Background: Harmonization of units is an important step to improve the comparability of clinical chemistry results, but few examples exist of successful harmonization efforts. We present the results of a pragmatic approach that was implemented in Belgium from 2012. Methods: After a large consultation and information of stakeholders, preferred units were proposed for 140 assays, including the 23 immunoassays discussed in more detail here. The change occurred in two phases, first involving assays for which there was no change in the numerical result, then changes involving a change in numerical results. Laboratories were invited to participate in this harmonization on a voluntary basis. The project was based on a bottom-up approach, large consultation and the pragmatic choice of the proposed units, including conventional and SI units. Results: The large heterogeneity of units was drastically reduced; adoption of the preferred units increased from 3% (insulin) - 45% (HCG) to 70% (insulin) - 96% (LH and FSH). Adoption of the preferred units was higher if it involved no change in numerical values (90%) than when there was a change (76%). Conclusions: We believe that the harmonization effort has reached its goals. Without aiming at implementing SI units for all parameters, our strategy was successful with a large majority of the laboratories switching to the proposed units. Moreover, the harmonization program is still progressing, with additional laboratories converting to the consensus units.
Background: Solid tumor tissue testing is the gold standard for molecular-based assays for metastatic colorectal cancer (mCRC). This poses challenges during treatment monitoring. Total DNA derived from urine specimens offers clear advantages to track the disease dynamics. Our study aims to evaluate the sensitivity for total DNA recovered from urine and its clinical relevance to mCRC. Methods: KRAS mutations in urine specimens were examined in 150 mCRC patients. Baseline concordance was established to determined clinical relevance. The total DNA quantities were also prospectively examined in serial samplings during treatment. Results: Analysis of the genetic mutations showed good agreement for baseline samples. Matched tumor and urine specimens' molecular profiles were observed to have 90% concordance. Comparing with healthy volunteers, we established a cutoff of 8.15 ng that demonstrated elevated total DNA levels was associated with mCRC patients (sensitivity: 90.7%; specificity: 82.0%). For patients treated with chemotherapy or anti-epidermal growth factor receptor inhibitors, DNA quantity mirrored early treatment response. Survival analysis showed that patients with sustained elevated quantities of KRAS mutations had poorer outcome. Conclusions: Total urine DNA offers a viable complement for mutation profiling in mCRC patients, given the good agreement with matched tumor samples. Our study also established that this is specific based on the results from healthy individuals. Serial monitoring of total DNA levels allowed early prediction to treatment response and was effective to identify high risk patients. This is potentially useful to complement current disease management.
Background: As effective quality management tools, quality indicators (QIs) are widely used in laboratory medicine. This study aimed to analyze the results of QIs, identify errors and provide quality specifications (QSs) based on the state-of-the-art. Methods: Clinical laboratories all over China participated in the Qls survey organized by the National Health Commission of People' Republic of China from 2015 to 2017. Most of these Qls were selected from a common model of Qls (MQI) established by the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC). All participants were asked to submit general information and original QIs data through a medical quality control data collection system. The results of Qls were reported in percentages and sigma, except turnaround time (TAT) which was measured in minutes. The 25th, 50th and 75th percentiles were, respectively, calculated as three levels of QSs, which were defined starting from the model proposed during the 1st Strategic Conference of the EFLM on "Defining analytical performance 15 years after the Stockholm Conference on Quality Specification in Laboratory Medicine". Results: A total of 76 clinical laboratories from 25 provinces in China continuously participated in this survey and submitted complete data for all Qls from 2015 to 2017. In general, the performance of all reported Qls have improved or at least kept stable over time. Defect percentages of blood culture contamination were the largest in the preanalytical phase. Intra-laboratory TAT was always larger than pre-examination TAT. Percentage of tests covered by inter-laboratory comparison was relatively low than others in the intra-analytical phase. The performances of critical values notification and timely critical values notification were the best with 6.0 sigma. The median sigma level of incorrect laboratory reports varied from 5.5 sigma to 5.7 sigma. Conclusions: QSs of QIs provide useful guidance for laboratories to improve testing quality. Laboratories should take continuous quality improvement measures in all phases of total testing process to ensure safe and effective tests.
