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

Adenosine 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.

Plasma 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 gamma and interleukin 4) was analyzed by flow cytometry. The ratio of interferon-gamma-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.

In 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).

Increased plasma adenosine may be involved in regulating the Th1/Th2 balance in hyperemesis gravidarum.