Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.


Standardization of Antinuclear Antibody Assessment on HEp-2 Cells by Automated Interpretation.

Egerer1,  Karl, Roggenbuck4,  Dirk, Hiemann6,  Rico, Weyer5,  Max-Georg, Lehmann3,  Barbara, Feist3,  Eugen, Burmester2,  Gerd R.

Charite-University Medicine, Berlin, Germany
Charite-University Medicine, Berlin, Germany
Charite-University Medicine
Medipan GmbH, Berlin Dahlewitz, Germany
Medizinisches Versorgungszentrum für Laboratoriumsmedizin, Mikrobiologie, Virologie und Infektionsepidemiologie, Hygiene und Umweltmedizin
University of Applied Science Lausitz

Introduction:

Analysis of antinuclear antibodies (ANAs) by indirect immunofluorescence (IIF) is a basic tool for the serological diagnosis of systemic rheumatic disorders. Automation of ANA IIF interpretation including pattern recognition can improve assay reproducibility and intra- and inter-laboratory variability. Automation of ANA reading meets the demand for cost-effective assessment of large numbers of samples in routine laboratories. Comparing automated and visual interpretation of ANA patterns, the usefulness for laboratory diagnostics was investigated.

Methods:

Antinuclear antibody detection by IIF on human epithelial-2 (HEp-2) cells including pattern recognition was performed in a total of 1222 consecutive sera of patients with suspected systemic rheumatic diseases from a university routine laboratory (n=924) and a private referral laboratory (n=298). IIF reading results obtained in routine diagnostics were compared with findings by a novel automated interpretation system employing mathematical pattern recognition algorithms.

Results:

Visual and automated interpretation of ANA showed a very good agreement regarding positive / negative discrimination (kappa=0.828). Only 98 (8.0%) of 1222 sera demonstrated discrepant results in the differentiation of positive from negative samples. The contingency coefficient of Chi-square statistics was 0.646 for the university laboratory cohort with an agreement of 93.0% and 0.695 for the private laboratory cohort with an agreement of 90.6%, p<0.0001, respectively. According to the McNemar test, there was no significant difference in the university cohort (1.08%, p=0.25).

Comparing respective immunofluorescence patterns, 111 (15.3%) sera yielded differing results in both cohorts. Discrepant results were mainly obtained when the AKLIDES algorithms assessed cytoplasmic signals as nuclear staining due to superposition.

Conclusions:

Automated interpretation of ANA by IIF on HEp-2 cells using an automated reading system is a reliable and robust method for positive/negative differentiation of IIF findings. Employing novel mathematical algorithms, automated interpretation provides reproducible detection of specific immunofluorescence patterns on HEp-2 cells. Automated interpretation can reduce drawbacks of ANA detection by IIF in routine diagnostics providing more reliable data for clinicians.

To cite this abstract, please use the following information:
Egerer, Karl, Roggenbuck, Dirk, Hiemann, Rico, Weyer, Max-Georg, Lehmann, Barbara, Feist, Eugen, et al; Standardization of Antinuclear Antibody Assessment on HEp-2 Cells by Automated Interpretation. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :911
DOI: 10.1002/art.28679

Abstract Supplement

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