Influence Of Hemolysis Research Articles

Validation of a Multiplex Molecular Macroarray for the Determination of Allergen-Specific IgE Sensitizations in Dogs.

Detecting IgE sensitizations in the serum of allergic dogs is commonly performed using allergen extracts, but these are difficult to standardize. This article details the development and validation of the Pet Allergy Xplorer (PAX; Nextmune, Stockholm, Sweden), the first multiplex macroarray for the detection of IgE sensitization in dogs using allergen extracts and molecular components; the PAX is derived from the Allergy Xplorer (ALEX2; MacroArray Diagnostics, Vienna, Austria). The selection of allergens, cartridge processing, strategy for identifying and blocking IgE directed against cross-reactive carbohydrate determinants (CCDs), and the method used for determining the positivity threshold are described. The validation of the PAX included evaluations of the specificity of its anti-IgE monoclonal antibody, specificity of IgE binding to target allergens, assay precision, and internal consistency. Additionally, the influence of possible confounding factors, such as sample type, the influence of hemolysis, lipemia, bilirubinemia, and elevated CCD-IgE, was tested. Finally, the sensitization rates of 23,858 European dogs to 145 environmental and Hymenoptera venom allergens were summarized. The PAX is accurate and reproducible and has a unique CCD-detection and blocking strategy; its molecular allergens offer a unique window on allergen cross-reactivity.

Effects of Hemolysis on Routine Coagulation Tests when Tested on an Optical Coagulation Analyzer.

The Clinical and Laboratory Standards Institute recommends rejecting hemolyzed samples for coagulation tests. Sysmex CS5100 analyzer using an optical method is commonly used in laboratories. The influence of hemolysis on coagulation test has rarely been studied when tested on Sysmex CS5100. Determining this influence is necessary. Freshly collected samples were artificially hemolyzed to simulate the hemolysis processes. Coagulation tests were conducted on a Sysmex CS5100 coagulation analyzer. Detection values before and after hemolysis were compared. The results showed that after hemolysis detection, the prothrombin time (PT) statistically decreased, while the partial thromboplastin time (APTT) statistically increased. There were no significant differences in fibrinogen (Fg), thrombin time (TT), D-dimer (DD) or fibrinogen degradation products (FDPs). Antithrombin activity was elevated in hemolyzed samples. Although differences in PT and APTT were statistically significant, there was no need for rejection of hemolyzed samples due to insufficient clinical effects when tested on Sysmex CS5100 analyzer. Falsely elevated AT result may lead to misdiagnosis in patients with severe diseases, which should be carefully considered.

Hemolysis interference on clinical chemistry tests analyzed on DxC 700 AU (Beckman Coulter®) and kaliemia rendering algorithm

The influence of hemolysis was evaluated for 26 clinical chemistry parameters on DxC 700AU (Beckman Coulter®). Ten sample pools were prepared and separated into six aliquots. These aliquots were overloaded with hemolysis in increasing amounts to reach levels equivalent to the maximum hemolysis thresholds H1 (+), H2 (++), H3 (+++) and H4 (++++). Each aliquot is compared to its reference aliquot (not hemolyzed) and a ratio is calculated for each parameter. We proposed that there was a significant difference if, for a given analyte and threshold, more than 20% of the ratios are above the total acceptable limit variability. A significant difference was found for TGP, TGO, cholesterol, creatine kinase (CPK), lactate deshydrogenase (LDH), phosphorus and potassium at H1 (+), chlorine, iron, γ-glutamyltransferase (GGT), and magnesium at H2 (++), amylase and alkaline phosphatase (PAL) at H3 (++++), and prealbumin at H4 (++++). No interference was found until H4 included for uric acid, calcium, creatinine, lipase, glucose, HDL-cholesterol, triglycerides, urea, sodium and immunoglobulins A, G and M. The overestimation of kalemia was calculated as a function of hemolysis, ranging from 0.28 mM +/–0.047 (upper H1 threshold) to 1.37 mM +/–0.126 (upper H4 threshold). Its estimation makes it possible to propose a result rendering algorithm of kalemia according to the hemolysis index. Evaluation of the automates hemolysis indexes is highly recommended for each laboratory. It can allow for some critical parameters the establishment of a decision tree facilitating the result rendering, after clinicobiological consultation.

