Serum immunoglobulins (IgG, IgA, IgM) in chronic hepatitis C. A comparison with non-cirrhotic alcoholic liver disease.

BACKGROUND/AIMS: Serum immunoglobulin concentrations are commonly elevated in patients with liver cirrhosis. Immunoglobulin class increase may vary depending on the cause of liver disease. Hepatitis C virus is, together with alcohol, a leading cause of chronic liver disease. The present study aimed to evaluate serum IgG, IgA and IgM levels in chronic hepatitis C. Results were compared with those of patients with non-cirrhotic alcoholic liver disease and healthy controls. Special attention was given to cases with minimal liver disease, as an approach to evaluate if the causing agent, independently of liver damage, influences serum immunoglobulin levels.

METHODOLOGY

A total of 274 patients with histologically-proven chronic hepatitis C, 121 alcoholics with non-cirrhotic liver disease (steatosis or alcoholic hepatitis), and 75 healthy controls were studied. Serum IgG, IgA, and IgM were assayed by nephelometry.

RESULTS

Serum IgG was increased in patients with chronic hepatitis C with respect to both alcoholics (p < 0.001) and healthy controls (p < 0.001). IgG levels were similar in alcoholics and in controls. IgA was increased in patients with non-cirrhotic alcoholic liver disease with respect to both chronic hepatitis C patients (p < 0.001) and controls (p < 0.001). IgA values were similar in subjects with chronic hepatitis C and controls. Selective IgG or IgA alteration was present in cases with minimal liver disease (chronic hepatitis C with a Knodell index equal or lower than 3, and alcoholics with liver steatosis, respectively).

CONCLUSIONS

Hepatitis C virus and alcohol are linked to a selective increase of serum IgG and IgA, respectively, even in cases with mild or minimal liver disease.