Müjgan Ercan

Stability of urine specimens stored with and without preservatives at room temperature and on ice prior to urinalysis

OBJECTIVES Laboratories determine the most appropriate approach for the collection and transport of urine specimens. We investigated the effect of a chlorhexidine-based preservative tube on sample stability, compared the results of refrigerated polystyrene tubes with no additives, and investigated the effect of temperature on the performance of preservative tubes. DESIGN AND METHODS Fresh urine specimen (n=48) aliquots in BD Vacutainer® Plus Urinalysis Preservative Tubes and polystyrene tubes were analyzed on an Iris Diagnostics iQ200. Samples in polystyrene tubes were refrigerated for 4 and 8h. Four aliquots in preservative tubes were kept at room temperature for 4, 8, 24, and 72h, while two aliquots were kept on ice for 4 and 8h. RESULTS There was good agreement for all chemistry and microscopy parameters with the exceptions of white blood cells (WBCs) at 24 and 72h and red blood cells (RBCs) at 72h. Preservative tubes on ice showed a significant decrease in concordance of WBCs and calcium oxalate (CaOx) parameters compared with the results at room temperature. Results of refrigerated polystyrene tubes showed good agreement with the exceptions of WBC clumps and amorphous crystal at 8h. CONCLUSIONS A chlorhexidine-containing preservative tube seems advantageous for urine sample transport from outside healthcare services. A preservative tube offers comparable results with urine samples kept in a refrigerator for 4-8h for the majority of parameters. Keeping samples at room temperature is recommended when preservative tubes are used because ice produces a negative effect on WBCs and CaOx.

Evaluation of H-800/FUS-100 automatic urine analyzer performance

Abstract Objective: Automated urine analysis is usually preferred for laboratories with intensive workload. The aim of this study was to evaluate the performance of the automated urine analyser H-800/FUS-100 and detect the error sources. Materials and methods: One thousand four hundred fifty nine fresh urine samples were analyzed with H-800/FUS-100 automated systems. The urine sediment of the samples with discrepant strip and microscopy results were confirmed by manual microscopy. Precision and carry over studies were performed. Results: The discrepancy is detected in a ratio of 5.89% between chemical analysis (H-800) and microscopic analysis (FUS-100) of the device. A total of 86 discrepant samples were detected. Fifty six of 86 were erythrocyte discrepancies (65.1%) and 30 of 86 were leukocyte discrepancies (34.9%). The results of carry over analysis for erythrocyte and leukocyte were 21.85% and 13.64%, respectively. Conclusions: Sixteen (1.09%) of 1459 patients’ results in FUS-100 were discrepant with manual microscopy. Commonly, yeasts and crystals affected erythrocyte counts and calcium oxalate and amorphous crystals affected the leukocyte counts. Images should be reviewed for every sample when automated systems are used for urine analysis. Especially if discrepancy is detected between chemical and microscobic analysis, the results should also be confirmed with manual microscopy.

The effect of measurement uncertainty for HOMA-IR in assessment of insulin resistance

In this study, it is aimed to estimate not just the uncertainty measurement for the parameters of glucose and insulin having role when calculating HOMA-IR, but also true positiveness and negativeness in terms of cut-off values. The evaluation of the acceptability of the uncertainty value was also among the goals of the study. The uncertainty measurement for glucose and insulin is calculated as uncertainty measurement of HOMA-IR based on Eurochem/CITAC Guide CG 4. The uncertainty measurement for glucose and insulin was estimated as 3.83% and 4.16%, respectively. The measurement uncertainty for the calculated test HOMA-IR was calculated with cut-off values as 27% (0.27). Based on the cut-off value for HOMA-IR of 2.5%, IR(+) and IR(-) patients were 155 and 265, respectively. If the uncertainty measurement for HOMA-IR was added to its calculation, the cut-off value was detected as 2.23-2.77%. We reported the measurement uncertainty of the calculated test HOMA-IR at 95 % CI as 0.27 between 2.23 - 2.77. Especially for the tests used for screening; determination of cut-off values as a range including measurement uncertainty instead of a single value will be more suitable. No data is found in the literature for the calculated test HOMA-IR up to date.

