The ANA-reflex test as a model for improving clinical appropriateness in autoimmune diagnostics.

Elio Tonutti,Luigi Cinquanta,Daniela Visentini,Marcello Bagnasco,Tiziana Imbastaro,Ignazio Brusca,Martina Fabris,Brunetta Porcelli,Danilo Villalta,Marilina Tampoia,Gabriella Morozzi,Antonella Radice,Giuseppina Barberio,Maria Concetta Sorrentino,Renato Tozzoli,Antonio Antico,Nicola Bizzaro,Desré Ethel Fontana,Maria Grazia Alessio,Giampaola Pesce,D Bassetti

doi:10.1007/s13317-016-0080-3

Abstract

Reflex tests are widely used in clinical laboratories, for example, to diagnose thyroid disorders or in the follow-up of prostate cancer. Reflex tests for antinuclear antibodies (ANA) have recently gained attention as a way to improve appropriateness in the immunological diagnosis of autoimmune rheumatic diseases and avoid waste of resources. However, the ANA-reflex test is not as simple as other consolidated reflex tests (the TSH-reflex tests or the PSA-reflex tests) because of the intrinsic complexity of the ANA test performed by the indirect immunofluorescence method on cellular substrates. The wide heterogeneity of the ANA patterns, which need correct interpretation, and the subsequent choice of the most appropriate confirmatory test (ANA subserology), which depend on the pattern feature and on clinical information, hinder any informatics automation, and require the pathologist’s intervention. In this review, the Study Group on Autoimmune Diseases of the Italian Society of Clinical Pathology and Laboratory Medicine provides some indications on the configuration of the ANA-reflex test, using two different approaches depending on whether clinical information is available or not. We further give some suggestions on how to report results of the ANA-reflex test.

Highlights

The term reflex test indicates a ‘‘cascade’’ diagnostic approach where a positive initial test automatically triggers further tests based on predefined rules applied to information systems
As we shall see shortly, this is related to the complexity of the diagnostic algorithm of the anti-nuclearcytoplasmic antibodies (ANA)-reflex test which does not rely on informatics automatism, but rather on the intervention of a pathologist based on clinical information and preceding results [6], and should, be more appropriately defined ‘‘ANA-reflective’’ testing [7]
The thyroid-stimulating hormone (TSH)-reflex test relies on the sequential execution of specific tests, inserted into a well-defined algorithm based on the TSH test result, without the need for decisional intervention by the operators

Summary

Introduction

The term reflex test indicates a ‘‘cascade’’ diagnostic approach where a positive initial (first level) test automatically triggers further (second level) tests based on predefined rules applied to information systems. The Study Group on Autoimmune Diseases of the Italian Society of Clinical Pathology and Laboratory Medicine provides some indications on the configuration of the ANA-reflex test, using two different approaches depending on whether clinical information is available or not.

Results

Conclusion