By Marilynn Larkin
NEW YORK (Reuters Health) - Researchers have created and validated discoid lupus erythematosus (DLE) classification criteria for use in observational and clinical trials.
"To date, lack of classification criteria has led to problematic heterogeneity in clinical trials," Dr. Scott Elman of Brigham and Women's Hospital in Boston told Reuters Health by email. "Our hope is that these first validated classification criteria for DLE will provide investigators with a foundation upon which to base observational and interventional trials, and a common language with which to communicate effectively about this patient population."
Dr. Elman and colleagues analyzed candidate criteria items applied by dermatologists and dermatopathologists for patients with DLE or a condition that could be confused for DLE (a DLE mimicker) at academic dermatology practices across the United States, Poland, Japan, and South Korea.
As reported in JAMA Dermatology, nine sites contributed 215 patients, 15 of whom had missing or incomplete data. The final DLE classification criteria model includes the following clinical variables, with an area under the receiving operating characteristic curve of 0.91: atrophic scarring (3 points); location in the conchal bowl (2 points); preference for the head and neck (2 points); dyspigmentation (1 point); follicular hyperkeratosis and/or plugging (1 point); and erythematous to violaceous in color (1 point).
A score of at least five points yielded a sensitivity of 84.1% and a specificity of 75.9%, with increasing scores yielding higher specificity.
Features from dermatopathological evaluations were reported for 86 patients: 88% had perivascular and/or periappendageal lymphohistiocytic infiltrate; 66%, interface/vacuolar dermatitis; 54%, mucin deposition; 36%, follicular keratin plugs; and 33%, basement membrane thickening.
The most common disease mimickers included dermatomyositis, subacute cutaneous lupus erythematosus, other forms of cutaneous lupus, lichen planopilaris and other lichenoid disorders, and psoriasis.
Clinical findings agreed with histopathological findings in 92% of patients in the sample.
The authors conclude, "These findings provide the initial validation of classification criteria for DLE for use in observational and clinical trials."
Dr. Elman said, "We propose that for clinical trials, additional validated metrics focused on disease activity, such as the Cutaneous Lupus Erythematosus Disease Area and Severity Index - Activity (CLASI-A), be utilized to define disease activity, as appropriate."
"Classification of DLE is part of a larger process to classify other subsets of cutaneous lupus erythematosus as well as other connective tissue diseases, with active efforts underway in dermatomyositis and morphea," he concluded.
Dr. Saakshi Khattri Director, Dermatology Service to Treat Systemic Diseases at the Icahn School of Medicine at Mount Sinai in New York City, commented by email, "Certainly there is an unmet need (for these criteria)."
"That being said," she noted, "given the variable phenotype - i.e., depending on whether its early DLE versus late or chronic DLE - the morphology of the lesion is different. The researchers' final model for DLE classification criteria, while a step in the right direction, might not be sufficient to differentiate between early versus late, and possibly might miss early DLE."
"In addition," she said by email, "the criteria need to be validated across different race/ethnicities to see if they are reproducible."
"As was pointed out, dermpath findings were only in 40% cases," she said. "It would be interesting to do a study where all DLE patients had both clinical and histological findings to see if the final model ends up being different compared to what these researchers came up with."
Further, she said, "this study was based in specialized referral centers where dermatologists and rheumatologists see and diagnose DLE a lot more compared to non-academic settings. I wonder if the data would be reproducible in a non-academic/tertiary care setting."
"Erythematous to violaceous color is also listed in the final model," she noted. "Given that DLE disproportionately affects people of color in the US, the possibility of missing erythema and the violaceous color of DLE lesions is a possible concern."
SOURCE: https://bit.ly/31rdoop JAMA Dermatology, online June 17, 2020.