Volume 45, Issue 2

In the postmenopausal period, cardiovascular diseases are a frequent chronic condition leading to high risk of myocardial infarction and death. Recently hyperhomocysteinemia and even mildly elevated plasma concentrations of homocysteine have been recognized as independent risk factors for vascular damage predisposing to arteriosclerosis. Elevated plasma levels of homocysteine induce vascular endothelial damage and are frequently associated with low folate levels. In this review we evaluate literature data on some aspects related to menopause and homocysteine metabolism. In particular, we show the effect of folic acid supplementation on homocysteine concentrations and on homocysteine-related thiols, such as cysteine and cysteine-glycine, as well as the relationship with glucose, insulin, and lipidic metabolism in postmenopausal women. We also analyze the influence of folate supplementation on endothelial function, by brachial artery flow-mediated dilatation (endothelium-dependent) and nitroglycerine-induced dilatation (endothelium-independent) before and after a methionine load. Folate administration in postmenopausal women is able to reduce high plasma homocysteine levels and to modify impaired endothelial function induced by hyperhomocysteinemia. Clin Chem Lab Med 2007;45:130–5.

Background: Homocysteine is associated with age, folate and vitamin B 12 . Our study investigated the functional and clinical characteristics of the elderly (aged 60–85 years) of San Teodoro, a village in Central Sicily, and evaluated associations with vitamin B 12 , folate and homocysteine. Methods: Subjects (n=280) were examined after door-to-door recruitment using interview, physician examination and laboratory tests. Results: A total of 19.3% of the population had a low blood level of folate (<7 nmol/L) and 3.2% had low vitamin B 12 concentration (<100 pmol/L). The level of dependency, determined by the Barthel index, influenced homocysteine blood levels (p<0.0001), independent of age (p<0.0001), folate (p=0.0028) and vitamin B 12 (p=0.0165). Homocysteine was significantly associated with stroke (p=0.0027) and peripheral arterial vascular disease (p=0.0001), but not with myocardial infarction, angina pectoris, venous thrombosis or cancer. Vitamin B 12 was lower in myocardial infarction and higher in diabetes and venous thrombosis compared to the other diseases. Conclusions: The prevalence of deficits in folate and vitamin B 12 was paradoxically high in the mountainous northeastern area of Sicily. Our study also underlines the association of homocysteine with dependency of the elderly and with stroke and peripheral arteriopathy. Clin Chem Lab Med 2007;45:136–42.

Background: Association of thyroid dysfunction with plasma homocysteine levels and vitamin B 12 has previously been reported. We evaluated these associations in the elderly in San Teodoro, a mountainous village of Sicily. Methods: Subjects (n=279) aged 60–85 years (119 males and 160 females) were examined using self-reported signs, clinical examination and laboratory tests. Results: Hypothyroidism and/or goiter were two characteristics that were not associated with a significant change in homocysteine when compared with euthyroidism and the absence of goiter. Vitamin B 12 was significantly higher in subjects in the first quartile of the thyroid-stimulating hormone distribution, compared with those in the fourth quartile (371±207 vs. 297±196 pmol/L, p=0.0121). Homocysteine was significantly higher in the first quartile of the free tri-iodothyronine distribution compared to the third quartile (18.0±5.7 vs. 16.0±6.2 μmol/L, p=0.0130) and was correlated with log tri-iodothyronine in euthyroid subjects (p=0.0254). In multivariate analysis, homocysteine was associated with vitamin B 12 (p=0.0014), folate (p<0.0001), creatinine (p<0.0001) and age (p<0.0001), but not with either free tri-iodothyronine (p=0.7680), tetra-iodothyronine (p=0.5706) or thyroid-stimulating hormone (p=0.2294). Conclusions: Our results suggest that the influence of thyroid hormones on homocysteine is much weaker in elderly subjects than in selected patients with hypothyroidism. Clin Chem Lab Med 2007;45:143–7.

