Prospective Evaluation of An Agvhd-Specific Proteomic Pattern in More Than 340 Patients.

Abstract 347

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a curative treatment for many hematologic malignancies or hematopoietic dysfunction syndromes, but the application is still limited due to major complications, such as severe graft versus host disease (GvHD) and infectious complications. Diagnosis GvHD is based on clinical features and biopsies, a non invasive, unbiased laboratory test does not exist.

To date the proteomic pattern specific for aGvHD was evaluated blindly on 961 samples collected from 345 patients undergoing allo-HSCT at MHH and 7 additional clinics, including the University of Michigan. The majority of the patients included were transplanted for hematological malignancies (n=329), 16 for hematopoietic failure syndromes, mainly severe aplastic anemia. Conditioning regimens included dose reduced conditioning regimens (FLAMSA and ClaraC for the majority of the patients of MHH), as well as standard conditioning regimens (TBI+Cy or Busulfan+Cy) for about 35% of the patients. GvHD-prophylaxis was cyclosporine A (CSA) and mycophenolate (MMF) or CSA metothrexate (MTX) as appropriate. In addition, about 80% percent of the patients received ATG (antithymocyte globulin) prior to HSCT.

A peptide pattern of 31 peptides - either absent/decreased (15) or present /increased (16) - was previously published (Weissinger et al. 2007). Prospective and blinded evaluation of the patients included in this diagnostic analysis for early recognition of patients at risk for aGvHD development revealed the correct classification of patients developing aGvHD about 7 days prior to the development of clinical symptoms for aGVHD with a sensitivity 76% and specificity of about 85% (fig.1). Additional data obtained from patients transplanted until September 2009 will be reported. Based on these data a pre-emptive therapy multicenter trial, administering steroids upon positivity of the proteomic pattern has been initiated now in 10 German centers, testing the efficacy of the pre-emptive therapy on incidence and severity of aGvHD and a possible benefit on overall survival of the patients.