Volume 48, Issue 9

During the past 20 years the diagnosis of coeliac disease has improved significantly. However, at the same time the true prevalence of the condition has doubled, involving more than 2% of the population in some countries. Due to mild or atypical symptoms, the diagnosis remains a challenge for the health care system. Highly sensitive and specific serum endomysial and transglutaminase-2 antibody tests are helpful in identifying patients for diagnostic endoscopy and small-bowel biopsy. The diagnosis of the disease is still based on the demonstration of gluten-induced small-bowel mucosal villous atrophy with crypt hyperplasia. However, coeliac disease may manifest itself before the development of the overt small-intestinal lesion. Positive endomysial and transglutaminase antibodies in patients with normal small-bowel mucosal villous architecture may indicate early stage coeliac disease. Currently, the only effective treatment for the condition is a life-long strict gluten-free diet. Long-term regular follow-up of patients is recommended in order to maintain good adherence to the diet. Clin Chem Lab Med 2010;48:1205–16.

Anemia of chronic disease (ACD), the most frequent anemia among hospitalized patients, occurs in chronic inflammatory disorders, such as chronic infections, cancer and autoimmune diseases. Different causes contribute to ACD including diversion of iron traffic, diminished erythropoiesis, blunted response to erythropoietin, erythrophagocytosis, hematologic malignancies and solid tumors. A particular case of ACD is represented by anemia of chronic kidney disease (CKD). ACD is characterized by hyposideremia and altered iron transport. Cytokines are implicated in the ACD by reducing erythropoiesis and increasing iron sequestration in the reticuloendothelial system. The regulation of iron absorption across the epithelium of the proximal small intestine is essential for maintaining body iron concentrations within a physiologically defined range. Hepcidin controls cellular iron efflux by binding to the iron export protein ferroportin, causing ferroportin to be phosphorylated and degraded in lysosomes. Finally, hepcidin inhibits iron release from the reticulo-endothelial system. Increased expression of hepcidin leads to decreased iron absorption and iron deficient anemia. Hepcidin, therefore, is a negative regulator of iron transport in plasma. Causes of anemia in patients with CKD are multifactorial, but the most well-known cause is inadequate erythropoietin production. In these patients, anemia increases the risk of either cardiovascular disease or renal failure. Clin Chem Lab Med 2010;48:1217–26.

Although the concept of Evidence-Based Medicine (EBM) is quite popular among English speaking physicians, it still needs to be adopted by an overwhelming majority of health care professionals in countries where English is not familiar. Thus, this concept can be translated in many different, and potentially misleading, ways. This is regrettable because the concept is, at least potentially, a very useful one. As an illustration, I have compiled some of the French translations of EBM that are currently in use in French speaking countries, and indicated briefly how most of these translations (except for one) are bound to be misleading. Many of these misleading translations currently in use strongly suggest that it is time for an international standardisation of the translations of EBM in different languages. Clin Chem Lab Med 2010;48:1227–8.

Background: Glycogen storage disease type Ia (GSD Ia) is an autosomal recessive disorder, and diagnosis depends on genetic testing. Recently, microarray analysis has become a useful new technique for mutation analysis. We developed a GSD Ia microarray capable of identifying known mutations in the G6PC gene and validate the feasibility of using it as a rapid detection method for DNA-based diagnosis. Methods: An approach based on universal DNA microarray (UA) and ligase detection reaction (LDR) was used. Fifteen mutations and one polymorphism were detected in this microarray. A total of 102 DNA samples from GSD Ia patients were tested. Results: The genotypes obtained using the DNA microarray were in full agreement with those obtained by direct sequencing. For each mutation, wild-type homozygote, heterozygote, and mutant-type homozygote were typed correctly into three groups. Conclusions: The shortened assay time and high specifi-city validated by 102 GSD Ia patients suggest that the GSD Ia microarray has the potential to become an efficient, rapid detection method for DNA-based diagnosis and carrier detection. Clin Chem Lab Med 2010;48:1229–34.

