Increased incidence of neurological complications in patients receiving anallogenic bone marrow transplantation from alternative donors

Objective-To compare the frequency and type of neurological complications a fter bone marrow transplantation (BMT) with an HLA identical unrelated dono r or a mismatched related donor (alternative donors) to the neurological co mplications after matched sibling BMT for standard and high risk leukaemia or myelodysplastic syndromes. Methods-Retrospective analysis of consecutively treated patients with (a) B MT from alternative donors (n=39), (b) treated with matched sibling BMT ror standard risk leukaemia, myelodysplastic syndromes, or aplastic anaemia (n =53), and (c) treated with matched sibling BMT for high risk leukaemia, mye lodysplastic syndromes, or aplastic anaemia (n=49). Results-A total of 72 neurological complications were found. Most of these occurred within the first 6 months after transplant. Thirty six patients de veloped a severe neurological complication: 17 Alternative donor patients ( 44%) by contrast with six standard risk patients (11%) and 13 high risk pat ients (27%; p<0.005). The most frequent complication was a metabolic enceph alopathy occurring in 18% of patients. Most of the encephalopathies were ca used by either the transplant procedure, cyclosporin, systemic infections, microangiopathic thrombopathy, or by complications induced by graft versus host disease. Infections of the CNS developed in 9% of patients, cerebrovas cular lesions in 3%. Conclusions-Severe neurological complications are more frequent after BMT f rom alternative donors. This is mainly due to increased treatment related m orbidity and to more profound immunosuppression after BMT from alternative donors.