M S Mohd Razi, Y Sugumaran, N A Mohd Haniz, K Khilmie, A H Osmera, E J Jauhary, A A Wahab
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引用次数: 0
Abstract
Introduction: Anti-nuclear antibody (ANA) testing is among the most common immunological test requested in the diagnostic immunology laboratory. The main purpose of this test is to screen for the underlying systemic autoimmune rheumatic diseases (SARDs). The gold standard laboratory method for ANA detection is by the indirect immunofluorescence (IIF) assay. In most laboratories, positive ANA-IIF is reported in terms of titration and pattern.
Objective: This study was conducted with the aim of determining the correlation between ANA-IIF titration and pattern for the diagnosis of SARDs.
Materials and methods: A retrospective study was conducted whereby the positive ANA-IIF samples from 1st July 2018 until 31st December 2019 and 1st January 2021 until 31st March 2021 were included in this study. The duplicate samples were excluded. ANA-IIF titration and pattern were recorded for all patients. The demographic, clinical, and final diagnosis data were retrieved from each patient's clinical note.
Results: A total of 179 patients were included for analysis. The majority of the patients were female (79.9%) and from Malay ethnicity (66.5%). Sixty-five patients (36.3%) had ANA-IIF positive at 1:80 titration followed by 45 patients (25.1%) positive at titration of equal or more than 1:160. Speckled was the predominant pattern visualised in 90 patients (50.3%) followed by homogeneous in 76 patients (42.5%). Forty-five patients (25.1%) were finally diagnosed with SARDs with 41 of them diagnosed as SLE. ANA titration was significantly associated with the final diagnosis of SARDs at all titres (p<0.001) but the best cut-off was noted at a titre of equal or more than 1:320 with the sensitivity and specificity of 86.7% and 77.6% respectively. The homogeneous pattern was also significantly associated with SARDs (p=0.04). The final diagnosis of SARDs were significantly higher in female (p=0.03) and their age was significantly younger (p<0.001).
Conclusion: ANA-IIF titration of equal or more than 1:320 can be used as the best titration for differentiating between SARDs and non-SARDs in a positive ANA sample. Patients with homogeneous pattern were more likely to be diagnosed with SARDs than other ANA-IIF patterns.
期刊介绍:
The Malaysian Journal of Pathology is the official journal of the College of Pathologists, Academy of Medicine Malaysia. The primary purpose of The Journal is to publish the results of study and research in Pathology, especially those that have particular relevance to human disease occurring in Malaysia and other countries in this region. The term PATHOLOGY will be interpreted in its broadest sense to include Chemical Pathology, Cytology, Experimental Pathology, Forensic Pathology, Haematology, Histopathology, Immunology, Medical Microbiology and Parasitology. The Journal aims to bring under one cover publications of regional interest embracing the various sub-specialities of Pathology. It is expected that the articles published would be of value not only to pathologists, but also to medical practitioners in search of a scientific basis for the problems encountered in their practice, and to those with an interest in diseases which occur in the tropics.