Background: As new biomarkers are validated and their significance in the natural history of specific diseases is established, these technologies can be rapidly transferred to clinical application. Since it has been shown that a single post-interferon-β (IFNβ) injection measurement of myxovirus-protein-A (MxA) mRNA correlates with IFNβ bioactivity in IFNβ treated patients with multiple sclerosis (MS), we had previously validated an assay for its quantification. Methods: We introduced a real-time PCR relative quantification assay into routine clinical practice and measured MxA mRNA expression in 564 samples from 500 unselected IFNβ treated MS patients over a 4-year period. Results: We confirmed that the assay is reproducible over time, and found that the percentage of patients lacking MxA mRNA induction is comparable to that described in studies performed worldwide after patient selection by pre-screening for the presence of anti-IFNβ antibodies. Conclusions: In view of its simplicity and reproducibility, this MxA assay is an alternative to anti-IFNβ antibody determinations for use in routine clinical practice. Clin Chem Lab Med 2010;48:1235–8.

Background: Erythropoietin therapy should be accompanied by an adequate iron supply in order to avoid functional iron deficiency (FID) related to enhanced erythropoiesis. Therefore, accurate monitoring of the body's iron homeostasis is needed. This study was conducted to investigate whether transferrin receptor (TfR) expression on reticulocytes can reflect iron status in patients with chronic renal failure (CRF). Methods: TfR expression [antibody binding capacity (ABC)] and the proportion of TfR positive reticulocytes (%TfR + Ret) relative to all reticulocytes were measured by a quantitative flow cytometric method at baseline and at 3 weeks in 34 dialysis patients. Iron status (plasma ferritin and soluble TfR) and hemoglobin (Hb) with advanced cellular indices, such as the percentage of hypochromic reticulocytes (%HYPOr) and cellular Hb in reticulocytes (CHr), were also analyzed. Results: Patients with FID had significantly higher TfR ABC and %TfR + Ret compared with patients with replete iron status (p=0.034 and p=0.006, respectively). In patients whose Hb concentrations showed a reduction, the mean increase (3 weeks – baseline) in TfR ABC was four-fold higher and %TfR + Ret was three-fold higher when compared with patients whose Hb was stable or had increased. The changes in TfR expression correlated significantly with the changes in reticulocyte indices [CHr (negatively), %HYPOr (positively)] and plasma ferritin (negatively). Conclusions: Reticulocyte TfR expression reflected the changes in the Hb level and the iron availability at the cellular level, and therefore it might be useful in the assessment of iron status in patients with CRF. Clin Chem Lab Med 2010;48:1239–45.

Background: DNA piezoelectric biosensors have become a promising tool in molecular medicine since they do not require any label or staining. Here, a DNA piezoelectric biosensor based on a quartz crystal microbalance (QCM) was created to identify abnormal genes causing α-thalassemia 1 (SEA deletion). Methods: The functionalized gold electrode of the quartz crystal was coated with avidin and the biotinylated DNA probe was attached. The target gene causing α-thalassemia 1 was amplified and hybridized with the immobilized probe. DNA hybridization was indicated by changes in the quartz resonance frequencies. Diagnostic ability of the new α-thalassemia 1 biosensor was validated using both known and unknown blood samples. Specificity was tested using samples of β-thalassemia and α-thalassemia 2. Stability of the sensor was also evaluated. Results: The new biosensor could clearly identify α-thalassemia 1 (SEA deletion), both carrier and disease states, from the normal genotype. Identification accuracy was compatible to the standard gel electrophoresis. It was specific only to α-thalassemia 1 since no cross reaction was found with β-thalassemia and α-thalassemia 2. The sensor could be kept at room temperature up to 6 months with consistent identification accuracy. Conclusions: The label free QCM based biosensor was successfully developed to diagnose an abnormal human globin gene causing α-thalassemia 1 (SEA deletion). Its accuracy, specificity and sensitivity were comparable to the standard method. Its stable diagnostic potency up to 6 months implied its field application in thalassemic control program. Clin Chem Lab Med 2010;48:1247–54.

Background: The aim of this study was to provide inter-laboratory imprecision comparisons of different groups of diagnostic systems as well as a comparison of professional laboratories with medical offices performance on the basis of 88,429 glucose results obtained in external quality assessment (EQA) schemes organized by three European EQA centers between 1996 and 2007. Methods: A simple, non-parametrical statistical model suited to all EQA results, including outliers, was used to calculate yearly and global performance. Results: The best performance was obtained from professional laboratories with a group of three diagnostic systems – Hitachi, Integra, and Vitros, followed by Cobas Mira, and finally by Reflotron. For medical offices, the best performance was achieved with the Cobas Mira diagnostic systems, followed by the Reflotron, SpotChem, and Vitros DT60 diagnostic systems. A slight but overall improvement in performance over time was observed for most diagnostic devices. Conclusions: The analysis of glucose EQA results collected over a 12-year period showed that professional laboratories obtained better performances than medical offices, and that a general improvement in yearly performance was observed for both types of laboratories. Clin Chem Lab Med 2010;48:1255–62.

