Bertin Daniel, Mouhajir Yassin, Bongrand Pierre, Bardin Nathalie
Laboratoire d'Immunologie, Hôpital de la Conception, Assistance Publique-Hôpitaux de Marseille, France.
Laboratoire d'Immunologie, Hôpital de la Conception, Assistance Publique-Hôpitaux de Marseille, France.
Clin Chim Acta. 2016 Feb 15;454:57-61. doi: 10.1016/j.cca.2015.12.034. Epub 2015 Dec 30.
Antinuclear antibodies (ANA) are useful biomarkers for the diagnosis and the monitoring of rheumatic diseases. The American College of Rheumatology has stated that indirect immunofluorescence (IIF) analysis remains the gold standard for ANA screening. However, IIF is time consuming, subjective, not fully standardized and presents several issues for accreditation which is the process leading to ISO 15189 certification for medical laboratories. We propose an innovative tool for accreditation by using the quantitative evaluation of the automated image capture and analysis "ICARE" (Immunofluorescence for Computed Antinuclear antibody Rational Evaluation).
We established the optimal screening dilution (1:160) and a fluorescence index (FI) cutoff for ICARE on a cohort of 91 healthy blood donors. Then, we evaluated performance of ICARE on a routine cohort of 236 patients. Precision parameters of ANA detection by IIF were evaluated according to ISO 15189.
ICARE showed an excellent concordance with visual evaluation (88%, Kappa=0.76) and significantly discriminated between weak to moderate (1:160-1:320 titers) and high (>1:320 titers) ANA levels. A significant correlation was found between FI and ANA titers (Spearman's ρ=0.67; P<0.0001). Using ICARE, we reported precision parameters such as repeatability (CV<13.8%) and reproducibility (CV<13.1%) as well as absence of inter-sample contamination for ANA detection by IIF according to ISO 15189 standards.
ICARE offers a precious help for the accreditation of IIF qualitative methods. This innovative quantitative approach is in adequacy with the process of continuous improvement of the quality of clinical laboratories.
抗核抗体（ANA）是用于诊断和监测风湿性疾病的有用生物标志物。美国风湿病学会指出，间接免疫荧光（IIF）分析仍是ANA筛查的金标准。然而，IIF耗时、主观、未完全标准化，并且在认证过程中存在若干问题，认证是医学实验室获得ISO 15189认证的过程。我们提出了一种创新工具用于认证，即使用自动图像捕获和分析“ICARE”（计算机抗核抗体合理评估免疫荧光法）进行定量评估。
我们在91名健康献血者队列中确定了ICARE的最佳筛查稀释度（1:160）和荧光指数（FI）临界值。然后，我们在236名患者的常规队列中评估了ICARE的性能。根据ISO 15189评估IIF检测ANA的精密度参数。
ICARE与视觉评估显示出极好的一致性（88%，Kappa = 0.76），并能显著区分低至中度（1:160 - 1:320滴度）和高（>1:320滴度）ANA水平。FI与ANA滴度之间存在显著相关性（Spearman秩相关系数ρ = 0.67；P < 0.0001）。使用ICARE，我们报告了精密度参数，如重复性（CV < 13.8%）和再现性（CV < 13.1%），以及根据ISO 15189标准通过IIF检测ANA时不存在样本间污染。
ICARE为IIF定性方法的认证提供了宝贵帮助。这种创新的定量方法符合临床实验室质量持续改进的过程。
