Hormone Immunoassay Interference: A 2021 Update
Khaldoun Ghazal 
, Pharm., Ph.D., Severine Brabant , M.D., Dominique Prie , M.D., Ph.D., and Marie-Liesse Piketty , Pharm., Ph.D.
Most Read
-
Review Article2022-01-01 Clinical Chemistry
Abstract : Immunoassays are powerful qualitative and quantitative analytical techniques. Since the first description of an immunoassay method in 1959, advances have been made in assay designs and analytical characteristics, opening the door for their widespread implementation in clinical laboratories. Clinical endocrinology is closely linked to laboratory medicine because hormone quantification is important for the diagnosis, treatment, and prognosis of endocrine disorders. Several interferences in immunoassays have been identified through the years; although some are no longer encountered in daily practice, cross-reaction, heterophile antibodies, biotin, and anti-analyte antibodies still cause problems. Newer interferences are also emerging with the development of new therapies. The interfering substance may be exogenous (e.g., a drug or substance absorbed by the patient) or endogenous (e.g., antibodies produced by the patient), and the bias caused by interference can be positive or negative. The consequences of interference can be deleterious when clinicians consider erroneous results to establish a diagnosis, leading to unnecessary explorations or inappropriate treatments. Clinical laboratories and manufacturers continue to investigate methods for the detection, elimination, and prevention of interferences. However, no system is completely devoid of such incidents. In this review, we focus on the analytical interferences encountered in daily practice and possible solutions for their detection or elimination.
-
Review Article2022-03-01 Clinical Chemistry
Review of the Use of Liquid Chromatography-Tandem Mass Spectrometry in Clinical Laboratories: Part I-Development
Brian A. Rappold
Ann Lab Med 2022; 42(2): 121-140 , B.S.Abstract : The process of method development for a diagnostic assay based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) involves several disparate technologies and specialties. Additionally, method development details are typically not disclosed in journal publications. Method developers may need to search widely for pertinent information on their assay(s). This review summarizes the current practices and procedures in method development. Additionally, it probes aspects of method development that are generally not discussed, such as how exactly to calibrate an assay or where to place quality controls, using examples from the literature. This review intends to provide a comprehensive resource and induce critical thinking around the experiments for and execution of developing a clinically meaningful LC-MS/MS assay.
-
Original Article2022-03-01 Clinical Chemistry
Biomarker Rule-in or Rule-out in Patients With Acute Diseases for Validation of Acute Kidney Injury in the Emergency Department (BRAVA): A Multicenter Study Evaluating Urinary TIMP-2/IGFBP7
Hyun Suk Yang
Ann Lab Med 2022; 42(2): 178-187, M.D., Ph.D., Mina Hur , M.D., Ph.D., Kyeong Ryong Lee , M.D., Ph.D., Hanah Kim , M.D., Ph.D., Hahn Young Kim , M.D., Ph.D., Jong Won Kim , M.D., Ph.D., Mui Teng Chua , M.D., Win Sen Kuan , M.D., Horng Ruey Chua , M.D., Chagriya Kitiyakara , M.D., Phatthranit Phattharapornjaroen , M.D., Anchalee Chittamma , Ph.D., Thiyapha Werayachankul , M.Sc., Urmila Anandh , M.D., Sanjeeva Herath , M.B., Ch.B., Zoltan Endre , M.D., Ph.D., Andrea Rita Horvath , M.D., Ph.D., Paola Antonini , M.D., and Salvatore Di Somma , M.D., Ph.D. on behalf of the GREAT NetworkAbstract : Background: Urine tissue inhibitor of metalloproteinases-2/insulin-like growth factor-binding protein 7 (TIMP-2/IGFBP7) (NephroCheck, Ortho Clinical Diagnostics, Raritan, NJ, USA) is a US Food and Drug Administration-approved biomarker for risk assessment of acute kidney injury (AKI) in critically ill adult patients in intensive care units; however, its clinical impact in the emergency department (ED) remains unproven. We evaluated the utility of NephroCheck for predicting AKI development and short-term mortality in the ED. Methods: This was a prospective, observational, five-center international study. We consecutively enrolled ED patients admitted with ≥30% risk of AKI development (assessed by ED physician: ED score) or acute diseases. Serum creatinine was tested on ED arrival (T0), day 1, and day 2 (T48); urine for NephroCheck was collected at T0 and T48. We performed ROC curve and reclassification analyses. Results: Among the 529 patients enrolled (213 females; median age, 65 years), AKI developed in 59 (11.2%) patients. The T0 NephroCheck value was higher in the AKI group than in the non-AKI group (median 0.77 vs. 0.29 (ng/m)2/1,000, P=0.001), and better predicted AKI development than the ED score (area under the curve [AUC], 0.64 vs. 0.53; P=0.04). In reclassification analyses, adding NephroCheck to the ED score improved the prediction of AKI development (P
