Who should get a second marrow transplant?

Second transplants need to be considered in two clinical situations after marrow transplantation. Firstly, failure of sustained engraftment; secondly, recurrence of the underlying malignancy. In patients with failure of sustained engraftment a trial of recombinant human GM-CSF is indicated first with a chance of improving blood counts in a significant proportion of patients. If this is unsuccessful a second transplant utilizing a preparative regime aimed primarily at further minimizing host immune competence such as a combination of antithymocyte globulin (ATG) and cyclophosphamide or ATG alone followed by a T-replete marrow infusion should be employed. A second marrow transplant can also be utilized for recurrence of the underlying haematological malignancy after first transplant. However, several large multi-institutional studies have now shown a striking difference in the long-term leukemia-free survival rate between those relapsing early (for example, less than six months) after the first transplant compared to those relapsing later after the first transplant. Leukemia-free survival post second transplant for those relapsing within six months of first transplant is less than 10%, whereas for those relapsing greater than six months from first transplant it is approximately 30%. Transplant-related mortality, particularly from complications influenced by chemotherapy, such as interstitial pneumonitis and hepatic veno-occlusive disease, are more common after second than after first transplant.(ABSTRACT TRUNCATED AT 250 WORDS)