You may have heard about using thymosin alpha-1 therapy for psoriatic arthritis (PsA). Since 1977, when the therapy was discovered, there have been claims about its benefits for treating many conditions, including infections, immune conditions, and cancer.
Researchers have not studied the potential benefits of thymosin alpha-1 for people with PsA, but it could be a helpful treatment because of its effects on immunity and inflammation.
This article explains what thymosin alpha-1 is and how it could work as a therapy for PsA.
Thymosin alpha-1 is a peptide (short chain of amino acids) that your body makes naturally. It’s made of 28 amino acids, which are the building blocks of proteins. Peptides can bind to cells and signal them to do specific things.
Your thymus gland makes thymosin alpha-1. The thymus is part of your lymphatic system and produces T cells (a type of white blood cell) that plays a crucial role in defending you against infection and other diseases. Thymosin alpha-1 is recognized for its role in immune function and inflammation.
Thymosin alpha-1 has been shown to reduce death caused by severe COVID-19 infection and to slow tumor growth in some types of cancer, such as lung and liver cancers. These associations are based on retrospective case studies, and data is limited.
The synthetic (human-made) form of thymosin alpha-1, thymalfasin (Zadaxin), is approved for use in more than 35 countries to treat hepatitis B, hepatitis C, and certain types of cancer. However, in the United States, neither thymalfasin nor thymosin alpha-1 is approved by the U.S. Food and Drug Administration (FDA) to treat any condition.
Scientists have studied thymosin alpha-1 for treating a variety of immune conditions, infections, and cancers, including:
Researchers don’t fully understand how thymosin alpha-1 works, but they think it is related to its ability to stimulate the immune system and T cells. T cells are white blood cells that help your body fight infection and cancer.
Thymosin alpha-1 can regulate the immune system by interacting with toll-like receptors on myeloid cells (blood cells) in the bone marrow. Here, thymosin alpha-1 promotes T-cell maturation into more specialized T cells that play an important role in fighting infections and cancer.
Thymosin alpha-1 also interacts with the toll-like receptors on dendritic cells. Dendritic cells are found all over the body. They can stimulate an immune response by showing antigens (foreign substances) to T cells and other immune cells. Thymosin alpha-1 can stimulate this response, which can help your body fight infections.
Thymosin alpha-1 changes the production of certain cytokines (signaling proteins) that can enhance the immune response. It can also decrease inflammation by reducing levels of other cytokines like interleukin (IL) and tumor necrosis factor-alpha (TNF-alpha). This may be beneficial for people who are immunocompromised.
To date, no clinical trials have studied thymosin alpha-1 therapy in people with PsA or other autoimmune diseases. Researchers think that thymosin alpha-1 may benefit people with PsA because of the key role it plays in stimulating the immune system and controlling inflammation. However, there is no information on how taking thymosin alpha-1 might affect PsA symptoms.
One study compared the serum levels of thymosin alpha-1 in healthy people and those with PsA. The researchers found that people with PsA had significantly lower levels of thymosin alpha-1 than those without the disease. Thymosin alpha-1 levels in people with PsA remained low even when they received treatment with disease-modifying antirheumatic drugs (DMARDs), especially when combined with a corticosteroid.
Thymosin alpha-1 could also play a role in regulating T cells and cytokines. Increased T cells in the joint fluid are associated with more PsA disease activity. Thymosin alpha-1 might improve disease activity by increasing T-cell activity. However, this has not been proved by any clinical trials.
Thymosin alpha-1 has been shown to decrease levels of the inflammatory cytokines TNF-alpha and interleukins that cause inflammation in people with PsA. Many common biologic treatments for PsA work by blocking TNF-alpha, IL-17, or IL-23 to reduce inflammation. Scientists believe that because thymosin alpha-1 reduces the activity of these key cytokines, it might improve inflammation in PsA.
Thymosin alpha-1 is a solution that is usually given twice a week by subcutaneous (under the skin) injection.
In the U.S., you may take thymosin alpha-1 if you are part of a clinical trial. However, there are currently no clinical trials recruiting people with PsA to use thymosin alpha-1.
Thymosin alpha-1 is generally well tolerated. The most common side effect is irritation, redness, or discomfort at the injection site.
Rarely, thymosin alpha-1 can cause serious side effects, such as:
At this time, there is not enough clinical evidence to support the use of thymosin alpha-1 as a treatment for PsA. Also, keep in mind that people who are immunosuppressed should not take thymosin alpha-1. Because more research is needed to confirm whether this drug is safe and effective in treating PsA, talk to your doctor or rheumatologist to see if thymosin alpha-1 therapy can benefit you.
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