Hospital Central Laboratory Research Articles

PRE-ANALYTICAL ERRORS IN THE CLINICAL LABORATORY AND HOW TO MINIMIZE THEM

Since evidence based medicine (EBM) is now become the main principle guiding clinical practice and is being followed universally the role of laboratory medicine in EBM needs not to be over- emphasized. So it is the need of the hour to ensure that the best evidence on testing is made available through the help of the laboratory to the clinician. This would result in making the best decision based on test results which would lead to increased probability of improved health outcomes. So it is necessary for the laboratory to maintain the strictest quality possible. Here we would see the steps of pre-analytical phase and the various points at which error can arise and how to mitigate them. The present study was carried out in our hospital central laboratory and data were collected and analyzed. Pre-analytical phase is most important in testing process and involves variables that are not under the control of the laboratory. So much care needs to be taken to deeply scrutinize this step of analysis and keep a tab on errors arising in it.

Prevalence of dyslipidemia among human immunodeficiency virus infected Nigerians

Dyslipidemia is a significant risk factor for premature cardiovascular disease. People infected with human immunodeficiency virus (HIV) have been shown to develop alterations in body composition, lipid and glucose metabolism, which predisposes them to cardiovascular disease. Human immunodeficiency virus (HIV) infection and its therapies may contribute to these changes. These metabolic changes in addition to the other traditional risk factors may contribute to the excess cardiovascular disease (CVD) morbidity and mortality observed in HIV-infected individuals. We, therefore set out to describe the prevalence of dyslipidemia among HIV infected Nigerians. This is a cross sectional study, was conducted in HIV specialty clinic of Aminu Kano Teaching Hospital (AKTH) between May and August 2009. HIV infected patients were recruited. Half of them were on HAART for 6 months and above while the other half were HAART naïve. Patients who satisfied inclusion criteria were recruited consecutively until the required sample size was obtained. Data were collected using the pre-tested interviewer administered questionnaire. Socio-demographic information, anthropometric measurements and blood pressure were obtained from the subjects in a standardized manner. Venous samples were collected for necessary investigations and analyzed at the hospital central laboratory. Two hundred subjects were studied, the mean age for all the participants was 32.5 ± 7.55 years. The age ranged from 20 to 50 years, 64% of the respondents (128) were aged between 20 and 34 years. Forty three (21.5%) of them were above the age of 40 years. Fifty percent were on HAART and the other 50% were HAART naïve. The duration of HAART treatment ranged from 6-84 months. The mean CD4 cell counts was higher for subjects on HAART compared to HAART naive 376.33±215.66 and 261.09 ±195.64, respectively (P < 0.001). High TC (31% vs. 7%, P ≤ 0.001), low HDL-C (61% vs. 76%, P = 0.022), high LDL (36% vs. 26%, P = 0.126), high TG (19% vs. 13%, P = 0.247). HIV infected patients on HAART demonstrated higher prevalence of high TC while HAART naïve subject showed higher prevalence of low HDL.

Renalase and Endothelial Dysfunction in Heart Transplant Recipients

IntroductionRenalase, an enzyme that cetabolyzes catecholamines, such as circulating adrenaline and noradrenaline, is released by the human kidney to regulate blood pressure. In solid organ transplant recipients endothelial dysfunction is often present. The aim of our study was to assess correlations among renalase, blood pressure, endothelial injury markers, and kidney function in 130 prevalent heart allograft recipients (OHT). MethodsComplete blood counts, urea, serum lipids, fasting glucose and creatinine were measured using standard laboratory methods in the hospital central laboratory. We assessed markers of endothelial function/injury: vWF (von Willebrand factor), inflammation: hsCRP, interleukin (IL)-6, TRAIL (tumor necrosis factor related apoptosis-inducing ligand), TWEAK (tumor necrosis factor-like weak inducer of apoptosis) and midkine renalase using commercially available kits. ResultsThe mean serum renalase among OHT was significantly higher compared with a control group (P < .001). Among heart transplant recipients renalase correlated weakly (P < .05) with time after transplantation and TRAIL; moderately (P < .01), with ejection fraction and age; and strongly, with kidney function, IL-6, vWF, midkine, and New York Heart Association class (P < .05). Multiple regression analysis revealed renalase values to be 70% predicted by serum creatinine measurements. ConclusionImpaired kidney function was strongly associated with endothelial damage and inflammation. Renalase, which was highly elevated among heart transplant recipients, was predominantly dependent on renal function, which deteriorated with time after transplantation and in correlation with age.

