Idiopathic inflammatory demyelinating diseases of the central nervous system in patients following allogeneic hematopoietic stem cell transplantation: a retrospective analysis of incidence, risk factors and survival.

BACKGROUND: Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a curative therapy for many hematological diseases, but there are many complications following allo-HSCT, among which neurological complications (NC) are one of the most commonly described ones. However, little is known about idiopathic inflammatory demyelinating diseases (IIDDs) of the central nervous system (CNS) in patients following allo-HSCT.

METHODS: A nested case-control study was conducted in a large cohort of 1365 patients, who underwent allo-HSCT at the Institute of Hematology and Peking University People's Hospital, between January 2004 and December 2009, 36 patients of whom developed CNS IIDDs. Kaplan-Meier method, univariate and multivariate Cox regression were applied in our statistical analysis using SPSS 16.0.

RESULTS: The cumulative incidence of all cases of IIDDs at 6 years posttransplantation was 3.6%. Thirty-five patients (97.2%) suffered IIDDs after transplantation, 16 patients (44.4%) between day 0 to day 100 post-transplantation, 10 patients (27.8%) between day 100 to 1 year post-transplantation, and 9 patients (25.0%) 1 year post-transplantation. Multivariate regression analysis identified donor type (P = 0.031), infection (P = 0.009), and acute lymphatic leukemia (P = 0.017) as independent risk factors for posttransplantation IIDDs. The median survival time of patients with IIDDs was 514 days after transplantation (95%CI: 223 - 805). Survival at 6 years was significantly lower in patients who developed the diseases compared to those who did not (26.6% vs. 73.5%, P < 0.001). Of the 36 patients experiencing IIDDs, 58.3% (n = 21) died. The causes of death were graft-versus-host disease (GVHD) (n = 4), underlying disease relapse (n = 3), infections (n = 12), and other causes (n = 2).

CONCLUSIONS: IIDDs is an uncommon but serious complication of allo-HSCT, especially in patients with a primary diagnosis of acute lymphatic leukemia, mismatched transplants, and infections. Our study results indicate that patients with IIDDs tend toward a poor prognosis following allo-HSCT.