Evaluation of the analytical performance of the Beckman Coulter Unicel DXI 800 Access Total 25(OH) Vitamin D immunoassay

Abstract Background As vitamin D has recently been implicated in various diseases, vitamin D testing has gained a lot more significance. Vitamin D deficiency is quite prevalent, and detection of this condition is important. Several manufacturers have developed new automated immunoassays for this purpose. In this study, we aimed to evaluate the analytical performance of the Access Total 25(OH) Vitamin D immunoassay on the Beckman Coulter Unicel DXI 800 analyzer, through comparison with the reference method, liquid chromatography/tandem mass spectrometry (LC-MS/MS). Methods The study was conducted with 148 patient samples which were sent to Ankara Numune Training and Research Hospital for routine vitamin D testing. Every sample was analyzed with both Unicel DXI 800 immunoassay analyzer and LC-MS/MS. The concordance of the results was evaluated with Passing-Bablok regression analysis and Bland-Altman plot. Additionally, imprecision, interference, limit of blank (LOB), recovery, linearity and carry-over studies were performed for the Beckman Coulter Unicel DXI 800 analyzer. Results When compared to LC-MS/MS, the Access Total 25(OH) Vitamin D immunoassay on the Beckman Coulter Unicel DXI 800 analyzer had an R-value of 0.957 (intercept: −3.938, slope: 1.185) and a mean bias of 9.5%. The concordance correlation coefficient (CCC) between the two methods was 0.916. The intra-assay, inter-assay and total coefficient of variation (CV%) for the Unicel DXI 800 vitamin D immunoassay were 3.3%, 5.3% and 8.3%, respectively, at 31.7 ng/mL concentration, and 2.1%, 3.2% and 7%, respectively, at 66.8 ng/mL concentration. Conclusions The Access Total 25(OH) Vitamin D immunoassay method has acceptable analytical performance, and the results are in concordance with the LC-MS/MS results.

Biological variation components of glycated hemoglobin HbA1c on tosoh G7 HPLC

1 Müjgan Ercan1, Esin Avcı2, Emiş Deniz Akbulut3, Esra Fırat Oğuz4, Canan Topçuoğlu4, Çiğdem Yücel4, Sedat Abuşoğlu5, Turan Turhan4 1Department of Biochemistry, Bozok University Faculty of Medicine, Yozgat, 2Department of Biochemistry, Pamukkale University Faculty of Medicine, Denizli, 3Biochemistry Laboratory, Çukurova Dr. Aşkım Tüfekçi State Hospital, Adana, 4Biochemistry Laboratory, Ankara Numune Training and Research Hospital, Ankara, 5Department of Biochemistry, Selçuk University Faculty of Medicine, Konya, Turkey Biological variation components of HbA1c Biological variation components of glycated hemoglobin HbA1c on tosoh G7 HPLC

Comparison of the effect of gel used in two different serum separator tubes for thyroid function tests

Selection and verification of blood collection tubes is an important preanalytical issue in clinical laboratories. Today, gel tubes are commonly used with many advantages, although they are known to cause interference in immunoassay methods. In this study, we aimed to compare SSTs of two different suppliers (Ayset clot activator & Gel and Becton Dickinson (BD) Vacutainer SST II advance) with reference tubes and evaluate the effect of storage time in terms of commonly used endocrine tests such as thyroid‐stimulating hormone (TSH), free thyroxine (fT4), and free triiodothyronine (fT3).

Serum asymmetric dimethylarginine and nitric oxide levelsin Turkish patients with acute ischemic stroke

