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Biomedical subjects

Mario Plebani

Publications and source records attributed to Mario Plebani.

At least 37 records · Page 2Linked to original sources

C-reactive protein in hypertensive disorders in pregnancy.

Hypertension is the most frequent medical complication of pregnancy. A recent report demonstrates the flogistic pathogenesis of pregnancy-induced hypertension. Because C-reactive protein (CRP) is a marker of inflammation, it can be used in the differential diagnosis of hypertensive disorders of pregnancy. A total of 322 pregnant women at 24 to 32 weeks' gestation were enrolled. The control group (A) comprised 190 women. Sixty-three women had preeclampsia (PE, group B), 31 women presented transient hypertension (TH, group C), 19 had HELLP syndrome (HS, group D) and 19 had chronic hypertension (CH, group E). CRP serum concentrations were significantly higher in groups B, C, and D in comparison with the group A. In the whole population, systolic and diastolic pressure value inversely correlate with weight at delivery and weeks of gestation at delivery. CPR levels in patients with PE and HS inversely correlate with birth weight and gestational week at delivery. Normal plasma levels of CRP may be an important marker of differential diagnosis between TH and CH. In TH, PE, and HS, CRP levels were higher than in the control and CH groups, suggesting that inflammation may be the common pathogenetic cause of TH and PE. Finally CRP levels in preeclampsia are believed to correlate with preeclamptic process severity.

Biomarkers↗

Mitochondrial DNA D-loop in pancreatic cancer: somatic mutations are epiphenomena while the germline 16519 T variant worsens metabolism and outcome.

We ascertained the frequency of mitochondrial DNA (mtDNA) D-loop region somatic mutations in pancreatic cancer (PC) and verified whether polymorphisms were linked to diagnosis, prognosis, and PC-associated diabetes mellitus (DM) in 99 PC cases, 42 chronic pancreatitis (CP) cases, 18 pancreatobiliary tract tumors, and 87 healthy control subjects (CSs). Tissue samples were obtained from 19 patients with PC and 5 with CP. The D-loop region was sequenced from all tissue samples and from blood DNA of the same patients and 12 CSs. D-loop somatic mutations were found in 3 PC tissue samples (16%). Four single nucleotide polymorphisms (SNPs; T152C, T16189C, T16519C, A73G), more frequently found in PC than in CS, were analyzed by denaturing high-performance liquid chromatography-restriction fragment length polymorphism using blood DNA as the starting template in all cases. The T allele of 16519 SNP correlated with DM. The survival of patients with PC correlated with tumor stage and grade and with DM at diagnosis. When survival analysis was performed considering only patients with locally advanced disease, the T allele of mtDNA 16519 SNP correlated with shorter life expectancy. mtDNA D-loop somatic mutations, rarely found in PC, cannot be considered causative events for this tumor type and probably are epiphenomena; the mtDNA D-loop 16519 variant, which worsens PC prognosis, seems to be a predisposing genetic factor for DM.

Adenocarcinoma↗

Laboratory network of excellence: enhancing patient safety and service effectiveness.

Clinical laboratories have undergone major changes due to technological progress and economic pressure. While costs of laboratory testing continue to be the dominant issue within the healthcare service worldwide, quality, effectiveness and impact on outcomes are also emerging as critical value-added features. Five Italian laboratories are therefore promoting a network of excellence by investigating markers of effectiveness of laboratory services and sharing their experience of using them in clinical practice. In the present study we report preliminary data on indicators of quality in all phases of the so-called total testing process, the key to evaluating all phases of the total testing process, including the appropriateness of test requests and data interpretation. Initial findings in evaluating pre-analytical causes of specimen rejection in three different laboratories and the effects of introducing three laboratory clinical guidelines are reported. These data should stimulate debate in the scientific community and encourage more clinical laboratories to use the same indicators to improve clinical effectiveness and clinical outcomes within the healthcare service.

Clinical Laboratory Techniques↗

Preanalytical variability: the dark side of the moon in laboratory testing.

