Be on the lookout for coexisting autoimmune conditions in patients with CLE

Patients with cutaneous lupus erythematosus (CLE) may be at an increased risk for coexisting autoimmune conditions, especially those who are Caucasian, have a family history of autoimmunity or a positive antinuclear antibody test (ANA), and—surprisingly—who never smoked, according to study results published in JAMA Dermatology.

“Patients with autoimmune conditions are susceptible to developing others, likely due to commonly shared genetic abnormalities. Several genetic polymorphisms have been found in multiple autoimmune diseases, including genes for protein tyrosine phosphatase nonreceptor type 22 (PTPN22), tumor necrosis factor-induced protein 3 (TNFAIP3), signal transducer and activator of transcription 4 (STAT4), and cytotoxic T-lymphocyte-associated protein 4 (CTLA4),” write the study’s authors, led by Elaine Kunzler, MD, Department of Dermatology, University of Texas Southwestern Medical Center, Dallas, TX, and medical student, Northeast Ohio Medical University, Rootstown, OH.

In this cross-sectional study, Dr. Kunzler and fellow researchers sought to assess the prevalence and risk factors for coexisting autoimmune conditions in CLE patients. Using the University of Texas Southwestern Cutaneous Lupus Registry, they identified 129 subjects (median age: 49 years; 79.1% female) with a dermatologist-confirmed diagnosis of CLE and used demographic and disease characteristics to compare those with CLE only and those with CLE and one or more other autoimmune diseases.

In all, 17.8% of these patients had coexisting autoimmune conditions, with autoimmune thyroid disease being the most common (4.7%). Sjögren's syndrome and rheumatoid arthritis (RA) were also common.

Upon multivariable logistic regression, these researchers found a significant association between having coexisting autoimmune conditions and these patient characteristics:

• Caucasian (OR: 2.88, 95% CI: 1.00-8.29; P=0.05),
• Never smoking (OR: 3.28; 95% CI: 1.14-9.39; P=0.03),
• Family history of autoimmune disease (OR: 3.54; 95% CI: 1.21-10.39; P=0.02), and
• History of positive ANA test result (OR: 4.87; 95% CI: 1.69-14.03; P=0.003)
• In patients with a family history of autoimmunity, the most common diseases included systemic lupus erythematosus (SLE), Hashimoto's thyroiditis, and RA.

Dr. Kunzler and colleagues also noted that eight subjects progressed from having CLE only to SLE within a median of 4.3 years. One patient had one or more coexisting autoimmune conditions and subacute CLE, while three had positive ANA test results at baseline.

They plan to confirm these results with larger longitudinal studies. Until then, they offered some recommendations for clinicians treating patients with CLE.

“We recommend checking for symptoms, physical examination findings, and laboratory test abnormalities associated with thyroid disease in patients with CLE, especially in those with systemic complaints such as fatigue that may mimic SLE,” they wrote.

This study was supported, in part, by the National Institute of Arthritis and Musculoskeletal and Skin Diseases and the National Center for Advancing Translational Sciences, both of the National Institutes of Health.