Tests for Vasculitis

Dr M Chingkheilemba *

Vasculitis refers to a rare group of conditions characterised by inflammation of blood vessels. Most commonly, in the absence of an identifiable cause, it is called primary vasculitis. When an underlying cause can be identified, it is called secondary vasculitis. Secondary vasculitis may be triggered by an allergic reaction to a medication, in response to an infection such as hepatitis C, or as a result of an autoimmune disease, such as rheumatoid arthritis. In some cases, secondary vasculitis is seen as a complication of blood cell cancers such as leukaemia and lymphoma.

Vasculitis can affect any type of blood vessel, including veins, arteries, and capillaries. It can result in narrowed or blocked vessels that limit the circulation of blood, leading to tissue or organ damage. In some cases, a bulge in a weakened vessel, called an aneurysm, can occur. An aneurysm can be life-threatening complication because it can rupture, leading to heavy internal bleeding.

Vasculitis can affect anyone, though some types are more common among certain groups. Depending on the type one has, one may improve without treatment. Or one might need only medications to control the inflammation and flare-ups.

Vasculitis is also known as angiitis and arteritis.

SYMPTOMS AND COMMON TYPES OF VASCULITIS

The signs and symptoms of vasculitis vary greatly and are often related to decreased blood flow throughout the body. The presentation of symptoms can vary considerably from person to person. In addition to these diffuse symptoms, someone can have organ-specific, localised symptoms associated with the particular type of vasculitis that person has. The size and specific blood vessels that are affected often lead to a characteristic set of symptoms for each type. Because vasculitis is a systemic illness, symptoms can be non-specific and include those typical of inflammation, such as:

o Fatigue
o Weight loss
o Loss of appetite
o Fever
o Body aches

Some common types of vasculitis, each having specific symptoms of its own, include: Behchet’s syndrome, Giant Cell Arteritis (GCA), Polymyalgia Rheumatica, Takayasu Arteritis, Buerger disease, Kawasaki disease, Polyarteritis Nodosa, Cryoglobulinemia, Churg-Strauss syndrome, Wegener’s Granulomatosis, Microscopic Polyangitis, etc.

TESTS FOR VASCULITIS

A tissue biopsy is the gold standard test for diagnosis of vasculitis. It involves taking a tissue sample from a blood vessel or affected organ and examining it for signs of inflammation or damage.

Before taking a biopsy, certain laboratory and imaging tests can be performed to determine which organs are involved.

LABORATORY TESTS

o COMPLETE BLOOD COUNT (CBC): It evaluates a person’s red blood cells and haemoglobin for anaemia and checks the white blood cell count, which can be increased in infection or reduced following some treatments. Increased numbers of white blood cells are seen with some types of vasculitis.

o C-REACTIVE PROTEIN (CRP): This test detects inflammation in the body.

o ERYTHROCYTE SEDIMENTATION RATE (ESR): This test also detects the presence of inflammation and can be increased in several types of vasculitis.

o CREATININE: This test assesses the kidney function, which may be affected by vasculitis.

o LIVER FUNCTION TESTS: These tests assess liver function to determine if liver is affected by vasculitis.

o URINALYSIS: It looks for the presence of protein and red blood cells in the urine, which can indicate inflammation within the kidney.

o ANTI-NEUTROPHIL CYTOPLASMIC ANTIBODY (ANCA): This test is a useful marker for some systemic vasculitis conditions.

IMAGING AND OTHER TESTS

o IMAGING STUDIES: Chest X-ray, CT scan, MRI are done to check for chest problems. Sometimes, an angiogram is done where abdominal organs such as the kidneys and gut are involved.

o ECHOCARDIOGRAM/ECG: Used to assess the heart.

o LUNG FUNCTION TEST: Used to determine if airflow is restricted when vasculitis is affecting the lungs.

o NERVE CONDUCTION STUDIES: They are done if there are symptoms of numbness or tingling.

o COLOUR DOPPLER ULTRASOUND: Colour Doppler ultrasound displays a pathognomonic circumferential wall thickening in large-vessel vasculitis. Even small arteries like the temporal arteries can be easily examined with modern ultrasound equipment.