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Biomedical subjects

Mario Plebani

Publications and source records attributed to Mario Plebani.

At least 19 recordsLinked to original sources
PubMed2003

Appropriateness in programs for continuous quality improvement in clinical laboratories.

BACKGROUND: External reviews and the accreditation of medical laboratories involve more than the mere assessment of conformance with standards for organisational processes. The new approaches to quality improvement suggest that, rather than using inspection to correct unusual errors, there should be more emphasis on improving the processes of health care to ensure that desired outcomes are produced. Appropriateness plays a key role in programs for quality improvement. METHODS: Appropriateness in laboratory medicine can be assessed, and improved, through the governance of the entire testing process. This begins with test selection, proceeds through valuable pre-, intra- and post-analytical procedures, and concludes by assuring the correct interpretation and utilization of laboratory information. RESULTS: The International Standard, specifically developed for medical laboratories (ISO 15189) recognizes the value of appropriate interpretation and advisory services, although it does not specify requirements for assessing appropriateness, requesting tests and interpreting results. The effectiveness of clinical laboratories can be assessed by using surrogate markers, which indicate physicians' satisfaction, and clinical audits. Effectiveness is also enhanced by stressing the importance of the technical and professional competence of evaluators. CONCLUSIONS: Inappropriate laboratory utilization unjustifiably increases health care costs, can harm patients and perpetuates the vision of laboratory testing as a commodity. Improvement in laboratory appropriateness can be achieved by seeking a better relationship with physicians and by stressing the role of laboratory specialists in providing clinical advice for the selection of laboratory tests, and the interpretation and utilization of their results, thus leading to more satisfactory clinical outcomes.

Clinical Laboratory Techniques↗
PubMed2003

Interpretative comments and reference ranges in EQA programs as a tool for improving laboratory appropriateness and effectiveness.

INTRODUCTION: Laboratory information is generated when a meaning is given to certain data. This is usually achieved by comparing a laboratory test result with the reference range/decisional limit (RL), and by providing consultation for the interpretation of data, advice, and follow-up testing. AIM: In this paper, we investigate factors affecting the conversion of data into useful information with regard to biochemical markers of myocardial damage (CK-MB mass, myoglobin, and troponins), in view of their importance in detecting myocardial necrosis. Our aim was to report results obtained in order to verify the consensus between laboratories with reference to interpretative comments and the reference ranges/decisional limits added to clinical reports. METHODS: A questionnaire and simulated medical reports on three different patients were distributed to participants (94 laboratories) in the 2001 cycle of the External Quality Assessment (EQA). Moreover, we analysed 113 medical reports sent by laboratories during the most recent EQA cycle 2002, and checked the number of different RLs used, both independent and within the diagnostic system used. We also compared each laboratory result of a control sample, obtained in the 2002 cycle, with declared RL in order to verify the clinical significance of results ("normal" or "pathological") for troponin I and CK-MB. RESULTS: Our findings show that few laboratories regularly add interpretative comments to medical reports. On the contrary, they cooperate with clinicians who require consultation, advice, and information for the appropriate use of biochemical markers. There is a general consensus among participants regarding probable syndromes suggested by the interpretation of the same result and most laboratories also agree on further investigations to be carried out for several diseases. Concerning RL, the data demonstrate that numerous different RLs are used to report the results of the biochemical markers evaluated, both when considered independent of the diagnostic system used and within the diagnostic system used. DISCUSSION AND CONCLUSIONS: The biochemist does not have the opportunity to verify the efficacy of the interpretation that he/she provided. An audit of this activity is therefore required to allow the laboratory to monitor its own performance and to assure good practice. The evaluation of interpretative comments, through specific surveys, should be a prime objective of EQA organisers. Well-designed EQA programs can, moreover, support laboratories in establishing appropriate RL and in verifying the clinical significance of their results with respect to that of other laboratories. Our survey on interpretative comments and the analysis of the RLs further demonstrate how laboratory medicine can contribute to the objective evaluation of the patients' health status.