The early diagnosis of rheumatoid arthritis (RA) has become a priority owing to the availability of effective disease-modifying agents that can improve patient wellbeing and influence the clinical outcome. However, this represents a real challenge, as no clinical, radiological or immunological features are pathognomonic at the time of presentation. For this reason, development of the anti-cyclic citrullinated peptide (CCP) antibody assay, a highly disease-specific serological marker for RA, has been a great step forward for the rheumatologist and the clinical laboratory. Over recent years, this test has increased in popularity and many studies have been performed. This review briefly considers the most recent data on the diagnostic accuracy of the CCP test, the genetic background that predisposes to antibody production, the diagnostic, prognostic and predictive values, and the clinical use of the assay in patients with RA. Clin Chem Lab Med 2007;45:150–7.

Movement of body water from compartment to compartment during any time period is attributable to forces active within and upon each space. The result of these forces leads to transfer of water between intravascular and extravascular compartments, as well as shifts between extracellular and intracellular spaces. The importance of these shifts and of the associated mechanism was described by Ernest Starling in 1896 in very much the same manner as it is viewed today. The end result of fluid transfer and its physiological and laboratory consequences has not been fully appreciated. Despite awareness that fluid shifts can affect laboratory analytical results, little recent investigation has addressed the problem in the routine clinical laboratory. Thus, the potential for significant misinterpretation remains. For example, it is known that individual laboratory test values can vary widely, depending on many factors including the subject's posture during and immediately before phlebotomy, leading to significant changes in the interpretation of blood analyte values. Furthermore, a variety of ubiquitous environmental effects have additional impact on fluid distribution and thus on test values. In other words, patient hydration status is a major pre-analytical variable that needs to be addressed by the clinical laboratory. The need to adjust data for patient hydration status is especially important in the case of colloid analytes for which the dynamic range includes a narrow “gray zone” where hydration changes of a few percentage points can change the clinical implications. The crucial importance of this adjustment is underscored by the fact that neither the testing laboratory nor the clinician are aware of this unseen circumstance and are thus compelled to work with data that do not necessarily reflect the clinical situation. Clin Chem Lab Med 2007;45:158–66.

Background: Hepatitis C virus (HCV) genotyping and accurate subtyping is becoming increasingly relevant to epidemiological studies, clinical management, pathogenicity, and vaccine development. Methods: The TRUGENE ® HCV 5′NC Genotyping Kit, the new VERSANT ® HCV Genotype 2.0 Assay (LiPA), and a new laboratory-developed HCV NS5b sequencing assay designed for automated sequencing of the HCV NS5b region were used. Clinical samples and a molecular diagnostics HCV genotyping proficiency program panel were used to determine accuracy and differentiate performance characteristics of the three methods. Results: All amplified samples from among the members of a HCV genotyping proficiency program panel that contained a single HCV genotype were subtyped correctly using all three HCV genotyping assays. With the TRUGENE ® HCV 5′NC Genotyping Kit, the HCV subtype was determined in 357 of 441 of routine clinical samples. When the 84 samples with only genotype results were retested with the VERSANT ® HCV Genotype 2.0 Assay (LiPA), 61 could be further subtyped accurately. With the new laboratory-developed HCV NS5b sequencing assay, all 84 could be subtyped accurately. Conclusions: The two new methods show advantages over the routinely used TRUGENE ® HCV 5′NC Genotyping Kit in terms of genotyping and subtyping accuracy by utilizing part of the HCV core region and NS5b region, respectively. Clin Chem Lab Med 2007;45:167–70.

