Predicting severity and clinical course of acute rejection after liver transplantation using blood eosinophil count

Acute cellular rejection remains an important source of morbidity after liver transplantation, particularly if rejection is moderate or severe, as this usually is treated. Currently liver biopsies are seldom performed, so diagnostic noninvasive markers would be useful. We evaluated 690 consecutive first liver transplant patients to assess whether peripheral eosinophilia could predict moderate‐severe rejection and its course. A protocol biopsy was performed 6 ± 2.5 days after transplant. A second biopsy was taken 6.1 ± 2 days after the first in 487 patients to assess histological improvement. Liver function tests, peripheral eosinophil count and changes between first and second biopsy, were evaluated using logistic regression. Histological rejection was present in 532 patients (77.1%), with moderate (30.6%) and severe rejection (3.9%). Peripheral eosinophil count was strongly associated with moderate‐severe rejection (OR = 2.15; P = 0.007), although the area under ROC curve (AUROC) was 0.58. On second biopsy, rejection improved in 119 (24.4%) patients. The delta in eosinophil count between the first and second biopsies was the only independent predictor of histological improvement (OR = 3.12; P = 0.001), irrespective of whether bolus steroids were used (OR = 2.77; P = 0.004); AUROC was 0.72. Peripheral eosinophilia is not sufficiently predictive of moderate‐severe histological rejection. However the changes in eosinophil count over time can accurately predict the histological resolution of rejection.