Papers

Abstract

Indirect immunofluorescence (IIF) is the main technique for the detection of antinuclear antibodies (ANA) and antineutrophil cytoplasmic antibodies (ANCA). The fully automated IIF processor HELIOS is the first IIF processor that is able to automatically prepare slides and perform automatic reading. The objective of the present study was to determine the diagnostic performance of this system for ANA and ANCA IIF interpretation, in comparison with visual IIF. ANA detection by visual IIF or HELIOS was performed on 425 sera samples including: 218 consecutive samples submitted to a reference laboratory for routine ANA testing, 137 samples from healthy subjects and 70ANA/ENA positive samples. For ANCA determination, 170 sera samples were collected: 40 samples for routine testing, 90 samples from healthy blood donors and 40 anti-PR3/anti-MPO positive subjects. Good correlation was found for the visual and automated ANA IIF approach regarding positive/negative discrimination of these samples (kappa = 0.633 for ANA positive samples and kappa = 0.657 for ANA negative samples, respectively). Positive/negative IIF ANCA discrimination by HELIOS and visual IIF revealed a complete agreement of 100 % in sera from healthy patients and PR3/MPO positive samples (kappa = 1.00). There was 95 % agreement between the ANCA IIF performed by automated and visual IIF on the investigation of routine samples. Based on these results,HELIOS demonstrated a high diagnostic performance for the automated ANA and ANCA IIF interpretation that was similar to a visual reading in all groups of samples

Authors

O. Shovman, N. Agmon-Levin, B. Gilburd, T. Martins, A. Petzold, T. Matthias, Y. Shoenfeld

View full Publication online on www.springer.com

Abstract

Indirect immunofluorescence (IIF) plays an important role in immunological assays for detecting and measuring auto-antibodies. However, the method is burdened by some unfavorable features: the need for expert morphologists, the subjectivity of interpretation, and a low degree of standardization and automation. Following the recent statement by the American College of Rheumatology that the IIF technique should be considered as the standard screening method for the detection of anti-nuclear antibodies (ANA), the biomedical industry has developed technological solutions which might significantly improve automation of the procedure, not only in the preparation of substrates and slides, but also in microscope reading.

Authors

Nicola Bizzaro, Antonio Antico, Stefan Platzgummer, Elio Tonutti, Danila Bassetti, Fiorenza Pesente, Renato Tozzoli, Marilina Tampoia, Danilo Villalta, Study Group on Autoimmune Diseases of the Italian Society of Laboratory Medicine, Italy

View full Publication online on www.elsevier.com

Abstract

Anti-nuclear antibody (ANA) assay is a screening test used for almost all autoimmune rheumatic diseases, and in a number of these cases, it is a diagnostic/classification parameter. In addition, ANA is also a useful test for additional autoimmune disorders. The indirect immunofluorescence technique on monolayers of cultured epithelial cells is the current recommended method because it has higher sensitivity than solid phase assays. However, the technique is time-consuming and requires skilled operators. Automated ANA reading systems have recently been developed, which offer the advantage of faster and much easier performance as well as better harmonization in the interpretation of the results. Preliminary validation studies of these systems have given promising results in terms of analytical specificity and reproducibility. However, these techniques require further validation in clinical studies and need improvement in their recognition of mixed or less common staining patterns.

Authors

Pier Luigi Meroni, Nicola Bizzaro, Ilaria Cavazzana, Maria Orietta Borghi and Angela Tincani

View full Publication online on www.biomedcentral.com

Abstract

Indirect immunofluorescence (IIF) plays an important role in immunological and immunometric assays for detecting and measuring autoantibodies. This technology was the first multiplex method used to detect cardinal autoantibodies for the diagnosis of autoimmune diseases. Over the last 20 years, research has enabled the progressive identification of cell and tissue autoantigens which are the target of autoantibodies originally detected by IIF. Accordingly, newer immunometric methods, capable of measuring concentrations of specific autoantibodies directed against these autoantigens, allowed for a gradual replacement of the IIF method in the autoimmunology laboratory. Currently, IIF remains the method of choice only in selected fields of autoimmune diagnostics. Following the recent statement by the American College of Rheumatology that the IIF technique should be considered as the standard screening method for the detection of ANA, the biomedical industry has developed technological solutions which significantly improve automation of the procedure, not only in the preparation of substrates and slides, but also in microscope reading. This review summarizes the general and specific features of new available commercial systems (Aklides, Medipan; Nova View, Inova; Zenit G Sight, A. Menarini Diagnostics; Europattern, Euroimmun; Helios, Aesku.Diagnostics; Image Navigator, Immuno Concepts; Cytospot, Autoimmun Diagnostika) for automation of the IIF method. The expected advantages of automated IIF are the reduction in frequency of false negative and false positive results, the reduction of intra and inter-laboratory variability, the improvement of correlation of staining patterns with corresponding autoantibody reactivities, and higher throughput in the laboratory workflow.

Authors

Renato Tozzoli, Antonio Antico, Brunetta Porcelli, Danila Bassetti

View full Publication online on www.springer.com