Clinical Laboratory Techniques↗
PubMed2003

Appropriateness of cholesterol and triglycerides reporting checked by External Quality Assessment programs.

BACKGROUND: The recommendations of the Second Joint Task Force of European and Other Societies on Coronary Prevention and the third Adult Treatment Panel report (ATPIII) released by the National Cholesterol Education Program are based on accumulating evidence concerning the contribution of lipoproteins and other risk factors in the development of coronary heart disease (CHD). The laboratories play an important role in the successful adoption of these guidelines. METHODS: In External Quality Assessment (EQA) programs managed by the Center of Biomedical Research, results and respective reference intervals (RI) are sent as laboratory's medical form. We assessed how well the 200 participants to EQA scheme 2002 for clinical biochemistry reported total cholesterol (TC) and triglycerides (TGs) results according to either European or National Cholesterol Education Program (NCEP) guidelines. RESULTS: Only 18% of laboratories reported total cholesterol concentrations correctly in terms of desirable, borderline-high, and high risk for the CHD development, 12% reported a single desirable value (180, 190, or 200 mg/dl), and 70% reported the RI (85 laboratories in the whole interval, 34 are the only upper reference limit and 15 are the desirable value in addition to RI). The upper reference limit was 200 mg/dl in 65% of cases, but 32% of laboratories presented higher limits, reaching values as high as 250-260 mg/dl. Only the 3.7% of laboratories reported triglyceride concentrations in terms of risk-oriented ranges for the CHD development, 6.8% the single desirable value, and 89.5% the RI. CONCLUSION: Our study demonstrates that the current practice of reporting results for cholesterol and triglycerides does not follow the guidelines, and appropriate changes are required to be made.

Cholesterol↗
PubMed2003

Serum human glandular kallikrein (hK2) and insulin-like growth factor 1 (IGF-1) improve the discrimination between prostate cancer and benign prostatic hyperplasia in combination with total and %free PSA.

BACKGROUND: There is growing evidence describing an association of hK2 and IGFs with cancer. The aim of this study is to investigate the differences in serum levels of hK2 and IGFs in a large group of patients with benign prostatic hyperplasia (BPH) or prostatic carcinoma (CaP) and to examine the value of these variables, as well as their various combinations with PSA, for discriminating between these two clinical entities. METHODS: Human glandular kallikrein 2 (hK2), insulin-like growth factor-1 (IGF-1), free and total PSA concentrations were measured with non-competitive immunological procedures. Receiver operating characteristic (ROC) analysis as well as univariate and multivariate logistic regression analysis were performed to investigate the potential utility of the various markers and their combinations for discriminating between BPH and CaP. RESULTS: hK2 and IGF-1 concentrations were increased in CaP patients, in comparison to BPH patients. hK2/free PSA and free/total PSA ratios (area under the curve, AUC = 0.70) were stronger predictors of prostate cancer than the IGF-1/total PSA ratio (AUC = 0.56) in the group of patients with total PSA <4 microg/L. The hK2/free PSA ratio (AUC = 0.74) was found to have significant discriminatory value in patients with total PSA within the "gray zone" (4-10 microg/L). Multivariate logistic regression models confirmed the observed relationships and identified IGF-1/free PSA and hK2/free PSA as independent predictors of CaP. CONCLUSIONS: hK2/free PSA and IGF-1/free PSA ratios may be useful adjuncts in improving patient selection for prostate biopsy.

Aged↗
PubMed2003

Endothelin receptor blockade lowers plasma aldosterone levels via different mechanisms in primary aldosteronism and high-to-normal renin hypertension.