VAP-1, a Novel Molecule Linked to Endothelial Damage and Kidney Function in Kidney Allograft Recipients

VAP-1 (vascular adhesion protein-1) is a copper-containing SSAO (semi-carbazide sensitive amine oxidase) secreted by vascular smooth muscle cells, adipocytes, and endothelial cells with functional monoamine oxidase activity. The oxidation process generates harmful products that may be involved in causing atherosclerosis and vascular damage in diabetes. Elevation of SSAO activity is observed in atherosclerosis, diabetes mellitus and obesity. On the other hand, renalase, with possible monoamine oxidase activity, which breaks down catecholamines like SSAO, is also expressed in the endothelium as well as in the kidney The aim of the study was to assess VAP-1 levels and its correlations with endothelial injury markers and renalase in 50 kidney allograft recipients. Methods: Complete blood count, urea, serum lipids, fasting glucose, creatinine, were studied by standard laboratory method in the hospital central laboratory. We assessed markers of endothelial function/injury: vWF (von Willebrand factor), thrombomodulin, ICAM (intracellular adhesion molecule), VCAM (vascular cell adhesion molecule), CD40L, CD44, CD146, inflammation: hsCRP, and IL-6 and adipocytokines: leptin, adiponectin, visfatin, apelin with commercially available assays. Results: The mean serum VAP-1 in Tx was significantly higher comparing to the control group. In kidney transplant recipients VAP-1 correlated with BMI (r=0.39, p< 0.01), CD44 (r=0.27, p< 0.05), hsCRP (r=0.28, p< 0.05), serum creatinine (r=0.29, p< 0.05), eGFR (CKD-EPI formula r=-0.27, p< 0.05, by MDRD r=-0.27, p< 0.05, by Cockcroft-Gault r=-0.35, p< 0.01), serum urea (r=0.27, p< 0.05), CD146 (r=0.49, p< 0.001), CD40L (r=0.26, p< 0.06), and renalase (r=0.34, p< 0.05)Figure: [VAP-1 and renalase in Ktx]In multiple regression analysis VAP-1 was predicted 80% by serum creatinine (beta value 0.33, p=0.01), and CD146 (beta value 43, p=0.0005) F=12.26, SE= 71.83 and p< 0.000001. Concluding, VAP-1, elevated in kidney transplant recipients, is predominantly dependent on endothelial damage and kidney function, which deteriorated with time after kidney transplantation and age.

The Xpert® MTB/RIF assay evaluation in South Korea, a country with an intermediate tuberculosis burden

A central hospital laboratory in South Korea. To evaluate the usefulness of the Xpert® MTB/RIF assay in a country with an intermediate tuberculosis burden. A total of 71 real-time polymerase chain reaction-positive sputum sediments were tested within 24 h by the Xpert MTB/RIF assay. Mycobacterium tuberculosis detection was compared with smear microscopy and culture. Rifampicin (RMP) resistance was compared with a culture-based method and rpoB gene sequencing. We also assessed the limit of detection for mutant proportions and time savings in diagnosis. The Xpert MTB/RIF assay detected M. tuberculosis in 71 (100%) specimens (32 smear-positive, 39 smear-negative). This assay showed 100% (62/62) concordance with drug resistance confirmed by culture and 98.4% (61/62) concordance with sequencing. A specimen containing approximately 50% of mutant p.His526Tyr was falsely interpreted as wild-type bacilli by this assay. The minimal detection ratio was 5:1 of mutant vs. wild-type cells. The median time saved was 18.5 days (range 9-30) for the diagnosis of M. tuberculosis and 81.5 days (65-136) for RMP susceptibility in smear-negative, culture-positive patients. The Xpert MTB/RIF assay showed high sensitivity in detecting M. tuberculosis with information on RMP resistance, and had a more rapid time to diagnosis compared to conventional tests; however, the location and amount of mutation may affect test sensitivity.

