What Causes Vasculitis in Humans?

Vasculitis Explained - What Triggers It & How It’s Treated

Vasculitis is also known as the inflammation of blood vessels. Inflammations can cause the thickening of the walls of blood vessels. There are a variety of factors that can cause vasculitis in humans, although the exact cause is still unknown and is under research.  

Possible Causes of Vasculitis in Humans

These are some of the possible causes of vasculitis in humans, including:

• Autoimmune Disorders: Conditions, such as lupus, scleroderma, and rheumatoid arthritis, can cause vasculitis, as in these conditions, our immune system mistakenly attacks blood vessels. The immune system exhibits abnormal behaviour under these autoimmune disorders. Thus, it gets turned against its cells and tissues. Rheumatoid arthritis or systemic lupus can cause vasculitis, especially in the hands and feet.   
• Infections: Infections, such as Hepatitis B or C, can trigger vasculitis in certain individuals, as the HBV and HBC induce the production of antibodies against the viral proteins. These antibodies form complexes with the viral antigen, which gets deposited on the inner walls of blood vessels. The depositions of these immune complexes activate the complement system, which eventually causes inflammation and damage.   
• Medications: Certain drugs, like propylthiouracil and hydralazine, can trigger vasculitis through an immune-mediated reaction. Both these drugs can trigger the production of autoantibodies, which attack the body’s tissues, including the blood vessels. Studies suggest that PTU also produces anti-neutrophil cytoplasmic antibodies (ANCAs), which are markers for vasculitis.  
• Blood Cancer: Lymphoma, a specific type of blood cancer, can cause vasculitis through two main mechanisms: direct infiltration of blood vessels and paraneoplastic effects. This blood cancer produces abnormal antibodies, known as cryoglobulins, which are deposited in the walls of blood vessels. Lymphoma cells can directly infiltrate and damage blood vessels, causing inflammation and obstructed blood flow.
• Genetic Factors: Various genetic factors can increase the risk of developing vasculitis. Those factors include specific HLA (Human Leukocyte Antigen) alleles, like HLA-DRB104, HLA-B51, SERPINA1, and HLA-B52:01. These alleles are mainly present on Chromosome 6, which primarily causes giant cell arteritis. In addition, the MEFV gene causes Behçet’s disease and leads to vasculitis.  
• Stress: Extreme levels of stress can contribute to vasculitis flare-ups due to the release of stress hormones, such as cortisol. Higher cortisol levels worsen the immune system and potentially trigger or worsen vasculitis. Frequent stress can disrupt the delicate balance of the immune system, leading to granulomatosis.  
• Environmental Factors: Certain environmental factors, like smoking or tobacco usage, can trigger vasculitis, especially in adults. Toxins in cigarettes promote vascular inflammation, increasing the expression of IL-1β, IL-6, and TNF-ɑ. These cytokines trigger the production of increased autoantibodies, leading to inflammation of blood vessels. 

Symptoms of Vasculitis

In most types of Vasculitis, symptoms include:

• Fever
• Headache
• Aches & Pains
• Tiredness
• Weight Loss

Other Symptoms which mainly depends on the parts of the body affected:

• Ears: Dizziness, sudden hearing loss may happen, ringing in the ears
• Eyes: Vasculitis can cause red, painful eyes (scleritis), vision changes, or even sudden blindness. Giant cell arteritis is a medical emergency that can cause double vision and permanent blindness in one or both eyes if not treated immediately.
• Hands or feet: Reduced blood flow can cause numbness, weakness, or skin changes in the extremities. Buerger's disease specifically affects blood flow to the hands and feet.
• Digestive System: In case, vasculitis affects the stomach or intestines, so an individual may face pain after meal. Ulcers or tears are possible which may cause blood in stools.
• Lungs: This can cause shortness of breathing or coughing up blood.
• Skin: Bleeding under the skin can show up red spot on the surface. Vasculitis can cause lumps or open sores on the skin.

Risk Factors

Vasculitis can occur to anyone. Factors that may increase the risks include: 

• Age: Gaint history is rare before the age of 50. However, Kawasaki disease is the most common in children under age of 5-year-old.
• Family History: While most vasculitides are not directly inherited, having a family member with a condition like Behçet's disease may slightly increase an individual's risk, suggesting a potential genetic component.
• Medicines: Medicines including minocycline, allopurinol and hydralazine can cause vasculitis sometimes.
• Toxin Exposure: The use of certain drugs, specifically cocaine (particularly cocaine contaminated with levamisole), is a known trigger for a specific form of vasculitis.
• Autoimmune Diseases: People with existing autoimmune conditions such as Rheumatoid Arthritis, Lupus (SLE), or Sjögren's syndrome have an increased risk of developing vasculitis.
• Infections: Individual having hepatitis B or C can also increase the chances of vasculitis

Treatments for Vasculitis

Treatments for vasculitis primarily focus on managing inflammation and suppressing the abnormal immune response. These treatments are a combination of different medications to enhance the overall response.

Here are certain types of medications to treat vasculitis:

• Corticosteroids: Prednisone is a common corticosteroid which can be beneficial in reducing inflammation of blood vessels and controlling vasculitis. As it may have certain side effects, you must consult with healthcare providers before using it.   
• Immunosuppressive Agents: Immunosuppressive agents, such as methotrexate, mycophenolate mofetil, and mycophenolate, can suppress your immune system. This will eventually reduce the inflammation, preventing the immune system from self-attack.    
• Biologics: Doctors recommend certain biologics, like TNF inhibitors, rituximab, or tocilizumab, to target specific immune system complexes. These molecules act as antagonists to those proteins that are responsible for vasculitis. 
   

Apart from these, doctors sometimes provide blood-thinning medicines. These medicines prevent blood clots and damage to the blood vessels.

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