Influence of Haemolysis on the Mineral Profile of Cattle Serum.

Simple SummaryThe results of blood tests routinely used in clinical chemistry can be altered by haemolysis, the disruption of red blood cells. Haemolysis of serum samples is recognized to be the leading cause of preanalytical errors in clinical laboratories. The influence of haemolysis must be specifically studied for each analyte and species of clinical interest, as it is often not known how serum samples are affected. Little is known about the potential alterations in the concentrations of mineral elements in haemolyzed serum in general and the phenomenon has not been specifically studied in bovine serum samples. We investigate how haemolysis affects the mineral content of bovine samples.Haemolysis of serum samples is the leading cause of preanalytical errors in clinical laboratories. Little is known about the potential alterations in the concentrations of mineral elements in haemolyzed serum and the phenomenon has not been specifically studied in bovine serum samples. We investigate how haemolysis affects the mineral content of bovine samples. We used ICP-MS to measure the concentrations of 12 mineral elements (Ca, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, P, Se and Zn) in bovine whole blood, serum and gradually haemolyzed samples and observed significant differences between the different types of samples, particularly in the Fe and Zn concentrations. However, in practice, the high interindividual variability makes it difficult to establish whether a given value corresponds to normal or haemolyzed samples. In response to this problem, we propose to consider that a result is significantly biased when the haemolysis threshold (the degree of haemolysis above which the concentration of an element in serum is significantly altered) of a given element is surpassed. The haemolysis threshold values for the different elements considered were found as follows: 0.015 g Hb L−1 for Fe, 2 g for Zn, 4 g for Cr and 8 g for Ca, Se and Mo.

The influence of haemolysis on the determination of vitamin E in cattle

The study deals with the influence of haemolysis on the results of vitamin E determination in plasma (serum) in cattle. Although nowadays specific High Performance Liquid Chromatography (HPLC) techniques are used almost exclusively for the determination of vitamin E, this indicator is also influenced by haemolysis. This occurs in the pre-analytical phase due to the fact that iron contained in haemoglobin is able to catalyze peroxidation reactions. Subsequently, changes occur mainly in polyunsaturated fatty acids in the lipoprotein components of serum/plasma. The vitamin E present inhibits this process, as a result of which its concentration is reduced. The experiment was performed by preparing model samples with a defined degree of haemolysis by adding haemolysate to the centrifuged plasma in the range of ca 0–12 g/l, i.e. mild to severe haemolysis. After 4 h of incubation at room temperature, the vitamin E concentration was determined by the HPLC method. Haemolysis was found to reduce the test result; mild one (approximately up to 2 g/l) non-significantly, medium and severe haemolysis by up to tens of percent, which warrants repeated sampling. False reductions in results will not endanger the patient’s health, but economic losses may occur due to unnecessary check-ups and increased vitamin E supplementation.

Evaluation of the Effect of Hemolysis on Quantitative Chemiluminescent Immunoassay Results for 10 Analytes.

The aim is to evaluate the effect of hemolysis on the quantitative chemiluminescent immunoassay results of 10 analytes and to provide a basis for formulating specific sample rejection criteria and reviewing report results. Hemolysis based on the clinical hemolysis index, hemolysis 1+, 2+, and 3+ samples and matched normal samples were collected. The quantitative chemiluminescent immunoassay results of 10 analytes from the two samples (hemolysis and normal) were determined and differences between the results obtained from samples with different degrees of hemolysis and those obtained from normal samples were evaluated. A total of 34 pairs of samples were collected, including 10 pairs of 1+ hemolysis samples, 10 pairs of 2+ hemolysis samples, and 14 pairs of 3+ hemolysis samples. The quantitative chemiluminescence immunoassay detection results for the 10 analytes showed that regardless of the degree of hemolysis, the differences in alpha fetoprotein (AFP), carcinoembryonic antigen (CEA), carbohydrate antigen (CA19-9), luteinizing hormone (LH), folli-cle-stimulating hormone (FSH), and ferritin (FER) between the hemolysis and normal samples were all lower than the total allowable error (TEa) based on biological variation; there were no statistically significant differences between the samples. However, the results for insulin (INS) began to decrease significantly at a hemolytic index of 1+, folic acid (FOL) showed an increase at a hemolytic index of 2+, and there was a significant difference at a he-molytic index of 3+. This research identified the analytes that are susceptible to hemolysis interference in chemiluminescent immunoassays. The influence of hemolysis on hemolytic clinical laboratory tests was closely related to the assay system used; thus, laboratories should evaluate the effect of hemolysis on their own analysis systems and define assay-specific hemolysis warning indices.

