Development and Validation of Serum Markers as Noninvasive Diagnostic Methods for Achalasia

Abstract

INTRODUCTION: Currently, the diagnosis of achalasia mainly relies on invasive or radioactive examinations. This study aimed to develop a noninvasive diagnostic method for achalasia based on specific serum markers. METHODS: Serum levels of profilin-1, galectin-10, immunoglobulin heavy variable 3–9, vasodilator-stimulated phosphoprotein, and transgelin-2 were measured in patients with achalasia and controls by enzyme-linked immunosorbent assay. The diagnostic values and thresholds were determined by the receiver operating characteristic curve analysis. Then, patients with dysphagia were prospectively enrolled to validate the ability of these molecules for achalasia diagnosing. RESULTS: A total of 142 patients with achalasia and 50 nonachalasia controls (healthy volunteers and patients with reflux esophagitis) were retrospectively included. The serum levels of profilin-1, galectin-10, and transgelin-2 in patients with achalasia were significantly higher than those in healthy volunteers and patients with reflux esophagitis (P all < 0.001). Profilin-1, galectin-10, and transgelin-2 were of good performance in diagnosing achalasia, with optimal thresholds of 2,171.2, 33.9, and 1,630.6 pg/mL, respectively. Second, 40 patients with dysphagia were prospectively enrolled to the validation of achalasia. For profilin-1, the positive predictive value, negative predictive value, sensitivity, and specificity were 100.0%, 64.5%, 45.0%, and 100.0%, respectively. The figures for transgelin-2 were 65.5%, 90.9%, 95.0%, and 50.0%. When both increased, the positive predictive value reached to 100.0%. When both indexes were normal, the negative predictive value was 100.0%. DISCUSSION: Profilin-1 and transgelin-2 were promising biomarkers for achalasia diagnosis and performed better in combination. Further multicenter studies are necessary to verify their application as preliminary screening tools for achalasia.