Eosinophilic esophagitis (EoE) is a food allergy-associated inflammatory disease characterized by esophageal eosinophilia. EoE has become increasingly common, but current management strategies are nonspecific. Thus, there is an urgent need to identify specific immunological pathways that could be targeted to treat this disease. EoE is associated with polymorphisms in the gene that encodes thymic stromal lymphopoietin (TSLP), a cytokine that promotes allergic inflammation, but how TSLP might contribute to EoE disease pathogenesis remains unknown. Here, we describe a new mouse model of EoE-like disease that developed independently of IgE but was dependent on TSLP-elicited basophils. Therapeutic TSLP neutralization or basophil depletion also ameliorated established EoE-like disease. Critically, in human subjects with EoE, we observed elevated TSLP levels and exaggerated basophil responses in esophageal biopsies, and a gain-of-function TSLP polymorphism was associated with increased basophil responses. Together, these data suggest that the TSLP-basophil axis could be therapeutically targeted to treat EoE.

Our data indicate that the human precorneal tear film can be measured with excellent reproducibility using ultrahigh-resolution optical coherence tomography. This technique may be a valuable tool in the management of dry eye syndrome.

A noninvasive, multimodal photoacoustic and optical coherence tomography (PAT/OCT) scanner for three-dimensional in vivo (3D) skin imaging is described. The system employs an integrated, all optical detection scheme for both modalities in backward mode utilizing a shared 2D optical scanner with a field-of-view of ~13 × 13 mm2. The photoacoustic waves were detected using a Fabry Perot polymer film ultrasound sensor placed on the surface of the skin. The sensor is transparent in the spectral range 590-1200 nm. This permits the photoacoustic excitation beam (670-680 nm) and the OCT probe beam (1050 nm) to be transmitted through the sensor head and into the underlying tissue thus providing a backward mode imaging configuration. The respective OCT and PAT axial resolutions were 8 and 20 µm and the lateral resolutions were 18 and 50-100 µm. The system provides greater penetration depth than previous combined PA/OCT devices due to the longer wavelength of the OCT beam (1050 nm rather than 829-870 nm) and by operating in the tomographic rather than the optical resolution mode of photoacoustic imaging. Three-dimensional in vivo images of the vasculature and the surrounding tissue micro-morphology in murine and human skin were acquired. These studies demonstrated the complementary contrast and tissue information provided by each modality for high-resolution 3D imaging of vascular structures to depths of up to 5 mm. Potential applications include characterizing skin conditions such as tumors, vascular lesions, soft tissue damage such as burns and wounds, inflammatory conditions such as dermatitis and other superficial tissue abnormalities.

We demonstrate noninvasive structural and microvascular contrast imaging of different human skin diseases in vivo using an intensity difference analysis of OCT tomograms. The high-speed swept source OCT system operates at 1310 nm with 220 kHz A-scan rate. It provides an extended focus by employing a Bessel beam. The studied lesions were two cases of dermatitis and two cases of basal cell carcinoma. The lesions show characteristic vascular patterns that are significantly different from healthy skin. In case of inflammation, vessels are dilated and perfusion is increased. In case of basal cell carcinoma, the angiogram shows a denser network of unorganized vessels with large vessels close to the skin surface. Those results indicate that assessing vascular changes yields complementary information with important insight into the metabolic demand.

Microchannels created in the upper skin layers by microneedles are less invasive than previous histology predicts. OCT has the potential to play a highly influential role in the future development of microneedle devices and other transdermal delivery systems.