Influence of hemolysis on serum procalcitonin measured by electrochemiluminescence in an emergency room.

To investigate the effect of hemolysis on serum procalcitonin (PCT) detected by electrochemiluminescence (ECL) and to explore the possibility of establishment of a correction equation. Fifty-one blood samples from 17 patients were collected. Hemolytic samples, of which the final concentrations of hemoglobin (Hb) were 5, 10, 15 and 20 g L-1, were prepared by adding lysed homologous RBCs to serum, and then the PCT levels were detected and compared. with the increasing degree of sample hemolysis, PCT bias elevated from -13.12% to -38.86% as the hemolysis degree increased from 5 g L-1 to 20 g L-1, respectively. There was a linear correlation of PCT levels between the original and hemolytic samples with the same hemolytic degree (r > 0.97). Using the correction equation log10PCTcorr = 0.962(log10PCThemo) +0.251(log10Hb) - 0.126, the corrected PCT values from the hemolytic samples showed acceptable consistency with the original values (p > 0.05). Hemolysis has a negative interference on PCT values assayed by ECL. The serum PCT level is correlated negatively with the Hb level in the blood sample. The established correction equation could reduce inappropriate antibiotics application and improve the experience of patients in the emergency department.

Simultaneous determination of 8 beta-lactams and linezolid by an ultra-performance liquid chromatography method with UV detection and cross-validation with a commercial immunoassay for the quantification of linezolid

Linezolid and beta-lactams are anti-infective drugs frequently used in intensive care unit patients. Critical illness could induce alterations of pharmacokinetic parameters due to changes in the distribution, the metabolism and the elimination process. Therapeutic drug monitoring (TDM) is therefore recommended to prevent mainly under-dosing of beta-lactams or hematological and neurological toxicities of linezolid. In Multi-or Extensively-Drugs Resistant-Tuberculosis Bacteria, the regimen could include linezolid with meropenem and amoxicillin/clavulanate justifying the development of a method allowing their simultaneous quantification.The aim of this work was to develop an in-house ultra-performance liquid chromatography method with UV detection (UHPLC-PDA) allowing the simultaneous determination of 8 beta-lactams (amoxicillin, aztreonam, cefepime, ceftazidime, ceftriaxone, cefuroxime, meropenem and piperacillin) and linezolid and to cross-validate the linezolid quantification with a new commercial immunoassay (ARK kit) tested on a Cobas analyzer. The main advantages of the immunoassay are a 24/24 h random access assay which is fully automated and results provided within 2 h.The interference due to potential co-administrated drugs was evaluated on both methods. The preanalytical factors (type of matrix, stability) for linezolid were also investigated. The influence of hemolysis, icteria or lipemia on the spectroscopic detection of the immunoassay was assessed. The analytical performances were evaluated using the accuracy profiles approach with acceptance limits fixed at ±30%. Seventy patient samples were measured using both methods.No cross-reaction with the tested anti-infective drugs as well as no influence of hemolysis, lipemia, icteria were observed. The linezolid concentration could be measured on heparinized plasma or serum without a significant difference and remained stable for at least 72h at 4°C.The UHPLC-PDA method performed well in the analytical range investigated (0.25–50 mg/L for meropenem, 0.75–50 mg/L for linezolid and 1–200 mg/L for other beta-lactams) with an intermediate precision and a relative bias below 7.6 and 7.7%, respectively. The analytical range of the immunoassay was narrower, from 0.85 to 18.5 mg/L. The precision and relative bias were lower than 8.1% and 4.2%, respectively. Results obtained on clinical samples showed an acceptable difference between methods with a mean bias of -1.8% [95% confidence interval: -5.2% – 1.6%].To conclude, both methods showed acceptable performance to perform TDM of linezolid considering the therapeutic through target of 2-8 mg/L. The choice of the method should be made according to the degree of emergency of the response required and the field of application justifying or not the simultaneous quantification of beta-lactams and linezolid.

The Estimation of Postmortem Serum Urea via the Ultrafiltration of Hemolyzed Blood.

