Is a Risk Factor for Early Mortality Weight Gain in the First 10 Days after Hematopoietic Stem Cell Transplantation Is a Risk Factor for Early Mortality Lucila Nassif Kerbauy, Erika MM Costa, Juliano Cordova Vargas, Claudia Mac Donald Bley Nascimento, Joyce Esteves Hyppolito, Ricardo Helman, Alessandro de Moura Almeida, Jose Mauro Kutner, Juliana Folloni Fernandes, Andreza Alice Feitosa Ribeiro, Iracema Esteves, Eduardo Cerello Chapchap, Guilherme Fleury Perini, Paulo Vidal Campregher, Jairo Sobrinho, Claudio Galvão de Castro Junior, Breno Moreno Gusmão, Fabio R. Kerbauy, Nelson Hamerschlak and Fabio P S Santos A landmark analysis at D+100 revealed that the negative impact of weight gain by D+10 on survival was restricted to the first 100 days, as after this time point there was no survival difference between the two groups (HR 1.35; p=0.41; 95% CI 0.65-2.83).  Table 2 – Multivariate Cox Analysis Introduction: Hematopoietic stem cell transplantation (HSCT) is an effective treatment option for patients with hematological and neoplastic diseases. Despite recent improvements, HSCT is still associated with a significant risk of mortality. Determining risk factors for death within the first 100 days after HSCT could help to identify patients who would benefit from interventions in order to decrease that risk. We analyze the impact of weight gain on early (100-days) mortality in patients who underwent HSCT at our institution. Results: Variable Hazard Ratio P 95% Confiance Interval Gender (male vs female) 1.25 0.341 0.78 - 2.01 Other HSC sources vs Autologous Matched Related Donors 1.36 0.462 0.60 - 3.08 Matched Unrelated Donors 1.20 0.687 0.48 - 3.02 Mismatched related/unrelated donors 1.39 0.487 0.54 - 3.55 Cord blood units 2.75 0.020 1.17 - 6.45 Age 1.01 0.153 0.99 -1.02 Other Diagnosis vs acute leukemia or chronic myeloid disorders Lymphoma/multiple myeloma 0.39 0.014 0.18 - 0.82 Non-malignant hematological disorders 0.43 0.034 0.19 - 0.91 ≥6% BW gain 2.72 0.0001 1.65 - 4.48 The results of the ROC curve defined the cut-point of 6% weight gain by 10 days post-SCT as the best predictor for OS. Twenty-one percent of patients had a ≥6% gain in BW until the first 10 days post-HSCT. Table 1 – Baseline Features Feature (n=331) % Median age (range), years old 43 (<1-76) Male sex 60 Source of cells Autologous Cord blood Matched related donor Matched unrelated donor Cord blood Mismatched related/unrelated donors 46 16 12 10 Disease Acute leukemia or chronic myeloid neoplasias Lymphoma, multiple myeloma Non-malignant hematological disorders 34 42 24 Objectives: To determine the impact of weight gain during the first 10 days post-HSCT on 100 days mortality. Conclusions ≥6% BW gain by D+10 is a risk factor for early mortality in both autologous and allogeneic HSCT. The most common cause of death in these patients is infectious-related complications. An increase in BW is related to the development of an inflammatory state, probably induced by the conditioning regimen. BW gain is a simple variable that can be easily used to determine prognosis of patients post-allogeneic HSCT, and further studies are needed to determine its etiology. Material and Methods: We retrospectively reviewed the medical charts of 331 patients who underwent HSCT at our institution from January, 2007 until December, 2013. Weight gain definition: The highest body weight during conditioning regiment and 10 days post-SCT periods was used to calculate body weight increase in relation to baseline BW The primary endpoint was mortality within 100 days post HSCT. Overall survival (OS) was estimated from the time of HSCT until death, and surviving patients were censored at last follow-up. There was no difference in baseline levels of C-reactive protein (4.8 mg/L vs. 7.4, p=0.37), but by D+10 patients who gained more BW had higher CRP (116.7 mg/L vs. 178.6 mg/L; p=0.01). In a logistic regression analysis, a ≥6% BW gain by D10 was associated with an increased risk of being dead within 100 days (coefficient 1.75; p<0.0001; 95% CI 0.90-2.61). Among 18 patients who died within 100 days and had a ≥6% BW gain by D+10, causes of death included pneumonia (N=4), septic shock (N=9), fungal endocarditis (N=1), ischemic stroke (N=1) and disease progression (N=3). Contact Details Lucila N Kerbauy/Fabio PS Santos Department of Stem Cell Transplantation Hospital Israelita Albert Einstein 627 Albert Einstein Avenue Sao Paulo, SP – ZIP CODE: 05651-901 +55 (11) 97043-2223 santos.fabio2@einstein.br Disclosure There are no relevant conflicts of interest to disclose.