G.W. Chan

Prospective study of extracorporeal photopheresis in steroid-refractory or steroid-resistant extensive chronic graft-versus-host disease: analysis of response and survival incorporating prognostic factors

Summary:We enrolled 25 patients with extensive, steroid-refractory chronic graft-versus-host disease (cGVHD) in a prospective trial evaluating the efficacy of extracorporeal photophoresis (ECP) in both skin and visceral cGVHD. The median time from transplant to initiation of ECP was 790 days. ECP was administered for 2 consecutive days every 2 weeks in 17 patients and once a week in eight patients until best response or stable disease. The median duration of therapy was 9 months (range 3–24 months). In all, 20 patients had improvement in cutaneous GVHD and six had healing of oral ulcerations. Steroid sparing or discontinuation of immunosuppressive medications was possible in 80% of patients. Response rates were similar between patients receiving treatment weekly vs every 2 weeks and in patients commencing ECP less than vs greater than 18 months from transplant (70 vs 66%). When patients were stratified based on the Akpek prognostic score, there was no difference in overall response between the favorable (Akpek score<2.5) and unfavorable risk groups, but patients with progressive onset cGVHD tended to have a higher response than those with de novo onset. In summary, we report improvement in skin and/or visceral cGVHD in 71% overall and 61% of high-risk patients.

Persistence of host dendritic cells after transplantation is associated with graft-versus-host disease

Graft-versus-host disease (GVHD) causes significant morbidity and mortality in patients undergoing allogeneic bone marrow transplantation following either a conventional or reduced-intensity preparative regimen. In a murine model, inactivation of host dendritic cells (DCs) was associated with a significant reduction in acute GVHD, suggesting that host DCs may play an important role in the pathogenesis of acute GVHD. The role of host DCs in the development of GVHD following allogeneic stem cell transplantation in humans, however, is unclear. We examined DC chimerism in patients with various hematologic malignancies who underwent a reduced-intensity preparative regimen of extracorporeal photophoresis, pentostatin, and reduced-dose total body irradiation (n = 21) or a conventional preparative regimen of cyclophosphamide and total body irradiation (n = 3). Full donor hematopoietic reconstitution was demonstrated in 19 of 21 patients who underwent a reduced-intensity preparative regimen and in all patients who underwent a conventional preparative regimen. Grade 0 to I acute GVHD and limited or no chronic GVHD were observed in 18 patients who underwent a reduced-intensity regimen and 1 patient who underwent a conventional regimen who achieved full donor DC chimerism at day +100 posttransplantation. In contrast, grade II to IV acute GVHD and extensive chronic GVHD were observed in the 2 patients who underwent a conventional regimen and the 1 patient who underwent a reduced-intensity regimen who had host rather than donor DC chimerism. The persistence of host DCs at day +100 posttransplantation is correlated with the development of severe acute and chronic GVHD (P =.001). Host DCs may represent a therapeutic target for reducing GVHD in allogeneic bone marrow transplants.