Postmortem serum urea has been demonstrated as an objective indicator for the forensic diagnosis of cause of death. However, samples used in postmortem biochemical analysis are always affected by hemolysis. To investigate whether hemolysis affects the biochemical analysis of urea and to explore the feasibility of using ultrafiltration to process hemolyzed blood samples, three different levels of hemolyzed blood samples were used to assess the influence of hemolysis on postmortem biochemical analysis of urea, and two ultrafiltration methods were used to process the hemolyzed blood samples. Bias% was used to assess the interference of hemolysis. Our results showed that heavy hemolysis had a significant influence on the biochemical analysis of urea. Both ultrafiltration methods in the present study could significantly reduce the interference of hemolysis, with the |bias%| of methods A and B decreasing from 69.74% ± 99.14% to 12.18% ± 7.23% and 10.77% ± 8.09%, respectively, compared to the original serum. After regression correction, there was no significant difference between the urea concentration in the ultrafiltrates of the two ultrafiltration methods and that in the original serum, which suggested that the postmortem serum urea concentration could be estimated by the corrected urea concentration in the ultrafiltrate. The current study also provided possible pretreatment methods for postmortem biochemical analysis of other biomarkers in hemolyzed blood samples of forensic practice.

Hemolysis interference in 10 coagulation assays on an instrument with viscosity‐based, chromogenic, and turbidimetric clot detection

Hemolysate in plasma samples from patients may cause misleading results in coagulation assays. Even though modern coagulation instruments often are equipped with modules that can detect hemolysis, icterus, and lipemia (HIL), studies that report the influence of these interferences are still limited. The present paper focuses on the influence of hemolysis on 10 coagulation assays. Artificial hemolysis was created by freezing/thawing, and the hemolysates generated were added to pools of patient plasma. Pathological and normal levels were pooled separately. These spiked samples were analyzed on a STA R Max 2 instrument. The coagulation assays evaluated utilize clot, chromogenic, or immunoturbidimetric detection. Four of the evaluated assays were not influenced by hemolysis: fibrinogen, von Willebrand factor antigen, activated partial thromboplastin time, and factor VIII. Interestingly, normal and slightly elevated prothrombin time (INR<2.0) was insensitive to hemolysis, whereas samples with a high INR (≥2.0) exhibited falsely high readings. The assays for antithrombin and fibrin D-dimer displayed an intermediate sensitivity to hemolysis. The most sensitive assay turned out to be anti-Xa, followed by protein C and protein S. For the anti-Xa assay, the results are decreased by 10% already at 0.5g/L hemoglobin. The present study shows that hemolysis affects several of commonly used coagulation assays. Since the sensitivity for hemolysis is dependent on the brand of the assay as well as the instrument and principle of measurement, it is necessary to evaluate the influence of each specific combination.

Influence of hemolysis, icterus and lipemia on coagulation tests as performed on Cobas t511 new analyzer.

: In the coagulation laboratory, spurious hemolysis, icterus and lipemia (HIL) in test samples represent by far the leading diagnostic prenalytical challenges. The aim of this study was to assess the performance of the preanalytical module on the new hemostasis analyser Cobas Roche t511. We assessed the influence of HIL on prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (Fib), antithrombin and D-dimer on plasma pools aliquots with different interference degrees. Moreover, we evaluated spontaneous hemolysis by comparing results on 50 paired samples (hemolysed versus nonhemolysed). Spurious hemolysis interference studies highlight the absence of a clinical significant impact on PT, APTT and antithrombin test results at all hemoglobin concentration investigated. For Fib and D-dimer assays a clinically significant difference was observed in the most hemolysed aliquot for Fib and in the two most hemolysed aliquots for D-dimer. Spontaneous hemolysis interference studies showed no clinical significant differences for PT and antithrombin assays, instead for APTT, Fib and D-dimer we found significant statistical and clinical differences between hemolysed and non hemolysed specimens. Bilirubin interference studies and lipemic samples interference studies enable us to confirm that the differences in the results obtained between the different aliquots and reference pool is not clinically significant for all assays. HIL check preanalytical module of Cobas Roche t511 analyzer displaied excellent performance for routine use in clinical laboratories. Regardless of analytical considerations, the type of interference encountered with spurious HIL is substantially different and requires different approaches.

