Clinical Chemistry Podcast RSS

This is the April 2014 issue of Clinical Chemistry, Volume 60, Issue 4.

Type 1 diabetes is a chronic progressive autoimmune disorder with complex, polygenic susceptibility. Environmental factors which are poorly defined also contribute to the pathogenesis. This disease is characterized by lymphocyte infiltration into the islets of Langerhans in the pancreas, leading to inflammation and selective destruction of the insulin-producing beta cells resulting in hyperglycemia.

The latest incarnation of polymerase chain reaction, Digital PCR, takes three decades of development in enzyme chemistry and assay design and applies them with formidable precision and sensitivity.

Hemoglobin A1C is one of the analytes most commonly measured in clinical laboratories in patients with diabetes mellitus. Physicians use Hemoglobin A1C to monitor long-term glycemic control, adjust therapy, and predict complications of diabetes. It was recently added as a criterion for diagnosis of diabetes.

Although standardization of barcodes and label formats has lowered the number of mislabeled specimens in clinical laboratories, it remains a potential source of pre-analytical error. Published error rates of mislabeled specimens range up to as high as just over 1 percent.

On the cover this month: Activated platelets. These irregularly shaped blood components are vital for the normal clotting process. However, platelets also play a role in blood clot formation on arterial stents or on ruptured atherosclerotic plaques, leading to blockage of blood flow and tissue ischemia. For some patients, antiplatelet agents must be used to prevent arterial thrombosis. During therapy, platelet function tests are used to monitor response. Newer approaches to monitoring coagulation, such as viscoelastic coagulation testing, are being introduced. Controversy exists surrounding the tests for monitoring response to antiplatelet therapy or for guiding transfusion decisions in critically ill patients. This issue of Clinical Chemistry contains a Q&A in which 4 experts discuss how they define aspirin and clopidogrel response, what platelet function tests are used at their institutions, the role of the laboratory in guiding antiplatelet therapy, and what tests they believe have the greatest potential to predict the risk of bleeding during invasive procedures.

Gestational diabetes mellitus is often defined as any degree of glucose intolerance during pregnancy. Fetal complications and adverse outcomes for both the fetus and the mother are important concerns in gestational diabetes.

Acute kidney injury is an important health problem. Patients who develop acute kidney injury have increased in-hospital mortality, and if they do survive, they still suffer long-term increased morbidity and mortality. For that reason there has been great interest in the development of biomarkers that could identify kidney injury in its earliest stages, at a time when interventions might be more successful.

In March of 2013, the ACMG, The American College of Medical Genetics and Genomics, issued a clinical laboratory guideline for the reporting of incidental findings observed through exome and genome sequencing, including the ethical implications of reporting these incidental findings.

The discovery phase of proteomics is essential for the identification of suitable markers for exploration and validation of promising new clinical tests. But can researchers be certain if what they believe they are measuring is in fact what they are actually measuring?

This is the February 2014 issue of Clinical Chemistry, Volume 60, Issue 2.

Until recently, much of the research in medical literature used primarily male populations. Slowly we've come to appreciate the importance of studying female populations due to the differences in normal physiology as well as disease pathology between men and women.

Women who present with acute coronary events are less frequently to be properly diagnosed and often have worse outcomes than men. Part of the problem may be that women are less apt to manifest increased biomarkers or often receive less aggressive guideline-mandated care. Women also have lower reference values for biomarkers of cardiac injury that are rarely taken into account.

The development of in vitro fertilization in the 1970s has revolutionized the treatment of infertility. The ability to culture embryos has allowed for the development of the preimplantation genetic diagnosis. This involves removing a cell from the developing embryos for genetic testing before choosing one to implant. Just like prenatal diagnosis, it is used to screen for various genetic diseases before birth. For women of advanced maternal age or couples with known genetic mutations, the ability to screen of embryos free of certain genetic mutations is reassuring.

The January 2014 issue of Clinical Chemistry is devoted to the area of women's health. It includes a multi-center report on the application of measuring the circulating products of the proteolytic enzyme carboxypeptidase-N for the early detection of breast cancer. Accompanying that paper was an editorial by Eleftherios Diamandis on the tumor microenvironment and if released peptides could form the basis for early diagnosis breast cancer tests.