Retrospective Evaluation of the Results of Women Patients of Childbearing Age Investigated at a Microbiology Laboratory for Screening Toxoplasma gondii, in Antalya

Infection with Toxoplasma gondii usually does not cause clinical symptoms in humans, but an acute infection during pregnancy can lead to congenital toxoplasmosis. Infection in early pregnancy may cause abortion, stillbirth or serious abnormalities of the fetus. In this study, determination of T. gondii seroprevalence among women of childbearing age who presented to our hospital's clinics is aimed. Toxoplasma IgM antibodies were investigated in 5013 sera and Toxoplasma IgG in 2986 sera of women between 15-49 years, in our hospital central laboratory, between 01 November 2008 and 31 August 2010. Eighty-nine (1.8%) seras were detected positive for Toxoplasma IgM and 968 (32.4%) for Toxoplasma IgG antibodies. It has been determined that 67.6% of women in the province of Antalya and its surroundings are susceptible to acute Toxoplasma infection during childbearing age and their babies are an at risk group for congenital toxoplasmosis.

Vascular adhesion protein-1 and renalase in regard to diabetes in hemodialysis patients

IntroductionVascular adhesion protein-1 (VAP-1) is a copper-containing semicarbazide-sensitive amine oxidase (SSAO) secreted by vascular smooth muscle cells, adipocytes, and endothelial cells with functional monoamine oxidase activity. Renalase, with possible monoamine oxidase activity, which breaks down catecholamines like SSAO, is also expressed in the endothelium as well as in the kidney. The aim of the study was to assess VAP-1 level and its correlation with renalase level in 60 hemodialyzed (HD) patients.Material and methodsComplete blood count, urea, serum lipids, fasting glucose and creatinine were studied by the standard laboratory method in the hospital central laboratory. We assessed VAP-1 and renalase with commercially available assays.ResultsThe mean level of VAP-1 as well as renalase was significantly higher in HD patients when compared to the control group (291.01 ±94.91 ng/ml vs. 158.34 ±56.89 ng/ml, p < 0.01; 27.53 ±9.394.91 µg/ml vs. 4.00 ±1.37 µg/ml, p < 0.001, respectively). In hemodialysis patients VAP-1 correlated with presence of diabetes (r = 0.27, p < 0.05), presence of hypertension (r = 0.32, p < 0.05), use of calcium channel blockers (r = 0.30, p < 0.05), use of β-blockers (r = 0.25, p < 0.05), ejection fraction (r = –0.38, p < 0.01), systolic blood pressure before (r = 0.52, p < 0.001) and after hemodialysis (r = 0.30, p < 0.01), and weight gain (r = 0.41, p < 0.01). Renalase was not significantly different in diabetic and non-diabetic patients or between hypertensive and normotensive patients. In multiple regression analysis VAP-1 was predicted 77% by serum ejection fraction and fibrinogen.ConclusionsVascular adhesion protein-1, elevated in patients on hemodialysis, was predominantly dependent on blood pressure and diabetes, both factors associated with endothelial damage and promoting cardiovascular complications. Renalase appeared to be unrelated to VAP, at least in the HD population.