Background: Serum uric acid is a critical clinical indicator, and results without equivalence among laboratories cause troubles for disease diagnosis and patient management. External quality assessment (EQA) is a common tool for enhancing harmonization/standardization, therefore, the National Center for Clinical Laboratories in China has initiated a category 1 EQA for serum uric acid measurement since 2010 for evaluating its process of standardization. Methods: Commutable EQA samples with target values assigned by reference measurement procedures were sent to participant laboratories. Both concentrations were measured 15 times in 3 days then means and intra-laboratory coefficient of variations (CVs) were reported. Biological variation criteria were used for analysis with CLIA88 criteria as a comparison. Results: A total of 1250 laboratories participated in EQA programs from 2010 to 2017, pass rates calculated according to desirable specifications in biological variation database were on a rise overall and inter-laboratory mean bias and CVs were on a decrease. Homogeneous systems showed better inter-laboratory CVs and pass rates than heterogeneous systems. For the mostly used measurement systems; Abbott, Beckman, Roche Modular, Siemens and Hitachi showed desirable performances other than Roche Cobas, according to biological variation criteria. Conclusions: Our study provides reliable information on the standardization of measurement procedures for serum uric acid for manufacturers and laboratories. Further improvements for standardization are still needed to make laboratories more patient-centered.
Background: The commutability of electrolyte trueness verification materials (ETVs) and commercial general chemistry materials (GCs) was evaluated to investigate their suitability for use in an external quality assessment (EQA) program for serum sodium and potassium measurements. Methods: Eighty fresh individual human samples (40 for sodium measurements and 40 for potassium measurements), six ETVs and three GCs were analyzed by five routine methods (validated methods) and by inductively coupled plasma mass spectrometry reference methods (comparative methods) for the determination of sodium and potassium. The commutability was analyzed according to Clinical and Laboratory Standards Institute (CLSI) EP14-A3 protocol and difference in bias approach, respectively. The linearity, bias and imprecision of the routine methods were also assessed according to CLSI guidelines. Results: According to EP14-A3 protocol, ETVs were commutable for all assays, and GCs were commutable for 3/5 assays for sodium. ETVs were commutable in most assays except Cobas C501, while GCs showed no commutability except in case of AU5821 for potassium. According to a difference in bias approach, the commutability of ETVs was inconclusive for most routine assays for both sodium and potassium, and GCs were inconclusive for sodium and non-commutable for potassium in most routine assays. The routine methods exhibited excellent linearities and precisions. The majority and minority of relative biases between the routine and reference methods were beyond the bias limits for sodium and potassium, respectively. Conclusions: Superiority in the commutability of ETVs over GCs was observed among the sodium and potassium assays whichever evaluation approach was applied.
Recently, nuclear magnetic resonance spectroscopy (NMR)-based metabolomics analysis and multivariate statistical techniques have been incorporated into a multidisciplinary approach to profile changes in small molecules associated with the onset and progression of human diseases. The purpose of these efforts is to identify unique metabolite biomarkers in a specific human disease so as to (1) accurately predict and diagnose diseases, including separating distinct disease stages; (2) provide insights into underlying pathways in the pathogenesis and progression of the malady and (3) aid in disease treatment and evaluate the efficacy of drugs. In this review we discuss recent developments in the application of NMR-based metabolomics in searching disease biomarkers in human blood samples in the last 5 years.