Background : Based on quantification of relative changes in lipopolysaccharide (LPS)-regulated mRNA transcripts, the present study aimed to establish a robotic method to isolate RNA from stabilized frozen whole blood suitable for gene expression analysis. Methods : Whole blood (±LPS) was stored in EasyLyse™ solution or PAXgene ® tubes (room temperature and −70°C) for comparison of storage methods, then subjected to robotic isolation of total RNA. Yield, quality and relative changes in 11 selected mRNA transcripts were examined. Method precision (% coefficient of variation) for a longitudinal control was established. The influence of globin mRNA from reticulocytes in quantitative RT-PCR was examined. Results : All storage methods gave a similar high-quality RNA yield. The differences in the 11 specific mRNA quantities stored in EasyLyse or PAXgene ® at −70°C were small: mean −0.01 (95% CI –0.19 to 0.17). The CV for mRNAs in the longitudinal control ranged from 3% to 150%. Thus, the number of replicates necessary to detect a 20% difference (power 0.8) ranged from 2–50. Globin mRNA had no influence on quantitative RT-PCR Conclusions : Based on measuring the relative changes in specific mRNAs in LPS-exposed whole blood, we conclude that PAXgene ® tubes stored at −70°C could preferentially be used. This may open opportunities for monitoring gene expression changes in clinical settings. Clin Chem Lab Med 2007;45:171–6.

Background : The level of HER-2/neu in breast cancer cells is normally measured by immunohistochemistry (IHC) and/or fluorescence in situ hybridization (FISH). It determines whether patients should be treated with trastuzumab (Herceptin ® ). In this study, HER-2 protein in breast cancer tissue was measured using a quantitative method. Methods : Tissue samples of malignant and adjacent benign breast tissue were collected from 118 consecutive women admitted for surgical treatment of breast cancer. The HER-2 protein concentration was determined by 2 HER-2 assays: ELISA and the Bayer ADVIA Centaur assay. Paraffin-embedded tissue sections of the corresponding tumors were analyzed by IHC and FISH. Results : Increased HER-2 concentrations in cancer tissue were found compared to autologous reference tissue (p<0.0001, Wilcoxon test) and normal breast tissue (p<0.0001, Mann-Whitney test). Good concordance rates were observed between the methods: 95.8% for IHC and FISH; 86.4% for IHC and ELISA; and 87.3% for FISH and ELISA. The HER-2 positivity rate was determined to 26.3% by ELISA, 12.7% by IHC and 16.9% by FISH. No correlation was found with tumor grade, axillary node status or serum HER-2 levels. Conclusions : Detection of HER-2 overexpression by measuring HER-2 in tissue extracts by ELISA seems to be more sensitive than IHC and FISH. This suggests that some patients deprived of Herceptin treatment may benefit from this treatment and may also explain the conversion phenomenon from HER-2-negative to HER-2-positive observed in relapse and metastatic disease. Clin Chem Lab Med 2007;45:177–82.

Background : Distinct host immune status predisposes to different forms of pulmonary aspergillosis. Methods : Patients with chronic cavitary pulmonary aspergillosis (CCPA; n=15) or allergic bronchopulmonary aspergillosis (ABPA; n=7) of Caucasian origin were screened for single nucleotide polymorphisms (SNPs) in the collagen region of surfactant proteins A1 ( SP-A1 ) and A2 ( SP-A2 ) and mannose binding lectin ( MBL ). Results : The T allele at T1492C and G allele at G1649C of SP-A2 were observed at slightly higher frequencies in ABPA patients (86% and 93%) than in controls (63% and 83%), and the C alleles at position 1492 and 1649 were found in higher frequencies in CCPA patients (33% and 25%) than in ABPA patients (14% and 7%) (all p>0.05). However, the CC genotype at position 1649 of SP-A2 was significantly associated with CCPA (χ 2 =7.94; p corr ≤0.05). Similarly, ABPA patients showed a higher frequency of the TT genotype (71%) at 1492 of SP-A2 than controls (43%) and CCPA patients (41%) (p>0.05). In the case of MBL , the T allele (OR=3.1, range 1.2–8.9; p≤0.02) and CT genotype (χ 2 =6.54; p corr ≤0.05) at position 868 (codon 52) were significantly associated with CCPA, but not with ABPA. Further analysis of genotype combinations at position 1649 of SP-A2 and at 868 of MBL between patient groups showed that both CC/CC and CC/CT SP-A2/MBL were found only in CCPA patients, while GG/CT SP-A2/MBL was significantly higher in CCPA patients in comparison to ABPA patients (p≤0.05). SNPs analysed in SP-A1 did not differ between cases and controls. Conclusions: Distinct alleles, genotypes and genotype combinations of SP-A2 and MBL may contribute to differential susceptibility of the host to CCPA or ABPA. Clin Chem Lab Med 2007;45:183–6.