Effects of two commercial insulin immunoassays on insulin c-peptide correlation

The molar ratio of insulin to C-peptide in peripheral venous blood argues for surreptitious/inadvertent insulin administration or insulinoma/sulfonylurea ingestion as the cause of the hypoglycemia. Commercial immunoassays for insulin are prone to discrepancy because of heterogeneity in circulating forms that react with antisera and cross-reactivity with proinsulin. In this study we compared molar ratio of insulin to C-peptide analyzed by different assays in independent patient groups. In this retrospective study patients admitted to Gaziantep University Hospital Central Laboratory between 2010-2011 recruited the study group. Patients with unknown or positive history of insulin therapy were excluded. Study groups were constructed according to insulin analysis methods; 78 patients whose insulin levels have been assayed by Abbott Architech i2000 (group 1) and by Immulite2000 (n:132, group 2). C peptide levels of the both groups have been analyzed by Immulite2000. Insulin to C-peptide ratio is higher for group1 than group 2 (p>0.05). The correlation coefficient of group 1 was lower than group 2 (r: 0,46 vs. r: 0,65, p

Serum Renalase Depends on Kidney Function But Not on Blood Pressure in Heart Transplant Recipients

Introduction Renalase, an enzyme that breaks down catecholamines like adrenaline and noradrenaline in the blood circulation, was discovered in 2005. The human kidney releases this protein into the bloodstream to regulate blood pressure. Heart transplant recipient show a high prevalence of hypertension. The aim of this study was to assess possible correlations between renalase, blood pressure, and kidney function among 130 prevalent heart transplant recipients. To obtain normal ranges we also studied renalase levels in 27 healthy volunteers. Methods Complete blood counts, urea, serum lipids, fasting glucose, and creatinine were measured using standard laboratory methods in the hospital central laboratory. Renalase was assessed using commercially available kits. Results In heart transplant recipients renalase levels correlated with age ( r = 0.25; P < .05); time after transplantation ( r = 0.22; P < .05); serum creatinine ( r = 0.85; P < .001); estimated glomerular filtration rate (chronic kidney disease-epidemiological study formula; r = 0.59; P < .0001; Modification of Diet of Kidney Disease ( r = −0.58; P < .001); Cockcroft-Gault ( r = −0.59; P < .001); 24-hour creatinine clearance ( r = −0.52; P < .001); NT-proBNP ( r = 0.41; P < .001); erythrocyte count ( r = −0.42; P < .001); hemoglobin ( r = 0.44; P < .001); cystatin C ( r = 0.82; P < .001); ejection fraction ( r = −0.26; P < .01; and New York Heart Association class ( r = 0.31; P < .001). Multiple regression analysis showed renalase concentration to be predicted in 75% by serum creatinine (beta value, 0.79; P = .0000000; SE 3.00; F statistics 15.96; P < .0000001). Serum renalase was higher among heart transplant recipients than healthy volunteers. Conclusion Renalase, highly elevated in heart transplant recipients, is predominantly dependent on kidney function, which deteriorates with time after heart transplantation and age. Further studies are needed to establish its putative role in the pathogenesis of hypertension after transplantation and possible novel targeted therapies. However, is seems that among heart transplant recipients renalase was not related to blood pressure.

A dedicated cardioversion unit for the treatment of atrial fibrillation

Atrial fibrillation (AF) is the most frequent arrhythmia seen in man. Many patients are admitted to the hospital to undergo transesophageal echocardiography (TEE) for thrombus exclusion and subsequent electrical cardioversion (ECV) under deep sedation to restore sinus rhythm. The present study investigated prospectively how workflow optimization can contribute to reducing time and costs in AF patients scheduled for ECV in an outpatient setting. A cardioversion unit (CU) was established and equipped to perform all ECV-associated procedures. Between November2007 and January2009, ECV was performed in 115patients in an outpatient setting. Three different settings were tested for ECV: (1) usual care (n = 19): preparation/follow-up in the outpatient clinic, blood testing in the central hospital laboratory (CHL), TEE in the echocardiography laboratory, and ECV in the intensive care unit; (2) optimized process1 (n = 41): preparation/follow-up, TEE + ECV during one sedation in the CU, blood testing in the CHL; (3) optimized process2 (n = 55): preparation/follow-up, TEE + ECV and point of care (POC) blood testing in the CU. All procedure-related costs were listed and classified according to material, human resources, and infrastructure. From setting1 to 3, there was a significant decrease in procedural time from 480 ± 105min to 205 ± 85min (p < 0.001). Likewise, ECV-associated costs could be reduced from 683 ± 104<euro> to 299 ± 63<euro> (p < 0.001). Establishing a CU for AF enables a more than 50% reduction in procedural time and costs. A combination of TEE and ECV in one sedation and POC testing in the CU were the major contributors to this time and cost reduction.

