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.
Review Article l 01 September 2023
Adil I. Khan, M.Sc., Ph.D. et al.
Ann Lab Med 2023; 43: 401-407Keywords: Artificial intelligence, Point-of-care testing, Lateral flow immunoassay, Immunoassay, Hematology, Bright-field microscopy, Microscopy, Convolutional neural network, Malaria, Hemoglobin, Anemia
Review Article l 01 September 2023
Tyng Yu Chuah, M.B., B.Ch. et al.
Ann Lab Med 2023; 43: 408-417Keywords: Reference values, Threshold limit values, Homeostasis
Review Article l 01 May 2023
Alexander E. Berezin, M.D., Ph.D. and Alexander A. Berezin et al.
Ann Lab Med 2023; 43: 225-236Keywords: Heart failure, Cardiac Biomarkers, Multiple Biomarker Models, Prediction, Management
Review Article l 01 January 2023
Wan Ling Cheng, M.Sc., Corey Markus et al.
Ann Lab Med 2023; 43: 5-18Keywords: Calibration, Mass spectrometry, Regression, Linearity, Statistics
Review Article2022-01-01 Clinical Chemistry
Khaldoun Ghazal , Pharm., Ph.D., Severine Brabant
, M.D., Dominique Prie
, M.D., Ph.D., and Marie-Liesse Piketty
, Pharm., Ph.D.
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 Article2021-11-01 General Laboratory Medicine
Giulia Bivona , M.D., Luisa Agnello
, Ph.D., and Marcello Ciaccio
, M.D., Ph.D.
Abstract : During a severe infection such as coronavirus disease 2019 (COVID-19), the level of almost all analytes can change, presenting a correlation with disease severity and survival; however, a biomarker cannot be translated into clinical practice for treatment guidance until it is proven to have a significant impact. Several studies have documented the association between COVID-19 severity and circulating levels of C-reactive protein (CRP) and interleukin-6, and the accuracy of the CRP level in predicting treatment responses has been evaluated. Moreover, promising findings on prothrombin and D-dimer have been reported. However, the clinical usefulness of these biomarkers in COVID-19 is far from proven. The burst of data generation during this pandemic has led to the publication of numerous studies with several notable drawbacks, weakening the strength of their findings. We provide an overview of the key findings of studies on biomarkers for the prognosis and treatment response in COVID-19 patients. We also highlight the main drawbacks of these studies that have limited the clinical use of these biomarkers.
Review Article2021-11-01 General Laboratory Medicine
Tahir S. Pillay , MBChB., Ph.D. and Serge Muyldermans
, Ph.D.
Abstract : Antibodies have proven to be central in the development of diagnostic methods over decades, moving from polyclonal antibodies to the milestone development of monoclonal antibodies. Although monoclonal antibodies play a valuable role in diagnosis, their production is technically demanding and can be expensive. The large size of monoclonal antibodies (150 kDa) makes their re-engineering using recombinant methods a challenge. Single-domain antibodies, such as “nanobodies,” are a relatively new class of diagnostic probes that originated serendipitously during the assay of camel serum. The immune system of the camelid family (camels, llamas, and alpacas) has evolved uniquely to produce heavy-chain antibodies that contain a single monomeric variable antibody domain in a smaller functional unit of 12–15 kDa. Interestingly, the same biological phenomenon is observed in sharks. Since a single-domain antibody molecule is smaller than a conventional mammalian antibody, recombinant engineering and protein expression in vitro using bacterial production systems are much simpler. The entire gene encoding such an antibody can be cloned and expressed in vitro. Single-domain antibodies are very stable and heat-resistant, and hence do not require cold storage, especially when incorporated into a diagnostic kit. Their simple genetic structure allows easy re-engineering of the protein to introduce new antigen-binding characteristics or attach labels. Here, we review the applications of single-domain antibodies in laboratory diagnosis and discuss the future potential in this area.
Review Article2022-05-01 Diagnostic Hematology
Akriti G. Jain , M.D., Ling Zhang
, M.D., John M. Bennett
, M.D., and Rami Komrokji
, M.D.
