Reliability and Responsiveness of Endoscopic Disease Activity Assessment in Eosinophilic Esophagitis

BACKGROUND AND AIMS Endoscopic outcomes have become important measures of eosinophilic esophagitis (EoE) disease activity, including as an endpoint in randomized controlled trials (RCTs). We evaluated the operating properties of endoscopic measures for use in EoE RCTs. METHODS Modified Research and Development/University of California Los Angeles (RAND/UCLA) appropriateness methods and a panel of 15 international EoE experts identified endoscopic items/definitions with face validity, which were used in a 2-round voting process to define simplified (all items graded absent/present) and expanded versions (additional grades for edema, furrows, and/or exudates) of the EoE Endoscopic Reference Score (EREFS). Inter- and intra-rater reliability of these instruments (expressed as intraclass correlation coefficients [ICC]), were evaluated using paired endoscopy video assessments of two blinded central readers before and after 8 weeks of proton pump inhibitors, swallowed topical corticosteroids, or dietary elimination. Responsiveness was measured using the standardized effect size (SES). RESULTS The appropriateness of 41 statements relevant to EoE endoscopic activity (endoscopic items, item definitions/grading, and other considerations relevant for endoscopy) was considered. The original and expanded EREFS demonstrated moderate-to-substantial inter-rater reliability (ICCs 0.472-0.736, and 0.469-0.763, respectively) and moderate-to-almost perfect intra-rater reliability (ICCs 0.580-0.828, and 0.581-0.828, respectively). Strictures were least reliably assessed (ICCs 0.072-0.385). The original EREFS was highly responsive (SES 1.126 [95% CI 0.757, 1.534]), although both expanded versions of EREFS, scored based on worst affected area, were numerically most responsive to treatment (expanded furrows, SES 1.229 [95% CI: 0.858, 1.643]; all items expanded, SES 1.252 [95% CI: 0.880, 1.667]). The EREFS and its modifications were not more reliably scored by segment, and also not more responsive when proximal and distal EREFS scores were summed. CONCLUSIONS EREFS and its modifications were reliable and responsive, and the original or expanded versions of the EREFS may be preferred in RCTs. Disease activity scored based on the worst affected area optimizes reliability and responsiveness. FUNDING None

High-scatter T cells: a reliable biomarker for malignant T cells in cutaneous T-cell lymphoma

In early-stage cutaneous T-cell lymphoma (CTCL), malignant T cells are confined to skin and are difficult to isolate and discriminate from benign reactive cells. We found that T cells from CTCL skin lesions contained a population of large, high-scatter, activated skin homing T cells not observed in other inflammatory skin diseases. High-scatter T (THS) cells were CD4+ in CD4+ mycosis fungoides (MF), CD8+ in CD8+ MF, and contained only clonal T cells in patients with identifiable malignant Vβ clones. THS cells were present in the blood of patients with leukemic CTCL, absent in patients without blood involvement, and contained only clonal malignant T cells. The presence of clonal THS cells correlated with skin disease in patients followed longitudinally. Clonal THS cells underwent apoptosis in patients clearing on extracorporeal photopheresis but persisted in nonresponsive patients. Benign clonal T-cell proliferations mapped to the normal low-scatter T-cell population. Thus, the malignant T cells in both MF and leukemic CTCL can be conclusively identified by a unique scatter profile. This observation will allow selective study of malignant T cells, can be used to discriminate patients with MF from patients with other inflammatory skin diseases, to detect peripheral blood involvement, and to monitor responses to therapy