(s-cobalamin, p-tHcy and p-methylmalonic acid (MMA)) weredetermined at inclusion and after 1 month.

Results: There was no significant difference in cobalamin statusbetween the groups at inclusion (p=0.18–0.58). After 1 month,infants given cobalamin had 256% higher s-cobalamin than controlsand a reduction in median p-tHcy (from 8.83 to 4.05 μmol/L,p<0.001) and p-MMA (from 0.85 to 0.14 μmol/L, p<0.001); whileboth metabolites were essentially unchanged in the controls.Compared to the controls, the intervention infants had a significantimprovement in their AIMS percentile (p<0.001) and a 52% versus21% reduction in regurgitations (p=0.01).

Conclusion: Cobalamin supplementation improved cobalaminstatus, motor development and gastrointestinal reflux in moderatelydeficient infants. Cobalamin deficiency should be considered adifferential diagnosis in childrenwith subtle symptoms and strategiesto prevent cobalamin deficiency in mothers and children should beaddressed.

doi:10.1016/j.clinbiochem.2011.03.050

Effects of n-3 PUFAs supplementation on chronic inflammationand insulin resistance in hemodialysis patientsLj. Bokan a, Z. Rasic-Milutinovic b, G. Pekovic c, I. Djuricic d

a Biochemical Laboratory, University Hospital Zemun/Belgrade, Serbiab Department of Endocrinology, University Hospital Zemun/Belgrade,Serbiac Department of Nephrology and Dialysis, University HospitalZemun/Belgrade, Serbiad Faculty of Pharmacy, Belgrade, Serbia

Aims/Hypothesis: This study investigates a possible effect of n-3PUFAs supplementation on some inflammatory markers and insulinresistance, hence, patients with chronic renal failure on maintenancehemodialysis (MHD) are presented with chronic inflammation andinsulin resistance.

Methods:This studyexplored the association between redblood cells(RBC) phospholipids long chain fatty acids (LC FAs) and components ofmetabolic syndrome(MeS) in35patients (meanage54.50±11.99 years)on MHD. Furthermore, the effects of omega-3 FA eight-week supple-mentation (EPA+DHA,2.4 g/day)on theMeS features and inflammatorymarkers TNF-alpha, IL 6, and hsCRP were examined.

Results: Supplementation increased EPA and DHA levels in RBCs(p=0.009 for EPA and p=0.002 for DHA). Data revealed a significantdecrease of total SFA:n-3 PUFAs ratio during the treatment (p=0.04).The values of serum insulin and calculated IR index-IR HOMA werereduced after supplementation (p=0.001 for both). There was asignificant decrease in the levels of all inflammatorymarkers (p=0.01for TNF alpha, p=0.001 for IL 6, p=0.001 for hsCRP and p=0.01 forferritin).In multivariate regression analysis, only the changes in n-6PUFAs:n-3 PUFAs ratio independently contributed to 40% of thevariance in IR HOMA, as well as to 18% of the variance in TNF alpha.

Conclusion: It was concluded that the EPA and DHA moderatedose administration in the patients on MHD had a beneficial effect oninsulin resistance and chronic inflammation.

doi:10.1016/j.clinbiochem.2011.03.051

Pediatric reference intervals for 10 enzyme biomarkerson the Abbott ARCHITECT c8000: A CALIPER study ofhealthy community childrenD. Brinc b, D. Colantonio a,b, L. Kyriakopoulou a,b, M.K. Chan a,A. Venner b, M. Diamandis b, L. Fu b,c, P. Yip b,d,D. Armbruster e, K. Adeli a,b

a Clinical Biochemistry Division, Department of Pediatric LaboratoryMedicine, Hospital for Sick Children, Toronto, Canadab Department of Laboratory Medicine and Pathobiology,University of Toronto, Toronto, Canadac Clinical Biochemistry, Sunnybrook Health Sciences Centre,Toronto, Canadad Department of Clinical Biochemistry, University Health Network,Toronto, Canadae Abbott Diagnostics, Abbott Park, Chicago, IL, USAE-mail address: khosrow.adeli@sickkids.ca.

Background: Physiological and metabolic changes influencepediatric reference intervals for many analytes measured in thelaboratory. Accurate and current reference intervals for the healthypediatric population are not available for enzymes, which can lead tomisdiagnosis and unnecessary treatment. CALIPER is a multi-centerstudy among children's hospitals across Canada to establish a currentand accurate database of age- and sex-specific pediatric referenceintervals.