Remarkable advances in instrument technology, automation and computer science have greatly simplified many aspects of previously tedious tasks in laboratory diagnostics, creating a greater volume of routine work, and significantly improving the quality of results of laboratory testing. Following the development and successful implementation of high-quality analytical standards, analytical errors are no longer the main factor influencing the reliability and clinical utilization of laboratory diagnostics. Therefore, additional sources of variation in the entire laboratory testing process should become the focus for further and necessary quality improvements. Errors occurring within the extra-analytical phases are still the prevailing source of concern. Accordingly, lack of standardized procedures for sample collection, including patient preparation, specimen acquisition, handling and storage, account for up to 93% of the errors currently encountered within the entire diagnostic process. The profound awareness that complete elimination of laboratory testing errors is unrealistic, especially those relating to extra-analytical phases that are harder to control, highlights the importance of good laboratory practice and compliance with the new accreditation standards, which encompass the adoption of suitable strategies for error prevention, tracking and reduction, including process redesign, the use of extra-analytical specifications and improved communication among caregivers.

Clinical Laboratory Techniques↗

Measurement of serum monoclonal components: comparison between densitometry and capillary zone electrophoresis.

Quantitative measurement of serum monoclonal protein (M-protein) is one of the most important tools for monitoring disease activity in monoclonal gammopathies. The aims of this study were to evaluate serum M-protein quantification by capillary zone electrophoresis (CZE) and to compare results with those obtained by densitometric scanning of high-resolution agarose gel electrophoresis (HRE-AGE). The evaluation was carried out on 82 samples from patients with various monoclonal gammopathies. All the suspected M-proteins were confirmed and characterised by immunofixation on agarose gel (IFE). CZE was performed on a Paragon CZE 2000 system (Beckman Coulter). Passing-Bablok regression was: y (CZE)=1.27 x(HRE-AGE)-5.21 g/L. The correlation coefficient was 0.92. Bland-Altman analysis demonstrated a mean difference of -1.83 g/L (95% CI -0.76 to -2.90) with clear evidence of a concentration-related bias. Densitometry gave higher values at low M-spikes (<20 g/L), whereas CZE gave higher values at large M-spikes (>20 g/L). The concentration-related bias was found to be independent of the immunoglobulin isotype. In conclusion, to compare previous results obtained by M-protein densitometric scanning with those obtained by direct measurement of CZE peaks, the calculation of a univocal transforming factor appears to be unreliable.

Antibodies, Monoclonal↗

Errors in clinical laboratories or errors in laboratory medicine?

Laboratory testing is a highly complex process and, although laboratory services are relatively safe, they are not as safe as they could or should be. Clinical laboratories have long focused their attention on quality control methods and quality assessment programs dealing with analytical aspects of testing. However, a growing body of evidence accumulated in recent decades demonstrates that quality in clinical laboratories cannot be assured by merely focusing on purely analytical aspects. The more recent surveys on errors in laboratory medicine conclude that in the delivery of laboratory testing, mistakes occur more frequently before (pre-analytical) and after (post-analytical) the test has been performed. Most errors are due to pre-analytical factors (46-68.2% of total errors), while a high error rate (18.5-47% of total errors) has also been found in the post-analytical phase. Errors due to analytical problems have been significantly reduced over time, but there is evidence that, particularly for immunoassays, interference may have a serious impact on patients. A description of the most frequent and risky pre-, intra- and post-analytical errors and advice on practical steps for measuring and reducing the risk of errors is therefore given in the present paper. Many mistakes in the Total Testing Process are called "laboratory errors", although these may be due to poor communication, action taken by others involved in the testing process (e.g., physicians, nurses and phlebotomists), or poorly designed processes, all of which are beyond the laboratory's control. Likewise, there is evidence that laboratory information is only partially utilized. A recent document from the International Organization for Standardization (ISO) recommends a new, broader definition of the term "laboratory error" and a classification of errors according to different criteria. In a modern approach to total quality, centered on patients' needs and satisfaction, the risk of errors and mistakes in pre- and post-examination steps must be minimized to guarantee the total quality of laboratory services.

