A panel of experts proposed a new set of criteria for the diagnosis of metabolic-associated fatty liver disease (MAFLD). These guidelines were published in the Journal of Hepatology. Diagnosis of MAFLD, formerly known as non-alcoholic fatty liver disease, currently involves the exclusion of other chronic liver disease sources, such as excessive alcohol intake. However, investigators proposed adding a series of “positive criteria” to the MAFLD definition, establishing a new set of clinical features that would be requisite for diagnosis. These new positive criteria are independent of alcohol consumption and applicable to patients in all clinical settings.
The present definition of MAFLD is based on the presence of steatosis in >5% of hepatocytes and the absence of excessive alcohol consumption or other causes of chronic liver disease. A panel of experts from 22 countries collaborated to produce updated diagnostic criteria, adding several new positive criteria to this list. Based on these new guidelines, a diagnosis of MAFLD would require the presence of hepatic steatosis in combination with 1 of the 3 following criteria: overweight/obesity; presence of type 2 diabetes mellitus; or evidence of metabolic dysregulation. Investigators defined metabolic dysregulation as having at least 2 of the following metabolic risk abnormalities: high waist circumference, high blood pressure, high cholesterol, pre-diabetes, insulin resistance, and high plasma C-reactive protein levels. These new diagnostic criteria take into account the strong pathological link between greater body weight, diabetes, and MAFLD. Diagnostic criteria based on exclusion fail to address the complexity of MAFLD, authors wrote. Additionally, existing benchmarks for “excessive” alcohol consumption may exclude eligible patients from MAFLD diagnosis. As such, investigators also suggested the use of a “dual etiology” category for patients who meet MAFLD criteria and report another source of liver dysfunction such as Hepatitis B or C.
Guideline authors suggested that MAFLD severity be graded on a continuum rather than dichotomized as steatohepatitic vs non-steatohepatitic. Specifically, they wrote that MAFLD severity would be better described by grade of activity and stage of fibrosis. Additionally, the group proposed a new set of criteria to define MAFLD-associated cirrhosis. To meet these new diagnostic criteria, patients with cirrhosis must have past or present evidence of metabolic risk factors with at least 1 of the following factors: documentation of MAFLD on a previous liver biopsy; or historical documentation of steatosis by hepatic imaging. Cirrhosis in patients with MAFLD should be described as MAFLD-related cirrhosis, authors wrote, rather than “cryptogenic cirrhosis.” Growing evidence suggests that cryptogenic cirrhosis is distinct from MAFLD-related cirrhosis, and that the 2 conditions have distinct clinical outcomes.
Consensus regarding the diagnostic criteria for MAFLD will ultimately improve clinical care by preventing misclassification of fatty liver from other sources. The use of more stringent criteria may also improve clinical trial relevance because fewer patients with fatty liver unrelated to metabolic dysfunction will be enrolled. “[The new] diagnosis is based on recognition of underlying abnormalities in metabolic health with acceptance that MAFLD may commonly co-exist with other conditions,” authors wrote.
Eslam M, Newsome PN, Anstee QM, et al. A new definition for metabolic associated fatty liver disease: an international expert consensus statement [published online April 8, 2020]. J Hepatol. doi: 10.1016/j.jhep.2020.03.039.