For the first time in more than 10 years, clinical guidelines from the American College of Gastroenterology (ACG) offer recommendations on the evaluation of abnormal liver values.
This is also the first time in a liver assessment guideline that authors have defined a normal healthy serum ALT level for women (19-25 IU/L) and men (29-33 IU/L). Authors recommend that levels above these ranges should be assessed further.
“For the purposes of this guideline,” the authors wrote, “we have opted to define a ‘normal’ ALT based on the available literature correlating ALT levels and liver-related mortality. However, clinical judgement still remains of paramount importance.”
Paul Y Kwo, MD, FACG, of the Stanford University School of Medicine and one of the authors of the guidelines, stated that the decision was based on emerging data collected during the past decade. Data showed ALT levels above the previously defined thresholds had been associated with higher liver-related mortality rates across populations worldwide, driven in part by the obesity epidemic.
“With the broad range of ‘upper limit of normal’ levels for ALT that vary from institution to institution, clinicians may not think to evaluate an ALT level of 70 IU/L, as this may be within the normal level for the reporting laboratory, even though this level of elevation is associated with increased liver-related mortality,” Dr. Kwo explained.
Many people have undiagnosed chronic hepatitis B and C, non-alcoholic fatty liver disease, advanced liver disease, and other, less-common conditions that all require evaluation. In addition, the increased prevalence of non-alcoholic fatty liver disease may be partly addressed through the identification and evaluation of these individuals prior to the development of advanced fibrosis.
The new guidelines take clinicians through a step-wise approach to the evaluation of elevated aminotransferase (ALT and AST), alkaline phosphatase, and bilirubin levels. The steps include appropriate history gathering, important physical examination findings, laboratory studies, radiologic evaluation, and liver biopsy if required.
The ACG Abnormal Liver Chemistries Guideline also includes algorithms to aid in a graded approach to patients with abnormal aminotransferase levels by categorizing the elevations as minimal, mild, moderate, and severe.
Specific guidelines also inform when immediate evaluation is required and when a more limited evaluation can be performed with subsequent evaluation, if liver chemistries fail to normalize. The authors recognize that it will take time for clinicians to recognize the newer lower limits of ALT levels that should now be considered normal.
These guidelines were jointly authored by Dr. Kwo, Stanley M. Cohen, MD, FACG, of Case Western Reserve University School of Medicine, and Joseph K. Lim, MD, FACG, of Yale University School of Medicine.
The full text of “ACG Practice Guideline: Evaluation of Abnormal Liver Chemistries” can be found at gi.org.