Clinical Laboratory Techniques↗

Clinical Governance: from clinical risk management to continuous quality improvement.

Reducing medical errors has become an international concern. Population-based studies from a number of nations around the world have consistently demonstrated unacceptably high rates of medical injury and preventable deaths. The introduction of effective reporting systems is a cornerstone of safe practice within hospitals and other healthcare organisations. Reporting can help to identify hazards and risks. However, reporting in itself does not improve safety. It is the response to reports that leads to change. Clinical teams must feel empowered to change the way in which they deliver their services, promoting effective clinical risk management. Process analysis, implementation of evidence-based practices, and a clear accountability system are effective tools not only for decreasing error rates, but also for improving effectiveness. Clinical Governance represents the context in which effective clinical risk management should be promoted and continuously improved. It should not be regarded as a separate activity, but should form part of the everyday practice of all healthcare professionals. It requires good multidisciplinary working and a willingness to reflect on and learn from errors to achieve a patient-centred and safer system.

Clinical Medicine↗

External Quality Assessment: an effective tool for Clinical Governance in laboratory medicine.

The implementation of Clinical Governance will require a redefinition of duties and accountability as a prerequisite to develop and achieve an overall improvement in clinical care through a culture of assessment and monitoring of quality. External Quality Assessment Schemes (EQAS) are the main tool enabling laboratories to measure the quality of their results; they must carefully assess and monitor all elements contributing to the formulation of laboratory information (results, reference ranges/decisional levels, interpretative comments and diagnostic algorithms). There are different ways to design and manage a Scheme and EQAS coordinators are mainly responsible for its effectiveness. The present paper reports, as an example, some experiences of the Centre of Biomedical Research (CRB), which manages EQAS according to high quality specifications and laboratories' needs, that can reflect the Clinical Governance philosophy. Our findings show that EQAS are able to control all the above aspects and, if organisers are committed to fulfilling the responsibility and accountability principles, they will be of great value in quality assessment and in developing an External Quality Assurance Program (EQAP). This is an inter-laboratory comparison designed and conducted to assure the following: evaluation of participants' performance (by evaluating not only analytical performance, but also test interpretation, and advice for clinicians on laboratory requests and diagnosis); evaluation of method performance; and continuous education, training and help. The main aim of the activities of an EQAP in Laboratory Medicine is to sustain improvements in the quality of services provided by participating laboratories for the benefit of patients.

Clinical Laboratory Techniques↗

Innotrac Aio!: a point-of-care or a routine analyzer? Analytical performance and plasma/whole blood comparison.

BACKGROUND AND METHODS: The aim of the present study was to evaluate the analytical performance of the Innotrac Aio! analyzer in measuring the cardiac markers troponin I (TnI), myoglobin (Myo) and creatine kinase-MB (CK-MB), both in lithium heparin plasma and in whole blood. RESULTS: TnI analytical sensitivity was 0.012 microg/L and the concentration corresponding to CV=10% was 0.036 microg/L. In healthy subjects, the 99th percentile TnI values were 0.023 and 0.016 microg/L in whole blood and in plasma, respectively. One hundred samples were tested both in whole blood and in plasma: TnI-whole-blood=1.16-plasma+0.011, bias=+0.18 (95% CI from -0.22 to +0.59); Myo-whole-blood=1.04-plasma-1.93, bias=+1.08 (95% CI from -6.17 to +8.32); CK-MB-whole-blood=1.11-plasma-0.09, bias=+0.96 (95% CI from -0.53 to +2.45). The method comparison with the RxL Dimension analyzer for TnI and Myo gave the following results: TnI Aio!=0.30 TnI RxL+0.00; bias=-5.80 (95% CI from -7.81 to -3.78), Myo Aio!=1.33 Myo RxL+0.42, bias=+53.09 (95% CI from +38.44 to +67.74). CONCLUSIONS: The analytical performance of the Innotrac Aio! analyzer was satisfactory for all three cardiac markers evaluated and, in particular, the TnI method provided sensitive and accurate results. The most important finding in this study is the possibility to perform the tests as either routine or point-of-care analysis, thus overcoming the variability of results obtained employing different methods.