-
Review Article2021-11-01 Clinical Chemistry
Second-Line Tests in the Diagnosis of Adrenocorticotropic Hormone-Dependent Hypercortisolism
Silvia Pinelli
Ann Lab Med 2021; 41(6): 521-531, M.D., Mattia Barbot , M.D., Ph.D., Carla Scaroni , M.D., and Filippo Ceccato , M.D., Ph.D.Abstract : Cushing’s syndrome (CS) is a rare disease caused by chronic and excessive cortisol secretion. When adrenocorticotropin hormone (ACTH) is measurable, autonomous adrenal cortisol secretion could be reasonably ruled out in a differential diagnosis of CS. ACTH-dependent CS accounts for 80%–85% of cases and involves cortisol production stimulated by uncontrolled pituitary or ectopic ACTH secretion. Pituitary adenoma is not detected in up to one-third of cases with pituitary ACTH secretion, whereas cases of CS due to ectopic ACTH secretion may be associated with either malignant neoplasia (such as small cell lung carcinoma) or less aggressive neuroendocrine tumors, exhibiting only the typical symptoms and signs of CS. Since the differential diagnosis of ACTH-dependent CS may be a challenge, many strategies have been proposed. Since none of the available tests show 100% diagnostic accuracy, a step-by-step approach combining several diagnostic tools and a multidisciplinary evaluation in a referral center is suggested. In this review, we present a clinical case to demonstrate the diagnostic work-up of ACTH-dependent CS. We describe the most commonly used dynamic tests, as well as the applications of conventional or nuclear imaging and invasive procedures.
-
Original Article2022-01-01 Clinical Chemistry
Comprehensive Laboratory Data Analysis to Predict the Clinical Severity of Coronavirus Disease 2019 in 1,952 Patients in Daegu, Korea
Eun-Hyung Yoo
Ann Lab Med 2022; 42(1): 24-35, M.D., Ph.D., Soon Hee Chang , M.D., Ph.D., Do-Young Song , M.D., Ph.D., Chae Hoon Lee , M.D., Ph.D., Gyu Young Cheong , M.D., Ph.D., Sunggyun Park , M.D., Ph.D., Jae Hee Lee , M.D., Ph.D., Sooin Lee , M.D., Ph.D., Sang-Gyu Kwak , Ph.D., Chang-Ho Jeon , M.D., Ph.D., and Kyung Eun Song , M.D., Ph.D.Abstract : Background: Laboratory parameter abnormalities are commonly observed in COVID-19 patients; however, their clinical significance remains controversial. We assessed the prevalence, characteristics, and clinical impact of laboratory parameters in COVID-19 patients hospitalized in Daegu, Korea. Methods: We investigated the clinical and laboratory parameters of 1,952 COVID-19 patients on admission in nine hospitals in Daegu, Korea. The average patient age was 58.1 years, and 700 (35.9%) patients were men. The patients were classified into mild (N=1,612), moderate (N=294), and severe (N=46) disease groups based on clinical severity scores. We used chi-square test, multiple comparison analysis, and multinomial logistic regression to evaluate the correlation between laboratory parameters and disease severity. Results: Laboratory parameters on admission in the three disease groups were significantly different in terms of hematologic (Hb, Hct, white blood cell count, lymphocyte%, and platelet count), coagulation (prothrombin time and activated partial thromboplastin time), biochemical (albumin, aspartate aminotransferase, alanine aminotransferase, lactate, blood urea nitrogen, creatinine, and electrolytes), inflammatory (C-reactive protein and procalcitonin), cardiac (creatinine kinase MB isoenzyme and troponin I), and molecular virologic (Ct value of SARS-CoV-2 RdRP gene) parameters. Relative lymphopenia, prothrombin time prolongation, and hypoalbuminemia were significant indicators of COVID-19 severity. Patients with both hypoalbuminemia and lymphopenia had a higher risk of severe COVID-19. Conclusions: Laboratory parameter abnormalities on admission are common, are significantly associated with clinical severity, and can serve as independent predictors of COVID-19 severity. Monitoring the laboratory parameters, including albumin and lymphocyte count, is crucial for timely treatment of COVID-19.