Background: Immunoassays are one main detection system used in the field of clinical chemistry. Recent developments of a new detection method utilizing a magnetic marker and magnetic sensor have enabled rapid and sensitive immunoassay without the need for bound/free (BF) separation. Methods: Newly-synthesized conjugated avidin was used as the magnetic marker for quantitative analysis of human interleukin-8 (hIL-8) and immunoglobulin E (hIgE) in several media. A superconducting quantum interference device sensor detected the magnetic fields from markers fixed to antigens by the sandwich method. Magnetic signals from unbound markers were nearly zero due to Brownian rotation. Results: Our magnetic immunoassay could detect four attomoles of model proteins (hIL-8, hIgE) in phosphate buffer without BF separation. Using our standard curve, the range of protein detected ranged from 40 femtomoles to 4 attomoles, and we observed a strong association between protein amounts and magnetic signals from the bound markers. The homogeneous immunoassay could also quantify three hundred cells from the fungus Candida albicans in phosphate buffer. Conclusions: The present study demonstrates the ability of magnetic markers for measuring biological targets without BF separation. This detection system has great potential for use as the next generation's analytical system. Clin Chem Lab Med 2010;48:1263–9.

Background: Phenylketonuria (PKU) is an autosomal recessive disorder caused by an impaired conversion of L-phenylalanine (Phe) to L-tyrosine, typically resulting from a deficiency in activity of a hepatic and renal enzyme L-phenylalanine hydroxylase. The disease is characterized by an increased concentration of Phe and its metabolites in body fluids. Methods: A modified assay based on an enzymatic-colorimetric methodology was developed for measuring blood Phe levels in PKU patients; this method is designed for use with undeproteinized samples and avoids the use of solvents or amphiphilic agents. Thus, the method could be suitable for incorporation into a simple home-monitoring device. Results: We report here on a comparison of blood Phe concentrations in PKU patients measured in undeproteinized plasma using this enzyme colorimetric assay (ECA), with values determined by amino acid analysis (AAA) of deproteinized samples, and HPLC and tandem mass spectrometry (MS/MS) analyses of dried blood spot (DBS) eluates. Pearson correlation coefficients of 0.951, 0.976 and 0.988 were obtained when AAA-measured Phe concentrations were compared with the ECA-, HPLC- or MS/MS-measured values, respectively. A Bland-Altman analysis revealed that mean Phe concentrations determined using AAA were on average 65 μmol/L lower than values measured by our ECA. These results may be the result of minimizing the manipulations performed on the patient sample compared with AAA, HPLC, and MS/MS methods, which involve plasma deproteinization or DBS elution and derivatization. Conclusions: The results reported here confirm that Phe concentrations determined by our ECA method are comparable to those determined by other widely used methods for a broad range of plasma Phe concentrations. Clin Chem Lab Med 2010;48:1271–9.

Background: Congenital disorders of glycosylation are a group of clinically and biochemically diverse defects. The current screening method (based on analysis of transferrin), which is used postnatally for the most frequent types, is however not suitable for prenatal diagnosis. The aim of the study was to investigate whether alterations in the microheterogeneity of α-fetoprotein would provide more reliable results. Methods: During the 14th–19th weeks of gestation, 140 amniotic fluid samples were obtained by amniocentesis and tested for fetal developmental abnormalities. α-Fetoprotein was analyzed using isoelectric focusing on Immobiline DryPlate pH 4–7, rehydrated in urea (8 mol/L), and molecular forms of the glycoprotein were detected by immunofixation and silver staining. Results: A difference in the relative proportion of individual α-fetoprotein bands (particularly increase of band II density) was found in a case where a congenital disorder of glycosylation was diagnosed postnatally, and in two other samples from pregnancies which resulted in termination, without further examination. Conclusions: Our potential for further testing is limited; thus far, no other congenital disorders of glycosylation-positive samples have been available. Verification of our results in another laboratory with the exclusion of several potentially pertinent variables is advisable. Clin Chem Lab Med 2010;48:1281–5.

