domain of lowdensity lipoprotein receptor (LDL-R). It is unclear whether serum sLDL-R is a marker of diseases associated with triglyceride (TG) metabolism. We investigated the association between serum sLDL-R concentrations and other biochemical parameters in healthy Japanese individuals. Methods: Study subjects consisted of 102 healthy adult Japanese volunteers (42 men, 60 women) with body mass index (BMI) &lt; 30 kg/m 2 and serum TGs, LDL cholesterol (LDL-C), aspartate aminotransferase, alanine aminotransferase, γ-glutamyl transpeptidase, and glucose concentrations within normal ranges. Serum sLDL-R concentrations were determined by enzyme-linked immunosorbent assay and their correlations with biochemical parameters were analyzed. Results: Mean serum sLDL-R concentration was 120.9 ± 39.9 ng/ml. Serum sLDL-R levels were significantly and positively correlated with BMI (rs = 0.252) and TG (rs = 0.408) and LDL-C (rs = 0.325) concentrations. Multiple regression analysis adjusted for age, gender, and smoking showed that BMI (β = 0.274), TG (β = 0.328), and LDL-C (β = 0.224) were factors independently correlated with sLDL-R levels. Conclusion: Serum sLDL-R concentration may be a marker of diseases associated with TG metabolism. This is the first report to date describing the clinical relevance of sLDL-R

Evaluation of antigen‐positive toxin‐negative enzyme immunoassay results for the diagnosis of toxigenic Clostridium difficile infection

Clostridium difficile (C. difficile)-associated diarrhea (CDAD) is a challenging nosocomial infectious disease. C. DIFF Quik Chek Complete assay is widely used to detect glutamate dehydrogenase (GDH) antigen and toxin A/B of C. difficile simultaneously. However, the interpretation of GDH positive/toxin negative results is problematic.We performed a retrospective study of patients with GDH positive/toxin negative results to determine the probability of detecting toxigenic C. difficile and its risk factors. Between April 2012 and March 2017, we investigated cultures of fecal specimens followed by toxin detection tests. The clinical histories of patients with and without toxigenic C. difficile were compared using univariate- and multivariate-analyses. In total, 2675 patients were examined using C. Diff Quik Chek Complete assay. Among 356 GDH positive/toxin negative patients, cultures were performed in 220 cases and toxigenic C. difficile was recovered from 139 (63.2%) specimens. Patients with toxigenic C. difficile had significantly lower body mass index than those without. Over half the GDH positive/toxin negative patients were infected with toxigenic C. difficile. Lower BMI was a CDAD risk factor in this patient population. These data can be utilized to initiate isolation and clinical interventions before confirmatory test results are available