BACKGROUND Nitric oxide synthase (NOS) is present in the brain and cerebral arteries and it enables the synthesis of nitric oxide (NO), which plays a critical role in brain perfusion. Asymmetrical dimethylarginine (ADMA) is an endogenous NOS inhibitor. OBJECTIVES The aim of this study was to evaluate serum ADMA levels, which are an indicator of endothelial dysfunction of the renal functions in patients with acute ischemic stroke, and to determine whether there is a possible correlation between ADMA and NO levels and the l-arginine-to-ADMA ratio. MATERIAL AND METHODS Fifty-two patients (22 male and 30 female; mean age: 75.2 ±10.1 years) with a diagnosis of acute ischemic stroke in the first 24 h post-stroke and 48 healthy individuals (controls; 13 male and 35 female; mean age: 60.1 ±7.92 years) were included in this study. The risk factors recorded and evaluated were age and gender of the patients, serum lipid levels, serum ADMA levels, nitrate-to-nitrite ratios, l-arginine, l-arginine-to-ADMA ratios, sedimentation rate, C-reactive protein (CRP), urea and creatinine levels, and glomerular filtration ratio (eGFR). RESULTS The mean serum ADMA level was 0.48 ±0.23 μM for the patients and 0.36 ±0.18 μM for the controls. The mean NO level was 2.78 ±0.59 μM for the patient group and 4.49 ±2.84 μM for the controls. The ADMA levels for the patient group were significantly higher than for the control group (p = 0.011); the NO levels for the patients were significantly lower than for the controls (p < 0.001). The logistic regression method demonstrated that ADMA and NO levels may be independent risk factors for the patient group, and the receiver operating characteristic (ROC) curve analysis showed that both of these variables were discriminative risk factors. CONCLUSIONS An increased serum level of the NOS inhibitor ADMA was found to be a possible independent risk factor for ischemic stroke.

Assessment of macroprolactinemia rate in a training and research hospital from Turkey

Abstract Objective: Macroprolactinemia detection is important to avoid unneccessary tests and overtreatment. High prolactin levels require routine screening and clinicians must be aware of macroprolactinemia frequency encountered with the method in use. In this study we aimed to determine the macroprolactinemia rate in our laboratory. Methods: Prolactin results of different patients analysed on two different immunoassay systems within two consecutive years were evaluated. Analyses were performed on Beckman Coulter UniCel® DxI800 and Roche Cobas® e601 immunoassay systems. Samples for macroprolactin analysis were precipitated using polyethylene glycol (PEG) 6000. Post-PEG recovery <40% was defined as positive, 40–60% as gray-zone and >60% as negative for macroprolactin. Results: For the samples analysed on DxI800 (n=14,958) hyperprolactinemia frequency was 8.1% (n=1208). One of 138 samples submitted for macroprolactin analysis was positive, while three of them were in the gray-zone. For the samples analysed on Cobas® e601 (n=14,040) hyperprolactinemia frequency was 13.9% (n=1954). Eighteen of 238 samples submitted for macroprolactin analysis were positive, while 21 of them were in the gray-zone. Conclusion: A difference was found between two immunoassay systems used in our laboratory in terms of macroprolactinemia rate. However, inability of simultaneous analyses on both systems, lack of evaluation with gel filtration chromatography, and heterophile antibody blocking tube were the limitations.

Comparison of vacuum and non-vacuum urine tubes for urinary sediment analysis

Abstract Urine collection systems with aspiration system for vacuum tubes are becoming increasingly common for urinalysis, especially for microscopic examination of the urine. In this study, we aimed to examine whether vacuum aspiration of the urine sample has any adverse effect on sediment analysis by comparing results from vacuum and non-vacuum urine tubes. The study included totally 213 urine samples obtained from inpatients and outpatients in our hospital. Urine samples were collected to containers with aspiration system for vacuum tubes. Each sample was aliquoted to both vacuum and non-vacuum urine tubes. Urinary sediment analysis was performed using manual microscope. Results were evaluated using chi-square test. Comparison of the sediment analysis results from vacuum and non-vacuum urine tubes showed that results were highly concordant for erythrocyte, leukocyte and epithelial cells (gamma values 1, 0.997, and 0.994, respectively; p < .001). Results were also concordant for urinary casts, crystals and yeast (kappa values 0.815, 0.945 and 1, respectively; p < .001). The results show that in urinary sediment analysis, vacuum aspiration has no adverse effect on the cellular components except on casts.

