Factors associated with persistent thrombocytopenia after liver transplantation

Thrombocytopenia typically resolves with resolution of portal hypertension after liver transplantation (LT) but persists in some patients. Identifying risk factors associated with persistent post- LT thrombocytopenia may provide important information about its pathogenesis.

Cirrhotic adults with platelet levels of <150,000 mu/L at the time of LT and followed at least 1 year were studied. A retrospective analysis of lab values, radiologic spleen index (SI), and donor data using nonparametric methods was performed to characterize patients having persistent thrombocytopenia, defined as persistently low platelet levels at 3 and 12 months after LT.

One hundred patients were studied: mean age 55 y (range 23-75 y); platelet count at LT 62,000/microL (range 14,000- 148,000/microL; mean total bilirubin 2.6 mg/dL; mean Mayo end-stage liver disease score 29; SI 1,476 (range 347-4,843 mL; normal 120-480 mL). Platelet count at 3 and 12 months after LT correlated with SI (r = -0.41 and -0.54; P < .001). Fifty-seven patients had persistent thrombocytopenia. Compared with patients whose platelet levels normalized by month 3 or 12, they had higher SI and lower platelet count before LT (P < .001). The SI and platelet levels at the time of LT were independent predictive factors for platelet levels at 3 and 12 months after LT (P < .001).

High SI and low platelet count at the time of LT are associated with persistent thrombocytopenia after LT. They are also independent predictive factors of platelet levels at 3 and 12 months after LT. This suggests that patients may have persistent thrombocytopenia after LT owing to persistence of some degree of hypersplenism and incomplete resolution of splenomegaly.