Inhibition of the procarboxypeptidase U (proCPU, TAFI, proCPB2) system due to hemolysis

Spurious hemolysis of samples is the leading cause of interference in coagulation testing and was described to interfere in fibrinolysis assays. The influence of hemolysis on the procarboxypeptidase U (proCPU) system is not known. By means of spiking of hemolysate in pooled normal plasma, the effect of hemolysis on CPU, proCPU, and functional clot lysis assays was assessed. The influence of hemolysis on CPU generation during in vitro clot lysis was also evaluated. Cutoffs corresponding to maximal acceptable bias were determined. When active CPU was added to pooled plasma, a severe decrease in activity - up to 97.2% inhibition - was seen with increasing plasma concentrations of oxyhemoglobin (oxyHb) and the 10% cutoff value was found to be 0.3g/L oxyHb. Using an activity-based assay, proCPU levels appeared to decrease gradually with increased hemolysis (maximal reduction of 19.5%) with a 10% cutoff value of 4.2g/L oxyHb. The relative clot lysis time (CLT) showed a maximal negative bias of 68.5%. The reduction in CLT paralleled a significant reduction of the first CPU activity peak during clot lysis. The cutoff value for the CLT was 0.4g/L oxyHb. In presence of thrombomodulin (TM), CLT+TM was not affected up to 8.0g/L oxyHb. These data indicate a clear inhibition of the CPU system because of hemolysis resulting in an increase of lysis in functional fibrinolysis assays. We were able to quantify the inhibitory effect and to propose cutoff values for every parameter.

Pengaruh Hemolisis Terdapat Kadar Serum Glutamate Pyruvate Transaminase (SGPT) Sebagai Salah Satu Parameter Fungsi Hati

AbstractSGPT examination is one of the important checks on the state of a particular patient, for example, in patients with liver disease, hepatitis, and so forth. The other purpose is to detect the presence of liver damage. So there was an effect in the event of an increase in maupaun drop in levels. And the serum circumstances that do not qualify, such as serum hemolysis, will greatly affect the actual levels of ALT. Based on the research background, the authors formulate the problem as follows: "Is there any effect of hemolysis on SGPT levels as one of the parameters of liver function?". The purpose of this study is to prove whether there is an influence of hemolysis on SGPT levels as one of the parameters of liver function. The sample was 20 samples and 20 samples of hemolysis hemolysis. Location and time of the research conducted at Muhammadiyah Hospital Clinical Laboratory Lamongan ie in January and July. Of the 20 samples analyzed, showing that levels higher than the hemolysis ALT SGPT levels no hemolysis. When the serum through lysis will experience a significant increase. To test the effect of hemolysis on SGPT levels paired t test was used because the data from this study with normally distributed. The results of a paired t test analysis between serum hemolysis and no hemolysis on levels of serum ALT levels showed a significant value 0.00 thus P &lt;0.05 it can be concluded that there is no difference between the levels of ALT SGPT levels of hemolysis with hemolysis. That means there is the influence of hemolysis on SGPT levels as one of the parameters of liver function. Key word : hemolysis, glutamate pyruvate transminase

Specificity of, and influence of hemolysis, lipemia, and icterus on serum lipase activity as measured by the v-LIP-P slide.

Measurement of pancreatic lipase in serum is being used for the diagnosis of pancreatitis. The aims of this study were to measure serum lipase activity by the v-LIP-P slide and serum canine pancreatic lipase immunoreactivity (cPLI) concentration by Spec cPL in dogs with exocrine pancreatic insufficiency (EPI) and in serum samples that were hemolyzed, lipemic, or icteric. Serum samples from 50 dogs with EPI, 8 samples spiked with canine hemoglobin, Intralipid, or ditaurobilirubin, and 8 samples from dogs with severe hypertriglyceridemia were evaluated using v-LIP-P and Spec cPL assays. Serum lipase activity (v-LIP-P) was in the lower 20% of the RI in 58% of EPI dogs, while serum cPLI (as measured by Spec cPL) was in the lower 20% of the RI in 98% of EPI dogs. The mean (±SD) observed-to-expected ratios for serum samples spiked with canine hemoglobin, Intralipid, or ditaurobilirubin were 63.0 ± 25.1%, 489.2 ± 469.7%, and 80.2 ± 11.6% for the v-LIP-P slide, respectively, and 99.3 ± 6.8%, 96.9 ± 9.4%, and 98.7 ± 11.0% for Spec cPL, respectively. However, naturally occurring hypertriglyceridemia did not appear to have a significant effect on serum lipase activity as measured by the v-LIP-P slide. These results show that Spec cPL is specific for pancreatic lipase, while the v-LIP-P slide is not. In addition, hemolysis and lipemia had no effect on Spec cPL, while severe icterus resulted in a slight decrease in Spec cPL. Hemolysis and icterus had a significant effect on the v-LIP-P slide. The effect of lipemia on the v-LIP-P slide cannot be conclusively established based on this study.

