Like alkaline phosphatase, also found in abundance in the<unk>  and bile ducts (also spleen, heart, and brain)
Elevation in conjunction with an elevation in alkaline phosphatase, suggests biliary stasis/obstruction
Liver function tests
Cardiac enzymes
HIV testing 
Cardiac ultrasound
ECG 
Urine toxicology screen
Microbiology 
Biliary ultrasound