Background : The platelet adenosine 5'-diphosphate (ADP) receptor P2Y 12 plays a crucial role in haemostasis. Only a few patients with haemorrhagic diathesis due to molecular defects in the P2Y 12 receptor have been described so far. We report a novel molecular defect in the gene coding for P2Y 12 in a patient with a history of epistaxis, easy bruising and excessive posttraumatic blood loss. Methods : Platelet aggregation studies, perfusion studies, in which patient blood was perfused over collagen surfaces at arterial shear rates, and PCR and sequencing were used. Results : Platelet aggregation studies showed impaired ADP and collagen-induced aggregation for patient G.S. Perfusion of patient blood over collagen surfaces showed small thrombi consisting of spread platelets overlayered with non-spread platelets. These thrombi were identical to control thrombi formed in the presence of a P2Y 12 antagonist. DNA analysis of the P2Y 12 gene revealed a novel heterozygous base pair C→A substitution in exon 3, changing codon 258 from proline to threonine in the third extracellular loop of the P2Y 12 receptor. Conclusions : We conclude that perfusion studies with patient blood are of added value in the diagnostic process, which resulted in identification of a novel molecular defect in the P2Y 12 gene of a patient with haemorrhagic diathesis. Clin Chem Lab Med 2007;45:187–9.

Background : We studied the incidence, classification and isotype distribution of monoclonal gammopathies and M-protein detected between 1992 and 2005 inclusive in the clinical laboratory of a healthcare district in Madrid (Spain) with an average population of 280,574 inhabitants. Methods : Serum electrophoresis was carried out on a cellulose acetate support up until 1997, and then using capillary zone electrophoresis systems, with M-protein identification carried out by agarose gel immunofixation. The age-adjusted incidences were standardized with respect to the WHO World Standard Population Distribution, based on the world average population between 2000 and 2025. The clinical diagnosis was recorded from the patient case history. Results : M-protein was detected in a total of 537 patients; of these, 42 had been diagnosed before 1992, representing a 0.19% prevalence in our population. The mean age-adjusted incidence of monoclonal gammopathy was 10.72 per 100,000 inhabitants/year (SE 1.31), ranging from 4.85/100,000 in 1992 to 14.28/100,000 in 2003 and 2004. The median patient age at diagnosis was 73 years (range 25–96 years), with males accounting for 46.8% of all cases of monoclonal gammopathy, and 57.8% of all malignant monoclonal gammopathies. A total of 54.1% of the patients were clinically defined as presenting monoclonal gammopathy of undetermined significance, 31.3% presented multiple myeloma, and the remaining 14.6% presented malignant gammopathies. The most frequent M-protein isotype was IgG (55.8%), followed by IgA (20.8%) and IgM (13.6%). A total of 88% of the light chain M-proteins, 54% of isotype IgM, 51% of isotype IgA and 36% of isotype IgG were associated with B lymphoproliferative diseases. Conclusions : We conclude that the clinical laboratory should play an important role in the study of monoclonal gammopathies, since it is the only location where all M-protein patients are observed. On the other hand, studies of this type should be carried out over long-term periods, owing to the variations we have noted in the detection of M-proteins. Clin Chem Lab Med 2007;45:190–6.

