Similar Frequency and Types of Neurological Complications in Patients Undergoing Matched Related and Matched Unrelated Donor Stem Cell Transplantation for Hematological Malignancies

Allogeneic hematopoietic stem cell transplantation (allo HSCT), exploiting donor T-cell activity against residual tumor cells, remains the treatment of choice in most patients with acute leukemia, and in those presenting with other advanced hematological malignancies. To overcome the lack of matched related donors (MRD) in many cases, stem cells from a match unrelated donor (MUD) or cord blood are used. However, this mode of therapy is associated with various clinical complications. While information regarding graft-versus-host disease (GvHD) and infections is abundant, there is paucity of data looking at post-HSCT neurological complications (NC).

The current retrospective study was aimed to assess the frequency and types of NCs associated with allo HSCT in the settings of MRD versus MUD SCT.

The study was approved by the IRB of the Rambam Health Care Campus, Haifa, Israel (Approval # 0269–12). The institutional electronic database was retrospectively searched for adult patients undergoing allo SCT as their first high-dose therapy, between January 2008 and December 2011. According to the institutional protocol, GvHD prophylaxis was identical for patients undergoing MRD and MUD transplants, including cyclosporine A and methotrexate. The following data were recorded: demographics, underlying hematological disease, time from diagnosis to SCT, disease status at transplantation, donor type, development of acute and chronic GvHD, NC features (vascular, infections, therapy-related, time of complication onset and management). Characteristics and risk factors of NC reported in patients undergoing MRD vs MUD SCT were compared.

One hundred and sixty one consecutive patients, undergoing an allo SCT, were analyzed. The median age at diagnosis was 43 years (range 17–71). Ninety six patients (60%) were males. The most common indication for HCT was acute myeloid leukemia (AML) (45.3 %), followed by acute lymphocytic leukemia (ALL) (16.8%), non-Hodgkin lymphoma (NHL) (17.4%) and others (20.5%). The median time from disease diagnosis to allo SCT was 224 days (range 37–5434). MRD accounted for 57.8% of transplants. There were no statistically significant differences in the characteristics of patients undergoing MRD versus MUD SCT. Within a year from SCT, 49 patients (30.4%) experienced 53 neurological events. The median time between SCT and occurrence of the first neurological complication was 66.5 days (range 1–349). Characteristics of neurological complications for the entire series and dependent on donor type are presented in Table 1. In a univariate analysis, diagnosis of ALL and a period longer than 9.5 months from diagnosis to transplant were found to be risk factors for neurologic insult occurrence (p= 0.015 and 0.031, respectively). In a multivariate analysis, only time between diagnosis and SCT remained a valid risk factor for the development of neurological complications (OR=1.977, CI 0.998–3.916).

The data obtained suggest that in patients with hematological malignancies, the MUD transplant is not a risk factor for the development of NCs during the first year after alloSCT. The donor type has no impact on the spectrum of NCs in this clinical setting.

No relevant conflicts of interest to declare.