BACKGROUND: Endothelin (ET)-1 contributes to raising blood pressure (BP) and inducing cardiovascular disease by vasoconstriction and potent stimulation of aldosterone secretion. In the rat this latter effect occurs via ET(B) receptors; in humans in vitro studies implicated both ET(A) and ET(B) receptors, but there is no conclusive evidence in vivo. METHODS: We recruited 13 consenting hypertensive patients: six with primary aldosteronism (PA) and seven with high-to-normal renin hypertension (HNRH). They were infused with a low dose (200 nmol/min for 5 min followed by 100 nmol/min for 10 min) of the ET(A)-selective antagonist BQ-123 either alone or, on a different day, together with an identical dose of the ET(B)-selective antagonist BQ-788. Plasma aldosterone, cortisol and ACTH concentration and plasma renin activity (PRA) were measured with radioimmunoassay at -15, 0, 30, 60, 120, 240, 360 min, while BP was recorded non-invasively. RESULTS: BQ-123 alone and combined with BQ-788 significantly lowered mean BP in both PA and HNRH patients (by 6-10 mmHg at nadir; P<0.01). In PA patients, a short-lived decrease of aldosterone was elicited by combined BQ-123 and BQ-788 (-14%; P<0.05), but not by BQ-123 alone; cortisol, ACTH, and PRA were unaffected by either treatment. In HNRH patients, BQ-123 both alone and combined with BQ-788 lowered aldosterone (-39 and -28%, respectively) and PRA (-43 and -16%, respectively), while cortisol and ACTH were unaffected. CONCLUSIONS: Endogenous ET-1 contributes to maintaining the high BP values and the aldosterone secretion in both PA and HNRH patients. In the former patients, the aldosterone secretagogue effect of ET-1 is mediated via ET(B) receptors, while in the latter it occurs mainly via ET(A)-mediated stimulation of renin production.

Adrenocorticotropic Hormone↗
PubMed2003

Clinical value and measurement of specific IgE.

The diagnosis of human allergic diseases involves the combined use of a careful clinical history, physical examination, and in vitro and in vivo assay methods for the detection of IgE antibodies of defined allergen specificities. In vivo (skin testing) and in vitro (measurement of specific IgE in serum) techniques cannot be considered interchangeable, the former reflecting not only the presence of IgE but also mast cell integrity, vascular and neural responsiveness. Both techniques have similarities and differences, advantages and disadvantages. Recently introduced "second generation" immunoassays have continued to improve the analytical sensitivity and reproducibility thanks to automation and improved reagent quality. Quantitative assays may allow the use of specific clinical thresholds able to differentiate symptomatic from asymptomatic patients. False-negative and false-positive results should derive from lability of some major extracts, and from possible cross-reactivities, respectively. Characterization of allergens at a molecular and submolecular level and, where necessary, the use of recombinant allergens can reduce cross-reactions and further improve the quality of immunoassays.

Allergens↗
PubMed2003

Helicobacter pylori infection in children and adults: a single pathogen but a different pathology.

BACKGROUND: The aims of this retrospective study were to ascertain in large series of children and adults: the relationship of the infecting strain to gastric mucosal lesions; and the relationship of the infecting strain to its duodenal localization. MATERIALS AND METHODS: We studied 307 and 604 consecutive children and adults. In gastric mucosal samples H. pylori was cultured, genotyped and histologically assessed, while inflammation, activity and intestinal metaplasia were graded. In a subset of 171 patients H. pylori ureaseA (ureA) and cagA genes were amplified (PCR) using mucosal biopsies from the duodenum. RESULTS: H. pylori infection was diagnosed in 40 children and 308 adults. cagA was identified in 50% and 65.5% of infected children and adults. Antral activity was associated with the density of infecting bacteria (p <.001) and with cagA (p <.01). Intestinal metaplasia was correlated with cagA (p <.001). The ureA gene was found in 56 duodenal samples from 82 H. pylori positive patients. Duodenal H. pylori ureA was significantly more frequent in patients with duodenal diseases than in those without (p <.01), cagA positive strains being mainly involved in the infection of this anatomical area (p <.01). CONCLUSIONS: A severe H. pylori-associated gastritis is more prevalent when the density of infecting bacteria is high and when cagA positive strains cause the infection. The most virulent cagA positive H. pylori colonizes not only the gastric, but also the duodenal mucosa, which can be directly damaged by the bacteria itself or by its products.

