Occurrence of GvHD

Abstract

Allogeneic hematopoietic stem cell transplantation (HSCT), today, is the treatment of choice for life-threatening diseases such as aplastic anemia (AA), severe combined immunodeficiency (SCID), leukemia, and many other diseases [69]. The spectrum of indications for allogeneic HSCTs has steadily increased in recent years. At present approximately 20,000 allogeneic or autologous HSCTs are performed worldwide every year [70]. Thus, it is not surprising that GvHD most often occurs in the context of allogeneic HSCT. However, as is evident from Table 2.1, GvHD can also develop in other quite different clinical situations. Before this is outlined in more detail, it should be stressed that the manifestation of GvHD depends on a number of immunological as well as nonimmunological factors, such as:

• 1. The degree of histoincompatibility between donor and recipient [8, 23]

• 2. The type of conditioning regimen employed [ 151 ]

• 3. The number of allogeneic donor T-lymphocytes transferred [220]

• 4. The type of GvHD prophylaxis used [52, 75, 245]

• 5. The age of donor and recipient [ 159, 255]

• 6. The microbial flora or infection of the recipient [27, 255]