Therefore, given the limitations of conventionally collected registry data (dubious follow-up information and extreme heterogeneity), we developed the: "EBMT non-interventional prospective study on allogeneic transplantation in AL Amyloidosis" which means that transplant centers that already do perform allogeneic transplants for AL Amyloidosis will be encouraged to register their patients with AL Amyloidosis very timely with the EBMT, followed by mandatory submission of EBMT MedB and follow-up forms. The diagnosis of AL Amyloidosis would be based on uniform criteria. All EBMT centres performing allogeneic transplants for Amyloidosis will be invited to participate in this study and centres will be asked to report all AL Amyloidosis cases referred for transplantation using a simple registration form and then to submit Amyloidosis MED B forms for each transplanted patient and follow-up forms as necessary. In conclusion, it should be possible to largely improve the usual quality of registry-based data and to generate scientifically sound knowledge on HSCT in an orphan disease such as AL Amyloidosis.