Our immune system is our body’s defense mechanism, protecting us from antigens (toxins, bacteria, viruses, and chemicals). The immune system has many tools (cells) at its disposal to protect us. One of these tools is a protein called antibodies aka immunoglobulins.
There are 5 different types of antibodies – IgA, IgD, IgM, IgE and IgG.
IgM is your early/first responders.
IgA lines the gut, respiratory tract, and urogenital tract.
IgD is found on naïve B-cells. They are not exposed to any antigens.
IgG is the bigwig of the antibodies. It is the major defender in fighting against invading antigens. Our body has the highest concentration of IgG antibodies. (There are 4 subclasses of IgG – IgG1, IgG2, IgG3, and IgG4)
IgE binds to allergens. It causes your white blood cells to release histamine, which leads to allergy symptoms.
Sometimes, the body creates antibodies to fight against itself, mistakenly treating organs and tissue as foreign intruders that need to be destroyed. That’s what is happening in my case. My immune system is mistaking my organs, especially my lungs, as a foreign substance that shouldn’t be there. It is over-producing the antibody IgG4 to fight what it believes are antigens, but what are really my vital organs. That’s why it’s important to get a correct diagnosis early and to begin treatment right away to avoid organ damage, organ failure, and sometimes even organ transplants.
This disease is rare, and most doctors don’t know to look for it. IgG4-RD can affect any organ and symptoms change depending on what organ is being affected. Many people are misdiagnosed and treated for the wrong disease. For example, if someone had an issue with their kidney’s and the doctor treats them for a kidney disease, they won’t improve because their body is still producing the antibody that was instructed to fight the kidney because it was confused for an antigen. Pretty scary, right?!
While there is evidence that the disease has existed for hundreds of years, it wasn’t until the early 2000’s that researchers discovered elevated IgG4 levels in patients with sclerosing pancreatitis. In the last 10 years, monumental advancements in IgG4-RD diagnosis and treatment process have been made. While this is still a relatively new disease, it’s difficult to receive a diagnosis and for insurance to approve some treatment options.
The standard treatment is the steroid, prednisone. It is usually taken for 3 months and then tapered for 2 months. If the IgG4 levels are back in normal range after treatment, you are in remission, which on average can last up to 6 months. Unfortunately, steroids also have several adverse side effects. Rituxan is another drug that is being used to treat IgG4-RD. It’s a drug delivered through an IV infusion, doesn’t have the bad side effects, and results in longer remission. However, it’s very difficult to get your insurance provider to approve Rituxan.