Adolescent↗
PubMed2003

Effects of Th2 cytokines on expression of collagen, MMP-1, and TIMP-1 in conjunctival fibroblasts.

PURPOSE: To determine whether cytokines involved in chronic allergic conjunctival disorders may affect formation of giant papillae and tissue remodeling. METHODS: Conjunctival fibroblast cultures were challenged with different concentrations of human recombinant interleukin (IL)-4, IL-13, interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha. Procollagens I (PIP) and III (PIIIP), matrix metalloproteinase (MMP)-1 and -9, and tissue inhibitor of metalloproteinase (TIMP)-1 were measured in supernatants, and their respective mRNAs were evaluated by RT-PCR. RESULTS: IL-4 and -13 (10 ng/mL) significantly increased production and expression of PIP compared with nonstimulated cells, whereas IFN-gamma elicited the opposite effect, at both the protein and mRNA levels. Both IL-4 and -13 significantly decreased production of MMP-1 and increased that of TIMP-1, whereas TNF-alpha increased production of MMP-1 and -9. Expression of MMP-1 was reduced by IL-4 and increased by the other tested cytokines, whereas expression of TIMP-1 was increased by all tested cytokines. CONCLUSIONS: IL-4 and -13 increased production of collagen and modified the equilibrium between MMP-1 and its inhibitor, TIMP-1. These effects were partially opposed by IFN-gamma and TNF-alpha.

Cell Division↗
PubMed2003

Tear levels and activity of matrix metalloproteinase (MMP)-1 and MMP-9 in vernal keratoconjunctivitis.

PURPOSE: To study levels and activity of matrix metalloproteinase (MMP)-1 and -9 and their tissue inhibitor (TIMP-1) in tears of patients with vernal keratoconjunctivitis (VKC), with and without severe corneal damage. METHODS: Tear samples were obtained from 16 patients with active VKC and 10 normal control subjects, after clinical evaluation and tear cytology. Tear levels of pro-MMP-1, pro-MMP-9, and TIMP-1 were measured by enzyme-linked immunosorbent assay (ELISA). Collagenase and gelatinase activity were measured in tears by MMP activity assays. Immunohistochemistry was performed on a fragment of superficial keratectomy from two vernal corneal ulcers. RESULTS: Tear levels of pro-MMP-1 and pro-MMP-9 were significantly increased in patients with VKC compared with control subjects (P < 0.001). MMP-1/TIMP-1 and MMP-9/TIMP-1 molar ratios were significantly increased (P < 0.001) in VKC. MMP-1 and MMP-9 activities were significantly increased in VKC tears compared with control samples (P < 0.005). MMP-9 activity correlated significantly with corneal involvement and giant papillae formation. Immunohistochemistry showed positive staining for MMP-9, fibronectin, and eosinophil cationic protein (ECP) on the superficial corneal stroma of the ulcer bed, but no inflammatory cells. CONCLUSIONS: Increased levels and activity of MMP-1 and -9 and an imbalance between MMPs and TIMP may be involved in the pathogenesis of VKC.

Adolescent↗
PubMed2003

Hepatocyte transplantation in the treatment of acute liver failure: microencapsulated hepatocytes versus hepatocytes attached to an autologous biomatrix.

A liver transplant is considered today to be the only effective therapeutic solution for many otherwise intractable hepatic disorders. However, liver transplantation is beset by shortage of donors. Over the years, many liver support systems have been developed to supply the liver functions, mostly as a bridge to transplantation. Transplantation of isolated hepatocytes (HcTx) instead of whole liver has constituted one of the most appealing possibilities to treat several diseases. We compared two different models of HcTx in a surgical model of acute liver failure in pigs, using microencapsulated hepatocytes (MHcTx) and hepatocytes attached to a porcine biomatrix (PBMHcTx), both transplanted into peritoneum. The collected data were survival, laboratory findings, hemodynamic parameters, light microscopy, histology, MTT, and glycogen content. The group with PBMHcTx has a better outcome than the group with MHcTx (p < 0.05). Histology showed normal morphology of the hepatocytes, high glycogen content, 75% viability, positive MTT, and 95% adhesion of the hepatocytes to the biomatrix. Our biomatrix (PBM) provides cell-to-cell contact and interaction with extracellular matrix, which have been shown to play major roles in hepatocyte survival and physiologic regulation of gene expression, and guarantee a prompt engraftment and an adequate neovascularization. PBMHcTx is a useful method to treat acute liver failure and it indicates a possible liver-direct gene therapy in the treatment of inherited and acquired disorders.

