Hepatocellular enzyme glutathione S-transferase alpha and intrahepatic cholestasis of pregnancy.

OBJECTIVE

To evaluate and compare plasma glutathione S-transferase alpha (GSTA) concentrations in the third trimester of pregnancy in patients with intrahepatic cholestasis of pregnancy (ICP) and in healthy pregnant women.

DESIGN

Non-randomized clinical study.

SETTING

Maternity unit and Department of Clinical Chemistry, Turku University Central Hospital, Turku, Finland.

POPULATION

Twenty-seven women with ICP and 49 healthy pregnant women.

METHODS

GSTA concentrations were assessed in plasma samples in the third trimester of pregnancy using an enzyme-linked immunoassay (HEPKIT Alpha, Biotrin, Sinsheim-Reihen, Germany).

MAIN OUTCOME MEASURES

Plasma GSTA, serum alanine and bile acid concentrations were compared between study and control group. Correlation between plasma GSTA levels and serum alanine aminotransferase and bile acid levels in the ICP patients were tested by Spearman correlation coefficients. Main perinatal outcome was compared between the groups.

RESULTS

GSTA concentration in the control group was 1.62 microg/l (range: 0.25-6.1). In the ICP patients, the mean plasma GSTA concentration was 51.0 microg/l (range: 2.1-183.5), the mean serum alanine aminotransferase concentration was 145.70 U/l (range: 6-393) and the mean bile acid concentration was 19.2 micromol/l (range: 3-63). There was a statistically significant correlation in ICP patients between plasma GSTA concentration and serum alanine aminotransferase concentration (r=0.694, p=0.0001), but not with serum bile acid concentration. Nor was there any statistically significant correlation between gestational weeks and plasma GSTA concentration in the study group.

CONCLUSION

Plasma GSTA measurements may provide a more sensitive and specific diagnostic tool for diagnosis of ICP than the evaluation of transaminases or bile acid concentrations alone. Further studies are needed to evaluate the role of GSTA in the follow-up of patients with ICP and its prognostic value for threatening fetal distress in patients with ICP.