Background : Vitamin B 12 deficiency and renal impairment are common in the aged, and therefore the screening test for vitamin B 12 deficiency should not be affected by renal function. Renal impairment has been associated with increased concentrations of plasma total homocysteine and methylmalonic acid, as well as increased total vitamin B 12 and holotranscobalamin concentrations. Methods : The effect of renal impairment on vitamin B 12 -related biochemical variables was assessed in 1011 aged subjects. Results : Renal function as indicated by serum cystatin C correlated strongly with plasma total homocysteine (r s =0.53, p<0.001) and serum methylmalonic acid (r s =0.27, p<0.001), but not with serum total vitamin B 12 (r s =−0.04, p=0.227) or holotranscobalamin (r s =−0.01, p=0.817). Conclusions : Either total vitamin B 12 or holotranscobalamin rather than homocysteine or methylmalonic acid should be used when screening an aged population prone to renal impairment. Clin Chem Lab Med 2007;45:197–201.

Background : One of the main criteria to establish a diagnosis of polycystic ovary syndrome (PCOS) is hyperandrogenemia. Recent observations suggest that total testosterone may not be a sensitive marker for the detection of androgen excess. The aim of the present study was to compare the value of different androgen determinations for diagnosis of PCOS. Methods : Untreated PCOS patients (n=133; mean age 28 years) and healthy control women (n=54; mean age 28 years) were included in the study. Measurements of total testosterone and sex hormone-binding globulin (SHBG), luteinizing hormone (LH), follicle-stimulating hormone (FSH), androstendione, dehydroepiandrosterone sulfate (DHEAS) and albumin were performed. In addition, the free androgen index (FAI), free and bioavailable testosterone were calculated. Clinical signs of hyperandrogenism were evaluated by physical examination. The area under the receiver operating characteristic curve (AUC-ROC) was used to compare the sensitivity and specificity of different androgen determinations to detect PCOS, defined as clinical hyperandrogenism and irregular cycles compatible with the National Institutes of Health criteria of chronic anovulation and clinical or biochemical hyperandrogenism. Results : All biochemical parameters of hyperandrogenism were significantly higher in PCOS patients than in controls (all p<0.0001). The highest AUC-ROC was found for bioavailable testosterone (0.852) followed by FAI (0.847) and free testosterone (0.837). Lower AUC-ROC was found for SHBG, total testosterone and androstendione (0.765, 0.799 and 0.706, respectively). When FAI=4.97 was taken as a cutoff value, sensitivity was 71.4% and specificity was 85.2%. A cutoff of 0.78 nmol/L for bioavailable testosterone had even higher sensitivity of 75.9%, but slightly lower specificity of 83.3%. FAI and bioavailable testosterone correlated significantly (all p<0.05) with total testosterone, androstendione, LH/FSH ratio and DHEAS. In addition, free testosterone, bioavailable testosterone and FAI correlated significantly with hirsutism scores, and ovarian volume and follicle count. Conclusions : ROC analysis provided evidence that calculated testosterone indices (bioavailable testosterone, FAI, free testosterone) are useful parameters for the discrimination of PCOS patients and healthy controls. Clin Chem Lab Med 2007;45:202–7.

Background : The presence of fibronectin fragments has been observed in some inflammatory diseases and is believed to reflect tissue breakdown. In this study, possible fibronectin fragmentation and alterations in its domain and sialyl and fucosyl glycotope expressions were analyzed in amniotic fluids in relation to intrauterine infection. Methods : Samples of amniotic fluid were taken from normal pregnancies and pregnancies (28 and 42 weeks) complicated by intrauterine infection. Fibronectin fragmentation was analyzed by immunoblotting. The expression of cellular, fibrin, C-terminal and EDA fibronectin domains, as well as α2,3- and α2,6-linked sialic acids, and α1,6-, α1,3- and α1,2-linked fucoses, was determined by ELISA, using domain-specific monoclonal antibodies and specific lectins, respectively. Results : Amniotic fibronectin immunoblots from pregnancies with intrauterine infection revealed three groups of results. In group 1, with the native fibronectin band, and in group 2 with bands of native fibronectin and several fibronectin fragments, only higher α1,6-linked fucose expression was observed. In the infection group 3, characterized by profound fragmentation of fibronectin, lower expression of all fibronectin domains analyzed and of α1,6-linked sialic acid and α1,2-linked fucose was found. Conclusions : Amniotic fibronectin status was found to be associated with pregnancy complicated by intrauterine infection. Such alterations could have a potential diagnostic value in the prevention of or intervention in fetal intrauterine infection. Clin Chem Lab Med 2007;45:208–14.