Glycosylation is among the most important post-translational modifications for proteins and is of intrinsic complex character compared with DNAs and naked proteins. Indeed, over 50%-70% of proteins in circulation are glycosylated, and the "sweet attachments" have versatile structural and functional implications. Both the configuration and composition of the attached glycans affect the biological activities of consensus proteins significantly. Glycosylation is generated by complex biosynthetic pathways comprising hundreds of glycosyltransferases, glycosidases, transcriptional factors, transporters and the protein backbone. In addition, lack of direct genetic templates and glyco-specific antibodies such as those commonly used in DNA amplification and protein capture makes research on glycans and glycoproteins even more difficult, thus resulting in sparse knowledge on the pathophysiological implications of glycosylation. Fortunately, cutting-edge technologies have afforded new opportunities and approaches for investigating cancer-related glycosylation. Thus, glycans as well as aberrantly glycosylated protein-based cancer biomarkers have been increasingly recognized. This mini-review highlights the most recent developments in glyco-biomarker studies in an effort to discover clinically relevant cancer biomarkers using advanced analytical methodologies such as mass spectrometry, high-performance liquid chromatographic/ultra-performance liquid chromatography, capillary electrophoresis, and lectin-based technologies. Recent clinical-centered glycobiological studies focused on determining the regulatory mechanisms and the relation with diagnostics, prognostics and even therapeutics are also summarized. These studies indicate that glycomics is a treasure waiting to be mined where the growth of cancer-related glycomics and glycoproteomics is the next great challenge after genomics and proteomics.
Background: Hypertrophic cardiomyopathy (HCM) is a serious disorder and one of the leading causes of mortality worldwide. HCM is characterized as left ventricular hypertrophy in the absence of any other loading conditions. In previous studies, mutations in at least 50 genes have been identified in HCM patients. Methods: In this research, the genetic lesion of an HCM patient was identified by whole exome sequencing. Real-time polymerase chain reaction (PCR), immunofluorescence and Western blot were used to analyze the effects of the identified mutation. Results: According to whole exome sequencing, we identified a de novo mutation (c.814T>C/p.F272L) of SET and MYND domain containing histone methyltransferase 1 (SMYD1) in a Chinese patient with HCM exhibiting syncope. We then generated HIS-SMYD1-pcDNA3.1+ (WT and c.814T>C/p.F272L) plasmids for transfection into AC16 cells to functionalize the mutation. The immunofluorescence experiments indicated that this mutation may block the SMYD1 protein from entering the nucleus. Both Western blot and real-time PCR revealed that, compared with cells transfected with WT plasmids, the expression of HCM-associated genes such as beta-myosin heavy chains, SMYD1 chaperones (HSP90) and downstream targets including TGF-beta were all disrupted in cells transfected with the mutant plasmid. Previous studies have demonstrated that SMYD1 plays a crucial role in sarcomere organization and heart development. Conclusions: This novel mutation (c.814T>C/p.F272L) may be the first identified disease-causing mutation of SMYD1 in HCM patients worldwide. Our research expands the spectrum of HCM-causing genes and contributes to genetic counseling for HCM patients.
Background: Although laboratory information system (LIS) is widely used nowadays, the results of routine urinalysis still need 100% manual verification. We established intelligent verification criteria to perform the automated verification process and reduce manual labor. Methods: A total of 4610 urine specimens were obtained from the patients of three hospitals in Beijing, China. Firstly, 895 specimens were measured to establish the reference intervals of formed-element parameters in UF5000. Secondly, 2803 specimens were analyzed for setting up the intelligent verification criteria (including the microscopic review rules and manual verification rules). Lastly, 912 specimens were used to verify the efficacy and accuracy of the intelligent verification criteria. Phase-contrast microscopes were used for the microscopic review. Results: Employing a results level corresponding relationship in specific parameters including hemoglobin (red blood cell [RBC]), leukocyte esterase (white blood cell [WBC]) and protein (cast) between the dry-chemistry analysis and formed-element analysis, as well as instrument flags, we established seven WBC verification rules, eight RBC verification rules and four cast verification rules. Based on the microscopy results, through analyzing the pre-set rules mentioned earlier, we finally determined seven microscopic review rules, nine manual verification rules and three auto-verification rules. The microscopic review rate was 21.98% (616/2803), the false-negative rate was 4.32% (121/2803), the total manual verification rate was 35.71% (1001/2803) and the auto-verification rate was 64.29% (1802/2803). The validation results were consistent. Conclusions: The intelligent verification criteria for urinary dry-chemistry and urinary formed-element analysis can improve the efficiency of the results verification process and ensure the reliability of the test results.
