Transference of CALIPER pediatric reference intervals to biochemical assays on the Roche cobas 6000 and the Roche Modular P.

OBJECTIVES: The Canadian Laboratory Initiative on Pediatric Reference Intervals (CALIPER) has recently established pediatric age- and sex-specific reference intervals for over 85 biochemical markers on the Abbott Architect system. Previously, CALIPER reference intervals for several biochemical markers were successfully transferred from Abbott assays to Roche, Beckman, Ortho, and Siemens assays. This study further broadens the CALIPER database by performing transference and verification for 52 biochemical assays on the Roche cobas 6000 and the Roche Modular P. DESIGN AND METHODS: Using CLSI C28-A3 and EP9-A2 guidelines, transference of the CALIPER reference intervals was attempted for 16 assays on the Roche cobas 6000 and 36 on the Modular P. Calculated reference intervals were further verified using 100 healthy CALIPER samples. RESULTS: Most assays showed strong correlation between assay systems and were transferable from Abbott to the Roche cobas 6000 (81%) and the Modular P (86%). Bicarbonate and magnesium were not transferable on either system and calcium and prealbumin were not transferable to the Modular P. Of the transferable analytes, 62% and 61% were verified on the cobas 6000 and the Modular P, respectively. CONCLUSIONS: This study extends the utility of the CALIPER database to two additional analytical systems, which facilitates the broad application of CALIPER reference intervals at pediatric centers utilizing Roche biochemical assays. Transference studies across different analytical platforms can later be collectively analyzed in an attempt to develop common reference intervals across all clinical chemistry instruments to harmonize laboratory test interpretation in diagnosis and monitoring of pediatric disease.

Predictors of peri-opertative morbidity and liver dysfunction after hepatic resection in patients with chronic liver disease.

BACKGROUND: Hepatic resection in patients with chronic liver disease (CLD) is associated with a risk of post-operative liver failure and higher morbidity than patients without liver disease. There is no universal risk stratification scheme for CLD patients undergoing resection. OBJECTIVES: The aim of the present study was to evaluate the association between routine pre-operative laboratory investigations, model for end-stage liver disease (MELD), indocyanine green retention at 15 min (ICG15) and post-operative outcomes in CLD patients undergoing liver resection. METHODS: A retrospective review of patients undergoing resection for hepatocellular carcinoma (HCC) at the University Health Network was preformed. ICG15 results, pre- and post-operative laboratory results were obtained from clinical records. Adjusted odds ratios (AOR) were calculated for associations between pre-operative factors and post-operative outcomes using multivariate logistic regression adjusting for patient age and number of segments resected. RESULTS: Between 2001 and 2005, 129 CLD patients underwent surgical resection for HCC. Procedures included 51 (40%) resections of ≤ 2 segments, 52 (40%) hemihepatectomies and 25 (19%) extended hepatic resections. Thirty- and 90-day post-operative mortality was 1.6% and 4.1%, respectively. Prolonged (>10 days) hospital length of stay (LOS) was independently associated with an ICG15 >15% {AOR [95% confidence interval (CI)]= 8.5 (1.4-51)} and an international normalized ratio (INR) > 1.2 [AOR (95% CI) = 5.0 (1.4-18.6)]. An ICG15 > 15% and MELD score were independent predictors of prolonged LOS. An ICG15 > 15% was also independently associated with MELD > 20 on post-operative day 3 [AOR (95% CI) = 24.3 (1.8-319)]. CONCLUSIONS: Elevated ICG retention was independently associated with post-operative liver dysfunction and morbidity. The utility of ICG in combination with other biochemical measures to predict outcomes after hepatic resection in CLD patients requires further prospective study.

Comparison of daily, weekly, and monthly vitamin D3 in ethanol dosing protocols for two months in elderly hip fracture patients.

BACKGROUND: Different dosing protocols have been used for vitamin D supplementation, but there has been a lack of comparative data among them. OBJECTIVE: Our objective was to determine whether the same cumulative dose of vitamin D3 produces different effects if it is given daily, weekly, or monthly. DESIGN: Women, age 81 +/- 8 yr (+/- sd, n = 48), who had undergone surgery to repair hip fracture were randomized to vitamin D3-supplementation protocols at 1,500 IU daily, or 10,500 IU once weekly, or 45,000 IU once every 28 d. The primary outcome measure was the serum 25-hydroxyvitamin D [25(OH)D] concentration attained. RESULTS: Initially, serum 25(OH)D concentrations for daily, weekly, and monthly groups were, respectively, 15.13 +/- 6.9, 15.7 +/- 10.1, and 16.2 +/- 10.1 ng/ml. By d 7, these had increased significantly in all the groups (P < 0.001). On the first day after the monthly dose, both serum 25(OH)D and serum 1,25-dihydroxyvitamin D had increased significantly (P < 0.012 each), whereas these did not change significantly on the day after daily or weekly doses. After 2 months, serum 25(OH)D with daily, weekly, and monthly dosing were, respectively, 33.2 +/- 8.5, 29.2 +/- 8.9, and 37.1 +/- 10.3 ng/ml; there were no significant differences among these values. CONCLUSIONS: Supplementation with vitamin D can be achieved equally well with daily, weekly, or monthly dosing frequencies. Therefore, the choice of dose frequency can be based on whichever approach will optimize an individual's adherence with long-term vitamin D supplementation.