Investigation of the hair and urine samples’ utility for screening lead poisoning

Objective: The aim of this study is to compare whole blood, 24 hour urine and hair lead levels which were measured concurrently, and evaluate the utility of hair and urine samples for screening of lead exposure. Methods: The data of 436 workers who referred to Ankara Occupational Diseases Hospital between 2010 and 2014 for periodic examination were evaluated. People who examined whole blood, 24 hour urine and hair lead levels concurrently were included in this study. People were evaluated according to two different whole blood exposure levels (10 μg/dL and 30 μg/dL). Results: 24 hour urine and hair lead levels of the groups classified according to whole blood exposure limits were different from each other and statistically significant (p<0,001). Whole blood lead level showed a positive correlation with 24h urine lead level and hair lead level (r=0,552; p<0,001, r=0,566; p<0,001, respectively). 24 hour urine specimens showed 53% sensitivity, 100% specificity, 0% false positivity and 49% false negativity, while the hair displayed 95% sensitivity, 64% specificity, 16% false positivity and 13% false negativity according to the 10 μg/dL limit value. Moreover, ÖZET Amaç: Bu çalışmanın amacı, eş zamanlı olarak bakılan tam kan, 24 saatlik idrar ve saç kurşun düzeylerinin birbiri ile karşılaştırılması ve kurşun maruziyetinin taranmasında saç ve idrar numunelerinin kullanılabilirliğinin araştırılmasıdır. Yöntemler: Ankara Meslek Hastalıkları Hastanesi’ne 2010-2014 yılları arasında periyodik muayene amacıyla başvuran 436 işçiye ait veriler değerlendirildi. Tam kan, 24 saatlik idrar ve saç kurşun düzeyleri eş zamanlı olarak bakılmış kişiler çalışmaya dâhil edildi. Kişiler iki farklı tam kan maruziyet düzeyine (10 μg/dL ve 30 μg/dL) göre değerlendirildi. Bulgular: Tam kan maruziyet sınırlarına göre sınıflandırılan grupların 24 saatlik idrar ve saç kurşun düzeyi birbirinden farklı ve istatistiksel olarak anlamlı idi (p<0,001). Tam kan kurşun düzeyi 24 saatlik idrar kurşun düzeyi ve saç kurşun düzeyi ile pozitif bir korelasyon gösteriyordu (sırasıyla; r=0,552; p<0,001, r=0,566; p<0,001). 10 μg/dL sınır değerine göre saç %95 duyarlılık, %64 özgüllük, %16 yalancı pozitiflik, %13 yalancı negatiflik gösterirken 24 saatlik idrar örnekleri %53 duyarlılık, %100 özgüllük, %0 yalancı pozitiflik ve %49 yalancı negatiflik gösteriyordu. 30 μg/dL sınır 1 Yıldırım Beyazıt Üniversitesi, Biyokimya Ana Bilim Dalı, Ankara 2 Ankara Meslek Hastalıkları Hastanesi, Farmakoloji Bölümü, Ankara 2 Aydın Halk Sağlığı Laboratuvarı, Biyokimya Bölümü, Ankara 2 Ümraniye Eğitim ve Araştırma Hastanesi, Biyokimya Bölümü, İstanbul 2 Ankara Meslek Hastalıkları Hastanesi, Toksikoloji Bölümü, Ankara Geliş Tarihi / Received : Kabul Tarihi / Accepted : İletişim / Corresponding Author : Ceylan BAL Yıldırım Beyazıt Üniversitesi Tıp Fakültesi, Bilkent Yerleşkesi, Çankaya, Ankara 06280 Ankara Türkiye Tel : +90 505 745 84 38 E-posta / E-mail : ceylandemirbal@gmail.com 02.03.2016 27.06.2016 DOI ID : 10.5505/TurkHijyen.2016.88896 Türk Hijyen ve Deneysel Biyoloji Dergisi Bal c, Büyülşekerci M, Ercan M, Torun-Güngör O, Tutkun E, Yılmaz FM. Kurşun maruziyetinin taranmasında saç ve idrar numunelerinin kullanılabilirliğinin araştırılması. Turk Hij Den Biyol Derg, 2016; 73(4): 303-310 Makale Dili “Türkçe”/Article Language “Turkish”