Immunoglobulin G (IgG) Subclass 1, Mass Concentration

What Is IgG1 Used For?

IgG1 is part of the broader immune response, particularly in defending against pathogens like bacteria and some viruses. It’s also involved in immune regulation and memory functions. Your doctor may check IgG1 levels if you have symptoms of immune-related conditions, such as recurrent infections, autoimmune diseases, or certain immune deficiencies.

Why Might Your Doctor Order This Test?

Your healthcare provider might request this test if you have concerns about immune function, such as frequent infections, unusual fatigue, or symptoms linked to low antibody levels. It can also be part of diagnosing or monitoring conditions like common variable immunodeficiency (CVID) or other immune disorders.

How Is This Test Performed?

A blood sample is drawn from a vein, usually in your arm. The blood is then processed to measure the concentration of IgG1 antibodies in your serum or plasma. The results are compared to standard reference ranges to determine your IgG1 level.

What Do the Results Mean?

Results may indicate whether your IgG1 levels are within normal ranges, lower than expected (hypogammaglobulinemia), or higher than expected. Low IgG1 levels could suggest an immune system that isn’t producing enough antibodies, while higher levels may require further investigation for conditions like chronic inflammation or certain immune disorders.