Buccal cells as a non-invasive model for filaggrin protein expression and degradation in patients with atopic dermatitis.

Although FLG gene expression exhibited substantial variability, FLG protein levels remained relatively stable across samples.

Notably, distinct FLG degradation profiles were observed in patients with atopic dermatitis, particularly involving low-molecular-weight fragments.

In addition, buccal cell pellets from patients with atopic dermatitis exhibited increased viscosity compared with those from controls, which was not explained by mucin expression.