Background: The injected mass of internal standard is often monitored in mass spectrometry assays to flag aberrant specimen processing. When simple protein precipitation is used for sample preparation, the protein volume (solids fraction) of the specimen is in principle a variable affecting the final concentration of the internal standard in the liquid phase. We examined the predicted extent of this variation for an example of protein precipitation for sample preparation used in a mass spectrometry assay for immunosuppressants in whole blood. Methods: Liquid and solid mass fractions of samples with hematocrit ranging from 15% to 60% were measured after protein precipitation of samples using a whole blood/precipitating reagent ratio of 1:4. Relative supernatant volumes as a function of hematocrit were determined. Results: Liquid volume variation was consistent with a predicted variation in the internal standard concentration of only approximately ±1% across this hematocrit range. Data were in close agreement with calculations based simply on protein density and concentration. Conclusions: Hematocrit affects the injected mass of internal standard in assays that utilize protein precipitation for sample preparation, due to predictable variation in solids and liquid fractions. The effect is small, however, compared to the typical variation observed for injected mass of internal standard. Clin Chem Lab Med 2007;45:215–9.

Background : Since atherosclerosis is a slowly progressive process at a young age, effective preventive measures should be taken early in life to prevent future events associated with cardiovascular disease. Methods : The study population comprised 132 young Japanese adults (mean age 21.4 years, range 18–31 years). We screened plasma total homocysteine and serum folate levels and evaluated mean carotid intima-media thickness and cardio-ankle vascular index. Results : Multiple regression analysis after adjustment for age and sex revealed that only folate levels were significantly correlated with plasma total homocysteine levels (β=–0.37, p=0.028). Carotid intima-media thickness adjusted for age and sex and compared between quintiles of total homocysteine levels was significantly increased in the highest quintile compared with other quintiles. Cardio-ankle vascular index increased with age in both women and men, but no additional determinants were identified in young adults. Conclusion : Serum folate is an independent determinant of plasma total homocysteine levels, and mild hyperhomocysteinemia may represent a risk factor for increased carotid intima-media thickness, even in young adults. Comprehensive health education from the early period of life, including the suggestion of appropriate dietary measures, is important for effective prevention of future atherosclerosis. Clin Chem Lab Med 2007;45:220–5.

Background : The aim of the study was to investigate the potential relationship between A-type (atrial) and B-type (brain) natriuretic peptides (ANP, BNP) and infarct size (IS), left ventricular (LV) function and remodelling as assessed by 99m technetium-hexakis-2-methoxy-isobutyl-isonitrile (99mTc-sestamibi) gated-single photon emission tomography (G-SPET). Methods : Plasma concentrations of ANP and BNP in peripheral blood were measured in 54 patients with coronary artery disease (CAD) and previous myocardial infarction (MI). Of these, 25 subjects had a recent (<2 weeks) and 29 subjects an old (>6 months) MI. IS, left ventricular ejection fraction (LVEF) and end diastolic (EDV), end systolic (ESV) and stroke volume (SV) were quantitatively calculated from at-rest G-SPET. Results : In either univariate or multivariate regression analysis that included IS and the other G-SPET derived parameters as co-variables, both BNP and ANP showed a significant association with IS (BNP p<0.002; ANP p<0.01). No significant relationship was found between the two peptides and LVEF, EDV or ESV values. BNP, but not ANP concentrations, were significantly higher in patients with antero-septal vs. infero-lateral (p=0.01) and recent vs. old MI (p=0.003). In these two subgroups, univariate and multivariate analyses confirmed the correlation between BNP and IS, whereas ANP demonstrated a relationship with IS only in subjects with recent MI. CAD extent had no influence on BNP and ANP levels. Conclusions : The present study showed a positive correlation between BNP and the perfusion defect measured by 99mTc-sestamibi G-SPET in patients with previous MI. Consequently, BNP may reflect the functional significance of myocardial damage and may be considered of prognostic value. ANP was also related to scintigraphic defects in the early phase after MI, but not in the chronic phase, confirming that ANP is a less sensitive marker of LV remodelling, depending also on atrial load conditions and dilatation. These preliminary data based on a small group of subjects need to be confirmed by prospective longitudinal studies involving larger populations. Clin Chem Lab Med 2007;45:226–31.