-
Review Article2022-09-01 Clinical Chemistry
Review of the Use of Liquid Chromatography-Tandem Mass Spectrometry in Clinical Laboratories: Part II–Operations
Brian A. Rappold
Ann Lab Med 2022; 42(5): 531-557, B.S.Abstract : Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is increasingly utilized in clinical laboratories because it has advantages in terms of specificity and sensitivity over other analytical technologies. These advantages come with additional responsibilities and challenges given that many assays and platforms are not provided to laboratories as a single kit or device. The skills, staff, and assays used in LC-MS/MS are internally developed by the laboratory, with relatively few exceptions. Hence, a laboratory that deploys LC-MS/MS assays must be conscientious of the practices and procedures adopted to overcome the challenges associated with the technology. This review discusses the post-development landscape of LC-MS/MS assays, including validation, quality assurance, operations, and troubleshooting. The content knowledge of LC-MS/MS users is quite broad and deep and spans multiple scientific fields, including biology, clinical chemistry, chromatography, engineering, and MS. However, there are no formal academic programs or specific literature to train laboratory staff on the fundamentals of LC-MS/MS beyond the reports on method development. Therefore, depending on their experience level, some readers may be familiar with aspects of the laboratory practices described herein, while others may be not. This review endeavors to assemble aspects of LC-MS/MS operations in the clinical laboratory to provide a framework for the thoughtful development and execution of LC-MS/MS applications.
-
Review Article2023-01-01 Clinical Chemistry
Calibration Practices in Clinical Mass Spectrometry: Review and Recommendations
Wan Ling Cheng
Ann Lab Med 2023; 43(1): 5-18 , M.Sc., Corey Markus , M.Sc., Chun Yee Lim , Ph.D., Rui Zhen Tan , Ph.D., Sunil Kumar Sethi , MBBS., and Tze Ping Loh , MB.BCh.BAO.; for the IFCC Working Group on Method Evaluation ProtocolsAbstract : Background: Calibration is a critical component for the reliability, accuracy, and precision of mass spectrometry measurements. Optimal practice in the construction, evaluation, and implementation of a new calibration curve is often underappreciated. This systematic review examined how calibration practices are applied to liquid chromatography-tandem mass spectrometry measurement procedures. Methods: The electronic database PubMed was searched from the date of database inception to April 1, 2022. The search terms used were “calibration,” “mass spectrometry,” and “regression.” Twenty-one articles were identified and included in this review, following evaluation of the titles, abstracts, full text, and reference lists of the search results. Results: The use of matrix-matched calibrators and stable isotope-labeled internal standards helps to mitigate the impact of matrix effects. A higher number of calibration standards or replicate measurements improves the mapping of the detector response and hence the accuracy and precision of the regression model. Constructing a calibration curve with each analytical batch recharacterizes the instrument detector but does not reduce the actual variability. The analytical response and measurand concentrations should be considered when constructing a calibration curve, along with subsequent use of quality controls to confirm assay performance. It is important to assess the linearity of the calibration curve by using actual experimental data and appropriate statistics. The heteroscedasticity of the calibration data should be investigated, and appropriate weighting should be applied during regression modeling. Conclusions: This review provides an outline and guidance for optimal calibration practices in clinical mass spectrometry laboratories.
-
Original Article2022-03-01 Clinical Chemistry
Impact of Individualized Hemolysis Management Based on Biological Variation Cut-offs in a Clinical Laboratory
Fernando Marques-Garcia
Ann Lab Med 2022; 42(2): 169-177, Ph.D., David Hansoe Heredero Jung , M.D., and Sandra Elena Pérez, B.D.Abstract : Background: Hemolysis is the most common type of preanalytical interference. Cut-offs based on the hemolysis index level can be established using different approaches. The Working Group for Preanalytical Phase of the European Federation of Laboratory Medicine has developed a protocol for hemolysis management based on cut-offs estimated from biological variation (BV) and the use of interpretative comments. We developed and assessed the implementation of the protocol in our laboratory. Methods: Hemolysates from whole blood were prepared following the Meites method, and pooled serum samples with known Hb concentrations were prepared. For each analyte (42 ), interferograms were generated and used to establish cut-offs: desirable analytical quality specification and reference change value. This protocol was assessed, both pre- and post-implementation, according to expert rules in the Laboratory Information System. Results: Among the analytes evaluated, we selected those that showed the highest degree of hemolysis interference: lactate dehydrogenase (LDH), aspartate aminotransferase, direct bilirubin, potassium, and folic acid. The cut-offs for LDH and direct bilirubin were the lowest. Only 28.16% of all LDH values were adequately reported in the pre-implantation retrospective study, but this percentage improved in the post-implementation stage. Conclusions: The development and implementation of a harmonized protocol for hemolysis management based on BV cut-offs and result reporting significantly improve hemolysis detection and lead to a decrease in the number of hemolyzed samples over time.
