Premium
Development of stratum corneum chymotrypsin‐like protease activity and natural moisturizing factors from birth to 4 weeks of age compared with adults
Author(s) -
Chittock J.,
Cooke A.,
Lavender T.,
Brown K.,
Wigley A.,
Victor S.,
Cork M.J.,
Danby S.G.
Publication year - 2016
Publication title -
british journal of dermatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.304
H-Index - 179
eISSN - 1365-2133
pISSN - 0007-0963
DOI - 10.1111/bjd.14568
Subject(s) - transepidermal water loss , filaggrin , stratum corneum , atopic dermatitis , medicine , protease , chymotrypsin , physiology , biology , immunology , pathology , biochemistry , enzyme , trypsin
Summary Background From birth, the functional properties of the neonatal epidermal barrier mature whereby the stratum corneum ( SC ) hydrates and the skin surface acidifies. The identification of a thinner infant SC compared with adults suggests underdeveloped mechanisms underlying differentiation and desquamation. Objectives To assess the functional properties of the neonatal SC from birth, in conjunction with the quantification of superficial chymotrypsin‐like protease activity [kallikrein‐7 ( KLK ‐7)] and filaggrin‐derived natural moisturizing factors ( NMF ). Methods A total of 115 neonates recruited to the Oil in Baby Skinca RE ( OBS eRvE) randomized controlled trial underwent a full evaluation of the SC at birth (< 72 h old) and at 4 weeks of age ( n = 39, no oil control group) using minimally invasive instrumentation and methodology. A cohort of 20 unrelated adults was recruited for comparison. Results At birth NMF levels correlated with SC hydration ( r = 0·50) and skin‐surface pH ( r = −0·54). From birth to 4 weeks, transepidermal water loss ( TEWL ), superficial KLK ‐7 activity and filaggrin‐derived NMF significantly elevated. Impaired epidermal barrier function at birth (> 75th percentile TEWL ) was accompanied by significantly elevated chymotrypsin‐like protease activity and reduced levels of NMF . Conclusions The biophysical, biological and functional properties of the developing neonatal SC are transitional from birth to 4 weeks of age and differ significantly from adults. The presence of impaired barrier function with elevated protease activity and reduced NMF at birth suggests why certain infants are predisposed to epidermal barrier breakdown and the development of atopic dermatitis.