Autoimmune hepatitis is a chronic liver disease, caused by a person’s defensive cells attacking their own liver. This leads to a process of inflammation and destruction that can end in cirrhosis and liver cancer.
The diagnosis of autoimmune hepatitis is made by analyzing the blood for the presence of autoantibodies (anti-nuclear, anti-smooth muscle, anti-mitochondrial, anti-LKM) and the quantification of immunoglobulins. However, 25% of autoimmune hepatitis are asymptomatic and 10% of them do not have any of the analytical features mentioned, and so they are difficult to diagnose and this can only be done by performing a liver biopsy.
An article, recently published in The Lancet, studies the frequency of autoimmune hepatitis in the general population. A total of 55,839 patients from North America, Europe, Asia and Oceania were included in the analysis. The study proves that women suffer from autoimmune hepatitis more frequently than men, as do people over 65 years of age.
How the incidence of hepatitis has evolved
The prevalence of autoimmune hepatitis has been increasing over time. Thus, between 1970 and 1999 this prevalence was 9.95 cases per 100,000 inhabitants, while from 2015 to 2022 it increased to 27.91 cases per 100,000 inhabitants. This indicates that the prevalence of autoimmune hepatitis has tripled since 2000.
There are several factors that could explain this increase. First, obesity, a risk factor for the onset of autoimmune hepatitis, has increased in the general population in recent years. The use of some antibiotics (nitrofurantoin, minocycline) has also been associated with the development of autoimmune hepatitis. In addition, improvements over time in living conditions, habits and diet can influence the bacterial flora of the intestine, which can contribute to the development of autoimmune hepatitis.
Furthermore, it has been shown that, with economic development, infectious diseases decrease but allergies and autoimmune diseases increase. Thus, in Spain, with the improvement of economic conditions, infectious diseases (such as hepatitis A) have decreased and the frequency of autoimmune hepatitis has increased. On the other hand, in underdeveloped countries some of the diagnostic tests for autoimmune hepatitis are not performed, so its frequency may be undervalued as it remains undiagnosed.
Dr. Carreño and his team have noticed a significant increase in patients with autoimmune hepatitis in recent years. It should be noted that, in our experience, with appropriate treatment, normalization of liver parameters is achieved in more than 40% of cases.