Effect of induced GVHD in leukemia patients relapsing after allogeneic bone marrow transplantation: single-center experience of 33 adult patients

Isolated Testicular Recurrence of AML in Patients With Chronic GVHD >1 Year Following Allogeneic Stem Cell Transplant

BACKGROUND

Patients with chronic graft-versus-host disease (cGVHD) following allogeneic transplant for myeloid leukemias seem to experience a reduced risk of relapse than comparable patients without cGVHD. It is unclear to what extent extramedullary sites are impacted by a graft-versus-leukemia effect.

DESIGN/METHOD

Case Series and review of the literature.

RESULTS

We present 2 cases of pediatric patients with Acute Myelogenous Leukemia who developed isolated testicular relapse more than a year following hematopoietic stem cell transplantation despite having had extensive cGVHD. Both patients were off immunosuppression and cGVHD medications when testicular relapse occurred. At time of relapse, these patients were negative for minimal residual disease in the marrow and the marrow contained all donor cells by engraftment studies. No evidence was found for lymphocyte infiltration into the affected testicle in either patient.

CONCLUSIONS

Although a reduction of marrow relapse can be appreciated in patients with myeloid leukemias and chronic GVHD, this graft-versus-leukemia process may be less robust in extramedullary sites and careful surveillance should be maintained to allow early intervention before overt marrow involvement.

Treatment of chronic graft-versus-host disease with bortezomib

Chronic graft-versus-host disease (cGVHD) following allogeneic hematopoietic stem cell transplantation (HSCT) has emerged as a predominant complication following HSCT and has a distinct etiology. We and others have previously demonstrated that bortezomib, a proteasome inhibitor, can prevent but not treat acute GVHD in mice. To assess the effects of bortezomib on cGVHD, a mouse minor histocompatibility antigen-mismatched strain combination was used to mimic clinical cGVHD sclerodermatous pathogenesis and phenotype. Treatment of ongoing cGVHD with bortezomib ameliorated cutaneous lesions, which were also associated with a reduction in total numbers of germinal center B cells and lower B-cell activating factor gene expression levels in cutaneous tissues. Importantly, lymphoma-bearing mice receiving allogeneic HSCT with bortezomib preserved graft-versus-tumor (GVT) effects. Based on these animal studies, we initiated an intrapatient dose escalation clinical trial in patients with extensive steroid-intolerant, dependent, or resistant cGVHD. Marked clinical improvement was observed in patients, which was also associated with reductions of peripheral B cells and minimal toxicity. These results indicate that bortezomib can be of significant use in the treatment of cGVHD and may also allow for maintenance of GVT. This trial was registered at www.clinicaltrials.gov as #NCT01672229.