Effect of Plasma Exchange on Acute Graft Versus Host Disease after Allogeneic Hematopoietic Stem Cell Transplantation.

Acute graft versus host disease (aGVHD) is one of the major complications after allogenic hematopoietic stem cell transplantation (allo-HSCT) with high morbidity and mortality. Myeloablative treatment and the application of immuno-suppressive drugs (such as CsA, FK506 and MMF) are the main methods of prevention and cure. As it can separate pathogen, toxin, antigen and antibody from the plasma, plasma exchange (PE) is widely used to prevent and treat autoimmune disease, the rejection of stereo-organ transplantation, acute intoxication, severe hepatitis and acute hepatic failure. But up to now, PE is still rarely used to treat aGVHD. Here we present our review of cases where PE was accepted as a treatment modality for refractory aGVHD at our center. From October 2001 to March 2004, eight patients underwent PE due to aGVHD after Allo-HSCT with little response to immuno-suppressive drugs. Four of them had initial diagnosis of chronic myeloid leukemia (CML), and the other four were diagnosed with acute myeloid leukemia M2a,M4,M5,M6 respectively. The age of patients was from 14 to 38 years old (median 31). The “BuCY2” scheme (MMF+MTX+CsA) was used to prevent GVHD. After transplantation, all of them developed II-IV degree aGVHD. Each of them underwent 1 or 2 times of PE, with a volume ranging from 2500ml to 4000ml for a single PE. The overall response rate is favorable (fever, tetter, bellyache, diarrhea and liver function were ameliorated with various degree), with 3 cases (37.5%) having overt response, which was especially seen in patients with intestinal tract symptoms. Also, the level of TNF-α in the serum of the patients after plasma exchange was lower than that of the patients before plasma exchange(P=0.018). These results suggested that intestinal tract plays an important role in magnifying illness and “cytokine storm”, and TNF-α is the pivotal cytokine in the Intestinal tract GVHD. And the non-immunity aspects of GVHD can be described as an inflammatory process. PE may block this kind of inflammation by decreasing the cytokines, especially the level of TNF-α in serum after PE. Thus, the combination of PE and immuno-suppressive drugs is a rather good therapeutic method to control the symptoms of refractory aGVHD after allo-HSCT.