Iron Metabolism in Kidney Allograft Recipients: Still a Mystery?

Introduction All living organisms have evolved sophisticated mechanisms to maintain appropriate iron levels in their cells and within their body. Recently our understanding of iron metabolism has dramatically increased. Overt labile plasma iron (LPI) represents a component of non-transferrin-bound iron (NTBI) that is both redox active and chelatable, capable of permeating into organs and inducing tissue iron overload. LPI measures the iron-specific capacity of a given sample to produce reactive oxygen species. We studied NTBI correlations with markers of iron status and inflammation in prevalent kidney allograft recipients. Methods Complete blood count, urea, creatinine, serum lipids, fasting glucose, ferritin, serum iron, and total iron-binding capacity (TIBC) were studied by standard laboratory method in the hospital central laboratory. NTBI was assessed by FeROS eLPI kit by Aferrix Ltd (Tel Aviv, Israel). A test result of 0.6 U of LPI or more indicated a potential for iron-mediated production of reactive oxygen species in the sample. Results In kidney transplant recipients NTBI was correlated with TIBC ( r = .46, P < .001) and ferritin ( r = .31, P < .05), with tendencies to correlate with C-reactive protein. Patients with LPI units ≥ 0.6 showed higher serum iron ( P < .05), TIBC ( P < .05), ferritin ( P < .001) and mean corpuscular volume. High ferritin values together with elevated NTBI content were observed among patients undergoing multiple transfusions before and/or after transplantation. Conclusions Elevated NTBI as well as ferritin levels in kidney transplant patients may be due to disturbed iron metabolism, since the human body has no possibility to remove an iron excess. NTBI could be responsible for excessive synthesis of reactive oxygen species. Therefore, it may be linked to complications such as atherosclerosis, which is frequently encountered among this population.

Renalase, A Novel Regulator of Blood Pressure, Is Predicted by Kidney Function in Renal Transplant Recipients

Background Renalase is an enzyme that catabolizes catecholamines such as adrenaline and noradrenaline in the circulation. The human kidney releases this protein into the bloodstream to regulate blood pressure. In kidney transplant recipients, the prevalence of hypertension is 60%–80%. Objective The aim of our study was to assess possible correlations between renalase, blood pressure, and kidney function among 89 prevalent kidney allograft recipients. To obtain normal ranges, we also studied renalase levels in 27 healthy volunteers. Methods Complete blood counts, urea, serum lipids, fasting glucose, and creatinine were measured by standard laboratory methods in the hospital central laboratory. Renalase was assessed with the use of a commercially available kit. Results In kidney transplant recipients renalase was significantly higher than in healthy volunteers ( P < .001). In kidney transplant recipients, renalase correlated with age ( r = 0.29; P < .05), time after transplantation ( r = 0.34; P < .01), systolic blood pressure ( r = 0.28; P < .05), diastolic blood pressure ( r = 0.27; P < .05), serum creatinine ( r = 0.49; P < .001), estimated glomerular filtration rate (Chronic Kidney Disease Endemiology collaboration: r = −0.44; P < .0001; Modification of Diet in Renal Disease: r = −0.43; P < .001; Cockcroft-Gault r = −0.39; P < .01), serum phosphate ( r = 0.34; P < .05). Upon multiple regression analysis renalase was predicted by 70% using age (beta value 0.21, P = 0.043), time after transplantation (beta value, 0.22; P = .037), serum creatinine (beta value, 0.50; P = .016), and diastolic blood pressure (beta value, 0.33; P = .027). Conclusions Renalase is highly elevated in kidney transplant recipients, predominantly dependent on kidney function, which deteriorates with time after kidney transplantation and age. Further studies are needed to establish its putative role in the pathogenesis of hypertension after transplantation and possible novel targeted therapies.

