Abstract: Objective To analyze the clinical significance of changes in the number and subpopulations of placental macrophages in patients with intrahepatic cholestasis of pregnancy (ICP). Methods 105 ICP patients who were hospitalized and delivered in our hospital from May 2022 to July 2024 were selected and divided into a mild ICP group (n=51) and a severe ICP group (n=54); during the same period, 30 hospitalized healthy pregnant women were selected as the control group. Compare the total number of placental macrophages and subgroups of M1 and M2 macrophages, as well as the levels of IL-10, IL-4, IL-12, INF - γ, TNF - α, TBA, ALT, AST, and TBil in three groups. Methods The total macrophages, M1 subtype, and M2 subtype in the severe ICP group were (3.04 ± 0.87)%, (19.75 ± 5.73)%, and (81.84 ± 10.98)%, while in the mild ICP group they were (2.07 ± 0.54)%, (28.42 ± 7.65)%, and (72.11 ± 9.86)%. The control group had (0.32 ± 0.10)%, (46.55 ± 12.44)%, and (50.76 ± 8.57)%, respectively. There were statistically significant differences among the three groups (F=171.265, 100.055, 92.183, all P<0.05) There was no significant difference in IL-10 levels among the three groups (P>0.05); The levels of IL-4, IL-12, INF - γ, and TNF - α in the severe ICP group were (37.01 ± 10.35) pg/mL, (51.44 ± 8.51) pg/mL, (181.76 ± 15.64) pg/mL, and (108.35 ± 12.73) pg/mL, while those in the mild ICP group were (76.33 ± 19.32) pg/mL, (38.94 ± 7.63) pg/mL, (153.54 ± 12.65) pg/mL, and (84.53 ± 11.71) pg/mL. The control group had levels of (128.17 ± 22.54) pg/mL, (23.95 ± 6.42) pg/mL, (136.22 ± 11.73) pg/mL, and (62.34 ± 10.08) pg/mL. The differences were statistically significant (F=273.158, 122.976, 117.775, 152.725, all P<0.05). The TBA, AST, ALT, and TBil levels in the heavy ICP group were (83.54 ± 11.35) μmol/L, (198.76 ± 51.85) U/L, (347.95 ± 103.74) U/L, and (23.54 ± 3.11) μmol/L, while those in the light ICP group were (30.07 ± 5.23) μmol/L, (50.21 ± 11.38) U/L, (64.35 ± 18.26) U/L, and (11.72 ± 2.89) μmol/L. The control group had (14.15 ± 4.57) μmol/L, (28.93 ± 8.76) U/L, (30.17 ± 9.78) U/L, and (7.29 ± 1.32) μmol/L. The differences between the three groups were statistically significant (F=892.232, 349.851, 320.673, 420.008, all P<0.05). The levels of total macrophages, M2 subtype, IL-4, IL-12, INF-γ, and TNF-α were positively correlated with liver function in ICP patients (P<0.05); The M1 subtype and IL-4 levels were negatively correlated with liver function in ICP patients (P<0.05); There was no significant correlation between IL-10 levels and liver function in ICP patients (P>0.05). Conclusion There are abnormalities in the number and subpopulation differentiation of placental macrophages in ICP patients. Imbalance of M1/M2 macrophage subpopulations may cause damage to the maternal fetal interface immune microenvironment, resulting in disease onset and progression.

Key words: Pregnancy complicated with intrahepatic cholestasis, Placenta, M1 type macrophages, M2 macrophages, Interleukin, Tumor necrosis factor-α, Liver function