Background: Minor histocompatibility antigens influence the occurrence of graft-vs.-host disease and graft-vs.-leukemia effects after hematopoietic stem cell transplantation (HSCT). We determined the population frequencies of HA-1 and HA-2 alleles in Taiwan and exploited their potential applications in allogeneic HSCT. Methods: HA-1 and HA-2 were genotyped using polymerase chain reaction and restriction fragment length polymorphism in healthy controls (221 for HA-1 and 306 for HA-2) and HLA-matched donor-recipient sibling pairs with HSCT (92 for HA-1 and 38 for HA-2). The association of genetic polymorphisms with HSCT outcome was evaluated by univariate and multivariate analyses. Results: The allele frequencies in controls were 35.3% and 64.7% for HA-1 H and HA-1 R , and 89.0% and 11.0% for HA-2 V and HA-2 M , respectively. HA-1 disparity was denoted in 16.3% of HLA-matched donor-recipient sibling pairs, while it was not associated with HSCT outcome. HA-2 disparity was not observed in the donor-recipient pairs studied. The possibilities of using HA-1 and HA-2 variabilities as molecular markers for hematopoietic chimerism after HSCT were 39.2% and 18.4%, respectively. Conclusions: Our data provide the information on allele and genotype frequencies of HA-1 and HA-2 in a Taiwanese population, and suggest that prospective genomic typing for HA-1 and HA-2 alleles of the donor and recipient could be a useful approach for molecular identification of hematopoietic chimerism after HSCT, rather than prognosis of clinical outcome. Clin Chem Lab Med 2010;48:1287–93.

Background: The goal of this study was to evaluate the dynamics of blood cell and iron status laboratory analytes in preterm and full-term infants during the first year of life. Methods: This was a prospective study of 100 preterm and 50 full-term infants. Preterm infants received iron supplementation beginning at 3 weeks of age. Laboratory tests were serially analyzed up to 12 months of corrected age. Results: Estimated means and the 95% reference intervals (RIs) from 20 weeks of age and onwards are presented separately for preterm and full-term infants. At the age of 20 weeks, mean hemoglobin (Hb) in preterm infants was lower than mean Hb in full-term infants, but this difference changed during follow-up. Ferritin concentrations were initially lower in preterm infants, but decreased to similar levels in both groups. Estimated mean values for transferrin receptor and reticulocyte Hb content were quite stable between the ages of 20 and 55 weeks in both groups. Conclusions: Our study suggests that the same RIs for preterm and full-term infants can be used from the age of 20 or 30 weeks onwards, depending on the analyte. The RIs will help physicians detect iron deficiency or other problems of erythropoiesis in infants. Clin Chem Lab Med 2010;48:1295–301.

Background: Colorectal cancer (CRC) is the second leading cause of cancer-related deaths. However, prevention is possible by early detection. In the present work, we have demonstrated and validated a novel quantitative method based on a DNA integrity assay and mutation in faeces of CRC patients using denaturing high performance liquid chromatography (dHPLC). Methods: Faecal DNA (fDNA) was isolated from 28 CRC, 96 healthy and 61 patients with adenomas. Adenomatosis polyposis coli (APC)-Long-DNA and its mutations were analysed using dHPLC and the Sanger sequencing method. The diagnostic performance was assessed using receiver operating characteristic curve analysis. Results: We detected APC-Long-DNA in 21/28 CRC subjects with a sensitivity of 75% and specificity of 91.7%. A cut-off ratio of 0.2317 was used for APC/β-actin. The Q-dHPLC detection limit was 0.02 ng/injection. The average initial fDNA presence based on a single gene of β-actin was 26.12±13.39 ng/mL for healthy, and 49.61±46.28 ng/mL for CRC subjects, with a sensitivity of 71.4% and a specificity of 84.4% at a cut-off value >29 ng/mL. We also detected a novel mutation at codon 1576 Lys/Glu using dHPLC. Conclusions: This study highlights a novel application of Q-dHPLC in the DNA integrity assay, which demonstrates high performance, good reproducibility, and low cost for the CRC detection using faeces. Further studies in a larger population are needed to confirm these results. Clin Chem Lab Med 2010;48:1303–11.

