Morphometric Histology for Infant Gastroesophageal Reflux Disease: Evaluation of Reliability in 497 Esophageal Biopsies

Objectives: We sought to determine the reliability of morphometric measurements on infant esophageal biopsies using a light microscope with eyepiece micrometer. Methods: We measured epithelial thickness, basal layer thickness (B), papillary height (P) and epithelial lymphocyte and eosinophil numbers on ≈500 existing esophageal suction biopsies from infants previously evaluated for reflux esophagitis. We tested these measurements for interobserver, test‐retest and internal consistency reliability. Results: Infants ages 0.25 to 23.75 (median, 6.25) months provided 497 biopsies. Both investigators scoring the biopsies independently judged 93% of them scorable. Of the biopsies scored by both, the 2 readings were within 0.15 of each other for P in 97% and for B in 81%. In addition to these correlative measures of consistency, categoric measures demonstrated that 373 (89%) of the 420 scorable biopsies with visible papillae produced agreement as to P being abnormal (317, 85%) or normal (56, 15%). Similarly, 360 (78%) of the 463 scorable biopsies produced agreement as to B being abnormal (339, 94%) or normal (21, 6%). P values were 0.17 to 0.94 (median, 0.67), and B values were 0.13 to 0.91 (median, 0.34). Lymphocytes numbered 0 to 40 (median 5) per high‐power field. Only 12% had any eosinophils; none of those with completely normal morphometrics had any eosinophils; and only 2% had >5 eosinophils per high‐power field. Conclusions: Simple quantitative esophageal histological morphometric parameters are reliably measurable on suction biopsies from infants using a light microscope fitted with an ocular micrometer, even by nonpathologists.