Biomarkers↗

Research translation: a new frontier for clinical laboratories.

Translational research and translational medicine (referred to hereafter as translational research) are interchangeable terms that underline the pressing need to translate into practical benefits for those affected by disease the extensive investments divested by the private and public sectors in biomedical research. For people more directly involved in clinical practice (physicians, clinical laboratory professionals and patients), translational research responds to the need to accelerate the capture of benefits of research, closing the gap between what we know and what we practice. This basically means the transfer of diagnostic and therapeutic advances proven effective in large, well-conducted trials (and, therefore, evidence-based) to daily medical practice. Translational research should be regarded as a two-way road: bench to bedside, and bedside to bench. In particular, to make possible a more effective translation process, a new road map should be implemented through interaction and cooperation between basic researchers, clinicians, laboratory professionals and manufacturers. Some examples of recent developments in clinical laboratory testing, including markers of cardiovascular diseases, clinical proteomics and recombinant allergens, may explain the importance of careful evaluation of all variables that allow the introduction of such new insights into clinical practice to assure better clinical outcomes. The vital role of laboratory medicine in the delivery of safer and more effective healthcare requires more careful evaluation not only of the analytical characteristics, but also of any other variable that may affect the clinical usefulness and diagnostic performances of laboratory tests, thus allowing more accurate interpretation and utilization of laboratory information.

Albuminuria↗

Analytical and clinical evaluation of a new heart-type fatty acid-binding protein automated assay.

BACKGROUND: The accurate and rapid recognition of myocardial injury in patients presenting in the emergency department (ED) with chest pain continues to be a clinical challenge. Heart-type fatty acid-binding protein (H-FABP) appears to be one of the best candidates among the new early cardiac markers studied. METHODS: We evaluated the analytical characteristics of a new quantitative and fully automated H-FABP assay (Randox Laboratories Ltd., Crumlin, UK) and compared its clinical performance with respect to the myoglobin (Myo) assay (Dade Behring, Milan, Italy). A precision study was carried out by testing three levels of quality control (QC) material and two in-house pool (P) samples. To test the accuracy of H-FABP determinations in plasma (lithium-heparin) samples, H-FABP concentrations measured in a set of matched sera and plasma samples were compared. A total of 77 non-consecutive patients (51 males and 26 females; 62+/-16 years) who presented to the ED with chest pain suggesting myocardial ischemia were enrolled. The patients were classified into two groups (acute myocardial infarction, n=22; non-acute myocardial infarction, n=55) on the basis of the discharge diagnosis. RESULTS: The between-day imprecision for three levels of control material and serum pool samples was 6.26%-8.04% (range 2.32-44.03 microg/L) and 9.03%-12.63% (range 11.85-65.13 microg/L), respectively. In the serum vs. plasma study, bias was +0.178 (95% CI -0.033 to +0.389). The best cut-off and the associated diagnostic efficacy were 95 microg/L and 89.47% for Myo and 5.09 microg/L and 98.70% for H-FABP, respectively. CONCLUSIONS: H-FABP determination in patients with ischemic symptoms may be a more reliable early indication of cardiac damage than myoglobin.

Aged↗

Celiac disease in North Italian patients with autoimmune Addison's disease.