Methods: The study followed the CLSI/IFCC C28-A3 guidelines.Serum samples were collected and analyzed from healthy children inthe ethnically diverse city of Toronto, Canada. A minimum of 120samples were collected for each of the 6 age partitions between 0 and18 years. Samples were analyzed on the Abbott ARCHITECT c8000system: Alkaline phosphatase, alanine aminotransferase (ALT),activated ALT, aspartate aminotransferase (AST), activated AST,amylase, gamma-glutamyl transferase, cholinesterase, lactate dehy-drogenase and lipase. Outliers and results affected by commoninterferences were removed. Age- and gender-specific partitioningwas determined for each analyte individually. Parametric and non-parametric methods were used to establish the 2.5th and 97.5thpercentiles for the reference intervals.

Results: Age and gender specific reference intervals wereestablished for several analytes. A separate set of analytes did notrequire partitioning and a common reference interval was estab-lished. Reference intervals for each analyte will be presented.

Conclusions: Pediatric reference intervals for 10 enzyme biomar-kers derived from a large population of healthy children are provided.These updated reference intervals will contribute to improvedassessment of pediatric patients and set a benchmark for futurelaboratory biomarker reference studies.

doi:10.1016/j.clinbiochem.2011.03.052

Simple method for salivary cortisol determinationin preterm infantsH.N. Bui a, A. Cranendonk b, A.R.C. Laarmanb,M.M. van Weissenbruch b, A.C. Heijboer aa Department of Clinical Chemistry, VU University Medical Center,Amsterdam, The Netherlandsb Department of Pediatrics, VU University Medical Center, Amsterdam,The NetherlandsE-mail address: h.bui@vumc.nl.

In infants, salivary cortisol is used as a marker of stress/pain and toinvestigate the functioning of the hypothalamic–pituitary–adrenalaxis. Because saliva is scarce and difficult to obtain in preterm infants,creative solutions are needed. Neu et al. validated the use of filterpapers for saliva collection. We developed a simple procedure toprocess these filter papers for cortisol determination.

50, 100 and 250 μL from a saliva pool was pipetted on aWhatmann Grade 42 filter paper which was put into a preweighedborosilicate tube with plug, and stored at −20 °C. The tubes wereweighed again before processing. Cortisol was extracted by adding2 mL dichloromethane (DCM) and vortex-mixing. The DCM was

Abstracts / Clinical Biochemistry 44 (2011) 520–549 525

decanted into a clean tube and evaporated to dryness under N2. Theextract was dissolved in PBS and stored at −20 °C until assayed withthe Architect i2000 random access analyzer as described by Heijboeret al. The same procedure was applied on filters with saliva obtainedfrom 8 preterm infants. Two halves of a filter were folded and placedon both sides in the mouth for several minutes.

The extraction procedure showed a recovery of 94–104%. Theamount of saliva obtained from the infants ranged from 80 to 300 μLand measured cortisol ranged from 1.4 to 63 nmol/L.

Extraction of cortisol from filter papers, used to obtain saliva frompreterm infants, seems to be an easy method to prepare the samplesfor assaying. The described procedure might be applicable to othercortisol (immuno)assays.

Heijboer et al., Ann Clin Biochem 2009, 46, 261–262.Neu et al., Early human devel 2007, 83, 47–54.

doi:10.1016/j.clinbiochem.2011.03.053

Children with chronic kidney disease: Schwartz formulafor estimating glomerular filtration rate is replaced bycystatin c formulaI. Cachapuz a, E. Oliveira b, E. Cruz b, V. Alves aa Clinical Pathology Service, Matosinhos Local Health Care Unit,Matosinhos, Portugalb Pediatric Service, Matosinhos Local Health Care Unit , Matosinhos,PortugalE-mail address: isabel.cachapuz@ulsm.min-aude.pt.

Background: Compare glomerular filtration rate (GFR) estimatedby Schwartz formula (GFR-Sw) and GFR estimated by cystatin c (GFR-Cy) in a pediatric population with chronic kidney disease (CKD).

Methods: Prospective study, during 2010, in 34 CKD outpatients ofPediatric Nephrology Service fromMatosinhos Local Health Care Unit.Patient inclusion criteria: CKD in stages I and II. Patient exclusioncriteria: acute infection, vomiting, diarrhea, neoplasm, liver or thyroiddisease. Majority of patients were female (18). Average age: 8.7 years(SD=3.2), ranging 4–15 years. Each patient provided a serum sample,where creatinine was dosed by spectrophotometric assay (alkalinepicrate) and cystatin c by turbidimetric immunoassay (PETIA). Foreach patient it was determined the GFR-Sw (K×Height/serumcreatinine; K=For children of age 1 to 12 years, K=0.55) (1) andGFR-Cy, developed for Abbott® in architect c systems (K×71/cystatinc 1.28, K=juvenile factor for children below the age of 14=1.332) (2).(1) ranging from9.0 to 153.7 mL/min/1.73 m2 and (2) ranging from48to 199 mL/min/1.73 m2.

