Your doctor will order these tests while you are taking biologic drugs for your inflammatory arthritis.
Your rheumatologist has prescribed a biologic drug for the treatment of your inflammatory arthritis – like rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, juvenile idiopathic arthritis or lupus. After getting a detailed medical history and having a discussion with you about your preferences, safety and concerns, he or she will perform a battery of lab tests before starting a biologic and while you are on the drug. These may include:
- Skin or blood tuberculosis (TB) test. Even if you’ve never had TB, the bacteria can lie quiet in your body for many years. Taking medications that suppress the immune system increases the risk that the infection will become active. Your doctor will continue to monitor for TB throughout your treatment.
- Hepatitis B virus (HBV) screening. HBV reactivation can occur in patients treated with any biologic, in some cases resulting in liver failure and even death. You will be screened for HBV infection before treatment and monitored for it during and after treatment.
- Liver enzyme or liver function test. Treatment with a biologic can damage the liver, especially if you’ve had hepatitis or tuberculosis. A liver enzyme test can help determine if HBV has been reactivated or if your liver is being damaged by the drug.
- Complete blood count (CBC). For most biologics, a CBC is required before, during and after treatment. This test monitors white blood cells, which help fight infection; platelets, which are needed to clot blood; and red blood cells, which carry oxygen throughout the body. Based on your counts, your drug may be reduced or stopped. Signs to look for include fever, bruising or bleeding easily, and looking pale.
- Lipid panel. Treatment with interleukin inhibitors (such as anakinra or tocilizumab) and JAK inhibitors (tofacitinib) can cause an increase in blood cholesterol levels in some people. Your doctor will periodically check these levels and may prescribe a medication to lower it if it becomes too high.
- Skin examination. Regardless of the biologic you are prescribed, having rheumatoid arthritis increases your risk of skin cancer compared to the general population. B-cell and TNF inhibitors may add to this risk, and they can also worsen psoriasis. You will need to get annual skin examinations.
- Blood glucose test. Abatacept can give falsely elevated glucose readings in people with diabetes because it has maltose in its IV injection.
- Blood pressure and heart monitoring. If you have high blood pressure already, an infusion will make this worse. You will need to be monitored very closely during and after the drug is infused, especially if you have congestive heart failure and you’ve been prescribed infliximab.
Depending on other conditions you may have, your rheumatologist will monitor you closely, particularly during the first 6 to 12 months of treatment. As your condition improves, your risk of side effects will diminish and your doctor may spread your monitoring blood tests out more.