OBJECTIVE: Patients with autoimmune Addison's disease (AAD) are prone to develop other autoimmune manifestations. An increased prevalence of celiac disease (CD) has recently been demonstrated in Northern European patients with AAD. IgA deficiency is the most frequent type of immunodeficiency among humans and is present in about one in every 600 individuals in the population. IgA deficiency is frequent in patients with other autoimmune diseases, but data concerning AAD are still unavailable. DESIGN: The aim was to define the prevalence of CD and of IgA deficiency in a group of Italian patients with AAD. METHODS: One hundred and nine patients with AAD were enrolled and examined for tissue transglutaminase autoantibodies of the IgA class, circulating levels of IgA and adrenal cortex antibodies. RESULTS: Two (1.8%) of the patients were affected by already diagnosed CD and were already on a gluten-free diet. Out of the remaining 107 patients, four (3.7%) were found to be positive for IgA antibodies to human tissue transglutaminase. Three of the four patients who were positive for tissue transglutaminase autoantibodies agreed to undergo endoscopy and duodenal biopsies and, in one, a latent form of CD was identified. The clinical, silent or latent form of CD was present in six out of 109 (5.4%). This prevalence was significantly higher (P = 0.0001) than that reported for the Northern Italian population which was equal to 0.063%. Specifically, CD was present in 12.5% of the autoimmune polyglandular syndrome (APS) type 1 cases, in four out of 60 (6.7%) of the APS type 2 cases and in one out of 40 (2.5%) of the isolated AAD cases. IgA deficiency was present in two out of 109 patients (1.8%), all of whom had normal IgG anti-gliadin. Autoantibodies to the adrenal cortex were detected in 81 out of 109 patients (74.3%). CONCLUSIONS: In patients with AAD there is a high prevalence of both CD and IgA deficiency. Consequently, it is important to screen for CD with tissue transglutaminase autoantibodies of the IgA class and for IgA levels.

Addison Disease↗

Evaluation of a new capillary zone electrophoresis system for the identification and typing of Bence Jones Protein.

OBJECTIVES: Capillary electrophoresis has recently emerged as a new sensitive technique for the separation of urinary proteins. We evaluated a new method for Bence Jones Protein (BJP) detection and characterization on native urine samples by the Paragon CZE 2000 system. To avoid interference in electrophoretic separation, urine samples were preliminarily treated for the selective removal of interfering salt particles. DESIGN AND METHODS: The evaluation was done on a total of 350 fresh 24-h urine samples. The salt particle removal consisted of a manual chromatographic separation, optimized in the course of our evaluation. Capillary zone urinary protein electrophoresis (CZ-UPE) was compared with conventional high-resolution electrophoresis on an agarose gel, while capillary immunosubtraction (CZU-IFE) was compared with agarose gel immunofixation. RESULTS: After finding a consistent protein loss in eluates, the preanalytical treatment was optimized by changing sample dilution and eluate collection. The within- and between-run imprecision values for monoclonal peaks corresponding to BJP ranged from 0.4-12.2% to 3.3-6.3%, respectively. The detection limit for BJP, defined as the lowest measurable monoclonal peak on CZ-UPE, was 0.0012 g/L for kappa BJP and 0.0007 g/L for lambda BJP. CZ-UPE and CZU-IFE sensitivities were significantly lower in urine samples with a total protein level < or = 100 mg/L (67% and 78%, respectively) compared to those with total protein >100 mg/L (92% and 94%, respectively). Comparison between BJP measurements obtained from densitometric scanning with those from absorbance tracing showed a correlation coefficient of 0.994 and a bias of 29.8 mg/L. CONCLUSIONS: Paragon CZE 2000 can be introduced in routine for screening and typing of BJP; in urine samples with a total protein level >100 mg/L, the performance is consistent with results from published validation studies on CZE applied to serum samples.

Bence Jones Protein↗

Role of blood AFP mRNA and tumor grade in the preoperative prognostic evaluation of patients with hepatocellular carcinoma.

