[A study of the central nervous system complications after hematopoietic stem cell transplantation.]

To study the incidence, risk factors and prognosis of central nervous system (CNS) complications after hematopoietic stem cell transplantation (HSCT) in order to prevent or reduce its occurrence, provide better diagnosis and treatment and improve the survival of the patients.

A total of 640 patients who consecutively underwent HSCT in our hospital between May 2001 and December 2007 were included. The clinical outcomes of the patients who developed CNS complications were analyzed.

The patients received stem cells from haploidentical family members (Haplo, n = 289), identical siblings (IS, n = 237), unrelated donors (URD, n = 83), unrelated cord blood (n = 14), syngeneic siblings (n = 9) or autologous peripheral blood (n = 8). Fifty-seven of 640 patients (8.9%) developed CNS complications. The incidences were 12.0%, 13.5% and 3.4% in URD-HSCT, Haplo-HSCT and IS-HSCT respectively (P < 0.001). The incidences of CNS complications were 19.4% and 8.3% in cases who received or did not receive conditioning with TBI (P = 0.047). There was no significant difference in the incidences of CNS complications between children (15.3%) and adults (8.3%) (P = 0.072). Similar incidences of CNS complications were seen in patients with hematological malignancies (8.9%) and non-malignant hematological disorders (7.7%) (P = 1.000). Five of the 57 patients developed two kinds of CNS complications. The patterns of CNS complications included relapse (17 cases), infections (15 cases), cyclosporine or FK506 encephalopathy (9 cases), cerebral hemorrhage (8 cases), cerebral infarction (2 cases), Wernicke's encephalopathy (1 case), skull fracture (1 case), drug-related meningitis (1 case), hepatic encephalopathy (3 cases), post-transplant lymphoproliferative disorder (1 case) and undetermined causes (4 cases). The overall mortality in the patients who developed CNS complications was 57.9% and 66.7% of them died of CNS complications.

CNS complications are not uncommon after HSCT and they have high mortality and poor prognosis. Our data suggest that haplo-HSCT, URD-HSCT and conditioning with TBI, but not the age and types of hematological diseases are the risk factors for development of CNS complications. Relapse and infections are the most common CNS complications in HSCT recipients. Early diagnosis and appropriate management are crucial to the improvement of clinical outcomes in these patients.