Antinuclear antibody testing in a Turkish pediatrics clinic: is it always necessary?

T�lay G�nsay,Aysenur Ersoy,Ahmet Hakki Kapici,Gafur Dogdu,Fatmat�zzehra Yazici,Özge Nur Çam,Berat Aky�z,Dilruba Basbug,Nesibe Saglam,Edanur Karapinar,Fatih Mehmet Kelesoglu,Rukiye Eker Ömeroglu,Nazli K�bra Okumus,Sirin Atay,Nur Gökçe Aydin,Dilara Akça,Melike Zeynep Can,Erhan Ayg�n

doi:10.11604/pamj.2019.32.181.13793

Abstract

IntroductionThe term anti-nuclear antibody (ANA) is used to define a large group of autoantibodies which specifically bind to nuclear elements. Although healthy individuals may also have ANA positivity, the measurement of ANA is generally used in the diagnosis of autoimmune disorders. However, various studies have shown that ANA testing may be overused, especially in pediatrics clinics. Our aim was to investigate the reasons for antinuclear antibody (ANA) testing in the general pediatrics and pediatric rheumatology clinics of our hospital and to determine whether ANA testing was ordered appropriately by evaluating chief complaints and the ultimate diagnoses of these cases.MethodsThe medical records of pediatric patients in whom ANA testing was performed between January 2014 and June 2016 were retrospectively evaluated. Subjects were grouped according to the indication for ANA testing and ANA titers.ResultsANA tests were ordered in a total of 409 patients during the study period, with 113 positive ANA results. The ANA test was ordered mostly due to joint pain (50% of the study population). There was an increased likelihood of autoimmune rheumatic diseases (ARDs) with higher ANA titer. The positive predictive value of an ANA test was 16% for any connective tissue disease and 13% for lupus in the pediatric setting.Conclusionin the current study, more than one-fourth of the subjects were found to have ANA positivity, while only 15% were ultimately diagnosed with ARDs. Our findings underline the importance of an increased awareness of correct indications for ANA testing.

Highlights

The term anti-nuclear antibody (ANA) is used to define a large group of autoantibodies which bind to nuclear elements
None of the patients with antinuclear antibody (ANA) titers less than 1:160 were diagnosed with autoimmune rheumatic diseases (ARDs), while subjects with titers > 1:160 had a similar rate of ARDs (p = 0.2) (Table 3)
Lupus patients who referred to the clinic with skin and joint symptoms were generally diagnosed as a result of further investigation

Summary

Introduction

The term anti-nuclear antibody (ANA) is used to define a large group of autoantibodies which bind to nuclear elements. There was an increased likelihood of autoimmune rheumatic diseases (ARDs) with higher ANA titer. Conclusion: in the current study, more than one-fourth of the subjects were found to have ANA positivity, while only 15% were diagnosed with ARDs. Our findings underline the importance of an increased awareness of correct indications for ANA testing. 80-85% of the data leading to a diagnosis is obtained via a comprehensive medical history. Obtaining a detailed medical history and meticulous evaluation of the data is of utmost importance in the rheumatology clinic. In addition to clinical evaluation, autoantibody measurements have become a powerful guide for diagnosis and may provide important data in terms of prognosis, disease activity and treatment of rheumatic diseases. Antinuclear antibody (ANA) testing has become instrumental in the diagnosis of certain autoimmune rheumatic diseases (ARDs). Quantification of autoantibodies may suggest the presence of an autoimmune disease or inform the clinician about the severity of the disease and/or the immune response associated with the disease [6]

Objectives

Methods

Results

Discussion

Conclusion