[Study of relationship between T helper cell type-1 and type-2 cytokines and intrahepatic cholestasis of pregnancy].

OBJECTIVE

To investigate the effect of T helper cell type-1 (TH(1)) cytokines [interferon-gamma (IFN-gamma), tumor necrosis factor-a (TNF-alpha)] and T helper cell type-2 (TH(2)) cytokines [interleukin-4 (IL-4)] on pathogenesis of intrahepatic cholestasis of pregnancy (ICP).

METHODS

The peripheral blood mononuclear cells (PBMC) from 20 cases of ICP patients (study group) and 20 cases of normal pregnant women (control group) were cultured with photohemglutinin stimulation. TNF-alpha, IFN-gamma and IL-4 were determined in the supernatant by enzyme- linked-immunoassay.

RESULTS

(1) In supernatants of cultured PHA induced PBMC, the levels of IFN-gamma and TNF-alpha of study group were (639 +/- 156) ng/L and (1 021 +/- 231) ng/L, which were significantly higher than those of control group, (464 +/- 147) ng/L and (728 +/- 175) ng/L (P < 0.001); the IL-4 level of study group was (22 +/- 4) ng/L, which was lower than that of control group, (27 +/- 6) ng/L (P < 0.05); (2) In supernatants, the ratio of TNF-alpha/IL-4 of study group was 48 +/- 11, which was significantly higher than that of control group (30 +/- 8), the ratio of IFN-gamma/IL-4 of study group was 30 +/- 8, which was also higher than that of control group (19 +/- 6, P < 0.001); (3) There were significant positive correlations between total bile acid and concentrations of the TH(1) cytokines, the correlation coefficients(r) were 0.458 and 0.692, respectively (P < 0.01).

CONCLUSIONS

A shift in the balance of cytokine profiles away from TH(1)-type reactivity to TH(2)-type reactivity occurs in ICP. The enhanced cell-mediated immune reaction disturbs the immune tolerance balance between mother and fetus; The enhanced TH(1)-type immune response of ICP may contribute to the damage of hepatic cells and the occurrence of cholestasis.