Serologic Clarity for CLE and SLE

In his data-driven session, “Autoimmune Disease Serologies​,” Dr Joseph Merola walked attendees through the maze of autoimmune serologic testing.

Dr Merola opened by highlighting the confusion surrounding autoimmune labs, particularly for patients with cutaneous lupus erythematosus (CLE) and systemic lupus erythematosus (SLE).

He emphasized urinalysis (UA) as one of the most valuable tests: “What’s the most cost-effective, probably most impactful study you can do on your lupus patient? UA. Correct.”

Dr Merola shared a practical framework for initial vs longitudinal lab testing and warned against the overuse of antinuclear antibody (ANA) monitoring. “We don’t need to be repeating an ANA at every visit,” he stressed. He also reminded attendees that ANA positivity is common in the general population and only significant when paired with clinical symptoms. “It’s all about clinical context,” he said. “Thirty percent of healthy individuals can have a positive ANA at 1:40 dilution.”

When it comes to pregnancy, Dr Merola drove home the importance of Ro/SSA testing. “The identification of cutaneous-NL in an anti-SSA/Ro exposed infant is particularly important since it predicts a 6- to 10-fold risk for a subsequent child with cardiac-NL,” he quoted from the literature, advocating for hydroxychloroquine use during pregnancy as a proven protective strategy.

He also gave attendees clarity on drug-induced lupus, emphasizing that “the clinical and lab profiles are drug-specific” and that anti-histone positivity, often assumed to define drug-induced lupus, is also present in idiopathic SLE in up to 80% of cases.

Whether navigating anti-dsDNA for nephritis or deciphering Ro/La associations in photosensitivity and neonatal lupus, attendees walked away with sharper skills in applying serologic results to the real-life lupus spectrum.

Reference

Merola J. Autoimmune disease serologies​. Presented at: Masterclasses in Dermatology APP Institute; October 11–12, 2025; Dallas, TX.