Predictive Value of Combination of D-dimer and Fibrinogen in Diagnosing Acute CVST

Background: Cerebral venous sinus thrombosis (CVST) is an uncommon subtype of stroke, and the role of D-dimer and fibrinogen in early diagnosis of CVST has been studied with varying results. The present study aims to study the role of the combination of D-dimer and fibrinogen in early diagnosis of acute CVST. Methods: Forty consecutive confirmed acute CVST cases admitted at a tertiary care center were recruited for the study. D-dimer and fibrinogen were assessed by a rapid semiquantitative latex agglutination assay. Results: Out of the 40 CVST patients, 21 (52.50%) were females. The mean age of the patients was 37.58 years ± 19.17 years. Common clinical features were headache ( N = 38 [95%]), papilloedema ( N = 15 [37.5%]), and seizures ( N = 12 [30%]). Although the sensitivity (75%) of the combination of D-dimer and fibrinogen assay was lower than that of D-dimer or fibrinogen alone, the specificity and positive predictive value (75% each) was higher. Conclusions: The combination of D-dimer and fibrinogen testing may aid in an early diagnosis of acute CVST and in better management.

Development of a Bacteriophage Tail Fiber-Based Latex Agglutination Assay for Rapid Clinical Screening of Burkholderia pseudomallei

Melioidosis is a life-threatening disease in humans caused by the Gram- negative bacterium Burkholderia pseudomallei. As severe septicemic melioidosis can lead to death within 24 to 48 hours, a rapid diagnosis of melioidosis is critical for ensuring an optimal antibiotic course is prescribed to patients. Here, we report the development and evaluation of a bacteriophage tail fiber-based latex agglutination assay for rapid detection of B. pseudomallei infection. Burkholderia phage E094 was isolated from rice paddy fields in northeast Thailand, and whole genome sequenced to identify its tail fiber (94TF). The 94TF complex was structurally characterized, which involved identification of a tail assembly protein that forms an essential component of the mature fiber. Recombinant 94TF was conjugated to latex beads and developed into an agglutination-based assay (94TF-LAA). 94TF-LAA was initially tested against a large library of Burkholderia and other bacterial strains before a field evaluation was performed during routine clinical testing. The sensitivity and specificity of the 94TF-LAA were assessed alongside standard biochemical analyses on 300 patient specimens collected from an endemic area of melioidosis over 11 months. The 94TF-LAA took less than 5 minutes to produce positive agglutination, demonstrating 98% (95% CI; 94.2%−99.59%) sensitivity and 83% (95% CI; 75.64%−88.35%) specificity when compared to biochemical-based detection. Overall, we show how a Burkholderia-specific phage tail fiber can be exploited for rapid detection of B. pseudomallei. The 94TF-LAA has the potential for further development as a supplementary diagnostic to assist in clinical identification of this life-threatening pathogen. IMPORTANCE Rapid diagnosis of melioidosis is essential for ensuring optimal antibiotic courses are prescribed to patients, and thus warrants the development of cost-effective and easy-to-use tests for implementation in under-resourced areas such as Northeast Thailand and other tropical regions. Phage tail fibers are an interesting alternative to antibodies for use in various diagnostic assays for different pathogenic bacteria. As exposed appendages of phages, tail fibers are physically robust, easy to manufacture, and critically many tail fibers (such as 94TF investigated here) can target a given bacterial species with remarkable specificity. Here, we demonstrate the effectiveness of a latex agglutination assay using a Burkholderia-specific tail fiber 94TF against biochemical-based detection methods that are the standard diagnostic in many endemic areas of meilodosis.

Evaluation of Plasma D-Dimer Concentration Among Normal and Complicated Pregnancies, Saudi Arabia

Objectives: The purpose of the current work is to evaluate D-dimer plasma level among both normal and complicated pregnancies such as gestational diabetes (GD) and hypertension (GH) among Saudi females. It is also focused on exhibiting any possible factors that could also play a role in rising D-dimer levels besides the age of the pregnant woman and the period of gestation. Materials and Methods: A semi-quantitative latex agglutination assay was performed in the blood sample of healthy non-pregnant, pregnant and pregnant females with GD and GH. Results: The results exhibited that 92% of pregnancies with GH and 90% of multiple pregnancies had high D-dimer levels. The analysis of the effect of age of pregnant women on D-dimer concentrations presented that 100% of pregnant women with GD, GH or multiple pregnancies aged above 40, had high levels of D-dimer. The results of the relationship between gestational age of pregnancies and D-dimer showed that by reaching the third trimester, about 66.6% of women who had multiple pregnancies had D-dimer concentration above 2000 ng/mL. Interestingly, all the pregnant females with GH had D-dimer concentrations above 2000 ng/mL. Conclusions: This study postulated that the concentrations of D-dimer significantly increase during pregnancy associated with common complications such as GD and GH. It is the first study to demonstrate the possible risk factors during pregnancy, which include age, number of pregnancies, gestational age and pregnancies with GD and GH, especially among Saudi Arabian women.