La transtiretina (prealbumina) nella infiammazione e malnutrizione

A. Myron Johnson*, Giampaolo Merlini, Joanna Sheldon , Kiyoshi Ichihara, Mario Nuvolone
*Departments of Pediatrics and Obstetrics & Gynecology, University of North Carolina School of Medicine, Chapel Hill, NC, US

Biochimica Clinica: 2007; 31(2): 97-104 [Article in italian]

ABSTRACT. Transthyretin (prealbumin) in inflammation and malnutrition. A large number of circumstances are associated with reduced serum concentrations of transthyretin (TTR), or prealbumin. The most common of these is the acute phase response, which may be due to inflammation, malignancy, trauma, or many other disorders. Some studies have shown a decrease in hospital stay with nutritional therapy based on TTR concentrations, but many recent studies have shown that concentrations of albumin, transferrin, and TTR correlate with severity of the underlying disease rather than with anthropometric indicators of hypo- or malnutrition. The measurement of serum TTR should be always associated with the measurement of serum C-reactive protein in order to detect acute phase response and assess the prognosis. The assays for TTR have a relatively high level of uncertainty (‘‘imprecision’’). Further investigation is required to define the complex relationship between TTR and inflammation. In the meantime, clinical evaluation – history and physical examination – should remain the mainstay of nutritional assessment.

Esperienze pilota sulla Valutazione Esterna di Qualità della misura dell'emoglobina A2 con campioni di sangue intero e metodiche HPLC commerciali

A. Mosca*, R. Paleari, A. Giambona, M. Cannata, F. Leto, R. Li Muli, A. Maggio, per l’IFCC Working Group on Standardization of HbA2 e per la Società per lo Studio delle Talassemie e delle Emoglobinopatie
*Centro Interdipartimentale per la Riferibilità Metrologica in Medicina di Laboratorio (CIRME), Università degli Studi di Milano
Biochimica Clinica: 2007; 31(2): 105-110 [Article in italian]

ABSTRACT. Pilot External Quality Assessment studies on hemoglobin A2 (HbA2) measurement in Italy with HPLC systems. To evaluate the extent of interlaboratory variation and accuracy in HbA2 assay, two pilots studies of External Quality Assessment were organized in 2005 and 2006 among 48 and 65 Italian laboratories, respectively. As part of the study a survey was also performed by sending a questionnaire concerning some important analytical aspects related to the determination of HbA2. The trial specimens consisted of whole blood samples with a normal, pathological and borderline HbA2 content. All laboratories used HPLC analyzers from the same manufacturer (Bio-Rad Laboratories). Normal and pathological samples were clearly differentiated by all laboratories, while the data on the borderline sample partially overlapped the others. Overall interlaboratory CV were between 6.0% to 8.0% in the 2005 exercise, and between 8.9% and 9.6% in the 2006 exercise. To assign HbA2 target values to the samples, the median of the laboratory group was used, after the exclusion of the outliers (2 data only over the 2 years). The accuracy of HbA2 results was evaluated on the basis of allowable total error. The proportions of laboratories reporting unacceptable results at the thalassemic level were 14.9% (2005 exercise) and 27.7 % (2006 exercise). No abnormalities in the chromatographic separation patterns were reported by any of the laboratories. We conclude that quality in the measurement of the HbA2 should be improved.

Determinazione della buprenorfina: metodi ELISA e CEDIA a confronto

Immacolata Amoroso, Daniela Giardiello, Rita Fiore, Agnese Morani, Patrizia Padulano, Vincenzo Vitulano, Luigi Vrenna

Polo Tossicologico di Riferimento Territoriale per le Farmacodipendenze e le Patologie Correlate ”S.M. Loreto Crispi”, ASL Napoli 1, Napoli

Biochimica Clinica: 2007; 31(2): 111-114 [Article in italian]

