While yesterday’s article was good, today’s is really forward-thinking (Gastroenterol 213; 145: 1289-99). Last year in this blog, I reviewed the use of microRNA for studying EoE (MicroRNA signature for eosinophilic esophagitis | gutsandgrowth), this study expands on this idea with the development of the EoE diagnostic panel (EDP) which is a 96-gene quantitative polymerase chain reaction assay.
The authors (one of whom [JG] has joined our group) used this assay initially in 15 pediatric with EoE, in 14 pediatric non-EoE, and then in a subsequent cohort of 194 pediatric and adult patient samples (fresh or formalin-fixed tissue from one esophageal biopsy). Of the latter cohort, 91 had histologically-active EoE, 57 had either non-EoE or EoE in remission, 34 were histologically-ambiguous, and 12 had reflux.
Results -first of all you have to see the results to get the best sense of how impressive they are. Numerous figures show the EDP depictions of patients’ EoE transcriptome patterns.
- EDP had approximately 96% sensitivity and 98% specificity; EDP’s utility could be underestimated due to limitations in the current ‘gold standard’ for diagnosis
- EDP can distinguish EoE in remission from healthy controls as well as identify patients exposed to swallowed glucocorticoids. Thus, with current patients in remission, the tissue may appear healthy; nevertheless, EDP identifies molecular changes in this tissue.
- EDP can distinguish EoE from reflux
What this study means:
- Currently both the diagnostic standards (eg. cutoff values for eosinophils) and remission standards remain questionable. This molecular test has the potential to raise the standard for both diagnosis and response to treatment.
- EDP may elucidate differences in EoE pathogenesis which could vary from patient to patient.
- EDP may help in prospective trials and help in clinical practice by identifying patients who are most likely to benefit from the treatments that are available.
- EDP may help overcome the patchy nature of eosinophil distribution.
- EDP serves as a model for how molecular testing could influence many inflammatory conditions including asthma, inflammatory bowel disease and biliary atresia.
While I think this study is going to be highly influential, I have one unanswered question: how much will it cost? In the conclusion, the authors state “the EDP offers an accurate, rapid, informative, and low-cost diagnosis.” Yet, the authors do not elaborate on the expense of this technology.
Related blog entries: