CMV-Specific T Cells in a Good's Syndrome Patient with Recurrent CMV Infection
Sunday, March 6, 2016
South Exhibit Hall H (Convention Center)
Ponpan Matangkasombut, MD, Supanart Srisala, Wannada Laisuan, MD, Nopporn Apiwattanakul
Rationale: Our patient with Good's syndrome suffered from recurrent CMV infection despite adequate IVIg replacement. To assess for possible T cell defect in this patient, CMV-specific T cells number and function was evaluated.

Methods: Peripheral blood T cells were evaluated at 2 time points, during quiescence and during high CMV viremia with colitis. Flow cytometry, using CMV-HLA class I dexamer staining, was performed to quantify CMV-specific CD8+ T cells in comparison to unloaded dexamer control. Furthermore, PBMC were stimulated with CMV antigen in vitro and T cells- IFNγ production was analysed by flow cytometry, in comparison to unstimulated and isotype control.

Results:  At quiescence, 0.2% of total CD8+T cells was CMV-specific.  The percentage increased to 3.64 during high CMV viremia with CMV colitis. At quiescence, upon in vitro CMV stimulation, IFNγ-producing CD4+ T cells was 0.35% of total CD4+ T cells and IFNγ-producing CD8+ T cells was 0.22% of total CD8+ T cells. However, during high CMV viremia with colitis, only 0.1% of CD4+ T cells and 0.03% of CD8+ T cells produced IFNγ in response to in vitro CMV stimulation.  

Conclusions: The Good's syndrome patient's CMV-specific T cells number increased more than 15 folds during active CMV infection.  However, after in vitro CMV stimulation, T cells from active CMV infection showed lower IFNγ production than those in quiescence.