Biological Variation and Reference Change Value Data for Serum Neuron-Specific Enolase in a Turkish Population

BACKGROUND

Neuron-specific enolase (NSE) is a recognized biomarker for the assessment of cerebral injury in neurological disorders. This study aims to report a definitive assessment of the biological variation (BV) components of this biomarker, including within-subject BV (CVI), between-subject BV (CVG), index of individuality (II), and reference change value (RCV), in a cohort of Turkish participants using an experimental protocol.

METHODS

Six blood specimens were collected from each of the 13 apparently healthy volunteers (seven women, six men; ranging in age from 23 to 36) on the same day, every 2 weeks for 2 months. Serum specimens were stored at -20°C until analysis. Neuron-specific enolase levels were evaluated in serum samples using an electrochemiluminescence (ECLIA) immunoassay kit with a Roche Cobas e 411 auto-analyser. ANOVA test was used to calculate the variations.

RESULTS

The CVI and CVG for NSE were 21.5% and 28.8%, respectively. Analytical variation (CVA) was calculated as 10.2%. Additionally, II and RCV were calculated as 0.74 and 66% (95% confident interval, CI), respectively.

CONCLUSION

As the performance index (PI) was found to be less than 2 (PI = 0.95), it is concluded that the NSE measurements have a desirable performance for analytical imprecision. Since the II was found to be less than 1 (II: 0.74), the reference values will be of little use. Thus, RCV would provide better information for deciding whether a significant change has occurred.

Hemoglobinopathies in the Çukurova Region and Neighboring Provinces

To contribute to the creation of a mutation map of the region, we aimed to determine the mutation spectrum of thalassemias and abnormal hemoglobins (Hbs) in the Çukurova region and surrounding provinces. In this study, a total of 8135 samples from Adana, Hatay, Mersin, Konya and Kayseri provinces between 1993 and 2014 were analyzed. Complete blood cell (CBC) counts and Hb typing were carried out using automatic cell counters, cellulose acetate membrane electrophoresis and high performance liquid chromatography (HPLC), respectively. For the molecular analyses, genomic DNA was extracted using both manual and automated DNA extraction devices. Determination of Hb mutations were done by microarray, restriction fragment length polymorphism (RFLP), amplification refractory mutation system (ARMS) and gap-polymerase chain reaction (gap-PCR) methodologies. Samples were analyzed for abnormal Hb and thalassemia mutations. Out of 8135 samples, 1382 were observed to be carrying Hb mutations. It was identified that 826 mutation carriers included abnormal Hbs with a frequency of 59.7%, 416 carriers included β-thalassemia (β-thal) mutations with a frequency of 30.7% and 136 carriers included α-thalassemia (α-thal) mutations with a frequency of 9.9%. In this study, the most frequently observed abnormal Hb in the region was Hb S [β6(A3)Glu→Val (GTG > GAG), HBB: c.20T > A], whereas the most commonly observed mutations were the IVS-I-110 (G > A) (HBB: c.93-21G > A) point mutation in β-thal and the 3.7 kb deletion in α-thal.

Alterations in the serum biomarkers belonging to different metabolic systems of fish (Oreochromis niloticus) after Cd and Pb exposures

The serum of vertebrates including human gives sufficient data about the current health status of organism in concern. Biomarkers have gained importance in evaluation of data from biological monitoring studies. In this study, freshwater fish Oreochromis niloticus were individually exposed Cd or Pb using acute (10μM, 2 d) and chronic (20μM, 20 d) exposure protocols to investigate the alterations in serum parameters (ALP, ALT, AST, LDH, lipase, glucose, protein, cholesterol and triglyceride) and response of the endocrine system functioning in different axis, namely HPI (cortisol), HPT (TSH, T3, T4), gonadal (LH, FSH) and prolactin. Data showed that except LH, the levels of all hormones decreased significantly following exposure to Cd and Pb both in acute and chronic exposures. In acute exposures, the activity of ALP and levels of cholesterol and triglyceride decreased significantly following both Cd and Pb exposures, while glucose levels increased only after Cd exposure. In chronic exposures, both metal exposures caused significant decreases in ALP activity and levels of cholesterol and triglyceride, though there were increases in glucose level after Cd exposure and AST, ALT and LDH levels after Pb exposure. Data emphasized the importance of biomarker selection and multiparameter usage of relevant systems in ecotoxicological research to achieve proper evaluation of environmental data.

Biological variations of some analytes in renal posttransplant patients: a different way to assess routine parameters

BACKGROUND

Biological variation (BV) data of analytes have been used to evaluate the significant changes in serial results (reference change value, RCV) of healthy individuals in clinical laboratories. However, BV data of healthy subjects may not be identical to the analytes of patients with ongoing clinical condition. The aim of this study was to calculate intra-(CVw) (coefficient of variation for intra-individual BV) and inter-individual (CVg) BV, index of individuality, and RCV of nine serum analytes of renal posttransplant patients.

METHODS

Six serum specimens were obtained in an interval of two months in a one-year period from 70 transplant patients who had been stable for three years. Each time creatinine, uric acid, urea, sodium, potassium, calcium, inorganic phosphate, total protein, and albumin of these patients were analyzed with an integrated clinical chemistry/immunoassay auto-analyzer. ANOVA tests were used to calculate the variations. Results were compared with the data of healthy subjects obtained from BV database.

RESULTS

CVw of all nine analytes of the renal transplant patients were higher than the healthy subjects. RCVs of these analytes were calculated as 14.5% for creatinine, 16.5% for urea, 13.7% for urate, 12.57% for albumin, 8.26% for total protein, 3.25% for sodium, 12.81% for potassium, 5.88% for calcium, and 21.57% for inorganic phosphate.

CONCLUSION

RCV concept for predicting the clinical status in posttransplant population represents an optimization of laboratory reporting and could be a valuable tool for clinical decision.

Detection of 1311 polymorphism in the glucose-6-phosphate dehydrogenase gene by microarray technique

INTRODUCTION

Nucleotide 1311 polymorphism at exon 11 of the glucose-6-phosphate dehydrogenase (G6PD) gene is fairly common in various populations worldwide, especially among Mediterranean populations. In this study, 1311 polymorphism in G6PD-deficient cases was identified by microarray technique.

MATERIAL AND METHODS

Four hundred and fifty clinically healthy subjects were screened and 32 cases were found to have G6PD deficiency (7.11%). Our analysis of genomic DNA samples from 32 G6PD-deficient individuals revealed that the number and percentage of subjects who had a C-to-T alteration at nucleotide 1311 were 21 and 4.7% respectively. Given that the frequency of 1311 polymorphism has been reported in previous studies to be fairly high among G6PD-deficient people with the Mediterranean mutation, our data seem to be inconsistent with what we would expect for this particular region.

RESULTS

The highly diverse ethnic background of the Adana population which probably results from the high level of immigration into this part of Turkey may be one of the most sensible explanations for this unexpected finding. Nevertheless, it seems that our results need to be confirmed in larger studies.

CONCLUSIONS

The polymorphism studies in the G6PD gene may help us to illuminate the genetic basis of the G6PD deficiency in different regions and in various ethnic groups, and also to discover the influence of a specific polymorphism on the clinical course of the deficiency.