Characterization of Clinicopathological Features and Autoantibody Profiles in Patients with Cutaneous Lupus Erythematous: A Single-Center Retrospective Study.

Abstract

Background: Cutaneous lupus erythematosus (CLE) is an autoimmune condition characterized by a wide range of clinical manifestations and limited treatment options. There is little research on the impact of commonly used diagnostic tests including antinuclear antibodies (ANA) and extractable nuclear antigens (ENA) on disease course or responsiveness to treatment.

Objective: This single-center retrospective cohort study aims to address this gap by characterizing clinicopathological characteristics, patient demographics, and treatment response among patients with CLE.

Methods: The study included patients with a diagnosis of CLE based on the International Classification of Diseases, Ninth Revision (ICD-9) and Tenth Revision (ICD-10) codes evaluated in the outpatient clinics of the Department of Dermatology at Michigan Medicine between 1 January 2012 and 31 December 2022. Chart review was conducted to collect patient and clinical data including CLE subtype, patient demographics, disease course, presence of SLE, ANA and ENA results, and CLE treatments and response.

Results: 390 patients with CLE were included, 86% (n = 334) of whom had biopsy-proven CLE. Most patients were female (77%), non-Hispanic (97%), and Caucasian (58%). Of all patients, 35% (n = 138) were ANA negative. The most common CLE treatments were antimalarials (86%, n = 336), topical steroids (85%, n = 331), systemic steroids (42%, n = 164), and mycophenolate mofetil (30%, n = 119). Treatment response was determined by clinician documentation and ranged from stabilization of disease to complete remission. Treatments with the highest CLE response rates included systemic steroids (84%, n = 138), antimalarials (63%, n = 212), belimumab (54%, n = 29), and topical steroids (50%, n = 165). Factors associated with lower response rates to antimalarials using chi-squared tests included anti-double stranded (ds) DNA (n = 54, 57% response among anti-dsDNA+ versus n = 165, 74% response among anti-dsDNA-), anti-Smith (n = 33, 54% versus n = 82, 72%), anti-RNP (n = 48, 56% versus n = 67, 73%), anti-SmRNP (n = 44, 54% versus n = 171, 74%), anti-chromatin (n = 33, 50% versus n = 179, 74%), SLE (n = 81, 57% versus n = 143, 79%), and ACLE subtype (n = 28, 58% versus n = 195, 71%). When controlling for demographics, CLE subtype, and presence of SLE using a logistic regression, factors associated with lower antimalarial response rates included anti-dsDNA (OR 0.5), anti-Smith (OR 0.5), and anti-chromatin (OR 0.6) CONCLUSION: Our results suggest that numerous patient characteristics, namely the presence of ACLE, SLE, and its most commonly implicated autoantibodies (i.e., anti-dsDNA and anti-Smith), are associated with lower response rates to first-line therapies, including topical steroids and antimalarials.