Prediction of Severe Esophageal Varices in Patients With Cirrhosis Based on Levitt’s CO Breath Test: A Proof of Concept Study

This study investigated the feasibility of using erythrocyte (RBC) lifespan determined by Levitt’s CO breath test (LCOBT) to predict esophageal varices needing treatment (VNT) in patients with cirrhosis. BACKGROUND: Esophageal varix bleeding is a common fatal complication of cirrhosis and portal hypertension. The gold standard for identifying VNT is esophagogastroduodenoscopy (EGD), an invasive procedure with low patient compliance. VNT screening based on Baveno VI criteria has mediocre specificity. STUDY: RBC lifespan was determined by LCOBT in 53 cirrhotic patients (13 without varices, 11 mild/moderate varices, and 29 severe varices). Correlation of varix severity with RBC lifespan and other variables was analyzed. Rates of shortened RBC lifespan and thrombocytopenia (Baveno VI criteria) were compared. RESULTS: RBC lifespan correlated inversely with severity of varices (r=−0.793, P<0.001). Mean RBC lifespans were 129±31, 96±21, and 59±21 days for Nonvarix, Mild/Moderate, and Severe groups. Shortened RBC lifespan (<75 d) was observed in 79.3% (23/29) of patients with severe varices, a frequency similar or identical to thrombocytopenia rates [original Baveno VI criteria, 86.2% (25/29), P=0.487; expanded criteria, 79.3% (23/29), P>0.999]. Among 24 patients without severe varices, shortened RBC lifespan was observed in 1 patient whereas thrombocytopenia was detected in 13 and 8 patients based on the original (P<0.001) and expanded criteria (P=0.010), respectively. CONCLUSIONS: RBC lifespan correlates inversely with varix severity in patients with cirrhosis. LCOBT may enable specific screening for VNT.