A recent study (AJ Freeman, VL Ng, S Harpavat, A Hrycko, Z Apted, P Bulut, T Leong, SJ Karpen. Clin Gastroenterol Hepatol 2017; 15: 1133-35) describes the predictive value of γ-glutamyltransferase (GGT) in predicting thrombocytopenia/portal hypertension among biliary atresia patients.
In this retrospective study from three centers who had followup for at least 4 years, GGT values at 2 years of age were examined among biliary atresia patients (n=46) who continued with their native liver.
- GGT ≥100 U/L had a predictive positive relationship with thrombocytopenia at 4, 5, and 6 years of age. Patients with elevated GGT had lower platelet count (160 vs. 211) and their values continued to decline. GGT ≥100 U/L at 2 yrs predicted thrombocytopenia (<150) at age 4 with a sensitivity of 0.88, specificity of 0.57.
- Patients with normal GGT values had “essentially stable platelet counts over the next 4 years.” GGT <100 U/L at 2 yrs predicted a low risk of thrombocytopenia with negative predictive value of 0.89, 0.92, and 0.93 at age 4, 5, and 6 respectively.
My take: This study quantitates a useful point –patients with biliary atresia and elevated GGT values are likely to develop evidence of portal hypertension.