فصلنامه آزمایشگاه و تشخیص
پیاپی 54 (زمستان 1400)

D-dimer is a soluble fibrin degradation product deriving from the plasmin-mediated degradation of cross-linked fibrin. D-dimer can hence be considered a biomarker of activation of coagulation and fibrinolysis, and it is routinely used for ruling out venous thromboembolism (VTE). D-dimer is increasingly used to assess the risk of VTE recurrence and to help define the uoptimal duration of anticoagulation treatment in patients with VTE, for diagnosing disseminated intravascular coagulation, and for screening medical patients at increased risk of VTE. This review is aimed at (1) revising the definition of D-dimer; (2) discussing preanalytical variables affecting the measure- ment of D-dimer; (3) reviewing and comparing assay performance and some postanalytical varia- bles (e.g. different units and age-adjusted cutoffs); and (4) discussing the use of D-dimer measurement across different clinical settings.

Fusarium spp., have been recognized during the past decade to cause disseminated infection, particularly in granulocytopenic patients undergoing intensive antileukemic chemotherapy or bone marrow transplantation. The lung, sinuses, and skin are the primary portals of entry. The periungual regions of the toes notably may be a particularly important site of initial invasion. Invasive Fusarium infections produce a pattern similar to that of invasive aspergillosis. Fusarium infections in granulocytopenic patients are characterized by pulmonary infiltrates, cutaneous lesions, and sinusitis. This emerging fungal pathogen often responds only to high doses of Amphotericin B. Pseudallescheria boydii causes sinusitis, pneumonia, and dessiminated infections in immunocompromised hosts and mycetoma in immunocompetent patients. Pneumonia due to P. boydii is clinically indistinguishable from that due to Aspergillus spp. Infections due to P. boydii are frequently refractory to antifungal chemotherapy, including amphotericin B.

The concept quality cost for all clinical laboratories perform routine and specialized tests of any size and scope has many applications. Familiarity of managers and employees of clinical laboratories with quality cost concept prevent wasted resources and offers laboratory services with high quality to physicians, patients, and other internal and external customers with reasonable cost. Therefore, this research was aimed to explain the concept of quality cost, quality cost terminology, and it’s dimensions, types and applications in clinical laboratory.

This research was a literature review study condocted using searched articles in several databases and key words such as quality cost, clinical laboratory, internal and external failures without observing the time limit in terms of the years of publication of articles. A total of 122 articles were searched using inclusion and exclusion criterias and finally 36 articles selected for thos study.

Quality cost includes conformance cost and non-conforming event cost use for levels of quality inspectation, prevention of failures. Therefore, it is necessary, new process of work flow, employees’ training, competency testing of employees and manufacturers, customer orientation, and internal and external audits should be observed associated with quality cost. Although, measurement of hidden and clear quality costs to determine the total cost and budgeting in order to improvement of accreditation could be applied.

Conlusion:

Traditional thinking in the past led to select of quality improvement or costs spent alone by the managers of clinical laboratories. But, in new century, according to new approach, high quality could lead to increased of productivity, decreased of failures, and finally decreased of total quality costs in clinical laboratories.

Thyroid cancer is a malignancy of the thyroid parenchymal cells. There are four main types of thyroid cancer: papillary thyroid cancer (PTC), follicular thyroid cancer (FTC), anaplastic thyroid carcinoma (ATC), and Medullary thyroid carcinoma (MTC).
Medullary thyroid cancer (MTC) is a rare neuroendocrine tumor of the thyroid gland derived from parafollicular C-cells that produce calcitonin (CT) and accounts for 5-8% of all thyroid cancers. It is responsible for a disproportionate number of thyroid cancer deaths because of the lack of adjuvant treatment beyond surgery.
MTC may occur sporadically or be inherited. Hereditary pattern includes multiple endocrine neoplasia syndrome types 2A and 2B. The majority of MTC cases are sporadic, but a hereditary pattern is present in 20-30% of cases. RET mutations occur in over 90% of hereditary and 40% of sporadic MTC. Total thyroidectomy remains the standard treatment for MTC patients. Early diagnosis and treatment are necessary for a 100% cure rate.

Acute Respiratory Syndrome Coronavirus 2, which appeared in late 2019, can have negative effects on the cardiovascular system. Studies in different parts of the world indicate the importance of cardiac troponin as a predictor in coronary heart disease patients. Heart damage occurs frequently in Coronavirus 2 infection and is associated with a high risk of mortality in these patients. In people with Covid-19, various biomarkers are screened to assess the patient's condition and assess the severity of the disease. Measurement of serum troponin levels is of great importance. Increased troponin levels in the blood of these patients could indicate heart damage and indicate a high mortality rate in future patients.

The novel Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has caused respiratory infection, resulting in more than two million deaths globally and hospitalizing thousands of people until 2021. A considerable percentage of the SARS-CoV-2 positive patients are asymptomatic or pre-symptomatic carriers, facilitating the viral spread in the community by their social activities. Hence, it is critical to have access to commercialized diagnostic tests to detect the infection in the earliest stages, monitor the disease, and follow up the patients. Recently, CRISPR-based diagnostics have emerged as attractive alternatives to quantitative real-time PCR due to their faster turnaround time and their potential to be used in point-of-care testing scenarios. Clustered short palindrome repeats with regular intervals, abbreviated as CRISPR, and functions as a self-defense system for prokaryotes, detecting particular pathogenic nucleic acid, interfering with the functions of exoteric DNA, and protecting them against foreign invaders. Finally, we discuss challenges and future prospects of CRISPR-Cas system based diagnostic platforms in biomedicine, hoping to further inspire the development of biomedical diagnostics.