LAUSR

Background The antinuclear antibody (ANA) test is often used as a screening test to aid in the diagnosis of systemic lupus erythematous (SLE and other systemic autoimmune rheumatic diseases (SARD). However, recently it was reported that a certain autoantibody referred to as anti-dense fine speckled 70 (DFS70) are much more common (up to 25%) of non-SARD and healthy individuals but rare <5%) in SLE and certain SARD. The frequency of anti-DFS70 is even lower (i.e. <1%) if monospecific anti-DFS70 antibodies are found. Some reports suggested that anti-DFFS70 are more common in younger females, suggesting that hormonal factors may be responsible for the cognate B cell response. Objectives The primary objective of our study was to determine the frequency of ant-DFS70 in menopausal women who were referred for evaluation of undifferentiated arthritis (UA). Methods 282 women including 105 with UA and an age range of 27~91 years (mean=60.3) were enrolled. Menopausal women were divided into pre-, peri-, and post-menopausal stages according to menstrual regularity. (E2), Follicle stimulating hormone (FSH), rheumatoid factor (RF), ANA (by indirect immunofluorescence (IIF) (MBL) anti-cyclic citrullinated peptide antibody (ACPA: MBL ELISA) and C-reactive protein (CRP) were included in the serology workup. Postmenopausal arthralgia was designated PoMA and perimenopausal arthralgia PeMA. Results In PoMA women who received HRT for two months estradiol levels increased, FSH levels decreased and the joint pain visual analogue scale was reduced by 70%, as compared to baseline. Similarly in PeMA women, administration of 600 mg tocopherol N daily had the same efficacy as that observed in PoMA. The overall frequency of anti-DFS70 of 26.7% (28/105) in PoMA and PeMA women was significantly higher than that in UA females who were diagnosed with rheumatoid arthritis (RA) (7/65:10.8%) or primary Sjogren’s syndrome (SjS) (3/31: 9.7%) (p<0.05). In addition, anti-DFS70 Ab was observed primarily in low titer (1:40 – 1:160) ANA positive sera. On the other hand, higher titer ANAs (titer >1/320) were observed in the females that were diagnosed as systemic lupus erythematosus (SLE) (30%) or primary SjS (48.4%), the majority of whom had lower titers of anti-DFS70, although several sera contained both high titer ANA and anti-DFS70 (see figure).Abstract AB1325 – Figure 1 Relationship of ANA titers and anti-DFS70 levels in peri- and post-menopausal women The majority of anti-DFS70 positive sera had only low to modest ANA titers. ANA titer in vertical axis and anti-DFS70 titers by ELISA on the horizontal axis Conclusions Anti-DFS70 was found in higher frequency in PeMA and PoMA women than in women who developed a defined systemic autoimmune rheumatic disease such as SLE, SjS or RA. This is the first study to suggest that the presence of this autoantibody may reflect oestrogen fluctuations or deficiency. A negative association between ANA titer and anti-DFS70 levels by ELISA remains to be confirmed in larger studies. References [1] M. Mahler, P. L. Meroni, L. E. Andrade, M. Khamashta, N. Bizzaro, C. A. Casiano, and M. J. Fritzler. Towards a better understanding of the clinical association of anti-DFS70 autoantibodies. Autoimmun. Rev. 15:198–201, 2016. [2] K. Conrad, N. Rober, L. E. Andrade, and M. Mahler. The Clinical Relevance of Anti-DFS70 Autoantibodies. Clin. Rev. Allergy Immunol. 52:202–216, 2016. Disclosure of Interest K. Miyachi Shareholder of: none, Grant/research support from: none, Consultant for: none, A. Ihar: None declared, B. Sasse: None declared, M. Y. Choi: None declared, M. J. Fritzler: None declared