Editor: Deborah Sesok-Pizzini, MD, MBA, professor, Department of Clinical Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, and chief, Division of Transfusion Medicine, Children’s Hospital of Philadelphia.
Evaluation of ethanol interference on routine biochemical tests
March 2019—Ethanol, a central nervous system depressant widely consumed in many societies, is metabolized in the liver through multiple enzymatic pathways. If the liver’s capacity is exceeded, the excess alcohol will flood into the systemic circulation. Consequently, alcohol has the potential to interfere with laboratory tests and lead to uncertainty about the measurement results. The medical literature contains limited information about alcohol as a test interferent. The author conducted a study of the potential of alcohol to interfere with routine biochemical tests. He used serum pools from blood samples collected from patients seeking treatment at the emergency department. The author added ethanol, or ethyl alcohol, to the samples, and the final concentrations were negative, 50 mg/dL, 100 mg/dL, 200 mg/dL, and 400 mg/dL. The samples were divided into 20 equal portions, and routine biochemical tests were performed on each portion. The coefficient of variation, bias, and total error values were calculated for the measured parameters. The author found that alanine aminotransferase and lactate dehydrogenase activities decreased in proportion to ethanol level, causing false low results. High negative biases suggested dose-dependent negative interference. The total error values calculated for direct bilirubin and urea were higher than the allowable total error reported in the CLIA regulations. For direct bilirubin, it was observed that the cause of this shift was due to the increase in coefficient of variation values. The author concluded that ethanol may interfere with some biochemical tests, and the most prominent effect was observed for lactate dehydrogenase and alanine aminotransferase. Because clinical laboratory tests help drive clinical decision-making, awareness of potential interference is important. The author noted that the study findings would be valid for the selected samples and methods used in the analysis. Similar studies using other test methods and different automated instruments would be necessary to collect additional interference data.
Gumus A. Evaluation of ethanol interference on routine biochemical tests. Am J Clin Pathol. 2018;150:507–511.
Correspondence: Dr. Alper Gumus at dralpergumus@gmail.com
Development of a commercial reference lab elective for residents in clinical pathology
Nearly all hospitals send tests to commercial reference laboratories, whether to reference labs that perform highly specialized testing or regional or national reference labs that offer comprehensive testing services, including routine tests. In contrast, hospital-based laboratories have a more modest testing menu, offering high-volume automated testing, tests that require a quick turnaround time, and esoteric tests that are more cost-effective to perform in-house based on volume. Resident training in clinical pathology includes rotations in several areas and instruction in laboratory administration and management and other skill sets. Because most clinical pathology residents have limited exposure to commercial reference labs, Quest Diagnostics, working with Massachusetts General Hospital and Brigham and Women’s Hospital, developed a four-day commercial reference lab elective to address the significant impact of commercial reference labs on the field of laboratory medicine. The elective included 32 sessions composed of interactive didactic sessions and laboratory demonstrations and tours. Among the goals of the elective were to educate residents about the role of commercial reference labs in clinical pathology, demonstrate the operations of a high-volume highly automated laboratory, educate residents about the business features of a large reference lab, and provide residents with exposure to topics not ordinarily emphasized in their residency rotations. Ten residents who participated in the elective were asked to formally evaluate it using structured forms. The residents provided positive written comments that demonstrated that the goals of the elective were achieved. The most favorable feedback pertained to the laboratory tours and one-on-one sessions with the medical directors. The authors concluded that the residents’ training experience in the commercial laboratory was highly regarded and that the elective exposed residents to an area of laboratory medicine not encountered in most pathology training programs. The authors noted that their curriculum could serve as a model for other training programs.
Lewandrowski K, Keegan A, Makarenko V, et al. Development of a commercial reference laboratory elective rotation for residents in clinical pathology. Am J Clin Pathol. 2018;150:485–490.
Correspondence: Dr. Kent Lewandrowski at klewandrowski@partners.org