Hepatitis C is a blood-borne, infectious, viral disease that is caused by a hepatotropic virus called Hepatitis C virus (HCV). The infection can cause liver inflammation that is often asymptomatic, but ensuing chronic hepatitis can result later in cirrhosis (fibrotic scarring of the liver) and liver cancer.
The hepatitis C virus (HCV) is spread by blood-to-blood contact with an infected person's blood. The symptoms can be medically managed, and a proportion of patients can be cleared of the virus by a long course of anti-viral medicines. Although modification of diet and early medical intervention are helpful, people with HCV infection often experience mild symptoms, and consequently do not seek treatment.
An estimated 150-200 million people worldwide are infected with hepatitis C. In the U.S., those with a history of intravenous drug use, tattoos, or who have been exposed to blood via unsafe sex or social practices are high risk for this disease. Hepatitis C is the leading cause of liver transplant in the United States.
The hepatitis C virus is one of six known hepatitis viruses: A, B, C, D, E, G.
Acute Hepatitis C
Acute hepatitis C refers to the first 6 months after infection with HCV. Between 60% to 70% of people infected develop no symptoms during the acute phase. In the minority of patients who experience acute phase symptoms, they are generally mild and nonspecific, and rarely lead to a specific diagnosis of hepatitis C. Symptoms of acute hepatitis C infection include decreased appetite, fatigue, abdominal pain, jaundice, itching, and flu-like symptoms.
The hepatitis C virus is usually detectable in the blood within one to three weeks after infection, and antibodies to the virus are generally detectable within 3 to 12 weeks. Approximately 20-30% of persons infected with HCV clear the virus from their bodies during the acute phase as shown by normalization in liver function tests (LFTs) such as alanine transaminase (ALT) & aspartate transaminase (AST) normalization, as well as plasma HCV-RNA clearance (this is known as spontaneous viral clearance). The remaining 70-80% of patients infected with HCV develop chronic hepatitis C, i.e., infection lasting more than 6 months.
Previous practice was to not treat acute infections to see if the person would spontaneously clear; recent studies have shown that treatment during the acute phase of genotype 1 infections has a greater than 90% success rate with half the treatment time required for chronic infections, but that the majority of acute hepatitis C is cleared.
Chronic Hepatitis C
Chronic hepatitis C is defined as infection with the hepatitis C virus persisting for more than six months. Clinically, it is often asymptomatic (without jaundice) and it is mostly discovered accidentally.
The natural course of chronic hepatitis C varies considerably from one person to another. Virtually all people infected with HCV have evidence of inflammation on liver biopsy, however, the rate of progression of liver scarring (fibrosis) shows significant variability among individuals. Recent data suggests that among untreated patients, roughly one-third progress to liver cirrhosis in less than 20 years. Another third progress to cirrhosis within 30 years. The remainder of patients appear to progress so slowly that they are unlikely to develop cirrhosis within their lifetimes. Factors that have been reported to influence the rate of HCV disease progression include age (increasing age associated with more rapid progression), gender (males have more rapid disease progression than females), alcohol consumption (associated with an increased rate of disease progression), HIV coinfection (associated with a markedly increased rate of disease progression), and fatty liver (the presence of fat in liver cells has been associated with an increased rate of disease progression).
Symptoms specifically suggestive of liver disease are typically absent until substantial scarring of the liver has occurred. However, hepatitis C is a systemic disease and patients may experience a wide spectrum of clinical manifestations ranging from an absence of symptoms to debilitating illness prior to the development of advanced liver disease. Generalized signs and symptoms associated with chronic hepatitis C include fatigue, marked weight loss, flu-like symptoms, muscle pain, joint pain, intermittent low-grade fevers, itching, sleep disturbances, abdominal pain (especially in the right upper quadrant), appetite changes, nausea, diarrhea, dyspepsia, cognitive changes, depression, headaches, and mood swings.
Once chronic hepatitis C has progressed to cirrhosis, signs and symptoms may appear that are generally caused by either decreased liver function or increased pressure in the liver circulation, a condition known as portal hypertension. Possible signs and symptoms of liver cirrhosis include ascites (accumulation of fluid in the abdomen), bruising and bleeding tendency, bone pain, varices (enlarged veins, especially in the stomach and esophagus), fatty stools (steatorrhea), jaundice, and a syndrome of cognitive impairment known as hepatic encephalopathy.
Liver function tests show variable elevation of ALAT, AST and GGTP and periodically they might show normal results. Usually prothrombin and albumin results are normal.
Chronic hepatitis C, more than other forms of hepatitis, is diagnosed because of extrahepatic manifestations associated with the presence of HCV such as thyroiditis (inflammation of the thyroid) with hyperthyreosis or hypothyreosis, porphyria cutanea tarda, cryoglobulinemia (a form of vasculitis) and glomerulonephritis (inflammation of the kidney), specifically membranoproliferative glomerulonephritis (MPGN). Hepatitis C is also associated with sicca syndrome, thrombocytopenia, lichen planus, diabetes mellitus and with B-cell lymphoproliferative disorders.