A consolidated catalogue and graphical annotation of dbSNP polymorphisms in the human tissue kallikrein (KLK) locus.

The human tissue kallikreins, 15 secreted serine proteases, may play diverse roles in pathophysiology. The National Center for Biotechnology Information's dbSNP was mined for polymorphisms located within the kallikrein (KLK) locus using custom-designed "ParSNPs" and "LocusAnnotator" software tools. Using "ParSNPs", a filterable catalogue of 1856 KLK polymorphisms (1023 validated) was generated. "LocusAnnotator" was used to annotate the KLK locus sequence with gene and polymorphism features. A second locus was examined to validate the use of both programs on a non-kallikrein locus. This report may assist in the informed selection of KLK polymorphisms for future association and biochemical studies in relation to disease. Furthermore, "ParSNPs" and "LocusAnnotator" are available at no cost from our website (www.acdcLab.org/annotations) to examine other loci.

Evaluation of an algorithm for calculation of serum "bioavailable" testosterone (BAT).

OBJECTIVES: To evaluate a recently published algorithm for calculation of serum "Bioavailable" Testosterone (BAT) using serum Total Testosterone (TT), Sex Steroid Binding Globulin (SSBG) [also commonly known as Sex Hormone Binding Globulin (SHBG)] and albumin concentrations as parameters, in comparison with a locally available "salting-out" BAT method. If satisfactory, this calculation could serve as a substitute for the BAT assay, which would amount to a major cost saving and faster turnaround time. DESIGN AND METHODS: During a 6-month period, 426 serum samples referred for BAT analysis to the Hospitals In-Common Laboratory of Toronto were also analyzed in-house for TT, SSBG and albumin for computation of comparison calculated BAT results. RESULTS: A good statistical correlation was obtained, but only after unexpectedly drastic empirical modification of the association constant values: r=0.95, Calculated %BAT=0.971 x Measured %BAT + 0.008. The endocrinologist/andrologist of our team (JB), who was the responsible physician for all patients included in this study, reviewed the tabulated and charted calculated BAT results and verified that they were clinically equivalent. CONCLUSIONS: Although it is feasible to calculate BAT, the algorithm is not directly portable. Before adopting such a calculation each laboratory should compare it with the locally available BAT method and consider adjusting the calculation to optimize the correlation. Future reassessment may be necessary whenever the SSBG, TT or BAT assay is changed.

Lipase and pancreatic amylase versus total amylase as biomarkers of pancreatitis: an analytical investigation.

OBJECTIVE: To evaluate the biomarkers of pancreatitis Colorimetric Lipase, Total Amylase and Pancreatic Amylase (immunoinhibition) assays on the Roche COBAS INTEGRA 700. RESULTS: Pancreatic and Total Amylase assays and Colorimetric Lipase showed excellent imprecision of 1.6 to 2.3% and linearity (slope = 0.94-0.99, y-intercepts-1 to +3 U/L, r = 0.999) over the range of 17 to 900, 35 to 880, and 21 to 150 U/L, respectively. There was an excellent correlation between Pancreatic and Total Amylase: Pancreatic Amylase = 0.99 (+/- 0.02) x Total Amylase-36(+/- 8) (n = 106, r = 0.97, p < 1 x 10(-5), y intercept p < 1 x 10(-5)). Colorimetric Lipase showed some correlation to Total and Pancreatic Amylase results: Colorimetric Lipase = 1.54 (+/- 0.16) x Total Amylase-81(+/- 37) (n = 100, r = 0.70, p < 1 x 10(-6), y intercept p = 0.03), and Colorimetric Lipase = 1.78 (+/- 0.15) x Pancreatic Amylase-50(+/- 29) (n = 99, r = 0.78, p < 1 x 10(-6), y intercept p = 0.09). CONCLUSION: We recommend running the more specific Pancreatic Amylase as biomarker of pancreatitis on the Roche COBAS INTEGRA.