Effects of spleen status on early outcomes after hematopoietic cell transplantation

Abstract

To assess the impact of spleen status on engraftment and early morbidity and mortality after allogeneic hematopoietic cell transplantation (HCT), we analyzed 9,683 myeloablative allograft recipients from 1990 to 2006; 472 had prior splenectomy (SP), 300 splenic irradiation (SI), 1,471 with splenomegaly (SM), and 7,440 with normal spleen (NS). Median times to neutrophil and platelet engraftment were 15 vs. 18 days and 22 vs. 24 days for the SP and NS groups, respectively (p<0.001). Hematopoietic recovery at day +100 was not different across all groups, however the odds of days +14 and +21 neutrophil and day +28 platelet engraftment were 3.26, 2.25, and 1.28 for splenectomy, and 0.56, 0.55, and 0.82 for splenomegaly groups compared to normal spleen (p<0.001), respectively. Among patients with splenomegaly, use of peripheral blood grafts improved neutrophil engraftment at day +21, and CD34+ cell dose >5.7x106/kg improved platelet engraftment at day+28. After adjusting variables by Cox regression, the incidence of graft-versus-host disease (GVHD) and overall survival were not different among groups. Splenomegaly is associated with delayed engraftment while splenectomy prior to HCT facilitates early engraftment without impact on survival.

Splenectomy prior to allogeneic hematopoietic SCT increases the risk of post-transplant lymphoproliferative disease

“…Overall except for EBV-PTLD, our results are in agreement with Akpek et al 7 showing no major difference in the incidence of complications dependent on spleen status (Table 1). 7 Our results highlight the possibility that there might be a potentially higher risk for EBV-PTLD in patient sub-categories treated with ATG that have undergone splenectomy. Further, multi-center studies on patients treated with ATG are needed in order to verify our findings on the role of the spleen and EBV biology.…”

“…There are obvious differences between our patient material and the large cohort presented by Akpek et al 7 Our material is a mix of patients treated with MAC and RIC. The CIBMTR study only consists of MAC patients.…”

“…8 In addition, a vast majority of our patients are treated with ATG, which is also a known risk factor for EBV-PTLD due to an increase in inhibition of T-cell-mediated EBV control. 8 These two factors might very well increase the likelihood for EBV-PTLD compared to the large multi-center material presented by Akpek et al 7 Finally, in the CIBMTR-report all viral diseases were grouped together possibly masking a change in the frequency of EBV-PTLD alone. Overall except for EBV-PTLD, our results are in agreement with Akpek et al 7 showing no major difference in the incidence of complications dependent on spleen status (Table 1).…”

“…8 These two factors might very well increase the likelihood for EBV-PTLD compared to the large multi-center material presented by Akpek et al 7 Finally, in the CIBMTR-report all viral diseases were grouped together possibly masking a change in the frequency of EBV-PTLD alone. Overall except for EBV-PTLD, our results are in agreement with Akpek et al 7 showing no major difference in the incidence of complications dependent on spleen status (Table 1). 7 Our results highlight the possibility that there might be a potentially higher risk for EBV-PTLD in patient sub-categories treated with ATG that have undergone splenectomy.…”

“…5,6 In a recent 'Center for International Blood and Marrow Transplant Research' (CIBMTR) report, the authors analyzed the effects of spleen status on engraftment and other early outcomes after allo-SCT. 7 In this material, over 9000 patients were transplanted with myeloablative conditioning (MAC) and the authors showed a decrease in time of neutrophil and platelet engraftment in patients with splenectomy compared to individuals with normal spleen status. However, when analyzing other complications or the OS of the patient cohort no difference was observed between individuals with and those without a spleen.…”