Abstract
Thrombocytosis (platelet count ≥450 × 109/L) in the early postoperative period after lung transplantation has been correlated with acute cellular rejection (ACR). However, we have also observed significant elevations in platelet counts in the setting of reduced lung function secondary to allograft dysfunction in the late postoperative period. Herein, we describe a case series of three lung transplant recipients with thrombocytosis coincident with episodes of ongoing allograft rejection.
Three bilateral lung transplant recipients - a 21-year-old female with trauma-related acute respiratory distress syndrome (patient A), 68-year-old male with interstitial lung disease (patient B), and 60-year-old male with inherited emphysema (patient C) - each presented with few days’ history of exertional dyspnea at 4-months, 36-months, and 28-months post-transplant, respectively. Chest computed tomography revealed multifocal bilateral pulmonary consolidations and ground glass changes in patient A, mild upper lobe reticular changes in patient B, and subtle nodular opacities in the upper lobes in patient C. Bronchoscopy with transbronchial lung biopsy revealed influenza virus and grade A2 ACR in patient A. Biopsies in patient B and C showed no evidence of ACR, but revealed focal lung injuries. Marked thrombocytosis was observed on peripheral blood smear in all three patients at the time of admission, and complete blood count showed elevated platelet counts of 525 × 109/L, 626 × 109/L, and 681 × 109/L. Trends of patients’ platelet counts and corresponding lung function measures are shown in Figure 1.
We observed waxing and waning thrombocytosis which corresponded with gradual decline in lung function that ultimately trended towards accelerated chronic lung allograft dysfunction in all three patients. Exploration of this hematologic phenomenon in the setting of late postoperative allograft dysfunction is warranted.