Thyroxine-binding globulin (TBG) is a globulin that binds thyroid hormones in circulation. It is one of three transport proteins (along with transthyretin and serum albumin) responsible for carrying the thyroid hormones thyroxine (T4) and triiodothyronine (T3) in the bloodstream. Of these three proteins, TBG has the highest affinity for T4 and T3 but is present in the lowest concentration. Despite its low concentration, TBG carries the majority of T4 in the blood plasma.

Immunoglobulin A (IgA) is a crucial antibody in the immune system, predominantly found in mucous membranes of the respiratory and gastrointestinal tracts. It helps protect against infections by neutralizing pathogens before they can cause harm. Testing IgA levels can provide insights into immune health, indicating potential issues such as chronic infections, autoimmune diseases, or immunodeficiency disorders. Elevated or decreased IgA levels can signal various health conditions, making this test valuable for diagnosing and managing immune-related issues. For those experiencing frequent infections or gastrointestinal issues, an IgA test can be an essential diagnostic tool.

Includes liver and kidney function, glucose and electrolytes

The Rheumatoid Arthritis Factor is often evaluated in patients suspected of having any form of arthritis or destructive articular disease even though positive results can be due to other causes, and negative results do not rule out disease. But, in combination with signs and symptoms, it can play a role in both diagnosis and disease prognosis. It is part of the usual disease criteria of rheumatoid arthritis.