Quality assessment program forEuroFlow protocols: Summary results of four‐year (2010–2013) quality assurance rounds

Abstract

Flow cytometric immunophenotyping has become essential for accurate diagnosis, classification, and disease monitoring in hemato-oncology. The EuroFlow Consortium has established a fully standardized "all-in-one" pipeline consisting of standardized instrument settings, reagent panels, and sample preparation protocols and software for data analysis and disease classification. For its reproducible implementation, parallel development of a quality assurance (QA) program was required. Here, we report on the results of four consecutive annual rounds of the novel external QA EuroFlow program. The novel QA scheme aimed at monitoring the whole flow cytometric analysis process (cytometer setting, sample preparation, acquisition and analysis) by reading the median fluorescence intensities (MedFI) of defined lymphocytes' subsets. Each QA participant applied the predefined reagents' panel on blood cells of local healthy donors. A uniform gating strategy was applied to define lymphocyte subsets and to read MedFI values per marker. The MedFI values were compared with reference data and deviations from reference values were quantified using performance score metrics. In four annual QA rounds, we analyzed 123 blood samples from local healthy donors on 14 different instruments in 11 laboratories from nine European countries. The immunophenotype of defined cellular subsets appeared sufficiently standardized to permit unified (software) data analysis. The coefficient of variation of MedFI for 7 of 11 markers performed repeatedly below 30%, average MedFI in each QA round ranged from 86 to 125% from overall median. Calculation of performance scores was instrumental to pinpoint standardization failures and their causes. Overall, the new EuroFlow QA system for the first time allowed to quantify the technical variation that is introduced in the measurement of fluorescence intensities in a multicentric setting over an extended period of time. EuroFlow QA is a proficiency test specific for laboratories that use standardized EuroFlow protocols. It may be used to complement, but not replace, established proficiency tests. © 2014 International Society for Advancement of Cytometry.

Immunophenotypic analysis of erythroid dysplasia in myelodysplastic syndromes. A report from the IMDSFlow working group

“…Harmonization, or even standardization, of methods may narrow differences and improve validity of conclusions from multicenter studies, as has been demonstrated within the Euroflow consortium. 30 Hence, grouping of data per technical procedure could have been informative from a practical perspective; yet, the power of the analyses within and between numerous subgroups of centers would have been strongly limited by sample sizes. Notably, in daily practice, FC results in subjects suspected of MDS should preferably be compared with a center's own cohort of control samples.…”

Multiple myeloma, immunotherapy and minimal residual disease

“…Results that are neither standardized nor harmonized may lead to erroneous clinical, financial, regulatory, or technical decisions. The need for extensive expertise to analyze MFC data, together with lack of well-standardized and harmonized MFC-MRD methods [59], has been pointed out as the main drawback of MFC immunophenotyping [60]. In recent years, new multivariate computational tools and visualization plots have been developed and integrated into innovative software for multidimensional identification and classification of different cells coexisting in a sample.…”

Results of external quality control study in flow cytometric acute lymphoblastic leukemia diagnostics

“…В связи с тем, что данные иммунофено-типирования (ИФТ) используются для стратификации пациентов в рамках крупных многоцентровых иссле-дований по терапии ОЛЛ, необходима максимально возможная стандартизация данного метода диагности-ки. В европейских и американских исследовательских группах эта проблема решается двумя путями: либо централизацией диагностики в нескольких крупных лабораториях, специалисты которых обладают доста-точным опытом работы, либо проведением жесткой процедуры стандартизации работы большого количества лабораторий, включающей контроль работы прибора, использование унифицированных панелей монокло-нальных антител, автоматический анализ данных при помощи специального программного обеспечения [4,5].…”