Significance of alanine aminotransferase testing in diagnosis of acute and chronic HBV infection.

Hepatitis B is a major public health problem world wide; more than 350 million people have chronic infection. Diagnosis of hepatitis is made by biochemical assessment of liver function. Alanine aminotransferase (ALT), a liver enzyme, is markedly elevated in hepatitis and with other causes of acute liver damage associated with hepatic necrosis, blood levels being elevated even before the clinical signs and symptoms of disease such as jaundice appear. HBsAg can be detected in the serum from several weeks before onset of symptoms to several months after onset of acute HBV infection. The presence of HBsAg indicates that the person is potentially infectious. In our study we found that 80% patients who were HBsAg positive had abnormal ALT levels, while the remaining 20% had normal ALT values. This is despite suffering from acute or chronic liver disease, providing a reason why some patients positive for hepatitis B have a normal ALT.