ABSTRACT. Determination of buprenorphine: comparison of ELISA and CEDIA methods. The requests for buprenorphine assay greatly increased after its recent use for treatment of drug addiction. This called for a rapid procedure for large numbers of samples and with a good analytical performance. Until 2003, buprenorphine was assayed by RIA or using 2nd level techniques, such as HPLC and gas-chromatography with mass spectroscopy, not suitable for routine use. In the past few years the CEDIA techniques, adaptable to any clinical chemistry analyser and entirely automatic, and the One step ELISA in microplate (which requires specific equipment and automated methodology) have become available. Our study assessed the analytical and diagnostic efficiency of the above techniques in 100 urinary samples from subjects referred by the Ser.T. To calculate intra and interassay CVs two controls with a known concentration (3 and 7 mg/L for CEDIA and 3 and 5 mg/L for One step ELISA) were assayed 20 times. The CEDIA showed a 11,63% (low concentration sample, intra-series) and a 12,85% (low concentration sample, inter-series) maximal CV. One step ELISA showed a 8,77% (low concentration sample, intra-series) and a 9,11% (low concentration sample, inter-series) maximal CV. The diagnostic efficiency of two methods were compared to the gold standard procedure using ROC curves. For CEDIA the optimal threshold was 21 mg/L with a diagnostic sensitivity of 94,6% and a diagnostic specificity of 87,3%; for One step ELISA, the 10 mg/L threshold was associated with a diagnostic sensitivity of 97,3% and a diagnostic specificity of 82,5%. Both techniques had high diagnostic sensitivity, but lower specificity. Therefore we suggest their use as screening procedures followed by 2nd level confirmatory tests for positive samples.

Esperienze nella misura della buprenorfina nelle urine con metodica cedia

Giovanni Cangiano*, Camillo Esempio, Maria Russo, Francesco Forte, Annachiara Latte, Rossella Garofano, Maurizio D’Amora, Andrea Risitano
*Laboratorio Patologia Clinica P.O, ASL NA1, Napoli
Biochimica Clinica: 2007; 31(2): 115-117 [Article in italian]

ABSTRACT. CEDIA assay of buprenorphine. A new immunoenzymatic method in homogenous phase has been applied to determine urinary buprenorphine and its high effectiveness has been demonstrated by our research. The automatic dilution of urine samples has permitted to quantify over 85% of the tested samples. Data coming from the urinary buprenorphine/creatinine ratio from every monitored subject for a long period of time were clinically relevant.

Sviluppo di un metodo in elettroforesi capillare per la determinazione del lattulosio e del mannitolo nelle urine e sue applicazioni allo studio della permeabilità intestinale in diabetici di tipo 1

Rita Paroni*, Isabella Fermo, Laura Molteni, Laura Folini, Matteo Rocco Pastore, Andrea Mosca, Emanuele Bosi
*Dipartimento di Medicina, Chirurgia e Odontoiatria, Università di Milano, Ospedale San Paolo, Milano
Biochimica Clinica: 2007; 31(2): 118-121 [Article in italian]

ABSTRACT. Development of a capillary electrophoresis method for urinary lactulose and mannitol determination to assess the intestinal permeability in patients with type 1 diabetes. The assessment of the unbalanced intestinal permeability to lactulose (LAC) and mannitol (MAN) after oral administration is used for the diagnosis of gluten-sensitive enteropathy. Aim of this study was to set up a method by capillary electrophoresis to detect the concentration of MAN and LAC in urine to estimate the intestinal permeability in controls and in patients affected by type I diabetes mellitus. In <10 min the underivatized carbohydrates were separated at pH of 12.5 and with indirect UV detection at 254 nm. In controls (n=41) 11.3 (median; interquartile range: 5.7-15.3) and 303 (237-440) mg of LAC and MAN were excreted during the 5 h urine collection after the carbohydrate administration, while in diabetes patients (n=24) 16.5 (12.8-24.3) and 229 (170-354) mg of LAC and MAN were found. This simple and rapid technique is suitable to study intestinal permeability alterations in different cohorts of patients.