Background : Hyperhomocysteinemia is considered an independent risk factor for vascular occlusive diseases. To date, there is no general agreement on hyperhomocysteinemia cutoff values. Methods : To establish a homocysteine cutoff value, we performed a case-control study in 118 patients suffering from venous thrombosis and in 115 healthy subjects. We calculated odds ratios at different cutoff points and considered hyperhomocysteinemia as homocysteine levels above which the risk of venous thrombosis was increased. Results : Initially we used the 97.5th percentiles for fasting homocysteine levels in the control group to calculate odds ratios (95% CI) of 9.5 (2.6–35.3), 3.7 (0.8–17.9) and 4.5 (1.7–123.8) for the total population, women and men, respectively. When individuals with well-known thrombotic risk factors were excluded (selected population), odds ratios were 10.5 (2.7– 41.1), 6.5 (1.3–32.1) and 11.2 (1.2–103.1), respectively, confirming hyperhomocysteinemia as an independent risk factor for venous thrombosis. We did not find any association of venous thrombosis with the homozygous methylenetetrahydrofolate reductase C677T mutation. When the hyperhomocysteinemia cutoff was set at other arbitrary points, odds ratios for the selected population were statistically significant only at >12 μmol/L. Conclusions : Based on our results, we propose 12 μmol/L as the hyperhomocysteinemia cutoff value. Clin Chem Lab Med 2007;45:232–6.

Background : Impaired glucose tolerance (IGT) is associated with an increased risk of atherosclerosis that may be due in part to dyslipidemia. The purpose of this study was to assess the regulatory role of lipid transfer proteins in the development of this dyslipidemia. Methods : Activities of cholesterol ester transfer protein (CETP) and phospholipid transfer protein (PLTP), as well as lipid and protein components of the major lipoprotein fractions, were evaluated in probands with IGT and were compared with those in subjects with normal glucose tolerance. The effect of a fat-rich meal on these variables was also investigated. Results : IGT probands had a higher triglyceride content in subfractions of low- (LDL) and high-density lipoprotein (HDL). IGT patients had higher fasting CETP activity. The latter was positively correlated with HDL2 triglycerides and negatively with HDL3 total cholesterol. PLTP activity and mass were not higher in IGT patients. However, PLTP activity correlated with components of VLDL and LDL and was influenced by the type of obesity. Neither CETP and PLTP activities nor PLTP mass were altered by a fat-rich meal. PLTP and CETP activities correlated in both fasting and postprandial conditions. Conclusions : Increased fasting CETP activity may contribute to increased risk of atherosclerosis in subjects with IGT. Clin Chem Lab Med 2007;45:237–43.

Background : In response to many stress stimuli, cardiomyocytes produce a common set of heat shock proteins (HSP). Up-regulation of HSP70-1 (the inducible isoform) is known to reduce the risk of myocardial cell damage during open-heart surgery and seems to be protective against ischemia. We assessed hsp70-1 gene expression during blood cardioplegic arrest in children undergoing surgical correction of congenital heart defects. Methods : In tissue samples taken from the right atrium of 59 pediatric patients, we examined hsp70-1 gene expression using a real-time quantitative reverse transcription PCR, with 18S rRNA as internal standard. Results : On average, hsp70-1 gene expression was higher than the baseline level by a factor of 1.44± 0.17 (mean±SEM). A significant relationship between hsp70-1 mRNA levels and aortic cross-clamp time was observed (R 2 =0.069, p=0.044). Conversely, no significant correlation was observed between hsp70-1 mRNA levels and temperature. Conclusions : These data suggest that blood cardioplegia can induce an increment in the expression of hsp70-1 , confirming its protective role in ischemia/reperfusion injury. Clin Chem Lab Med 2007;45:244–8.

