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A carrier prototype by Aerocom® (Schwäbisch Gmünd, Germany) for pneumatic tube systems (PTS) is able to transport 9 blood tubes which are automatically fixed by closing the lid. In this study, we examined the influence of the transport on blood sample quality using the carrier prototype comparing to courier transport and a conventional carrier (AD160, Aerocom®). Triplicate blood samples sets (1 lithium heparin, 1 EDTA, 1 sodium citrate) of 35 probands were split among the transportation methods: 1. courier, 2. conventional carrier, and 3. carrier prototype. After transport 51 measurands from clinical chemistry, hematology and coagulation were measured and compared. Overall, 49 of the investigated 51 measurands showed a good concordance among the three transport types, especially between the conventional carrier and the carrier prototype. Focusing on well-known hemolysis sensitive measurands, potassium showed no statistically significant differences. However, between courier and both carrier types lactate dehydrogenase (LDH) and free hemoglobin (fHb) showed statistically significant shifts, whereas the clinical impact of the identified differences was neglectable. The median concentration of fHb, for example, was 0.29 g/L (18 µmol/L), 0.31 g/L (19 µmol/L) and 0.32 g/L (20 µmol/L) for courier transport, conventional carrier and carrier prototype, respectively. These differences cannot be resolved analytically since the minimal difference (MD) for fHb is 0.052 g/L (3.23 µmol/L), at this concentration. The carrier prototype by Aerocom® is suitable for transportation of diagnostic blood samples. The overall workflow is improved by decreasing hands-on-time on the ward and laboratory while minimizing the risk of incorrectly packed carriers. [ABSTRACT FROM AUTHOR]

Background: Measuring the glucose concentration in whole blood samples is critical due to unsatisfactory glycolysis inhibition. Previous studies showed that Terumo tubes were superior, but they were taken off the European market in 2016 and alternatives were required. This initiated the present evaluation of glucose stability in five available tube types. Methods: Venous blood samples were collected from 61 healthy volunteers to test tubes supplied by Terumo (two sets), Greiner FC-Mix, BD FX-Mixture and BD serum. After sampling, the contents were thoroughly mixed and centrifuged within an hour. The glucose concentrations were determined and the samples resuspended except for BD serum tubes (gel barrier). The first 30 samples were stored at room temperature and the remaining 31 at 4 °C. After 24, 48, 72 and 96 h, all tubes were (re)centrifuged, and glucose concentration measurements were repeated. Results: Changes in glucose concentrations over time differed significantly between the investigated tube types and to a certain extent between the two storing conditions. Glycolysis was most evident in the BD FX-mixture tubes. Good glucose stability was observed in samples retrieved form BD serum and Greiner tubes. The stability in both Terumo tubes was comparable to that in other studies. Although Greiner and both Terumo tubes are supposed to contain the same glycolysis inhibitor, glucose stability differed between these tubes. Conclusions: We showed that Greiner is an acceptable alternative to Terumo and that glucose in serum that was rapidly separated from corpuscles by a gel barrier is stable for an extended time. [ABSTRACT FROM AUTHOR]

Background: Newborn screening (NBS) is an established screening procedure in many countries worldwide, aiming at the early detection of inborn errors of metabolism. For decades, dried blood spots have been the standard specimen for NBS. The procedure of blood collection is well described and standardized and includes many critical pre-analytical steps. We examined the impact of contamination of some anticipated common substances on NBS results obtained from dry spot samples. This possible preanalytical source of uncertainty has been poorly examined in the past. Methods: Capillary blood was obtained from 15 adult volunteers and applied to 10 screening filter papers per volunteer. Nine filter papers were contaminated without visible trace. The contaminants were baby diaper rash cream, baby wet wipes, disinfectant, liquid infant formula, liquid infant formula hypoallergenic (HA), ultrasonic gel, breast milk, feces, and urine. The differences between control and contaminated samples were evaluated for 45 NBS quantities. We estimated if the contaminations might lead to false-positive NBS results. Results: Eight of nine investigated contaminants significantly altered NBS analyte concentrations and potentially caused false-positive screening outcomes. A contamination with feces was most influential, affecting 24 of 45 tested analytes followed by liquid infant formula (HA) and urine, affecting 19 and 13 of 45 analytes, respectively. Conclusions: A contamination of filter paper samples can have a substantial effect on the NBS results. Our results underline the importance of good pre-analytical training to make the staff aware of the threat and ensure reliable screening results. [ABSTRACT FROM AUTHOR]

Background: Early detection of patients with chronic kidney disease is of great importance. This study developed reference limits for serum creatinine and serum cystatin C concentrations and for the estimated glomerular filtration rate (eGFR) in healthy subjects from the general population aged 25-65 years. Methods: This study defined a reference population including 985 subjects from the first follow-up of the Study of Health in Pomerania. Serum creatinine was measured with a modified kinetic Jaffé method. Serum cystatin C was measured with a nephelometric assay. The eGFR was calculated from serum creatinine according to the Cockcroft-Gault (eGFRCG) and the Modification of Diet in Renal Disease (eGFRMDRD) equation, respectively, as well as from serum cystatin C according to the formula by Larsson (eGFRLarsson). Non-parametric quantile regression was used to estimate the reference limits. For serum creatinine and serum cystatin C the 95th percentile and for eGFRCG, eGFRMDRD and eGFRLarsson the 5th percentile were selected as reference limits. All data was weighted to reflect the age- and sex-structure of the German population in 2008. Results: The reference limits for serum creatinine (men: 1.11-1.23 mg/dL; women: 0.93-1.00 mg/dL) and serum cystatin C levels (men: 0.92-1.04 mg/L; women: 0.84-1.02 mg/L) increased with advancing age. The reference limits for eGFR decreased with increasing age (eGFRCG men: 106.0-64.7 mL/min, women 84.4-57.9 mL/min; eGFRMDRD men: 82.5-62.2 mL/min/1.73 m2, women 75.0-58.2 mL/min/1.73 m2; eGFRLarsson men: 85.5-72.9 mL/min, women 94.5-75.7 mL/min). Conclusions: This study presents age- and sex-specific reference limits for five measures of renal function based on quantile regression models. [ABSTRACT FROM AUTHOR]