Cannabinoids present in Cannabis sativa (marijuana) exert biological effects via cannabinoid receptors CB1 and CB2.
Dr Ariane Mallat and colleagues from France recently demonstrated that CB1 and CB2 receptors regulate progression of experimental liver fibrosis.
The investigators therefore investigated the impact of cannabis smoking on fibrosis progression rate in patients with chronic Hepatitis C.
| 6 factors are independently related to a fibrosis progression rate greater than 0.07|
The investigative team studied 270 consecutive untreated patients with chronic Hepatitis C of known duration undergoing liver biopsy.
The team recorded demographic, epidemiological, metabolic, and virological data.
The investigators also obtained detailed histories of cannabis, alcohol, and tobacco use over the span of Hepatitis C virus infection.
Fibrosis stage, steatosis, and activity grades were scored according to Metavir system.
The team categorized 52% of patients as noncannabis users, 15% as occasional users, and 33% as daily users.
The relationship between cannabis use and fibrosis progression rate or fibrosis stage was assessed.
Using multivariate analysis, the team identified 6 factors independently related to a fibrosis progression rate greater than 0.07, the median value of the cohort.
The independent factors related to fibrosis progression rate included daily cannabis use, and Metavir activity grade A2 or higher.
The investigators also identified age at contamination of more than 40 years, genotype 3, excessive alcohol intake, and steatosis as independent risk factors.
The team noted that daily cannabis use was an independent predictor of a rapid fibrosis progression rate.
Finally, the investigators predicted severe fibrosis by daily cannabis use, independently of Metavir activity grade, and excessive alcohol intake.
The prediction of severe fibrosis by daily cannabis use was also independent of age at liver biopsy, steatosis, and tobacco smoking.
Dr Mallat's team concluded, “Daily cannabis smoking is significantly associated with fibrosis progression during chronic Hepatitis C.”
“Patients with ongoing chronic Hepatitis C should be advised to refrain from regular cannabis use.”