Skin biomarkers predict AD risk, severity in newborns

Predicting which newborn will go on to develop atopic dermatitis (AD) and how severe it will be is now feasible, according to the BABY* study.

Both term (gestational age 37-41 weeks) and preterm (gestational age <37 weeks) babies with elevated levels of the cytokine TARC (Thymus and Activation- Regulated Chemokine) at 2 months were found to be more than twice as likely to develop AD by the age of 2 years. This increased risk remained prevalent despite adjusting for parental atopy and filaggrin gene mutations, which are predisposing factors for AD.

The unadjusted hazard ratios (HRs) and adjusted HRs (adjusted for parental atopy and filaggrin gene mutations) in term babies were 2.11 (95 percent confidence interval [CI], 1.36–3.26; p=0.0008) and 1.85 (95 percent CI, 1.18–2.89; p=0.007), respectively.

In preterm babies, the HRs were 2.23 (95 percent CI, 0.85–5.86; p=0.1) and 2.60 (95 percent CI, 0.98–6.85; p=0.05), respectively.

Two other biomarkers – interleukin (IL)-8 and IL-18 – were also associated with moderate-to-severe AD in the study.

“This is the first study to show that skin biomarkers collected noninvasively from babies can be used to predict the subsequent onset and severity of paediatric atopic eczema (also known as AD),” said study author Dr Anne-Sofie Halling from the Department of Dermatology and Venereology, Bispebjerg Hospital, Denmark during a press briefing at EADV 2022.

BABY population

The study comprised 450 babies (300 born at term and 150 at preterm) who were followed until 2 years of age.

Tape strips were used to collect skin cells painlessly and noninvasively from the back of babies’ hands at 0–3 days and at 2 months in term children, and from the skin between the shoulder blades at 2 months of age in preterm children. The strips were analysed for immune biomarkers for the next 2 years.

Important findings

TARC levels were highest in children in whom AD onset occurred at a later age than those diagnosed before 6 months of age. Halling said this is important as this suggests that “TARC predicts AD occurring many months later.”

There was also a positive association between TARC level and AD severity. In children born at term, TARC increased the chances that the severity of AD would be greater than had it not been present (adjusted HR, 4.65; p=0.0007).

Increased levels of IL-8 and IL-18 at 2 months of age were also predictive of moderate-to-severe AD. The risk was more than double compared with those in whom IL-8 and IL-18 levels were not increased, but only in children born at term.

Halling said AD affects up to 20 percent of children and strategies are shifting toward disease prevention in those at risk. This makes the current findings important as the biomarkers could be used to help identify newborns at risk of developing AD who can be the target of future preventive strategies, she added.