Activation-associated phenotype of CD3 T cells in acute graft-versus-host disease

Abstract

During the effector phase of graft-versus-host disease (GvHD) response, donor T cells play an essential role and they are believed to change the expression of activation and co-stimulatory markers associated with functional alloreactivity. We analysed the expression of CD25, CD69, HLA-DR, CD154 and CD134 on CD4+ and CD8+ T cells by flow cytometry during acute GvHD (aGvHD) in 24 patients receiving human leucocyte antigen (HLA)-identical stem cell transplants. Expression of these molecules in nine patients with stages I-IV aGvHD was compared with 15 patients without aGvHD (n = 15). Serial analysis showed that peripheral blood of aGvHD patients presented a significant increase of CD4+ CD25+ cells (P < 0.03), CD4+ CD69+ (P < 0.04) and CD4+ CD134+ cells (P < 0.01). Additionally, there was a significant increase in CD8+ cells expressing CD134 (P = 0.007) and CD154 (P = 0.02). After resolution of aGvHD, the increased expression of these molecules returned to values comparable to patients without aGvHD. Only two of the 15 patients without clinical signs of aGvHD presented activated T cells that could not be attributed to development of aGvHD. In summary, our data show that multiple activation molecules are preferentially up-regulated on CD4+ and CD8+ T cells from patients with aGvHD. These patients had a significant increase in the expression of the co-stimulatory molecules CD134 and CD154.

Fig. 1

Phenotypic distribution of CD4⁺ cells from 105 samples of 24 patients. Samples were classified as acute graft-versus-host disease (aGvHD) (group I, group II and group III according to the time before, during and after the onset of GvHD, respectively) and non-aGvHD. CD25⁺, CD69⁺, DR⁺, CD134⁺ and CD154⁺ CD4⁺ cell subpopulations were quantified and expressed as percentage of CD4⁺ lymphocytes. The bar represents the mean of the percentage values for each group. The mean ± standard deviation is indicated under each group of samples. Differences between each group and the respective non-GvHD group were evaluated using t-test and the P-value indicated in parenthesis. P < 0·05 is considered statistically significant.

Fig. 2

Phenotypic distribution of CD8⁺ T cells from 105 samples from 24 patients. Samples were classified as acute graft-versus-host disease (aGvHD) (group I, group II and group III according to the time before, during and after the onset of GvHD, respectively) and non-aGvHD. CD25⁺, CD69⁺, DR⁺, CD134⁺ and CD154⁺ CD8⁺ cell subpopulations were quantified and expressed as percentage of CD8⁺ lymphocytes. The bar represents the mean of the percentage values for each group. The mean ± standard deviation is indicated under each group of samples. Differences between each group and the respective non-GvHD group were evaluated using t-test and the P-value indicated in parenthesis. P < 0·05 is considered statistically significant.