R value

Q: What is the significance of R value in liver hepatology?

Answer: The R-value, also called the R factor, may help to differentiate the type of liver injury, i.e., hepatocellular versus cholestatic. The formula is 

R value  =  (ALТ  ÷  ULN AԼT)  /  (alkaline phosphatase  ÷  ULN alkaline phosphatase)

ULN: Upper limit of normal

The R-value is interpreted as follows:

• ≥5: Hepatocellular injury
• >2 to <5: Mixed pattern
• ≤2: Cholestatic injury

          

#hepatology

          

          

References:

          

 1. Kalas MA, Chavez L, Leon M, Taweesedt PT, Surani S. Abnormal liver enzymes: A review for clinicians. World J Hepatol. 2021 Nov 27;13(11):1688-1698. doi: 10.4254/wjh.v13.i11.1688. PMID: 34904038; PMCID: PMC8637680.

 2. Fontana RJ, Liou I, Reuben A, Suzuki A, Fiel MI, Lee W, Navarro V. AASLD practice guidance on drug, herbal, and dietary supplement-induced liver injury. Hepatology. 2023 Mar 1;77(3):1036-1065. doi: 10.1002/hep.32689. Epub 2023 Feb 17. PMID: 35899384; PMCID: PMC9936988.