Apolipoprotein deficiency and chronic liver disease.

Deficiency of apolipoprotein can be of genetic origin or due to diseases like advanced chronic liver disease. Deficiency of apolipoprotein A causes Tangier disease without any major hepatic involvement being reported. Deficiency of apolipoprotein B causes abetalipoproteinemia or familial hypobetalipoproteinemia; with hepatic involvement in the form of raised transaminases, fatty liver and cirrhosis. Advanced chronic liver disease itself can cause reduction of apolipoprotein A and apolipoprotein B levels and acanthocytosis. In patients with chronic liver disease of undetermined etiology, lipid profile and apolipoprotein levels should be obtained routinely. If it suggests apolipoprotein B deficiency, then liver biopsy can be avoided, as the etiology of chronic liver disease is established. Isolated deficiency of either apolipoprotein A or apolipoprotein B suggests etiology of chronic liver disease, while deficiency of both apolipoprotein A and apolipoprotein B is a manifestation of advanced chronic liver disease.