Antinuclear antibody-negative systemic lupus erythematosus: How many patients and how to identify?
Department of Rheumatology, Fujian Medical University Union Hospital, Fuzhou, China
Keywords: Anti-double-stranded deoxyribonucleic acid, antinuclear antibody, antiphospholipid antibody, complement, systemic lupus erythematosus.
Objectives: This study aims to the prevalence of antinuclear antibody (ANA)-negative systemic lupus erythematosus (SLE) and their clinical characteristics in a large single-center SLE inception cohort to provide guidance for early diagnosis.
Patients and methods: Between December 2012 and March 2021, the medical records of a total of 617 firstly diagnosed SLE patients (83 males, 534 females; median age [IQR]: 33+22.46 years) who fulfilled the selection criteria were retrospectively analyzed. The patients were divided into groups with ANA-negative SLE and ANA-positive SLE, or with prolonged use of glucocorticoids or immunosuppressants (SLE-1) and without (SLE-0). Demographic, clinical characteristics, and laboratory features were collected.
Results: The total prevalence of ANA-negative SLE patients was 2.11% (13/617). The prevalence of ANA-negative SLE in SLE-1 (7.46%) was significantly higher than that in SLE-0 (1.48%) (p<0.01). The ANA-negative SLE patients had a higher prevalence of thrombocytopenia (84.62%) than ANA-positive SLE patients (34.27%). As with ANA-positive SLE, ANA-negative SLE also had a high prevalence of low complement (92.31%) and anti-double-stranded deoxyribonucleic acid (anti-dsDNA) positivity (69.23%). The prevalence of medium-high titer anti-cardiolipin antibody (aCL) IgG (50.00%) and anti-ß2 glycoprotein I (anti-ß2GPI) (50.00%) of ANA-negative SLE was significantly higher than that of ANA-positive SLE (11.22% and 14.93%, respectively).
Conclusion: The prevalence of ANA-negative SLE is very low, but it exists, particularly under the influence of prolonged use of glucocorticoids or immunosuppressants. Thrombocytopenia, low complement, positive anti-dsDNA, and medium-high titer antiphospholipid antibody (aPL) are the main manifestations of ANA-negative SLE. It is necessary to identify complement, anti-dsDNA, and aPL in ANA-negative patients with rheumatic symptoms, particularly thrombocytopenia.
Citation: Li H, Zheng Y, Chen L, Lin S. Antinuclear antibody-negative systemic lupus erythematosus: How many patients and how to identify?. Arch Rheumatol 2022;37(4):626-634.
The Cohort Study has full ethical approval from the ethics board of Fujian Medical University Union Hospital under the 2021KY139 project number. The study was conducted in accordance with the principles of the Declaration of Helsinki.
As this study was retrospective in nature, the requirement for informed consent was waived.
Data Sharing Statement:
The data that support the findings of this study are available from the corresponding author upon reasonable request.
Was responsible for study conception and design: H.L.; Supervised the study: S.L.; Was responsible for data collection and processing: H.L., Y.Z.; Was responsible for analysis and wrote the article: H.L., L.C.; All authors reviewed the manuscript.
The authors declared no conflicts of interest with respect to the authorship and/or publication of this article.
The authors received no financial support for the research and/or authorship of this article.