Introduction:
Intrahepatic cholestasis of pregnancy (ICP) and acute fatty liver of pregnancy (AFLP) are important pregnancy complications associated with poor maternal and fetal outcomes. We report the case of a DCDA twin pregnancy with an overlap of ICP and atypical AFLP associated with azathioprine use for Takayasu arteritis.
Case Presentation:
A 37-year-old G1P0 lady with an IVF DCDA twin pregnancy had a past medical history of Takayasu arteritis, diagnosed in 2016 with coeliac, left common carotid, left subclavian, axillary and brachial artery involvement. She was initially managed with prednisolone, then maintenance therapy azathioprine 125mg daily. In pregnancy her disease was stable on azathioprine (erythrocyte sedimentation rate 40mm/hr and C-reactive protein 10mg/L). Her pregnancy was uncomplicated except for gestational diabetes mellitus, diet controlled. At 29-weeks’-gestation she developed pruritis and diagnosed with ICP (non-fasting bile acids 62umol/L) with mildly abnormal liver function tests (LFTs) (aspartate aminotransferase (AST) 49 U/L and alanine aminotransferase (ALT) 36U/L). She was commenced on ursodeoxycholic acid.
At 31-weeks’-gestation she presented with hypoglycaemia, worsened LFTs (AST 53U/L, ALT 30U/L, gamma-glutamyl transferase 478U/L, alkaline-phosphatase 112U/L), bilirubin 67umol/L (conjugated bilirubin 55umol/L) and coagulopathy (INR 1.8.) She was asymptomatic without evidence of haemolysis, thrombocytopenia, pre-eclampsia or HELLP. Her twins demonstrated normal growth on USS with normal DVP and fetal doppler parameters. A liver ultrasound showed normal liver parenchyma, with gallbladder calculi but no biliary tree dilatation or intraductal calculi. Given the obstructive LFTs, she underwent an MRCP that was unremarkable. She met 5 Swansea criteria for AFLP, not meeting full diagnostic criteria. Her azathioprine was withheld given the possibility it contributed to her LFT derangement, especially given raised metabolites (6-MMP 15,661pmol/8x10^8 RBC, 6-TGN 526 pmol/8x10^8 RBC, ratio 29.8). She developed worsened LFTs and coagulopathy, hence a decision was made to deliver her twins via emergency cesarean-section, delivering healthy twins of 1.6kg and 1.7g. Day 6 post-partum her LFTs improved. Her azathioprine was reintroduced at day 10 at 75mg daily. One week later her LFTs improved, with significantly lower azathioprine metabolites (6-MMP 793pmol/8x10^8 RBC, 6-TGN 165pmol/8x10^8 RBC, 6-MMP/6-TGN ratio 4.8). She is planned for rheumatology follow-up with repeat imaging to assess the status of her arteritis.
Discussion:
This case details a presentation of ICP with overlap of likely atypical AFLP, in the setting of azathioprine use for Takayasu arteritis. It suggests there may be an association between azathioprine use and both ICP and AFLP (3), especially in the setting of raised azathioprine metabolites.