Are increased IgE-levels a signal of an acute graft-versus-host reaction?

IgE-levels are markedly elevated following bone-marrow transplantation in patients with and without GVHD. In patients with GVHD, there is a significant correlation between the timing of the IgE-increase and the appearance of clinical GVHD (p less than 0.01). The highest IgE-level (8000 kU/l) was noted in a recipient of a syngeneic graft. During the IgE-peak, the serum from this patient contained low concentrations of IgE reacting with several tested allergens as well as for the hapten TNP, which indicated polyclonal activation. In a patient with a known allergy to animal danders, RAST tests were positive against dog and cat both before and six weeks after total body irradiation and transplantation with marrow from a non-allergic donor. A slight increase in the amount of allergen-specific, IgE-antibodies was seen during the increase in total IgE. A non-allergic patient was transplanted with marrow from a donor allergic to timothy. Timothy-specific, IgE-antibodies were detected immediately after transplantation but they disappeared within a few days and could not be detected during the period of increase in total IgE. We believe that the IgE-elevation seen after conditioning with cytotoxic drugs and total body irradiation in BMT-patients is a polyclonal response in host B-cells induced during an acute, GVHR and influenced by disturbed regulatory T-cells. Lymphocytes from patients with acute GVHD had unusually large numbers of IgG/PFC in vitro after stimulation with staph. aureus Cowan 1 (p less than 0.001), which may reflect a clonal expansion of responsive B-cells.