Results: Statistical analysis shows a Pearson's correlation coeffi-cient of 0.35 (p=0.044; significance level of 5%) between (1) and(2). Statistical analysis was performed using SPSS (version 18.0).

Conclusions: Correlation between these two GFR was moderateand positive. Our results suggest that GFR-Cy can be a simple and anappropriate alternative to GFR-Sw. GFR-Cy reflects renal function inchildren independently of age, gender, height and body composition.GFR-Cy depends exclusively of serum samples, which is undeniablyan advantage.

doi:10.1016/j.clinbiochem.2011.03.054

Erythrocyte glutathione transferase: A new biomarker in chronickidney diseasesM. Dessì a, A. Noce a, R. Fabrini b, A. Bocedi b, G. Fucci a, A. Pastore c,S. Manca di Villahermosa a, G. Ricci b, C. Callà d,

a Department of Laboratory Medicine, Nephrology and Dialysis Unit,University Hospital ‘Tor Vergata’, Rome, Italyb Department of Chemical Sciences and Technologies, University Hospital‘Tor Vergata’, Rome, Italyc Biochemistry Laboratory, Children's Hospital and Research Institute‘Bambino Gesù’, Rome, Italyd Department of Laboratory Medicine, University Hospital ‘PoliclinicoGemelli’, Rome, ItalyE-mail address: c.calla@rm.unicatt.it.

Background: Glutathione transferases (GSTs) are enzymes in-volved in the cell detoxification. Increased levels of GST expressionhave been observed in tissues exposed to contaminants and in humanerythrocytes of uremic patients under chronic hemodialysis (HD). Aprevious study reported that no difference in the erythrocyte GSTexpression has been detected in patients under conservative therapy.Aim of our study was to compare erythrocyte GST (e-GST) activity inchronic kidney disease (CDK), in chronic hemodialysis (HD) and inhealthy subjects.

Methods: A total of 72 CKD patients under conservative therapy,62 HD patients and 80 healthy subjects were enrolled. CKD patientswere divided in four groups according to the National KidneyFoundation Dialysis Outcomes Quality Initiative (NK-DOQI). Erythro-cyte GST activity was assayed by means of a spectrophotometerprocedure at 340 nm on haemolysed whole blood adapted to anautomated Modular P800 apparatus (Roche).

Results: The e-GST activity was enhanced in HD patients (10.24±2.74 U/g Hb) when compared to healthy subjects (5.8±1.8 U/g Hb).Contrary to previous reports, a significant increase of e-GST activityrelated to CKD stage was also observed in pre-dialysis patients (7.4±2.43 U/g Hb, 8.13±4.55 U/g Hb, 9.46±2.49 U/g Hb, and 12.35±2.74 U/g Hb in stages I to IV). Interestingly, e-GST activity in stage IVpatients is higher than in HD subjects. No correlation has been foundbetween e-GST activity and levels of classical systemic inflammationmarkers.

Conclusion: The present findings suggest that e-GST could be agood marker for toxin exposition. The e-GST activity could be anew biomarker useful to substitute or to be complementary to thetime.

doi:10.1016/j.clinbiochem.2011.03.055

Accuracy and reliability of a new generation glucose meter in aneonatal intensive care settingJ. Christoph, J. Siegel, E. KattnerKinderkrankenhaus auf der Bult, Hannover, GermanyE-mail address: christoph@hka.de.

Background: Accuracy studies assessing the performance ofcommonly used glucose meters in a NICU setting have shown afailure to achieve national and international quality standards. Theaccuracy of these meters can be influenced by hematocrit oxygen andpatient medications.

Methods: We assessed the performance of the Nova BiomedicalStatStrip Glucose hospital whole blood glucose meter (specificallydesigned to correct for common interferences) in comparison to theroutinely used blood gas analyser ABL 835 using samples collectedfrom neonatal patients in intensive care.

Results:1. Patient method correlationLinear regression analysis shows a good correlation between thetwo methods.r 2=0.973, Intercept −4.112, Slope 1.018 mg/dL, Mean difference(method — reference) −2.61 mg/dL.

Abstracts / Clinical Biochemistry 44 (2011) 520–549526