Hepatic veno-occlusive disease (VOD), or sinusoidal obstruction syndrome (SOS), is a serious complication of hematopoietic stem cell transplantation (HSCT) with mortality in its severe form exceeding 80%. Although the incidence of VOD/SOS has fallen with contemporary transplantation practices, the increasing use of inotuzumab, the return of gemtuzumab, and the popularity of pharmacokinetic-guided high-dose busulfan may impact incidence. Early intervention with defibrotide improves survival, but prompt diagnosis can be difficult. We aimed to identify clinical parameters that could aid in early detection of VOD/SOS in a large, retrospective, cohort study. Of the 1823 adult patients who underwent myeloablative HSCT between 1996 and 2015 in our center, 205 (11%) developed VOD/SOS, with a median onset of day +14. We compared parameters in the 7 days preceding VOD/SOS onset for cases to 447 randomly selected control subjects in an analogous time frame to determine those with predictive value. Between 7 days before and the day of diagnosis, VOD/SOS patients had higher serum creatinine levels and were more likely to develop acute kidney injury (61% versus 33%, P < .0001), more commonly experienced refractoriness to platelet transfusion (48% versus 24%, P < .0001), and had higher trough serum tacrolimus levels (7 days before VOD/SOS onset: median 8.8 versus 7.3, P = .0002; day of onset: median 9.3 versus 7.2, P < .0001) compared with control subjects. Acute renal dysfunction, platelet refractoriness, and elevated or abnormal tacrolimus levels are dynamic clinical markers that should alert clinicians to the development of VOD/SOS before the presence of classical diagnostic criteria. Using these clinical features to recognize VOD/SOS earlier in its clinical course could promote earlier treatment and lead to improved outcomes of this potentially serious complication.

With improvement in transplantation practices in the modern era, nonrelapse mortality (NRM) following allogeneic hematopoietic stem cell transplantation (HSCT) has improved, while disease relapse rates have remained unchanged. Survival outcomes are therefore driven by NRM in the modern era. Myeloablative conditioning (MAC) regimens are used to maximize disease control and facilitate engraftment; however, their use is often limited by toxicity. The commonly used MAC regimens incorporate either chemotherapy plus total body irradiation (TBI) or combination chemotherapy. Furthermore, reduced-toxicity myeloablative (RTM) regimens, such as fludarabine/busulfan (FluBu), have emerged as alternatives to traditional MAC and their impact on outcomes in the current era have not been fully investigated. In this study, we compare outcomes following HSCT, using the chemotherapy only RTM MAC regimens FluBu with the chemoradiotherapy regimen cyclophosphamide/TBI (CyTBI), for patients with hematologic malignancies who underwent MAC HSCT at the Dana-Farber Cancer Institute. We hypothesized that the chemotherapy-only regimen would fare better, primarily due to improved NRM. A retrospective cohort analysis was performed on 387 patients with myeloid or lymphoid hematologic malignancies who underwent HLA-matched related (8/8), matched unrelated (8/8), or single-antigen mismatched unrelated (7/8) HSCT following myeloablative conditioning. Patients received FluBu (n = 158) or CyTBI (n = 229). The primary outcome was overall survival (OS) and all other outcomes were regarded as secondary. A subset analysis was performed for patients <55 years of age and for acute myelogenous leukemia/myelodysplastic syndrome patients of age <55 years. For the whole cohort, 3-year OS was similar for FluBu compared with CyTBI in unadjusted analysis. However, in multivariable analysis, FluBu resulted in superior OS compared with CyTBI (3-year adjusted estimate: 65% versus 55%, respectively; HR for death, .62; 95% CI, .40 to .97; P = .036). While relapse rates were similar between the 2 regimens, NRM and acute graft-versus-host disease (GVHD) (grade II to IV) were significantly worse with CyTBI compared with FluBu. Rates of chronic GVHD were similar between 2 regimens. These results were consistent in a subset of patients <55 years of age and in acute myelogenous leukemia/myelodysplastic syndrome patients below 55 years of age. The RTM chemotherapy-only regimen FluBu appears to be as effective and more tolerable than the chemoradiotherapy regimen CyTBI, leading to better OS driven by better NRM. The improvement in NRM was attributable chiefly to lower rates of grade II to IV acute GVHD. Relapse rates were not increased with FluBu. In the absence of randomized data, FluBu appears to be the optimal regimen for myeloablative HSCT in patients of all age groups.