Effect of comorbidities on hematopoietic stem cell transplantation outcome in adult patients with hematologic diseases

Abstract

Stem cell transplantation is a procedure that can restore marrow function for patients who have had severe marrow injury or abnormalities of the immune system. Marrow injury can occur because of primary marrow failure, destruction or replacement of marrow by disease, or intensive chemical or radiation exposure. HSC transplantation (HSCT) is a procedure in which the entire hematopoiesis and immune system are replaced by the donor’s cells. HSCT can be classified according to its purpose, HSC origin and HSC donor type. Most HSCT procedures are performed with autologous HSC for different forms of cancer, with multiple myeloma being the most common indication. Most allogeneic transplants are performed for patients with hematologic malignancies, mainly acute leukemias. Conventional allogenic hematologic cell trans-plantation is potentially curative treatment option for various hematologic diseases due to in part high dose conditioning and in part to graft versus host effects. Reduced intensity or non-myeloablative conditioning regimens have relied mostly on graft- versus- host tumour effects for disease control. However both HSCT modalities have been associated with organ toxicities and graft versus host disease, resulting in substantial non-relapse mortality. It has become increasingly important to optimize pre-transplant risk assessment in order to improve HCT decision making and clinical trial assignments. Single-organ comorbidity involving liver, lung, heart, or kidney before HCT has been traditionally found to cause organ toxicity after HCT. The HCT-comorbidity index (HCT-CI) has provided better prediction of HCT-related morbidity and mortality than other non-HCT-specific indices. The aim of the study is to investigate retrospectively the impact of various comorbidities on outcome of patients with hematologic diseases treated with HSCT either allogenic or autologous in relation to treatment related mortality and disease related mortality with specific emphasis on overall survival. Patients and methods: In this study a retrospective study was done in the bone marrow Transplantation Unit at the department of internal medicine at Faculty of medicine Ain Shams University on 119 patients fromThe patients included in the study were transplanted either autologous or allogenic (matched or mismatched related donor). The patients included different types of diseases; the most frequent hematologic disease was AML followed by multiple myeloma then ALL. All patients were aged >18y. The patients were either in complete remission or not in complete remission. They were categorized according to HCT-CI in to mild score (0) 43 patients (36.2%), moderate score (1-2) 60 patients (50.4%) and severe score (≥3) 16 patients (13.4%) The study data was collected frommedical notes, pathology reports and laboratory data. Results: After recording the results and using the suitable statistic methods, we found that, the most frequent comorbidity was hepatic comorbidity and it was significantly related to overall survival. There was statistically significant relation between HCT-CI and overall survival, disease free survival and mortality. Moreover, there was statistically significant relation between HCT-CI and the incidence of graft failure. In our study, we could conclude that the HCT-CI is a better predictor to detect the influence of comorbidity in patients with hematologic disorders on mortality, overall survival and disease free survival post HCT. At the end of our study, we suggest the use of HCT-CI in evaluating patients with hematologic diseases pretransplant to reduce mortality during transplantation and to improve overall survival post transplant.