Usefulness of serum sFas and sFasL determinations as apoptogenic markers in liver disease

Amr Ahmed Hassan*, Amal Abuel Fadl, Awad El-Abd, Fatma Abdel Salam, Mahmoud Negm
*Departments of Biochemistry, Benha, Egypt

Biochimica Clinica: 2007; 31(2): 122-126 [Article in english]

ABSTRACT. This work aimed to investigate the biochemical changes of serum sFas/sFasL system and its usefulness as apoptogenic marker in patients with Bilharzial hepatic fibrosis and liver cirrhosis with and without hepatocellular carcinoma. Fourty patients, 22 males and 18 females were selected for this study (age range: 30-67 years, average 48.4±8.9). They were clinically categorized as 15 patients with Bilharzial fibrosis, 15 patients with hepatitis C virus-related liver cirrhosis and 10 patients with hepatocellular carcinoma. Ten healthy subjects, age and sex-matched, were enrolled as controls. Statistical analysis showed that the mean value of serum sFas in Bilharzial fibrosis and liver cirrhosis, with and without hepatocellular carcinoma, was significantly higher than in control group (P <0.05). Moreover, the mean value of serum sFasL was significantly elevated in all patients with liver cirrhosis, with and without hepatocellular carcinoma, and lower, but not significantly, in patients with Bilharzial fibrosis in comparison with the control group. We conclude that the biochemical changes in sFas/sFasL system might be considered a potentially useful tool as apoptogenic marker in some liver diseases.

Formazione in Medicina di Laboratorio

Gian Cesare Guidi, Giuseppe Lippi
Sezione di Chimica e Microscopia Clinica, Dipartimento di Scienze Morfologico Biomediche, Università degli Studi di Verona

Biochimica Clinica: 2007; 31(2): 127-130 [Article in italian]

ABSTRACT. Education in Laboratory Medicine. Although the Italian health system is mainly administered and managed by publicly funded subjects, a competition with new suppliers of health services, principally private subjects, for a major efficiency is at last emerging in Italy as well, alike as in other EU countries. Innovation-linked concepts such as global service and outsourcing are already avowed worldwide and are expected to assume a clear connotation also within our country. Clinical laboratories are in the foremost line of the global competition and the laboratory professionals are challenged by evolving technologies on one side and limited resources on the other. The situation calls for a greater compliance and flexibility, both of which would allow laboratory professionals to express at a greater degree of efficiency. In this perspective, an efficient training program should be arranged, encompassing the two major emerging challenges represented by scientific innovation and professionalization. The complexity of this process requires an active commitment of the Scientific Societies, which are in the unique position to provide knowledgeable and appropriate education. A comprehensive training program should develop through a three-steps process, encompassing pre-degree, specialist and permanent formation, aimed at providing the students with in-depth learning of traditional and emerging topics in the field of Laboratory Medicine.

L’automazione della fase preanalitica

Giuseppe Lippi*, Gian Luca Salvagno, Gian Cesare Guidi
*Sezione di Chimica e Microscopia Clinica, Dipartimento di Scienze Morfologico-Biomediche, Università degli Studi di Verona
Biochimica Clinica: 2007; 31(2): 131-137 [Article in italian]

ABSTRACT. Automation of the preanalytical phase. Relevant changes have occurred in organization, complexity and role of medical laboratories in healthcare and automation has proven to be a powerful catalyst for this change. Improved efficiency and the pressure to have reliable and reproducible conditions for analyses have led to a high degree of automation in clinical laboratories worldwide. There is consolidated evidence that the lack of standardization of several preanalytical variables, from sample collection to specimen processing, exerts unfavourable influences on test results, consuming health care resources and influencing the patient’s outcome. The automation of repetitive, error-prone and bio-hazardous preanalytical processes endorses the potential to improve the turnaround time, abates the biological risk associated with operator’s exposure to hazardous biological material, reduces errors and costs associated with sample handling. This would ultimately contribute to reorganize the total testing process, reprofessionalize laboratory specialists, improve efficiency and quality, with favourable revenues for the outcome of the patients. Two alternative solutions can be pursued: total laboratory automation or modular workcells, which have the potential to automatically inspect, label, centrifuge, sort, aliquot and load specimens. Automated phlebotomy trays, conveyor belts, pneumatic systems and other innovative robotic facilities are also proposed to standardize, ease and accelerate the procedures for sample collection and transporting. Customized solutions, determined on a local basis according to specific needs and individual work-flows, will assist laboratories to remain competitive in the integrated healthcare network.

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