Abstract : Myelodysplastic syndrome (MDS) is a diverse hematological malignancy with a wide spectrum of presentations and implications. Treatment strategies for patients with MDS heavily rely on prognostic scoring systems, such as the revised international prognostic scoring system (IPSS-R). Bone marrow fibrosis (BMF) has been identified as an independent risk factor for poor survival in patients with MDS, irrespective of the IPSS-R risk category. However, BMF is not widely included in scoring systems and is not always considered by clinicians when making treatment decisions for patients. In this review, we discuss the available literature about the presentation and prognosis of patients with MDS and concurrent BMF. The prognostic impact of BMF should be factored in when deciding on transplant candidacy, especially for intermediate-risk patients.
Original Article2021-11-01 Diagnostic Immunology
Sojeong Yun , B.S., Ji Hyeong Ryu
, M.S., Joo Hee Jang
, B.S., Hyunjoo Bae
, M.S., Seung-Hyo Yoo
, M.T., Ae-Ran Choi
, M.T., Sung Jin Jo
, M.D., Jihyang Lim
, M.D., Jehoon Lee
, M.D., Hyejin Ryu
, M.D., Sung-Yeon Cho
, M.D., Dong-Gun Lee
, M.D., Jongmin Lee
, M.D., Seok Chan Kim
, M.D., Yeon-Joon Park
, M.D., Hyeyoung Lee
, M.D., and Eun-Jee Oh
, M.D.
Abstract : Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody assays have high clinical utility in managing the pandemic. We compared antibody responses and seroconversion of coronavirus disease 2019 (COVID-19) patients using different immunoassays. Methods: We evaluated 12 commercial immunoassays, including three automated chemiluminescent immunoassays (Abbott, Roche, and Siemens), three enzyme immunoassays (Bio-Rad, Euroimmun, and Vircell), five lateral flow immunoassays (Boditech Med, SD biosensor, PCL, Sugentech, and Rapigen), and one surrogate neutralizing antibody assay (GenScript) in sequential samples from 49 COVID-19 patients and 10 seroconversion panels. Results: The positive percent agreement (PPA) of assays for a COVID-19 diagnosis ranged from 84.0% to 98.5% for all samples (>14 days after symptom onset), with IgM or IgA assays showing higher PPAs. Seroconversion responses varied across the assay type and disease severity. Assays targeting the spike or receptor-binding domain protein showed a tendency for early seroconversion detection and higher index values in patients with severe disease. Index values from SARS-CoV-2 binding antibody assays (three automated assays, one LFIA, and three EIAs) showed moderate to strong correlations with the neutralizing antibody percentage (r=0.517–0.874), and stronger correlations in patients with severe disease and in assays targeting spike protein. Agreement among the 12 assays was good (74.3%–96.4%) for detecting IgG or total antibodies. Conclusions: Positivity rates and seroconversion of SARS-CoV-2 antibodies vary depending on the assay kits, disease severity, and antigen target. This study contributes to a better understanding of antibody response in symptomatic COVID-19 patients using currently available assays.
Brief Communication2021-11-01 Clinical Microbiology
Jaehyeon Lee , M.D., So Yeon Kim
, M.D., Hee Jae Huh
, M.D., Namsu Kim
, M.D., Heungsup Sung
, M.D., Hyukmin Lee
, M.D., Kyoung Ho Roh
, M.D., Taek Soo Kim
, M.D., and Ki Ho Hong
, M.D.
Abstract : The rapid antigen test (RAT) for coronavirus disease (COVID-19) represents a potent diagnostic method in situations of limited molecular testing resources. However, considerable performance variance has been reported with the RAT. We evaluated the clinical performance of Standard Q COVID-19 RAT (SQ-RAT; SD Biosensor, Suwon, Korea), the first RAT approved by the Korean Ministry of Food and Drug Safety. In total, 680 nasopharyngeal swabs previously tested using real-time reverse-transcription PCR (rRT-PCR) were retested using SQ-RAT. The clinical sensitivity of SQ-RAT relative to that of rRT-PCR was 28.7% for all specimens and was 81.4% for specimens with RNA-dependent RNA polymerase gene (RdRp) threshold cycle (Ct) values ≤23.37, which is the limit of detection of SQ-RAT. The specificity was 100%. The clinical sensitivity of SQ-RAT for COVID-19 diagnosis was assessed based on the Ct distribution at diagnosis of 33,294 COVID-19 cases in Korea extracted from the laboratory surveillance system of Korean Society for Laboratory Medicine. The clinical sensitivity of SQ-RAT for COVID-19 diagnosis in the Korean population was 41.8%. Considering the molecular testing capacity in Korea, use of the RAT for COVID-19 diagnosis appears to be limited.
