How Does the Arthus Phenomenon Occur in the Immune System?
Following the skin injection of soluble antigen into the subject previously immunised by a series of the same injections, the Arthus syndrome manifests as local swelling, tissue death, and redness. The tissue damage is the result of the precipitation of antigen-antibody complexes present in the walls of blood vessels; then, the deposits are ingested (phagocytosed) by the neutrophil white blood cells. This specific phenomenon was named after the French physiologist named Maurice Arthus.
Process
After an antigen is injected intradermally, the Arthus reaction occurs, in which the antigen or antibody complexes form in situ. An Arthus reaction occurs if the animal or patient has already been sensitised (has to circulate the antibody). Arthus manifests as local vasculitis due to the accumulation of IgG-based immune complexes in the dermal blood vessels, which is one of the most common mechanisms of type-III hypersensitivity.
Activation of the complement majorly results in the cleavage of soluble complement proteins forming C3a and C5a, which activate the recruitment of PMNs and local mast cell degranulation, resulting in the inflammatory response. The local fibrinoid necrosis with ischemia-aggravating thrombosis present in the tissue vessel walls is induced by the further accumulation of immune complex-related processes. The end result is given as a localized area of induration and redness that typically lasts either a day or so.
The Arthus reactions have been reported infrequently after the vaccinations containing tetanus and diphtheria toxoid. The CDC's description is given below:
Arthus reactions (which are the type-III hypersensitivity reactions) are reported rarely after the vaccination and can take place after either the diphtheria toxoid–containing or tetanus toxoid–containing vaccines. An Arthus reaction is given as a local vasculitis associated with the deposition of immune complexes and activation of the complement. Immune complexes are produced in the setting of high circulating antibody concentration and high local concentration of vaccine antigens.
These reactions are characterized by severe pain, swelling, induration, haemorrhage, edema, and necrosis occasionally. Usually, these signs and symptoms occur 4–12 hours after vaccination. And, ACIP has recommended that the persons who experience an Arthus reaction after the dose of tetanus toxoid–containing vaccine should not receive Td more frequently than for every 10 years, even for tetanus prophylaxis, being a part of the wound management.
Cause of Arthritis
There are no single or numerous causes for arthritis. This is because of the fact that there are around 150 multiple types of arthritis, and often many factors contribute to an individual developing this common problem.
Different Types of Arthritis
This disease also can also affect other body parts. Arthritis causes pain, loss of movement, and at times swelling. A few types of arthritis are given as follows:
Osteoarthritis, which is a degenerative joint disease, where the cartilage that covers the ends of bones present in the joint deteriorates, causing pain and movement loss as bone begins to rub against the bone. It is a very prevalent form of arthritis.
Rheumatoid arthritis, which is an autoimmune disease where the joint lining becomes inflamed as part of the immune system activity of the body. Rheumatoid arthritis is the most serious and disabling type, which mostly affects women.
Infective arthritis (Septic arthritis because of the direct infection to, Whipples and Lyme disease and the Chlamydia reactive arthritis from slow-growing occult infections)
Post Infectious arthritis (which is Reactive arthritis that follows the infections elsewhere such as Salmonella and Shigella Typhimurium. Note that arthritis itself is sterile and it is an aberrant immune response to infection)
Gout, which mostly affects men. Usually, it is the result of a defect in the chemistry body. Most often, this painful condition attacks the small joints, especially the big toe. Fortunately, gout almost always may be completely controlled with the medication and changes in diet.
Ankylosing spondylitis is a kind of arthritis, which affects the spine. Resultantly, inflammation, the bones of the spine grow together.
Juvenile arthritis is a general term for all types of arthritis that happen in children. Children can develop childhood forms of lupus or juvenile rheumatoid arthritis, ankylosing spondylitis, or other arthritis types.
The systemic lupus erythematosus (lupus) is a serious disorder, which can damage and inflame joints and other connective tissues throughout the whole body.
Scleroderma is a disease of the connective tissue of the body, which causes hardening and thickening of the skin.
Fibromyalgia, where the widespread pain affects the attachments to the bone and muscles. It mostly affects women.
Preventing Arthritis
As the particular causes of the various types of arthritis remain unclear, it is difficult to say what can assist in the prevention of arthritis development. However, a few steps that can be beneficial in reducing the effects of arthritis are given below.
Maintain Appropriate Weight.
Protect the joints from overuse and injuries
Regularly exercise to maintain healthy bones, joints, and muscles. Normal physiotherapy treatment is beneficial, maintaining optimum spinal or joint range of motion and flexibility.
Eat a Healthy Diet as the Nutrients are Vital for Joint Health
Hydrate your body
Water makes up 70% of the cartilage in joints and plays a primary role in the lubrication and shock-absorbing properties of healthy joints.
FAQs on Arthus Phenomenon Explained: Process, Types & Causes
1. What is the Arthus phenomenon?
The Arthus phenomenon, or Arthus reaction, is a localised form of Type III hypersensitivity. It occurs when an individual with a high level of circulating IgG antibodies is exposed to the same antigen again, typically through an intradermal or subcutaneous injection. This leads to the formation of antigen-antibody immune complexes that deposit in the walls of small blood vessels at the site, triggering a strong inflammatory response.
2. Why is the Arthus phenomenon classified as a Type III hypersensitivity reaction?
It is classified as Type III because its mechanism is entirely dependent on immune complex-mediated tissue damage. Unlike other hypersensitivity types, the primary pathology in an Arthus reaction is not caused by IgE (Type I) or cytotoxic cells (Type IV), but by the deposition of insoluble antigen-antibody complexes. These complexes activate the complement system and recruit neutrophils, which release enzymes that damage local blood vessels and surrounding tissue, a hallmark of Type III reactions.
3. What are the typical signs and symptoms of an Arthus reaction?
The symptoms of an Arthus reaction are localised to the site of antigen exposure and typically appear within 4 to 12 hours. The key signs include:
Severe pain at the site.
Pronounced swelling (edema) and hardening (induration).
Intense redness (erythema).
In severe cases, it can progress to localised bleeding (hemorrhage) and tissue death (necrosis).
4. How does an Arthus reaction differ from serum sickness?
Both are Type III hypersensitivity reactions, but they differ significantly in scope. The Arthus reaction is a localised phenomenon, with immune complexes forming and depositing at a specific site of antigen entry. In contrast, serum sickness is a systemic condition where immune complexes circulate throughout the bloodstream and deposit in various tissues, such as the joints, kidneys, and skin, causing widespread symptoms like fever, rash, and arthritis.
5. Can vaccines, like the tetanus booster, cause an Arthus reaction?
Yes, though it is an uncommon side effect, an Arthus reaction can occur following vaccination, particularly with booster shots like the tetanus and diphtheria (Td/Tdap) vaccine. It happens in individuals who already possess a very high level of pre-existing antibodies from prior immunisations. The injected vaccine antigen rapidly binds with these antibodies, forming large immune complexes at the injection site and triggering the characteristic localised inflammation.
6. What is the typical timeline and treatment for an Arthus reaction?
An Arthus reaction typically develops within 4 to 12 hours of antigen exposure and is generally self-limiting, resolving within several days to a week. Treatment is focused on managing symptoms and may include:
Applying cold compresses to reduce pain and swelling.
Administering anti-inflammatory medications (e.g., NSAIDs).
Avoiding the specific antigen in the future to prevent recurrence.
7. What specific components trigger the inflammatory cascade in an Arthus reaction?
The inflammatory cascade is triggered by the immune complexes themselves. Once these complexes deposit in the vessel walls, they activate the classical pathway of the complement system. This activation produces fragments like C3a and C5a, which are powerful chemoattractants for neutrophils. The recruited neutrophils attempt to phagocytose the immune complexes, releasing lytic enzymes and reactive oxygen species that cause vasculitis (inflammation of blood vessels) and localised tissue destruction.