Background: The purpose of our study was to investigate the efficacy of rapid intraoperative parathyroid hormone (rIO-PTH) analysis performed using material collected by fine needle aspiration as a parameter to distinguish anatomical structures which the surgeon is not able to identify clearly as parathyroid or lymph node during thyroid/parathyroid surgery. Before surgery, all patients gave written, informed consent. Methods: We measured the rIO-PTH on 50 anatomical structures, 32 presumed parathyroids and 18 presumed lymph nodes from 22 patients, who underwent thyroid/parathyroid surgery between May and September 2009. Results: The rIO-PTH values obtained on parathyroids ranged from 85.4 pmol/L to more than 2106 pmol/L, with a rIO-PTH median of 263.25 pmol/L. Results obtained on lymph nodes ranged from <0.52 pmol/L up to 20.4 pmol/L, with a rIO-PTH median equal to 1.31 pmol/L. Results of the Mann-Whitney test showed a rIO-PTH median significantly different (p<0.0001) between samples obtained from parathyroid glands and lymph node tissue. Conclusions: We demonstrated that rapid intraoperative measurement of parathyroid hormone is a good parameter for the differential diagnosis of parathyroid vs. lymph node tissue. We suggest extending the use of this technique to the field of parathyroid preservation during thyroid/parathyroid surgery in those cases where the parathyroids prove difficult to recognize on the basis of topographic or morphologic criteria. Clin Chem Lab Med 2010;48:1313–7.

Background : Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) proteomic signature might be of interest for the early detection and staging of hepatocellular carcinoma (HCC). However, published procedures have been criticized for the lack of data about analytical reproducibility, and the use of inadequate data processing. Methods : MALDI-TOF profiling of peptides bound to serum albumin (“albuminome”) was performed using 90 μL of serum from 45 study subjects (HCV-related cirrhosis, small, unifocal HCCs and advanced HCCs). To overcome the large intra-sample variability, a Quality Assurance protocol was implemented, and 4–8 samples for each subject were processed and analyzed. Overall, 522 subject samples and 299 quality-control spectra were analyzed. A machine-learning approach (Random Forest) was applied to analyze the data sets. Results : Mean intra-sample coefficient of variation (CV) of the analytical procedure was 17.6%–30.0%; inter-subject CV was in the range 48.8%–71.3% among the three study groups. The Random Forest procedure correctly classified 433/522 “patient samples” and 295/299 “reference samples”; 43/45 patients were correctly classified following this approach. Conclusions : Our data suggest that, notwithstanding the large analytical variability found, multiple proteomic profiles obtained from each subject can differentiate cirrhosis with and without HCC, and HCCs with and without vascular invasion, warranting further investigation in a prospective setting. Clin Chem Lab Med 2010;48:1319–26.

Background: Chronic atrophic gastritis (CAG) is a precursor of the intestinal type of gastric cancer, the second leading cause of cancer-related death worldwide. GastroPanel is a recently marketed serological kit for the non-invasive diagnosis of CAG, defined by some authors “even more reliable than biopsy histology”. The goal of this study was 1) to evaluate the agreement between the serum gastric profile provided by GastroPanel (PGI, PGII, G-17, AbHp) and histology over CAG diagnosis, and 2) to evaluate the prevalence of CAG by means of GastroPanel in a Northern Italian dyspeptic population. Methods: Basal blood samples for GastroPanel parameters evaluation (Biohit Plc, Finland) were collected after an overnight fast from 1387 dyspeptic patients (age range: 18–80 years; F 704). Gastroscopy with two biopsies each of the antrum and corpus was offered to a group of the first 400 consecutive patients (age 18–80 years, F 214) to compare the results of histology and GastroPanel in CAG. Results : Agreement between GastroPanel and histology for corpus-prevalent CAG was 94%, with a sensitivity and specificity of 80% and 96%, respectively. In our series of 1387 dyspeptic patients, the prevalence of corpus-prevalent CAG, of antral-prevalent CAG and of multifocal CAG (antrum+ corpus) was 10.7%, 3.6% and 2.4%, respectively. Out of the 34 patients with multifocal atrophic gastritis, 12% were under 30 years of age. Conclusions : GastroPanel is a reliable non-invasive test for diagnosis of CAG and deserves consideration for current use in clinical practice as a valuable diagnostic tool. Clin Chem Lab Med 2010;48:1327–32.

