Prevalence of lymphopenia in patients with Fontan circulation without protein losing enteropathy

Abstract

BackgroundLymphopenia without protein losing enteropathy (PLE) is found in patients with Fontan circulation on long term follow up. Fontan associated liver disease (FALD) is a serious complication in these patients. ObjectiveThe objective of this study is to assess the prevalence of asymptomatic lymphopenia in patients with Fontan circulation and its associations with other hematological and liver function parameters. MethodsRetrospective cohort study involving 48 patients with Fontan circulation. All patients had yearly complete blood count and liver function tests performed during their routine follow up. Patients with PLE were excluded. Lymphopenia defined as absolute lymphocyte count (ALC) < 1000 cells/μL and its correlation with other hematological and liver enzymes were studied. ResultsLymphopenia was present in 9 (18.75 %) patients and was found after 10 years of post Fontan duration in 7 patients, at 5.5 years in 1 patient, and at 6.7 years in 1 patient. The mean ALC of patients with and without lymphopenia was 748 ± 190.8 versus 2053 ± 844.9 cells/μL (P = 0.002). Patients with lymphopenia had lower total white blood cell count (3.9 ± 1.9 versus 6.02 ± 2.1 × 109/L, P = 0.006) and platelet counts (180.7 ± 94.6 versus 253.6 ± 80.3 × 109/L, P = 0.02). Lymphopenia correlated with elevated aspartate transaminase (AST) (43.2 ± 9 versus 29.8 ± 6.98 IU/L, P = 0.006), Gamma glutamyl transpeptidase (GGTP) (69.5 ± 61 versus 29.8 ± 6.98 IU/L, P = 0.04) and AST – platelet ratio index (APRI) (0.7 ± 0.5 versus 0.3 ± 0.1, P = 0.001). ConclusionAsymptomatic lymphopenia is common in patients with Fontan circulation. Identification of lymphopenia with associated thrombocytopenia, elevated AST, GGTP, and APRI are necessary as these are the markers of hepatic fibrosis. Further investigations, such as MRI and liver biopsy, can be considered in these patients.