Safety of probiotics

Probiotics are used by millions of people for their documented or anticipated health benefits. They usu-ally belong to the genera lactobacilli and bifidobacteria and are part of the normal flora. They have been studied in a wide variety of diseases and in the prevention of inflammatory and infectious dis-eases. The safety of probiotics has been approached by evaluating retrospective reviews, prospective studies and case reports. Different probiotic bacteria have shown safe use in critically ill children, patients with Clostridium diffi-cile diarrhoea, Crohn’s disease, children attending day care centers, patients with rotavirus diarrhoea, with Helicobacter pylori infection, with irritable bowel syndrome, with HIV infection–associated diar-rhoea, with necrotizing enterocolitis, in intensive care units. Lactobacillus rhamnosus GG (LGG) is the most studied probiotic with most thorough information on safety aspects. Lactobacilli have traditionally been consumed in fermented dairy foods in many countries and have during the last 20 years been introduced into dairy products. A possible impact of LGG on occurrence of bloodstream infections by lactobacilli was evaluated. In 1990 LGG was introduced in dairy products in Finland, after a slow start a sharp rise to 6L/person/year in 1999 emerged. Since 1990 lactobacillus isolates from blood culture specimens have been performed at Helsinki University Central Hospital laboratory and a national surveillance of all bloodstream infections. Of isolates originally reported to be Lactobacillus species, the percentage among all blood cultures was 0.021 and percentage among positive blood cultures was 0.19 and in the national surveillance register 0.24. During this 10 year in-terval no increase in these figures could be observed, despite a strong increase in consumption. Lactobacillus infections are rare despite abundancy in gut normal flora and widespread use. Prudence is needed when used for immunocompromised patients, premature infants, short bowel syndrome. The benefits seem to outweigh the potential for septic infections.

Evaluation of cost per test of clinical biochemistry tests at Parirenyatwa Central Hospital Laboratory, Harare, Zimbabwe

To determine the cost per test for selected clinical biochemistry tests at Parirenyatwa Central Hospital, Harare, Zimbabwe. A retrospective study for the month January 2003. Cost analysis was based on a 'bottom-up' micro cost analysis technique. Parirenyatwa Central Hospital Laboratory. There was wide variation between the cost of performing a test and the hospital fee schedule offered in payment. The greatest variation was obtained for low frequency tests and direct consumables accounted for 61.2% ofthe total costs. Laboratory tests are heavily subsidized and there is need to contain the escalating costs by adopting some aggressive cost recovery measures. Introduction of systematic teaching of health economics in the colleges of health sciences is also advocated.

Hospital Central Laboratory's Manpower Planning by Use of Queueing Theory

The function of the technicians in a hospital central laboratory is to collect the samples and to investigate these samples under the supervision of specialist doctors and prepare the report. When ever a patient arrives, the samples are collected by the technician of the sample collection counter and after that, he sends those samples to different departments of the central laboratory such as Pathology, Biochemistry and Microbiology etc.. After receiving the samples the technician of the concerned departments process those samples under the supervision of the specialist doctors and prepares the reports. The service facility is arranged in parallel; as in Fig.-1: technicians M1, M2, M3 etc. may be facilities, and incoming patients are served by any free technician. If no technician is free, patients must wait and may thus accumulate, forming a queue. Patients are usually all given the same priority, so that service is on a first come first served basis.

