1380haematologica | 2011; 96(9)
IntroductionGraft-versus-host-disease (GVHD) is the most common and life-threatening complication after allogeneic stem cell transplantation (allo-SCT).1,2 B-cell depletion with rituximab (RTX) has been successful in steroid-refractory chronic GVHD, showing response rates of 43-80%. [3][4][5][6][7][8] However, the nature of B-cell contribution, as well as to what extent B-cell depletion can restore physiological conditions, has so far not been clarified. Hypotheses obtained from mouse models of chronic GVHD and retrospective analysis of patient materials have been conflicting. For example, a correlation was found between high levels of B-cell activating factor (BAFF) in a retrospective analysis of 45 patients with active chronic GVHD.9 However, no significant correlation could be found between the levels of BAFF and RTX-responsiveness in the most recently published prospective phase II study of 37 patients. 10 In active chronic GVHD prior to response to immunosuppressants, expansion of activated CD27 + B cells has been observed. 9 Another retrospective study of 35 patients suffering from active chronic GVHD, in which treatment included prednisone and calcineurin inhibitors, showed significantly lower numbers of memory B cells (CD27 + ). 11 To our knowledge, no prospective comparisons have been made between immune subsets before and after B-cell depletion therapy of steroid-refractory chronic GVHD, so details on reestablishment of normal B-cell pools after RTX treatment, as well as changes in immune-pathology of the skin, still have to be clarified. Consequently, the aim of this study was to demonstrate effectiveness of B-cell depletion therapy in steroid-refractory chronic GVHD and to identify potentially involved cell subsets by a comprehensive immunological analysis in a prospective clinical trial.
Design and Methods
Patients and patient materialIn the course of a prospective study (Eudra-CT 2008-004125-42), a cohort of 20 chronic GVHD patients who received allo-SCT due to various hematologic malignancies was treated with 4 weekly doses of 375 mg/m 2 RTX (F. Hoffmann-La Roche Ltd., Basel, Switzerland). All patients had chronic GVHD with at least skin symptoms. Inclusion criteria were age over 18 years, life-expectancy of more than six months, and a World Health Organization (WHO)The immunological phenotype of rituximab-sensitive chronic graft-versus-host disease: a phase II study Chronic graft-versus-host disease is the major long-term complication after allogeneic stem cell transplantation with a suboptimal response rate to current treatments. Therefore, clinical efficacy and changes in lymphocyte subsets before and after rituximab treatment were evaluated in a prospective phase II study in patients with steroid-refractory chronic graft-versushost disease. Overall response rate was 61%. Only responding patients were found to have increased B-cell numbers prior to treatment. B cells had a naïve-antigen-presenting phenotype and were mainly CD5 negative or had a low CD5 expression...