Thrombocytopenia in Patients with Chronic Liver Disease: What’s in a Name?

Abstract

Thrombocytopenia is likely the most common haematological alteration that can be observed in patients affected by chronic liver disease [1]. In compensated cirrhosis, it is the most prevalent and incident peripheral blood cytopenia; in chronic hepatitis C patients, thrombocytopenia represents an obstacle to antiviral therapy in 6.5 % of patients who are otherwise good candidates for interferon treatment [2, 3]. Furthermore, besides being the hallmark of a possible increased risk of bleeding, thrombocytopenia has several diagnostic and prognostic meanings [4, 5]. This versatile use of platelet count and thrombocytopenia is supported by the multi-faceted etiology of decreased platelet count in chronic liver disease patients [1, 5]. Indeed, the platelet count is incorporated into numerous diagnostic algorithms aimed at non-invasively assessing the severity of chronic liver diseases and features of portal hypertension, can be used to pinpoint patients at higher risk of developing hepatocellular carcinoma in population studies, and is a predictor of death in cirrhotic patients with and without hepatocellular carcinoma [6–12]. The study by Hermos et al. [13] published in this issue of Digestive Diseases and Sciences describes the longitudinal course of platelet count in a large series of patients with non-hepatitis C-related chronic liver disease followed for a median of 3.3 years at the New England Veterans Administration Center, evaluating the occurrence of severe thrombocytopenia—defined as platelet count below 50 9 10/L—and significant bleeding, and the association between bleeding episodes and platelet counts. The relevance of this retrospective study lies in its ability to provide reliable data on the time-trend of platelet counts in a large cohort of chronic liver disease patients consistently followed over an adequate period of time, showing that severe thrombocytopenia occurs in a modest proportion of patients (13.4 %) and is expectedly more incident among patients with a baseline platelet count close to the threshold (i.e., 50 9 10/L). As compared to previous studies that assessed platelet count modifications over time, it has the merit of including patients with all forms of chronic liver disease while excluding patients with chronic hepatitis C virus infection where multiple causes of thrombocytopenia might have impaired interpretation of the results [14, 15]. The most important information contained in the study, however, is provided by the analyses of the association between platelet counts and bleeding episodes. Indeed, the current vision of the coagulopathy of chronic liver disease patients reflects the presence of a balanced coagulation asset despite altered blood coagulation tests, due to the lack of standardized tests able to adequately evaluate the derangement in both proand anti-coagulant factors [16]. Therefore, data regarding a possible association between platelet counts and bleeding might improve our knowledge on this topic. Overall, this study confirms that a decreased platelet count is a good indicator of the severity of chronic liver diseases, as patients with more compromised liver function and higher Model for End-stage Liver Disease (MELD) scores were prevalent in the group of patients with baseline severe thrombocytopenia. Bleeding as a primary cause of hospitalization occurred in 10.8 % of the patients, an incidence five times higher in patients with severe thrombocytopenia compared with patients with a platelet count above the lower limit of normal. Nevertheless, 98.1 % of the bleeding episodes reported in this study were gastrointestinal; unfortunately, no data were available regarding their relation to E. G. Giannini (&) Gastroenterology Unit, Department of Internal Medicine, University of Genoa, Viale Benedetto XV, no.6, 16132 Genoa, Italy e-mail: egiannini@unige.it