-
Original Article2022-07-01 Clinical Chemistry
Prognostic Utility of Procalcitonin, Presepsin, and the VACO Index for Predicting 30-day Mortality in Hospitalized COVID-19 Patients
Mikyoung Park
Ann Lab Med 2022; 42(4): 406-414 , M.D., Ph.D, Mina Hur , M.D., Ph.D, Hanah Kim , M.D., Ph.D, Chae Hoon Lee , M.D., Ph.D, Jong Ho Lee , M.D., Hyung Woo Kim , M.D., and Minjeong Nam , M.D., Ph.D.Abstract : Background: Biomarkers and clinical indices have been investigated for predicting mortality in patients with coronavirus disease (COVID-19). We explored the prognostic utility of procalcitonin (PCT), presepsin, and the Veterans Health Administration COVID-19 (VACO) index for predicting 30-day-mortality in COVID-19 patients. Methods: In total, 54 hospitalized COVID-19 patients were enrolled. PCT and presepsin levels were measured using the Elecsys BRAHMS PCT assay (Roche Diagnostics GmbH, Mannheim, Germany) and HISCL Presepsin assay (Sysmex, Kobe, Japan), respectively. The VACO index was calculated based on age, sex, and comorbidities. PCT and presepsin levels and the VACO index were compared using ROC curve, Kaplan–Meier method, and reclassification analysis for the 30-day mortality. Results: ROC curve analysis was used to measure PCT and presepsin levels and the VACO index to predict 30-day mortality; the optimal cut-off values were 0.138 ng/mL for PCT, 717 pg/mL for presepsin, and 12.1% for the VACO index. On Kaplan–Meier survival analysis, hazard ratios (95% confidence interval) were 15.9 (4.1-61.3) for PCT, 26.3 (6.4-108.0) for presepsin, and 6.0 (1.7-21.1) for the VACO index. On reclassification analysis, PCT and presepsin in addition to the VACO index significantly improved the prognostic value of the index. Conclusions: This study demonstrated the prognostic utility of measuring PCT and presepsin levels and the VACO index in COVID-19 patients. The biomarkers in addition to the clinical index were more useful than the index alone for predicting clinical outcomes in COVID-19 patients.
-
Original Article2022-03-01 Clinical Chemistry
Diagnostic Characteristics of Urinary Red Blood Cell Distribution Incorporated in UF-5000 for Differentiation of Glomerular and Non-Glomerular Hematuria
Hanwool Cho
Ann Lab Med 2022; 42(2): 160-168, M.D., Jaeeun Yoo , M.D., Hyunjung Kim , M.D., Hyunsik Jang , M.T., Yonggoo Kim , M.D., and Hyojin Chae , M.D.Abstract : Background: Automated urine sediment analysis has been developed to address the limitations of microscopic examination of dysmorphic red blood cells (RBCs). We evaluated the urinary RBC distribution (URD) parameter of a recently launched automated urinary flow cytometry analyzer, UF-5000 (Sysmex, Kobe, Japan), to differentiate glomerular hematuria (GH) from non-GH (NGH). Methods: Samples submitted for urine sediment analysis from patients with hematuria (>20 RBCs/μL) were divided into derivation (N=156; 101 GH, 55 NGH) and validation cohorts (N=107; 60 GH, 47 NGH). The clinical diagnosis of GH or NGH was established based on clinical data review. Differences in UF-5000 parameters (URD, small RBC, lysed RBC, RBC-P70FSC, RBC-SF-FSC-W, mean forward-scattered light, and mean side-scattered light) between GH and NGH, and areas under the ROC curves (AUC) were analyzed in the derivation cohort. The derived ideal cut-off value was evaluated in the validation cohort. We applied the Kitasato criteria to compare the diagnostic performance. Results: URD (%), differed significantly between GH and NGH (P20.1%, the sensitivity was 99.0%/89.4% and the specificity was 50.9%/63.3% in the derivation/validation cohort. When the Kitasato criteria were applied, the sensitivity and specificity were 80.2% and 52.7%, respectively. Conclusions: URD is a rapid, objective, and quantitative measure that can be used to differentiate GH and NGH.
Full Text
PDF
Pubmed
PMC
Search for
Follow us