AIM: To explore the potential prognostic role of preoperative tumor grade and blood AFP mRNA in a cohort of patients with hepatocellular carcinoma (HCC) eligible for radical therapies according to a well-defined treatment algorithm not including nodule size and number as absolute selection criteria. METHODS: Fifty patients with a diagnosis of HCC were prospectively enrolled in the study. Inclusion criteria were: (1) histological assessment of tumor grade by means of percutaneous biopsies; (2) determination of AFP mRNA status in the blood; (3) patient's eligibility for radical therapies. RESULTS: At preoperative evaluation, 54% of the study group had a well-differentiated HCC, 42% had AFP mRNA in the blood, 40% had a tumor larger than 5 cm and 56% had more than one nodule. Surgery (resection or liver transplantation) was performed in 29 patients, while 21 had percutaneous ablation procedures. After a median follow-up of 28 mo, 12-, 24-, and 36-mo survival rates were 78%, 58%, and 51%, respectively. Surgical therapy, performance status and three tumor-related variables (AFP mRNA, HCC grade and gross vascular invasion) resulted as significant survival predictors at univariate analysis. Nodule size and number did not perform as significant prognosticators. Multivariate study selected only surgical therapy and a biologically early HCC profile (AFP mRNA negative and well-differentiated tumor without gross vascular invasion) as independent survival variables. CONCLUSION: The preoperative determination of tumor grade and blood AFP mRNA status may potentially refine the prognostic evaluation of HCC patients and improve the selection process for radical therapies.

Adult↗

Effects of long-term administration of high-dose recombinant human antithrombin in immunosuppressed primate recipients of porcine xenografts.

BACKGROUND: Fibrin deposition is central to the acute humoral rejection process occurring in the presence of consumptive coagulopathy when pig organs are transplanted into primates. METHODS: To assess whether strategies aimed at preventing fibrin formation may extend xenograft survival, we administered high daily doses of recombinant human antithrombin (rhAT) (500 U/kg twice daily) to obtain both anticoagulant and anti-inflammatory effects in immunosuppressed primate recipients of porcine kidneys. RESULTS: Some degree of consumptive coagulopathy developed in both rhAT-treated (n=3) and untreated (n=3) primates. No major differences in the coagulation parameters analyzed were observed between the 2 groups. Similarly, no difference in survival was seen between rhAT-treated (20.6+/-4 days; range: 15-23 days) and untreated animals (17.3+/-11.6 days; range: 7-30 days), although the rhAT-treated primates had a higher bleeding tendency. Despite the high daily dose of rhAT, considerable fibrin deposition was observed in the graft as early as 2 weeks after transplantation. CONCLUSIONS: These results suggest that a high daily dose of rhAT fails to influence survival or prevent fibrin formation and deposition in the graft in our pig-to-primate model. However, the potential role of rhAT administered in combination with heparins or other clotting inhibitor concentrates in this model remains to be determined.

Animals↗

Is osteoporosis a peculiar association with primary biliary cirrhosis?

AIM: (1) To compare the prevalence of osteoporosis (t-score < or =-2.5 SD) between stage IV PBC patients, and two groups of age- and sex-matched controls: one with hepatitis C virus (HCV)-related cirrhosis, and the other one consisting of a group of healthy subjects from the general population; (2) to identify the main risk factors for the development of bone loss. METHODS: Thirty-five stage IV PBC patients (mean age 52.5+/-10 years), 49 females with HCV-related cirrhosis (mean age 52.9+/-5.8 years) and 33 healthy females (mean age 51.8+/-2.22 years) were enrolled in the study. Bone metabolism was evaluated by measuring serum calcium corrected for serum albumin (Ca corr.), 25-hydroxy vitamin D (25-OH vit D), parathyroid hormone, osteocalcin. Bone mineral density (BMD) was assessed at the lumbar spine by dual-photon X-ray absorptiometry. RESULTS: Osteoporosis was present in 5/35 PBC patients (14.2%) and in 7/49 HCV-related cirrhotic patients (14.3%), without any statistical difference between the two groups. Among healthy control subjects, none had osteoporosis. No difference was found between the three groups in serum parameters of bone metabolism. Univariate analysis showed that menopausal state and low BMI were significantly correlated with osteoporosis. Multivariate regression analysis showed that menopausal status, BMI <23, and old age were independent variables significantly correlated with osteoporosis. CONCLUSION: PBC in itself has no negative influence on BMD. End-stage liver disease patients carry a disease-specific risk for osteoporosis, but have an effective risk of bone loss in relation to individual potential risk for each patient. A practical message should be taken into account, that is, every effort should be made to prevent osteoporosis when a patient has simple osteopenia, or if it is a woman in or near menopausal age.

Adult↗