Hospital Central Laboratory's Manpower Planning by Use of Queueing Theory

The function of the technicians in a hospital central laboratory is to collect the samples and to investigate these samples under the supervision of specialist doctors and prepare the report. When ever a patient arrives, the samples are collected by the technician of the sample collection counter and after that, he sends those samples to different departments of the central laboratory such as Pathology, Biochemistry and Microbiology etc.. After receiving the samples the technician of the concerned departments process those samples under the supervision of the specialist doctors and prepares the reports. The service facility is arranged in parallel; as in Fig.-1: technicians M1, M2, M3 etc. may be facilities, and incoming patients are served by any free technician. If no technician is free, patients must wait and may thus accumulate, forming a queue. Patients are usually all given the same priority, so that service is on a first come first served basis.

Copeptin in Heart Transplant Recipients Depends on Kidney Function and Intraventricular Septal Thickness

Copeptin is cosynthesized with vasopressin, also known as antidiuretic hormone, with plasma levels similar to vasopressin. In the past 2 years, copeptin has been studied as a diagnostic and prognostic marker in infections and other diseases. In patients with destabilized heart failure, copeptin is an accurate prognostic marker for mortality. The aim of this study was to assess copeptin in orthotopic heart recipients in relation to New York Heart Association class and kidney function. The studies were performed on 139 prevalent patients after orthotopic heart transplantation-(OHT) including 105 males and 34 females. Glomerular filtration rate (GFR) was estimated using simplified Modification of Diet in Renal Disease (MDRD), Cockcroft-Gault, and new the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. In addition 24-hour creatinine clearances were performed on each patient. Complete blood count, urea, serum lipids, fasting glucose, creatinine, BNP were studied by standard laboratory method in the hospital central laboratory. Plasma copeptin was measured using a commercially available kit. Copeptin correlated with parameters of kidney function: creatinine ( r = .39, P < .001), estimated GFR by MDRD ( r = −.24, P < .01), estimated GFR by CKD-EPI ( r = −.25, P < .01), creatinine clearance by Cockcroft-Gault ( r = −.27, P < .01), 24-hour creatinine clearance ( r = −.21, P < .05), cystatin C ( r = .45, P < .001), and high-density lipoprotein ( r = .18, P < .05), BNP ( r = .25, P < .01), intraventricular septal diameter/thickness (IVS); r = −.30, P < .01), ejection fraction ( r = −.17, P < .05), ferritin ( r = .21, P < .05). Upon multiple regression analysis, predictors of copeptin were cystatin C and IVS, which explained 51% of copeptin variations (F = 3.21, P < .03 and Standard error of estimate was 0.57). Beta value for cystatin C was 0.51 ( P = .024) and for IVS was −0.59 ( P = .018). Copeptin in a heart transplant population was independently associated with kidney function and IVS.

The “hospital central laboratory”: automation, integration and clinical usefulness

Recent technological developments in laboratory medicine have led to a major challenge, maintaining a close connection between the search of efficiency through automation and consolidation and the assurance of effectiveness. The adoption of systems that automate most of the manual tasks characterizing routine activities has significantly improved the quality of laboratory performance; total laboratory automation being the paradigm of the idea that "human-less" robotic laboratories may allow for better operation and insuring less human errors. Furthermore, even if ongoing technological developments have considerably improved the productivity of clinical laboratories as well as reducing the turnaround time of the entire process, the value of qualified personnel remains a significant issue. Recent evidence confirms that automation allows clinical laboratories to improve analytical performances only if trained staff operate in accordance with well-defined standard operative procedures, thus assuring continuous monitoring of the analytical quality. In addition, laboratory automation may improve the appropriateness of test requests through the use of algorithms and reflex testing. This should allow the adoption of clinical and biochemical guidelines. In conclusion, in laboratory medicine, technology represents a tool for improving clinical effectiveness and patient outcomes, but it has to be managed by qualified laboratory professionals.

