Tryptase Levels Linked to Resolution of Chronic Spontaneous Urticaria in Children

Decreased tryptase levels are associated with resolution of chronic spontaneous urticaria in children, according to study results presented at the American Academy of Dermatology (AAD) Association 2023 conference, held from March 17 to 21, 2023, in New Orleans, Louisiana.

Researchers sought to identify biomarkers associated with efficacy of treatment for chronic spontaneous urticaria in children and assess the underlying mechanisms of the biomarkers and their role in treatment responses.

Children (N=109; mean age, 8.94 [SD 4.97] years; 55% girls) with chronic spontaneous urticaria who were treated at a children’s hospital in Montreal, Canada, from 2013 to 2022 were enrolled in the study.

The following biomarker levels were measured: thyroid-stimulating hormone (TSH); anti-thyroxine peroxidase (anti-TPO); C-reactive protein (CRP); total immunoglobulin E (IgE); CD63; tryptase; eosinophils; mean platelet volume (MPV); and platelets.

Treatment progression was documented as antihistamines at the standard dose, antihistamines at 4 times the standard dose, and omalizumab, to a goal of resolution. Univariate and multivariate logistic regression analyses were used to determine factors associated with the treatment levels and resolution.

Univariate logistic regression analysis showed that increased MPV levels were associated with use of 4 times the standard dose of antihistamines (odds ratio [OR], 1.052; 95% CI, 1.004-1.103), and younger age was associated with resolution (OR, 0.982; 95% CI, 0.965-0.999).

In multivariate logistic regression analysis adjusted for age, sex, TSH, anti-TPO, tryptase, CRP, total IgE, CD63, eosinophils, MPV, and platelets, increased tryptase levels were associated with antihistamine use at the standard dose (OR, 1.152; 95% CI, 1.019-1.302), and decreased tryptase levels were associated with resolution (OR, 0.861; 95% CI, 0.777-0.955).

Study limitations include the limited sample size and unbalanced size of treatment groups. In addition, other biomarkers including interleukin-6, D-dimer, vitamin D, and MMP-9 that have been shown to be associated with chronic spontaneous urticaria were not assessed in this study.

“Assessing underlying mechanisms for effects of tryptase may help identify pediatric patients with [chronic spontaneous urticaria] who will respond to different treatment options,” the study authors conclude.