Proteinemia normal en Costa Rica

The distribution of the several protein components of human serum was studied in a total of 500 subjects, of which 182 were women and 318 were men: in turn, out of these figures, there were 31 males and 69 females whose age was less than 9 years old. This group was taken as a representative sample fragment of Costa Rican population and Wolfson's method was used in all quan­titative determinations. The following results were obtained for the entire group: Total proteins = 7,00 ± 0,49 gr % Serum albumin = 3,89 ± 0,48 gr % Total serum globulins = 3,11 ± 0,39 gr % α globulin = 1,03 ± 0,23 gr % β globulin = 0,86 ± 0,45 gr % γ globulin = 1,22 ± 0,18 gr % A/G ratio = 1,25 ± 0,26 Also a comparison is made of the results obtained usings Wolfson's procedure with those of Kolmer's modified Greenberg and Van Slyke's. The influence of hemolysis in the fractionation of serum protein using Wolfson's method was also noticed.

Influence of Hemolysis on Analytic Results of Nuclear Magnetic Resonance-based Metabonomics

Influence of Hemolysis on Analytic Results of Nuclear Magnetic Resonance-based Metabonomics

A false positive case of cardiac troponin I identified with CK-MB reflex testing

The assessment of cardiospecific troponins, either troponin I (TnI) or T (TnT), is currently regarded as the mainstay for diagnosing myocardial injury, including acute myocardial infarction (AMI) [ [1] Aldous S.J. Cardiac biomarkers in acute myocardial infarction. Int J Cardiol. 2013; 164: 282-294 Abstract Full Text Full Text PDF PubMed Scopus (84) Google Scholar ]. Although the recent introduction of high-sensitivity troponin immunoassays has contribute to substantially increase the timely and accurate detection of myocardial injury, troponin testing is still plagued by a significant rate of false positive cases, which ultimately contribute to decrease the overall diagnostic specificity of these tests [ [2] Vafaie M. Biener M. Mueller M. et al. Analytically false or true positive elevations of high sensitivity cardiac troponin: a systematic approach. Heart. 2014; 100: 508-514 Crossref PubMed Scopus (34) Google Scholar ]. The leading sources of false positive results of troponin testing include genetic polymorphisms in the TnI and TnT genes which may impair antibody binging [ [3] Lippi G. Cervellin G. Genetic polymorphisms of human cardiac troponins as an unrecognized challenge for diagnosing myocardial injury. Int J Cardiol. 2014; 171: 467-470 Abstract Full Text Full Text PDF PubMed Scopus (7) Google Scholar ], as well as the interference from rheumatoid factor (RF) [ [4] Dupont J. Fromonot J. Franceschi F. et al. A case of false positive troponin elevation: role of the biological laboratory. Int J Cardiol. 2013; 162: e66-e67 Abstract Full Text Full Text PDF PubMed Scopus (7) Google Scholar ], heterophilic antibodies [ [5] Lippi G. Aloe R. Meschi T. Borghi L. Cervellin G. Interference from heterophilic antibodies in troponin testing. Case report and systematic review of the literature. Clin Chim Acta. 2013; 426: 79-84 Crossref PubMed Scopus (60) Google Scholar ] and spurious hemolysis [ [6] Lippi G. Avanzini P. Dipalo M. Aloe R. Cervellin G. Influence of hemolysis on troponin testing: studies on Beckman Coulter UniCel Dxl 800 Accu-TnI and overview of the literature. Clin Chem Lab Med. 2011; 49: 2097-2100 Crossref PubMed Scopus (26) Google Scholar ].