Serologic Diagnosis of Human Bocavirus Infection in Children

To the Editors: Blessing et al published recently in the journal their interesting findings on prolonged human bocavirus (hBoV) DNA shedding by repeated nasopharyngeal aspirates (NPA) in 6 children.1 The interval between the samples varied from 29 to 142 days. In the latter case, the prolonged shedding was documented by 6 samples taken on days 0, 25, 53, 78, 135, and 142.1 The authors concluded that, in contrast to most other respiratory viruses, hBoV DNA detection in a single NPA sample is not sufficient to implicate hBoV as the causative agent of acute respiratory tract disease. The authors proposed that serologic assays, detection of hBoV viremia or high viral loads in NPA samples may be more useful approaches. We have recently introduced new IgM and IgG enzyme immunoassays (EIAs) for the diagnosis of acute respiratory tract hBoV infection.2 In 48 wheezing children with hBoV infection diagnosed by EIA in paired sera, 45 (94%) had viremia and 35 (73%) had hBoV in NPA by polymerase chain reaction (PCR). The EIA test was diagnostic in 27/28 (96%) of those with a high load hBoV DNA in NPA, and in 45/49 (92%) of those with hBoV DNA in serum. The respective figure in those with a low load of hBoV in NPA was 38%. About 12 children had a single hBoV infection, though an extensive test panel, including PCR, culture, antigen detection, and antibody assays, was in use for other viruses.2 In 101 children with pneumonia, serologic evidence of acute hBoV infection was found in 12 (12%) by EIA.3 Significant increases in IgG antibodies were seen in 7 cases, IgM antibodies were seen in 11 cases, and both IgG and IgM findings were documented in 6 cases. In IgG positive cases, the increases in IgG antibodies between paired sera varied from 9- to >100-fold. Thus, our findings by antibody assays verify the notion of Blessing et al, as well as other recent findings4 that hBoV is a true pathogen in respiratory tract infections in children. Qualitative PCR in NPA alone is not sufficient for a reliable hBoV diagnosis. Our results highlight the role of antibody assays. Matti Korppi, MD, PhD Pediatric Research Center University Hospital, Tampere University Tampere, Finland Tuomas Jartti, MD, PhD Department of Pediatrics University Central Hospital Turku University Turku, Finland Klaus Hedman, MD, PhD Department of Virology Maria Söderlund-Venermo, PhD Department of Virology Helsinki University Central Hospital Laboratory Division Helsinki, Finland

Point-of-care testing for coagulation studies in a stroke protocol: a time-saving innovation

Study Objectives Time counts in thrombolytic therapy for stroke. An international normalized ratio (INR) greater than 1.7 may preclude its use. We studied whether the use of point-of-care testing (POCT) for INR in the emergency department (ED) may substitute for the same test done in the central hospital laboratory, thereby reducing time to treatment. Methods We performed a prospective observational study comparing a POCT analysis of INR (i-STAT-1; Abbott Inc, Abbott Park, Ill) with a simultaneously drawn sample sent to the central laboratory. We tested a convenience sample of adult patients taking warfarin who presented to the ED of a tertiary teaching hospital. Results Thirty-two patients were enrolled. A receiver operator curve analysis was performed. Sensitivity and specificity were calculated for laboratory INR cutoff of 1.7. The area under the curve was 0.979 (95% confidence interval [CI], 0.843-0.991). When POCT INR was 2.1, the sensitivity for laboratory INR being higher than 1.7 was 100% (CI, 62.9%-100.0%), and the specificity was 90.5 (CI, 69.6-98.5). When POCT INR was 1.8, the specificity for laboratory INR being lower than 1.7 was 100% (CI, 83.7%-100%), and the sensitivity was 62.5% (CI, 24.7%-91.0%). The regression coefficient ( r) value was 0.9648. Conclusion Correlation of POCT INR with that of the central laboratory and receiver operator curve characteristics are excellent. In general, POCT INR is about 0.3 higher than the laboratory INR. This is not generally of clinical importance, but when using cutoff of 1.7 (central laboratory), it may be. We describe a 3-tiered system for use of POCT INR in determining use of tissue-type plasminogen activator.