Prognostic value of chimerism in patients after allogeneic hematopoietic stem cell transplantation (allo-HSCT)
Maria V. Pryanishnikova, Alexandra A. Sipol, Irina S. Solomonova, Ildar M. Barkhatov, Elena V. Semenova, Liudmila S. Zubarovskaya, Boris V. Afanasyev
Memorial R.M. Gorbacheva Institute of Children Hematology and Transplantation, St. Petersburg Pavlov State Medical University, St. Petersburg, Russia
Summary
Introduction
For the last 20 years allo–HSCT has been one of the most effective treatments for different hematological malignancies. Hematopoietic chimerism analysis is an important method of monitoring the post-allo-HSCT outcome.
Patients and methods
In the study we included 142 patients with different hematological malignancies allografted between October 2002 and October 2008. The chimerism status was assessed by analyzing short tandem repeat polymorphisms.
Results
Overall survival in patients with complete donor chimerism on day +28 after allo-HSCT was 55% and 17% in patients with mixed chimerism or an absence of chimerism on the same day (p=0.0124). Similar results were observed by analyzing chimerism on day +60 following allo-HSCT. There were no significant differences in overall survival depending on chimerism value on day +28 and +60 in patients with myeloablative and nonmyeloablative conditioning regimen.
Of the patients with mixed chimerism or an absence of chimerism on day +28 after allo-HSCT, 67% had disease relapse, while 33% remained in remission (p=0.023).
Conclusions
Complete donor chimerism on day +28 and day +60 after allo-HSCT is associated with better prognosis. Mixed chimerism at day +28 after allo-HSCT is associated with an increased risk of relapse.
Keywords
chimerism, allo-HSCT, relapse, outcome