In ABCB11, formal statistical analysis was only performed for the 1331T>C polymorphisms (rs2287622), whereas for ABCC2 analysis, it included two highly linked polymorphisms. No correction according to Bonferroni was, therefore, required. Differences investigated in our study apply to a proportion of diseased sellckchem versus non-diseased individuals within the whole population, using an unmatched case control design. Response (ICP versus non-ICP) and predictors (T versus C) were both binary variables and were therefore best condensed into a 2 �� 2 table. Differences in genotype distribution between patients and controls were calculated with the ��2 test, and difference in allelic frequencies between two groups was performed using a 2 �� 2 Fisher exact test. P �� 0.05 was considered statistically significant.
RESULTS Patient characteristics A total of 25 unrelated patients with estrogen-associated intrahepatic cholestasis were prospectively enrolled in this study, 21 with ICP and four with oral CIC. Demographic data and laboratory findings in ICP patients are given in Table Table2.2. Only two patients showed elevated ��-GT levels > 1.5 ULN, while total bile acid levels were elevated in all patients in whom it was determined (16 out of 21; range, 1.7-17.3 ULN). Three patients had a previous history of ICP; three pregnancies were twin pregnancies, and one patient experienced cholestasis under previous oral contraception. Table 2 New group of patients with ICP (ICPnew) Characteristics of patients with CIC are given in Table Table3.3. One patient showed elevated ��-GT levels.
Total bile acid levels were elevated in all three patients in whom it was determined (three out of four; range, 1.6-22.3 ULN). Oral contraceptive preparations used in the four patients contained comparable amounts of ethinylestradiol (20-35 ��g) while the progesterone-like portion ranged from 50 to 150 ��g. All patients had a liver biopsy done for strictly diagnostic reasons, which showed intrahepatic cholestasis in three patients. One patient had a previous history of ICP. Table 3 Characteristics of patients with oral CIC Sequence analysis ABCB4 and ABCB11: Sequence analysis in the 25 newly recruited patients with estrogen-associated cholestasis revealed no disease-associated non-synonymous mutations in ABCB4 or ABCB11.
Furthermore, in line with previous findings[11], no ABCB4 polymorphism was found to be overrepresented in the ICP and CIC groups compared to pregnant women without cholestasis and healthy Caucasian individuals. All of the detected genetic variants in ABCB11 and ABCB4 were in Hardy Weinberg equilibrium. In contrast, the ABCB11 1331T>C �� V444A polymorphism was significantly more Brefeldin_A frequent in ICP and CIC patients compared to the two control groups. Specifically, the CC genotype was encountered in 57.