Background: a-Dicarbonyl compounds (alpha-DCs) have been detected in body fluids including plasma and urine and elevation of this sort of compounds in vivo has been associated with the development of many kinds of chronic diseases. However whether alpha-DCs are present in human saliva, and if their presence/absence can be related with various chronic diseases is yet to be determined. Methods: In this study, a pre-column derivatization HPLC-UV method was developed to measure 3-deoxyglucosone (3-DG), glyoxal (GO), methylglyoxal (MGO), diacetyl (DA), and pentane-2,3-dione (PD) in human saliva employing 4-(2,3-dimethyl-6-quinoxalinyl)-1,2-benzenediamine (DQB) as a derivatizing reagent. The derivatization of the alpha-DCs is fast and the conditions are facile. The method was evaluated and the results show that it is suitable for the quantification of alpha-DCs in human saliva. Results: In the measurements of these alpha-DCs in the saliva of 15 healthy subjects and 23 type 2 diabetes mellitus (T2DM) patients, we found that the concentrations of GO and MGO in the saliva of the diabetic patients were significantly higher than those in healthy subjects. As far as we know, this is the first time that salivary alpha-DC concentrations have been determined and associated with T2DM. Conclusions: The developed method would be useful for the measurement of the salivary alpha-DC levels and the data acquired could be informative in the early screening for diabetes.
Background: Epstein-Barr virus (EBV) DNA load monitoring in blood is essential for the diagnosis of EBV-associated diseases. However, the best-suited blood compartment for detection is still under discussion. The aim of this study was to evaluate the diagnostic value of EBV-DNA load in peripheral blood mononuclear cells (PBMC), plasma and whole blood (WB) samples. Methods: A total of 156 patients, including 45 patients with infectious mononucleosis (IM), 57 patients with EBV-associated hemophagocytic lymphohistiocytosis (HLH) and 54 patients with post-transplant lymphoproliferative disorders (PTLD), were enrolled in this study. The EBV-DNA load in PBMC, plasma and WB samples were measured with real-time quantitative polymerase chain reaction (PCR). Results: EBV-DNA load of patients with HLH showed no statistical difference in PBMC, plasma and WB samples, while patients with IM and PTLD showed a higher viral load in PBMC samples. The strongest correlation of EBV-DNA level was found between PBMC and WB samples among patients with IM, HLH and PTLD. The follow-up of EBV-DNA showed that the viral load became negative along with the recovery from the disease, while that in WB and PBMC would remain positive for a long time. Conclusions: For the diagnosis and monitoring of EBV-DNA, the type of specimen should be chosen reasonably according to the disease. As for IM and HLH, plasma is recommended to quantify the EBV-DNA load, while PBMC and plasma are preferred in PTLD.
Background: Proteinuria is a marker of poor outcomes in several diseases; however, few studies have been conducted to explore the prognostic value of proteinuria, assessed by urine dipstick test, for clinical outcomes in patients with type B acute aortic dissection (TBAD) undergoing thoracic endovascular aortic repair (TEVAR). Methods: Consecutive patients with TBAD undergoing TEVAR were enrolled from January 2010 to July 2015. Proteinuria was defined as trace or higher, according to the results of urine dipstick testing. Associations among proteinuria and adverse events were evaluated. Results: In total, 671 patients with a mean age of 44 +/- 15 years were included in the analysis. Proteinuria was detected in 281 patients (41.9%) before TEVAR. Multivariate logistic regression analysis showed that C-reactive protein and impaired renal function were independent predictors for proteinuria. During hospitalization, 21 patients died. In-hospital mortality was higher in patients with proteinuria (1.5% vs. 5.3%, p=0.005). After a median 3.4 years follow up, the post-TEVAR death rate was 10.4% (85 patients were lost to follow-up). The long-term cumulative mortality was significantly higher in patients with proteinuria (17.2% vs. 8.2%, log-rank = 11.36, p= 0.001). Multivariate Cox survival modeling indicated that proteinuria was significantly associated with long-term death, after adjustment for potential confounding risk factors (HR =1.92, p = 0.012). Conclusions: Pre-TEVAR proteinuria was identified as a prognostic marker in patients with TBAD and has potential for application as a convenient and simple risk assessment method before TEVAR.