Background and aims Positive ANA is one of Criteria for Classification of SLE for ACR and SLICC. As a follow-up to the International Consensus on ANA Patterns (ICAP) initiative (ANApatterns.org), the relevance of each ANA pattern is being re-evaluated.

Methods ANA test at 1/80 screening dilution was performed in 269 sequentially selected patients with SLE diagnosis, 918 healthy individuals, and 558 patients with non-SARD conditions. ANA interpretation was the consensus of 3 independent readers using 2 HEp-2 cell slide brands at 400x mag. Conversely, sequentially selected individuals presenting >1/640 titer Nuclear Dense Fine Speckled (DFS) ANA pattern (AC-2) in a large clinical laboratory within a 2 year period had the diagnosis assessed by interview with the respective physician.

Results Among 269 consecutive SLE patients, 96.3% had a positive ANA with the following principal nuclear patterns: homogeneous (29.3%), coarse speckled (14.7%), fine speckled (40.1%). Only one patient (0.3%) had the DFS pattern and the reactivity to DFS70 confirmed by ELISA. Conversely, among 118 ANA+ healthy individuals and 102 ANA+ patients with miscellaneous non-SARD conditions, 33% and 17% presented the DFS pattern, respectively. In addition, the 327 consecutive high-titer DFS individuals presented mostly non-SARD conditions or non-specific clinical presentation. Only 7 had possibly SARD-related presentations: 1 anti-phospholipid syndrome, 1 “possible” SLE (polyarthritis, arthritis, chronic urticaria), 1 WG, 1 DLE, 1 PBC, and 1 RA.

Conclusions Well-defined anti-DFS ANA, confirmed by antigen-specific reflex testing, should not be considered a criterion for SLE - either in the ACR or SLICC classification criteria.