Animals↗
PubMed2002

Sex hormone profile and endometrial cancer risk in primary biliary cirrhosis: a case-control study.

OBJECTIVE: To investigate the sex hormone profile and endometrial histology in primary biliary cirrhosis (PBC). STUDY DESIGN: A prospective case-control study. Twenty-two females with PBC and 22 sex- and age-matched healthy controls underwent complete gynaecological examination including endometrial biopsy and a sex hormone serological profile including: oestrone, 17-beta oestradiol, testosterone, progesterone, dehydroepiandrosterone sulphate (DHEA-S) and sex hormone binding protein (SHBG). The sex hormone profile was evaluated with respect to the body mass index (BMI), anthropometric measurements and endometrial histological/cytological patterns in each case. Statistical analysis was done with the chi-squared method, Student's t-test for unpaired data, linear regression analysis, Spearman's rank correlation test and stepwise multiple regression analysis. RESULTS: The BMI was comparable in the two groups, while PBC cases had significantly smaller subscapular, waist, bicipital, tricipital and calf fold measurements than controls. Testosterone serum levels were significantly lower in PBC cases than in controls (0.9+/-0.6 versus 1.4+/-0.7 mmol/l, P<0.03), whereas SHBG was significantly higher than in controls (88.6+/-72.1 versus 63.6+/-27.6, P<0.005). No significant differences between the two groups were found for oestrone, 17-beta oestradiol, DHEA-S, and progesterone levels. No difference patterns were observed in endometrial histological/cytological patterns. Multiple regression analysis identified SHBG as an independent variable associated with PBC. CONCLUSIONS: Changes in sex hormone profile are secondary to hepatic dysfunction in PBC. Females with PBC do not appear to carry a higher risk of endometrial cancer.

Adult↗
PubMed2002

Charting the course of medical laboratories in a changing environment.

BACKGROUND: In recent decades, dramatic changes have occurred in the organization, number and type of tests, and role of medical laboratories in healthcare. The role of laboratory professionals has undergone a radical change, which calls for greater analytical accuracy, and more stringent test selection, and interpretation of results. METHODS: The ancillary role of clinical laboratories in the past was analyzed in order to understand why the change has taken place, and to identify old and new areas in which laboratory information is largely used for improving upon decision making for treatment, and patient management. RESULTS: The availability of real-time laboratory results and more effective tests, the enhanced clinical consulting role, the involvement in therapeutic decisions, the efforts to prevent rather than cure disease, the shift from anecdotal care to evidence-based medicine, and the assessment of outcome for laboratory tests have all contributed to the changing role and duties of medical laboratories. CONCLUSIONS: Crucial elements in sustaining the changes in the role and contribution of medical laboratories to a high-quality healthcare are the ability of laboratory professionals to: guarantee the quality of laboratory tests irrespective of where they are performed; improve the quality of services; improve clinical outcomes; and perform joint clinical/laboratory research projects. A key factor in effecting the change has been the awareness of the importance of the knowledge and skills required for the new role of laboratory professionals.

Clinical Laboratory Techniques↗
PubMed2002

Continuing medical education: a challenge to the Italian Scientific Societies of Laboratory Medicine.

