High plasma levels of tumor necrosis factor (TNF)–alpha and adiponectin can be used to differentiate patients with psoriasis and psoriatic arthritis, according to Wen-Qing Li, PhD, of Brown University, Providence, R.I., and his associates.
In a research letter published in the British Journal of Dermatology, the investigators detailed an analysis of 180 patients with psoriasis only and 143 patients with psoriatic arthritis (PsA) from the Psoriatic Arthritis and Psoriasis Follow-up Study. Patients in both groups had a mean age of 51 years. Plasma levels of interleukin-6, C-reactive protein, TNF-alpha, leptin, total adiponectin, and high-molecular-weight (HMW) adiponectin were assessed as potential biomarkers by ultrasensitive enzyme-linked immunosorbent assay or immunoturbidimetric assay.
Median TNF-alpha plasma levels were higher in patients with PsA, compared with those with psoriasis (3.27 vs. 1.32 pg/mL–1), while total and HMW adiponectin levels were lower in patients with PsA, compared with those with psoriasis (4.66 vs. 5.36 mcg/mL–1; 2.58 vs. 3.01 mcg/mL–1). After logistic regression, TNF-alpha (adjusted odds ratio, 2.25; 95% confidence interval, 1.41-3.61) and total adiponectin (aOR, 0.61; 95% CI, 0.39-0.96) remained significantly associated as biomarkers. HMW adiponectin maintained marginal significance (aOR, 0.64; 95% CI, 0.41-1.01).
“Further large-scale investigation in a prospective setting of patients with PsO [psoriasis] would be warranted, if a clinically useful screening test is to be developed for risk prediction of PsA based on circulating biomarkers,” the investigators concluded.
Two study authors reported consulting with or advising numerous pharmaceutical companies.
SOURCE: Li W-Q et al. Br J Dermatol. 2019 Jan 29. doi: 10.1111/bjd.17700.