ABSTRACT
BACKGROUND: Allergen specific IgE (sIgE) assay is an important aid in the diagnosis and treatment of allergy. We evaluated the analytical performance of a quantitative chemiluminescence immunoassay for sIgE using the continuous random access ADVIA Centaur. METHODS: Six ADVIA Centaur sIgE reagents for common inhalant allergens in Korea, d1, d2, e1, e5, t3, and t7, were evaluated for precision, dilution recovery (parallelism), comparison with Pharmacia UniCAP sIgE assay and skin prick test, sample volume, and analytical speed according to the NCCLS guidelines (I/LA20-A, EP5-A2). Commercialized positive and negative quality control materials were used for a precision study, and samples from a total of 110 patients were used for dilution recovery and comparison studies. RESULTS: Within-run coefficients of variation (CV) of the 6 items were 3.45-6.14% and within-device CVs (total CVs) of all items were below 10%. Interdilutional CVs of all items were 2.84-11.95%, which showed a good linearity and parallelism over its measuring range. Positive/negative concordance rates of the 6 items with UniCAP sIgE assay were 76.3-96.1% (d1, 88.2%; d2, 96.1%; e1, 91.0%; e5, 77.0%; t3, 90.5%; and t7, 76.3%). Concordance rates of the six items with skin prick test were all above 80%. The quantity of sample volume (25 micro L/test) needed was relatively small, and a high throughput (120 tests/hr) and rapid turnaround time (47 min) could be achieved. CONCLUSIONS: The ADVIA Centaur sIgE assay was thought to be a convenient and efficient method to be used in medium- to large-sized laboratories.
Subject(s)
Humans , Allergens , Diagnosis , Hypersensitivity , Immunoassay , Immunoglobulin E , Indicators and Reagents , Korea , Luminescence , Quality Control , SkinABSTRACT
BACKGROUND: Recent blood gas analyzers offer electrolytes, Hb-derivatives (O2 Hb, HHb, COHb, MetHb and SulfHb), content of total hemoglobin (ctHb), and metabolites (glucose and lactate) as well as conventional blood gas parameters. Evaluation and efficient control of these instruments affect greatly monitoring and therapy of patients. The authors evaluated a recently introduced blood gas analyzer, the Roche OMNI 9 (Roche Diagnostics) for precision, analytic speed, function, features and comparability with other instruments according to NCCLS guidelines to see if it was suitable for the stat analyzer. METHODS: Commercial control materials, AUTO-trol PLUS Level 1, 2, 3 (Roche Diagnostics) were analyzed to evaluate the within-day precision, the between-day precision, and patient samples were used to evaluate comparability with other instruments. RESULTS: The within-day and the between-day precisions of the Roche OMNI 9 showed a very low CV of 0- 3.93% and 0- 3.99%, respectively, in all parameters except the lactate, which had moderate CV values of 7.74% and 5.93% in Level 3 QC material (low concentration). In compari-son with the Bayer instrument, correlation was high in all parameters with the r(2) value ranging from 0.9441 to 0.9901 except for COHb (r(2)=0.4239) and MetHb (r(2)=0.0034) whose concentrations were in the lower level. Glucose (r(2)=0.991), lactate (r(2)=0.9824), and hemoglobin (r(2)=0.9961) showed a rather high correlation. The Roche OMNI 9 could analyze 40 samples of blood gas and 27 samples of full parameter per hour, which was comparable to the Bayer M855. CONCLUSIONS: The Roche OMNI 9 showed high precision and rapid turnaround time for blood gas and in a selection of glucose, lactate and hemoglobin.