Original Article2022-03-01 Clinical Chemistry
Hyun Suk Yang , 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 Network
Abstract : 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
Original Article2022-03-01 Diagnostic Immunology
Mina Hur , M.D., Ph.D., Mikyoung Park
, M.D., Ph.D., Hee-Won Moon
, M.D., Ph.D., Won Hyeok Choe
, M.D., Ph.D., and Chae Hoon Lee
, M.D., Ph.D.
Abstract : Background: Non-invasive clinical algorithms for the detection of liver fibrosis (LF) can reduce the need for liver biopsy (LB). We explored the implementation of two serum biomarkers, enhanced liver fibrosis (ELF) and Mac-2 binding protein glycosylation isomer (M2BPGi), in clinical algorithms for LF in chronic hepatitis B (CHB) patients. Methods: Two clinical algorithms were applied to 152 CHB patients: (1) transient elastography (TE) followed by biomarkers (TE/ELF and TE/M2GPGi); (2) biomarker test followed by TE (ELF/TE and M2BPGi/TE). Using the cut-off value or index for the detection of advanced LF (TE≥F3; 9.8 in ELF and 3.0 in M2BPGi), LB was expected to be performed in cases with discordant TE and biomarker results. Results: In both algorithms, the expected number of LBs was lower when using M2BPGi than when using ELF (TE/ELF or ELF/TE, 13.2% [N=20]; TE/M2BPGi or M2BPGi/TE, 9.9% [N=15]), although there was no statistical difference (P=0.398). In the TE low-risk group (TE≤F2), the discordance rate was significantly lower in the TE/M2BPGi approach than in the TE/ELF approach (1.5% [2/136] vs. 11.0% [15/136], P=0.002). In the biomarker low-risk group, there was no significant difference between the ELF/TE and M2BPGi/TE approaches (3.9% [5/126] vs. 8.8% [13/147], P=0.118). Conclusions: Both ELF and M2BPGi can be implemented in non-invasive clinical algorithms for assessing LF in CHB patients. Given the lowest possibility of losing advanced LF cases in the low-risk group when using the TE/M2BPGi approach, this combination seems useful in clinical practice.
Original Article2022-01-01 Diagnostic Immunology
Sumi Yoon , M.D., Hee-Won Moon
, M.D., Ph.D., Hanah Kim
, M.D., Ph.D., Mina Hur
, M.D., Ph.D., and Yeo-Min Yun
, M.D., Ph.D.
Abstract : Background: Recently, two fully automated immunoassays for antinuclear antibody (ANA) screening were introduced: EliA CTD Screen (Thermo Fisher Scientific, Freiburg, Germany) and QUANTA Flash CTD Screen Plus (Inova Diagnostics, San Diego, USA). We evaluated their clinical performance in comparison with the indirect immunofluorescence assay (IIFA) and analyzed samples with discrepant results. Methods: In total, 406 serum samples (206 from patients undergoing routine checkups and 200 from rheumatology clinic patients) were assayed using EliA, QUANTA Flash, and IIFA. We evaluated assay concordance and agreement and confirmed the presence of anti-extractable nuclear antigen (ENA) antibodies in samples with discrepant automated immunoassay and IIFA results. Additionally, we compared the clinical performance of each assay in diagnosing ANA-associated rheumatic disease (AARD) and adjusted the cut-off values. Results: In rheumatology clinic samples, the concordance and agreement were 91.5% and strong between EliA and QUANTA Flash, 79.0% and weak between EliA and IIFA, and 80.5% and moderate between QUANTA Flash and IIFA, respectively. In automated immunoassay-positive, IIFA-negative samples (N=15), all anti-ENA antibodies detected (6/15) were anti-Sjögren’s syndrome antigen A/Ro (Ro60) antibodies. The automated immunoassays and IIFA showed high accuracy for diagnosing AARD, and adjusted cut-off values improved their sensitivities (EliA with 0.56 ratio, 82.9% sensitivity; QUANTA Flash with 9.7 chemiluminescent units, 87.8% sensitivity). Conclusions: The two automated immunoassays showed reliable performance compared with IIFA and can be efficiently used with the IIFA in clinical immunology laboratories. Clinical cut-off values can be adjusted according to the workflow in each laboratory.