Third-party verification of total and specific immunoglobulin E on analyzer Immulite® 2000XPi.

BACKGROUND: Although Immulite®2000XPi (Siemens) allergy testing is routinely used in laboratories worldwide; a well-designed comprehensive third-party verification of its analytical performance has not yet been published. Our aim was to verify stability, precision and reference intervals for total and some frequent specific IgEs, test trueness for several most common allergens and assess the comparability of fluorescent- and chemiluminescent-enzyme immunoassay for total IgE. METHODS: Verification was based on EP15-A3, EP9-A3 and EP28-A3c CLSI guidelines. Stability was tested on serum pools stored at 2-8 °C, during 7 days. Manufacturer's reference intervals were verified for children and adults. Acceptance criteria were based on manufacturer specifications and national External Quality Assessment provider data. RESULTS: Samples for total IgE analysis were stable at 2-8 °C for 7 days. Precision was within manufacturer's specifications for most of tested allergens, except for total IgE (92.5 kIU/L, CVs 5.6% and 7.6%) and w1 (9.3 kU/L, CV = 5.9%). Bland-Altman plot revealed statistically significant constant (-32.4 kIU/L) and proportional bias (-20.2%) for total IgE between two methods. Passing Bablok showed statistically but not clinically significant biases between two Immulite analyzers for betula verrucosa (constant and proportional), house dust mite and egg white allergens (proportional). For adults and children, total IgE results were within reference intervals declared by Siemens. CONCLUSIONS: Immulite®2000XPi assay has acceptable precision and trueness. Samples for total IgE are stable even longer than declared by the manufacturer. Declared reference intervals can safely be adopted for both adult and children population in our laboratory. Fluorescent- and chemiluminescent-enzyme immunoassay results of total IgE are not comparable.

How compliant are technicians with universal safety measures in medical laboratories in Croatia?--A pilot study.

INTRODUCTION: This pilot study aimed to investigate the use of personal protective equipment (PPE) and compliance to the code of conduct (rules defined in institutional, governmental and professional guidelines) among laboratory technicians in Croatian medical laboratories. In addition, we explored the differences in compliance between participants of different age groups, laboratory ownership and accreditation status. MATERIALS AND METHODS: An anonymous and voluntary survey with 15 questions was conducted among Croatian medical laboratory technicians (N=217). The questions were divided into two groups: demographic characteristics and the use of PPE. The questions of the second part were graded according to the Likert scale (1-4) and an overall score, shown as median and range (min-max), was calculated for each participant. Differences between the overall scores were tested for each group of participants. RESULTS: The majority of participants always wear protective clothes at work, 38.7% of them always wear gloves in daily routine, more than 30.0% consume food and almost half of them drink beverages at workplace. A significantly lower overall score was found for participants working in public compared to private laboratories (36 (16-40) vs. 40 (31-40), P<0.001). There were no statistically significant differences in overall scores for participants of different age groups (P=0.456) and laboratory accreditation status (P=0.081). CONCLUSION: A considerable percentage of laboratory technicians in Croatian medical laboratories do not comply with safety measures. Lack of compliance is observed in all personnel regardless laboratory accreditation and participants' age. However, those working in private laboratories adhere more to the code of conduct.