Interference of hemolysis in the estimation of plasma aspartate aminotransferase, potassium and phosphate

Objective: The objective was to analyze the effect of hemolysis on estimation of biochemical constituents in the plasma. Materials and Methods: Twenty different pooled plasma samples were collected from 80 apparently healthy volunteers at Alnaw Hospital and Khartoum teaching hospital and research laboratory unit. Hemolysate was prepared by freezing at −20°C overnight and serial dilution of hemolysate was prepared (0.125, 0.25, 0.5, 1, 2, 4, and 8 g/dl). Each pooled plasma samples was dispensed into 8 different tubes (900 μl in each tube) to which 100 μl of different concentration of the hemolysate were added in each of the tubes. A baseline control was prepared with 100 μl of distilled water. Plasma aspartate aminotransferase (AST), potassium and phosphate were measured in each of the tubes. Plasma level of AST and phosphate were measured using Hitachi 902 Analyzer (USA for Hitachi 920 analyzer), whereas potassium was measured using ion-selective electrode. Result: The result showed that plasma AST, potassium, and phosphate were significantly raised at hemoglobin (Hb) concentration of 0.4 and 0.8 g/dl (P < 0.0l), whereas plasma potassium and AST was significantly increased at Hb concentration of 0.1 and 0.2 g/dl (P < 0.01). Further at 0.05 g/dl Hb concentration, only plasma potassium was significantly increased (P < 0.05) but not others. Conclusion: There will definitely be a great influence of hemolysis on the estimation biochemical parameters in the plasma giving false-positive values.

Need for Randomized Clinical Trials on Intraoperative Parathyroid Hormone Kinetics

T he use of intraoperative PTH testing to assure that no abnormally functioning parathyroids remain in the patient after removal of 1 parathyroid adenoma has slipped into widespread clinical use. In my opinion, this is unfortunate since the outcomes of this strategy have not been subjected to randomized clinical trials. Observational studies from the active, experienced, and world-renowned endocrine surgeons at the University of California, San Francisco have demonstrated less than 50% predictive success rate in patients with double parathyroid adenomas, a 13% falsenegative rate with single parathyroid adenomas, a negative influence of hemolysis on the reliability of IOPTH measurement, and now the suggestion that race and BMI may impact PTH kinetics. I worry about the statistical validity of comparing 28 African American patients with 734 white patients, especially when other variables are in play (BMI, vitamin D deficiencies, and 24-hour urinary calcium excretion). Using IOPTH changes for clinical decision making in the operating room requires expense of time, material, and people, both in the operating room and in the laboratory. Reliability of this strategy suggests that all types of patients with all varieties of hyperparathyroidism would have uniform response of PTH kinetics in a predictable fashion. To me, this seems unlikely. Different anesthetics, length of operation, avenues for blood acquisition (peripheral vein, central vein, jugular vein, or peripheral artery), and operative techniques of parathyroid manipulation might all have effects on IOPTH kinetics and values. Because of their expertise and high volume of cases, the surgeons of the University of California, San Francisco and their cadre of trained fellows would be ideally suited to conduct a randomized clinical study in a standardized fashion that could determine the values, reliability, and costs of using IOPTH strategies vs not using them.

Skeletal Muscle Biomarkers in Heart Disease

On the other hand, methods on the market are nonstandardized, causing significantly different 99th percentile limits across the cTn assays [6]. Heterogeneity between assays is caused by the use of different antibodies for capture and detection of circulating cTn forms. A practical and convenient approach to deal with these differences has been proposed by Apple [6]. One of the factors taken into account in his scorecard for individual cTn assays is the analytical criterion recommended by the international guidelines, which requires a total imprecision equal to or less than 10% at the 99th percentile value [1,2]. Assays that are compatible with this requirement are designated as ‘guideline acceptable’. Using 20% as the maximal acceptable imprecision excludes a contemporary assay from clinical use, and assays with an imprecision between 10 and 20% are indicated as ‘clinically usable’ [6]. Another analytical issue that is important for clinical interpretation of cTn results is the impact of interferences. For example, human antimouse antibodies and rheumatoid factor cause falsely increased cTn, while anti-cTn autoantibodies cause falsely decreased cTn [7,8]. The influence of hemolysis appears to be method dependent, as it has been reported to increase cTnI on Vitros ECi (Ortho-Clinical Diagnostics) and to decrease cTnT on Roche instruments [9].