BACKGROUND: In the modern health service, it is no longer acceptable for any clinician or other professional to abstain from continuing education after qualification. This is particularly true in the field of laboratory medicine because of the dramatic changes that have occurred in the organization, number and types of tests, and role of medical laboratories. In Italy, a program for continuing education in medicine (Educazione Continua in Medicina (ECM)) has recently been promoted by the National Government. METHODS: Continuing education (CE) in laboratory medicine should include all educational activities that are pertinent to a person's professional skills, activities, interests, and growth. Continuing education can take many forms. In particular, a variety of programs are available that enable employees to improve their knowledge and skills while reducing their travel and absence from the laboratory. RESULTS: The present paper describes the recent redefinition of the mission, aims and structure of the Scientific Division of the Italian Society of Clinical Biochemistry and Clinical Molecular Biology (SIBioC) and the role it plays in making available to all associates a program for continuing education in the field of Laboratory Medicine. CONCLUSIONS: The activation of a national program for continuing education in medicine (ECM) in Italy provides a great opportunity for all professionals of the healthcare sector and for laboratorians, in particular. This educational project offers an unrivalled opportunity for the Italian Scientific Societies of Laboratory Medicine to weave quality improvement into their relationships with associates, thus reappraising their missions and goals.

Accreditation↗
PubMed2002

Cystatin C is a more sensitive marker than creatinine for the estimation of GFR in type 2 diabetic patients.

BACKGROUND: Glomerular filtration rate (GFR) is the best overall index of renal function in health and disease. Inulin and 51Cr-EDTA plasma clearances are considered the gold standard methods for estimating GFR. Unfortunately, these methods require specialized technical personnel over a period of several hours and high costs. In clinical practice, serum creatinine is the most widely used index for the noninvasive assessment of GFR. Despite its specificity, serum creatinine demonstrates an inadequate sensitivity, particularly in the early stages of renal impairment. Recently, cystatin C, a low molecular mass plasma protein freely filtered through the glomerulus and almost completely reabsorbed and catabolized by tubular cells, has been proposed as a new and very sensitive serum marker of changes in GFR. This study was designed to test whether serum cystatin C can replace serum creatinine for the early assessment of nephropathy in patients with type 2 diabetes. METHODS: The study was performed on 52 Caucasian type 2 diabetic patients. Patients with an abnormal albumin excretion rate (AER) were carefully examined to rule out non-diabetic renal diseases by ultrasonography, urine bacteriology, microscopic urine analysis, and kidney biopsy. Serum creatinine, serum cystatin C, AER, serum lipids, and glycosylated hemoglobin (HbA1c) were measured. GFR was estimated by the plasma clearance of 51Cr-EDTA. In addition the Cockcroft and Gault formula (Cockcroft and Gault estimated GFR) was calculated. RESULTS: Cystatin C serum concentration progressively increased as GFR decreased. The overall relationship between the reciprocal cystatin C and GFR was significantly stronger (r = 0.84) than those between serum creatinine and GFR (r = 0.65) and between Cockcroft and Gault estimated GFR and GFR (r = 0.70). As GFR decreased from 120 to 20 mL/min/1.73 m2, cystatin C increased more significantly that serum creatinine, giving a stronger signal in comparison to that of creatinine over the range of the measured GFR. The maximum diagnostic accuracy of serum cystatin C (90%) was significantly better than those of serum creatinine (77%) and Cockcroft and Gault estimated GFR (85%) in discriminating between type 2 diabetic patients with normal GFR (>80 mL/min per 1.73 m2) and those with reduced GFR (<80 mL/min/1.73 m2). In particular, the cystatin C cut-off limit of 0.93 mg/L corresponded to a false-positive rate of 7.7% and to a false-negative rate of 1.9%; the serum creatinine cut-off limit of 87.5 micromol/L corresponded to a false-positive rate of 5.8% and to a false-negative rate of 17.0%. CONCLUSIONS: Cystatin C may be considered as an alternative and more accurate serum marker than serum creatinine or the Cockcroft and Gault estimated GFR in discriminating type 2 diabetic patients with reduced GFR from those with normal GFR.

Aged↗