Background: The goal of the present study was to evaluate the diagnostic accuracy of B-type natriuretic hormone (BNP) assay in children with congenital heart disease (CHD) in the first month of life. Methods: BNP was measured in 152 neonates with CHD; 154 healthy children matched for age were used as controls. BNP was measured with a fully automated platform (Triage BNP reagents, Access Immunoassay Systems, Beckman Coulter, Inc., Fullerton, CA, USA). Results: BNP values were significantly higher (p<0.0001) in newborns and infants with CHD compared with control (CHD patients: median 1167.5 ng/L, range 25–54,447 ng/L; healthy children: median 150.5 ng/L, range 5–866 ng/L). The diagnostic accuracy of BNP was assessed using the receiver operating characteristic (ROC) analysis, taking into account the three different groups divided according to age. Group 1: all CHD patients and healthy newborns and infants as a whole (i.e., from birth to the 30th day of life); Group 2: from the 1st to 3rd day of life; Group 3: from the 4th to 30th day of life. The area under the curve (AUC) of the ROC curve for Group 3 (0.935) was significantly higher than that for Group 1 (0.843, p=0.009) and Group 2 (0.769, p=0.0003), while the AUC values of Group 1 and Group 2 were not significantly different (p=0.191). Conclusions: BNP may be considered a useful marker for screening in the integrated approach of newborns, infants and children with suspected CHD. However, the accuracy of the BNP assay varies greatly during the first month of extra-uterine life, showing the lowest diagnostic accuracy in the first 3 days after birth. After the second week of life, the biomarker becomes more accurate in ruling in CHD. Clin Chem Lab Med 2010;48:1333–8.

Background: Carcinoembryonic antigen (CEA), one of the most widely used tumor markers, has been recently associated with carotid atherosclerosis. The aim of our study was to evaluate whether CEA concentrations have a role in coronary artery disease (CAD). Methods: Serum CEA concentrations were evaluated in 89 patients, including 50 patients with acute coronary syndrome (ACS) (Group I, 44 with acute myocardial infarction, six with unstable angina, 38 males, 65±2 years) and 39 patients with stable CAD (Group II, 33 males, 66±3 years). In addition, 33 subjects (16 males, 62±2 years) were also included as a control group (Group III). Results: ACS was significantly associated with increased mean CEA concentrations (3.1±0.3 vs. 1.75±0.1 and 1.7± 0.2 ng/mL in Groups I, II and III, respectively, p<0.001). Increased CEA concentrations remained an independent determinant for ACS (OR=3.1, 95% CI=1.2–7.9, p<0.05) after correcting for other significant risk factors. Conclusions: CEA might represent a potential new candidate biomarker for the prediction of risk associated with ACS. Clin Chem Lab Med 2010;48:1339–43.

Background: Multiple human and animal studies have reviewed the (non-)actin scavenger functions of vitamin D binding protein (DBP). Recently, we demonstrated the partially lipid bound character of DBP. The purpose of the present study was to explore the link between actin, lipids and DBP in a cohort of patients undergoing cardiac surgery. Methods: The interplay between DBP, actin and lipids was investigated in a cohort study of 35 Caucasian patients who underwent cardiac surgery. Total and actin-free DBP concentrations were assessed by immunonephelometry and ELISA. Total cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides, aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, creatine kinase (-MB) and C-reactive protein (CRP) were measured using routine methods. Low-density lipoprotein cholesterol was calculated according to the Friedewald formula. The DBP phenotypes and the macromolecular bound DBP fractions were determined by polyacrylamide gel electrophoresis (PAGE) and confirmed by Western blotting. Results: Using PAGE and Western blotting with an anti-human DBP polyclonal antibody, the actin-bound DBP complex was identified in serum. Following cardiac surgery, total serum DBP concentrations were characterized by a two phased course. This was paralleled by a similar pattern in serum total cholesterol, HDL-cholesterol and triglyceride concentrations. Good correlation was found between total and actin free serum DBP concentrations (r=0.69, p<0.0001). The serum actin free DBP/total DBP ratio remained stable throughout the study period. Although no significant correlation between cumulative CK-MB enzyme release and delta serum total DBP concentration was observed (p=NS), the latter value correlated significantly with delta serum triglyceride concentrations (r=0.37, p<0.05). Conclusions: The lipid bound character is an underestimated property of DBP in the extracellular actin-scavenger system. Clin Chem Lab Med 2010;48:1345–50.