It all depends on the technic used , Because the normal level is :560 to 1800 mg/dL Since IgG is the major type of antibody found in the blood and interstitial fluid. It controls the body tissue infections and protects the body against these elements using many immune mechanisms. toxin neutralization
An increase of IgG may be due to : Chronic infection or inflammation,Hyperimmunization (the presence of a larger than normal number of antibodies to a specific antigen) , Liver disease ,Rheumatoid arthritis