Background: Our aim was to establish sex hormone reference intervals measured with a new AutoDelfia immunoassay method for aged men free of medication and/or conditions known to influence sex hormone levels. Methods: The reference population consisted of 466 individuals between 64 and 97 years (mean 72 years) and a mean body mass index (BMI) of 26.9 kg/m 2 . Results and conclusions: Because age correlated significantly with most sex hormones studied, we calculated reference intervals for three age groups (64–69, 70–74 and ≥75 years). In clinical practice, single ranges can be used for men aged 64 years or over for testosterone, estradiol and follicle-stimulating hormone (FSH) with the AutoDelfia method. For free testosterone and luteinizing hormone (LH), separate reference intervals should be used for men aged 64–74 years and those aged 75 years or over. For sex hormone-binding globulin, two separate reference intervals by age (64–69 and ≥70 years) are also needed for aged men. LH and FSH reference ranges should be judged with caution, because they may be too high due to cases of subclinical hypogonadism included in the reference population. Clin Chem Lab Med 2007;45:249–53.

Background : The Italian External Quality Control Programme for cystic fibrosis molecular diagnosis started in 2001; public laboratories distributed throughout Italy participated on a voluntary basis. Methods : The Italian Public Health Institute (Istituto Superiore di Sanità) sent six validated DNA samples to participating laboratories: technical and clinical information was provided for each sample. Laboratories were required to analyse all six samples. For each sample the laboratories had to provide the results (including raw data) and a report of molecular analysis within 2 months using current methods and nomenclature. Raw data and reports were evaluated by a Steering Committee and their comments were sent to each laboratory. Results : Genotyping results indicated a general good level of quality for all laboratories, i.e., ∼1% of alleles were incorrectly assigned each year due to analytical (45%) and misinterpretation (45%) errors. During the first 2 years, more than 70% of laboratories did not test for some regional Italian mutations. Commercial kits for reverse dot-blot and oligonucleotide ligation assay PCR were used to detect mutations by 52.8% and 29.5%, respectively, of the participating laboratories. Reporting of results was still inadequate; in 2004 a model for the written report was introduced, but not all laboratories used it. Conclusions : Our data show that few genotyping errors were made by laboratories and were principally due to misinterpretation and analytical reasons. However, reports are still inadequate and it will be interesting to evaluate the introduction of the reporting model in future years. Clin Chem Lab Med 2007;45:254–60.

Background : Using a questionnaire, the EC4 (European Communities Confederation of Clinical Chemistry and Laboratory Medicine) has collated an inventory of the accreditation procedures for medical laboratories in the EU. Results and discussion : Accreditation of medical laboratories in the countries of the EU is mostly carried out in cooperation with national accreditation bodies. These national accreditation bodies work together in a regional cooperation, the European Cooperation for Accreditation (EA). Professionals are trained to become assessors and play a prominent role in the accreditation process. The extent of the training is diverse, but assessors are kept informed and up-to-date by annual meetings. The frequency of assessments and surveillance visits differs from country to country and ranges from 1 to 4 years. More harmonisation is needed in this respect, based on a frequency that can be pragmatically handled by laboratory professionals. In the majority of EA bodies, accreditation is carried out on a test-by-test basis. Many professionals would prefer accreditation of the entire service provided within the actual field of testing (i.e., haematology, immunology, etc.), with accreditation granted if the majority of tests offered within a service field fulfil the requirements of the ISO 15189 standard. The scope of accreditation is a major point of discussions between the EC4 Working Group on Accreditation and representatives of accreditation bodies in the EA Medical Laboratory Committee. Clin Chem Lab Med 2007;45:268–75.