Advancing haemostasis automation--successful implementation of robotic centrifugation and sample processing in a tertiary service hospital.

BACKGROUND: Laboratories today face increasing pressure to automate operations due to increasing workloads and the need to reduce expenditure. Few studies to date have focussed on the laboratory automation of preanalytical coagulation specimen processing. In the present study, we examined whether a clinical chemistry automation protocol meets the preanalytical requirements for the analyses of coagulation. METHODS: During the implementation of laboratory automation, we began to operate a pre- and postanalytical automation system. The preanalytical unit processes blood specimens for chemistry, immunology and coagulation by automated specimen processing. As the production of platelet-poor plasma is highly dependent on optimal centrifugation, we examined specimen handling under different centrifugation conditions in order to produce optimal platelet deficient plasma specimens. To this end, manually processed models centrifuged at 1500 g for 5 and 20 min were compared to an automated centrifugation model at 3000 g for 7 min. RESULTS: For analytical assays that are performed frequently enough to be targets for full automation, Passing-Bablok regression analysis showed close agreement between different centrifugation methods, with a correlation coefficient between 0.98 and 0.99 and a bias between -5% and +6%. For seldom performed assays that do not mandate full automation, the Passing-Bablok regression analysis showed acceptable to poor agreement between different centrifugation methods. CONCLUSIONS: A full automation solution is suitable and can be recommended for frequent haemostasis testing.

Performance evaluation of the Access FT3 and FT4 assays, comparison with Immulite and AxSym, and the relationship to TSH values.

BACKGROUND: Different FT3 and FT4 assays report significantly different results. We compared the distribution of FT3 and FT4 in a cohort of Swiss patients measured with DxI 800, AxSYM, and Immulite 2000. METHODS: TSH, FT3, and FT4 values were measured in 1,938 serum samples. Patients were classified on the basis of their TSH values as low, normal, and high. For each class of TSH values, concordances of FT3 and FT4 results were determined among the three assays. RESULTS: For low TSH values in all three assays FT3 (FT4) concordance of DxI - AxSYM, DxI--Immulite, and AxSYM--Immulite was determined as 83.1%, 76.2% 68.5% (60.8%, 74.6%, 83.1%), for normal TSH as 89.2%, 79.0%, 75.3% (83.9%, 85.5%, 83.1%) and for elevated TSH as 78.0%, 86.0%, 78.0% (84.0%, 90.0%, 90.0%), respectively. Low FT4 concordance rates with DxI 800 were mainly caused by its FT4 upper reference limit of 14.1 pmol/L. Using a cut-off of 16.1 pmol/L concordances with AxSYM and Immulite were improved to 77.7% and 86.9% (low TSH), 92.5% and 96.2% (normal TSH), and 90.0% and 92.2% (high TSH). Low FT3 concordance rates with Immulite were caused by its low FT3 upper reference limit of 6.29 pmol/L as 11.6% of patient samples with normal TSH value showed unusually elevated FT3 results. CONCLUSIONS: We showed an overall good concordance of FT3 and FT4 results, when stratified according to corresponding TSH values and the appropriate reference range is used. However, our data also show that problems of interpretation of results based on numerical values have yet not been solved.

Heparinized blood provides equivalent results to EDTA in the CEDIA and FPIA cyclosporine immunoassays, thus facilitating routine cyclosporine determination.

BACKGROUND: CsA measurements are routinely used to allow adequate CsA dosage adjustments. CsA assays routinely require EDTA anticoagulated whole blood; EDTA has been preferred due to differences seen when using heparinized blood in the past. We hypothesized that with new, robust assays, heparinized blood might be appropriate for measuring CsA levels. METHODS: CsA levels from EDTA samples and heparinized samples were compared using the CEDIA assay on a BeckmanCoulter DXC. Also, CsA levels from heparinized blood were compared using the CEDIA assay (BeckmanCoulter) and the FPIA assay (Abbott Axsym). RESULTS: CsA levels from EDTA blood (x) and heparinized blood (y, n=81) showed very good correlation without deviation from linearity by Passing-Bablok analysis (y=-2.4524+1.0210x). In 187 samples obtained from heparinized blood, CsA levels determined by using the CEDIA assay (x) or the FPIA assay (y) also correlated equally well by Passing-Bablok analysis (y=6.1922+1.0221x), also without deviation from linearity. CONCLUSION: CsA determination from heparinized blood is easy to perform and accurate with the two assays described and evaluated. Using heparinized blood reduces handling time as well as hands on time. We suggest that this methodology be formally evaluated by the manufacturers for inclusion into CE labelling of their products to allow improved laboratory work flow.

Changes in biochemical markers after lower limb fractures.

BACKGROUND: The bone remodeling sequence after bone fracture changes the concentrations of biochemical bone markers, but the relationships of fracture size and of healing time to changes in biomarkers are unclear. The present pilot study was undertaken to determine the changes found in serum bone markers after plate osteosynthesis of closed distal tibial and malleolar fractures during a study period of 24 weeks. METHODS: We measured tatrate-resistant acid phosphatase (TRACP 5b), collagen type I C-terminal telopeptide (ICTP), bone-specific alkaline phosphatase (bone ALP), osteocalcin (OC), procollagen type I C-terminal propeptide (PICP), procollagen type III N-terminal propeptide (PIIINP), and human cartilage glycoprotein 39 (YKL-40) in 20 patients with lower limb fractures (10 malleolar, 10 tibia). A physical examination and radiographs were completed to assess evidence of union. RESULTS: All malleolar fractures healed within 6 weeks, whereas 2 tibial fractures did not show complete bone healing after 24 weeks. Changes were comparable but more pronounced in the tibia group, and marker concentrations remained increased at the end of study (bone ALP, 86 vs 74 U/L; OC, 14.9 vs 7.7 microg/L; ICTP: 5.6 vs 3.3 microg/L at day 84 after osteosynthesis, P <0.05 in tibia; 80 vs 70 U/L, 8 vs 5.2 microg/L, and 3.5 vs 3.2 microg/L, respectively, in the malleolar fracture group). CONCLUSIONS: In normal bone healing, changes in bone turnover markers were primarily dependent on the fracture size. Delayed tibia fracture healing may involve a disturbance in bone remodeling.

Lethargy in a newborn: lithium toxicity or lab error?

Lithium medication during pregnancy is uncommon and the problems of a neonate who has been exposed to lithium represents a rare situation in neonatology. The clinical presentation and management of a newborn whose mother received lithium during pregnancy is presented. The newborn manifested a four day course of lethargy with unexplained high lithium levels in the adult toxic range. The infant improved clinically under intravenous hydration therapy, nevertheless lithium serum levels increased again and we did not know for certain if our clinical instinct or the actual figures were correct. Finally we noticed that our confusion had resulted from test tubes containing lithium heparine.