Relationship between adenosine and T-helper 1 / T-helper 2 balance in hyperemesis gravidarum

BackgroundAdenosine modulates the T-helper (Th) 1 / T-helper (Th) 2 balance. We evaluated the relationship between changes in plasma adenosine and the T-helper (Th) 1 / T-helper (Th) 2 balance in hyperemesis gravidarum.MethodsPlasma adenosine concentrations and the Th1 / Th2 ratio were examined in the peripheral blood of 24 women with hyperemesis gravidarum and normal pregnancies. The proportion of CD4-positive cells that expressed intracellular cytokines (interferon γ and interleukin 4) was analyzed by flow cytometry. The ratio of interferon-γ-secreting cells to interleukin-4-secreting cells was taken as the Th1 / Th2 ratio in vivo. The change induced by adenosine-receptor blocker 8-sulfophenyltheophylline was also measured in vitro to evaluate the possible role of adenosine in modifying the Th1 / Th2 balance.ResultsIn hyperemesis gravidarum, plasma adenosine and the proportion of interleukin-4-secreting cells were increased significantly, and the Th1 / Th2 ratio was significantly lower than in normal pregnancy (p < 0.05). The decrease in the proportion of IL-4-secreting cells after adenosine receptor blockade in hyperemesis gravidarum significantly exceeded that of normal pregnancy (p < 0.05).ConclusionsIncreased plasma adenosine may be involved in regulating the Th1 / Th2 balance in hyperemesis gravidarum.