|image source: wikipedia|
Is it possible that problems relating to the kidneys, lungs, skin, eyes, nerves and bowel could have a common thread i.e. the blood vessels? Incredible proposition, many would say. But it’s actually quite probable and one of those probabilities is a rare and uncommon disease known as Microscopic Polyangiitis (MPA).
A Rare Form Of Vasculitis
Actually, MPA is rare form of a more general term Vasculitis. Derived from the Latin “vasculum” meaning vessel, Vasculitis strictly translates to blood vessel inflammation. Simply put, inflammation is your body’s generic response to irritation, infection or injury sustained by living tissues, which in turn is characterized by redness, swelling, warmth and/or pain in the target area.
In the case of vasculitis, the source of inflammation are transportation tubes of varying widths tasked with carrying blood to and from different parts of the body, otherwise known as blood vessels. Interestingly, this inflammation happens due to the body’s own internal defense (immune system) targeting the blood vessels’ walls by mistake.
A direct result of inflammation of blood vessels could lead to:
• Weakening and stretching of the lining to a point that aneurisms (bulges) appear. The danger then is of rupture thus leading to internal bleeding.
• Narrowing of the blood vessel thereby making it difficult for the blood to get through.
• Occlusion where the narrowing effect closes down the blood vessel completely thus starving the delivery point of oxygen and nutrients.
Microscopic Polyangiitis – A Specialized Case
Now, the blood circulation system is a lot similar to the pathway that a river takes from its source to the ocean or sea. Likewise, blood vessels also systematically reduce in thickness as they approach their respective delivery centers (organs) and bunch up again upon exiting them, thereby forming arteries, arterioles, capillaries, venules and veins in that order.
In MPA, the inflammation occurs around the smaller blood transportation pathways. Thus, the terms ‘microscopic’ and ‘polyangiitis’ specifically indicate that the smallest vessels of the circulatory network namely the arterioles, capillaries and venules are affected in large numbers.
Microscopic Polyangiitis Symptoms
MPA shares certain ‘constitutional’ symptoms with its other Vasculitis compatriots like Behcet’s syndrome; Buerger’s disease; Churg-Strauss syndrome; Cryoglobulinemia; polyarthritis nodosa etc. These include weight loss, fever, fatigue, loss of appetite, muscle and joint pain and nerve problems among other things.
Specifically though, MPA can produce advanced symptoms when it escalates to different organs in the body, some of which are mentioned below:
• Kidneys – glomerulonephritis (inflammation of the kidneys),
• Lungs – dry or blood soaked cough, wheeze and breathlessness
• Skin – necrosis (dead tissues), ulcers and rashes
• Eyes – dry, painful, gritty or blood shot eyes, and visual loss in advanced cases
• Nerves – loss of sensation, hypersensitivity at the extremities (hands and feet), and paralysis in rare cases
Microscopic Polyangiitis Causes And Who Is At Risk?
There is overwhelming evidence to associate the disease with the presence of special proteins in the immune system called ANCA antibodies in MPA patients. These antibodies are known to activate a certain type of white blood cells or WBCs (defensive components in the blood), and force them to cling to the walls of the blood vessels. The WBCs then release chemicals otherwise reserved for fighting infections to cause damage to the blood vessels.
However, being a disease resulting from a misfiring immune system, it must be noted that MPA in itself could be triggered by any number of stimulants. As such, its actual causes still remain a mystery to experts.
That being the case, MPA is commonest in middle aged population, but it can also affect people falling on either side of the above age spectrum. Furthermore, both males and females can be at from the disease.
Diagnosis And Treatment of Microscopic Polyangiitis:
Given the ubiquitous nature of the disease, a combination of clinical features and lab tests, like blood test for ANCA and tissue biopsies are needed by medical professional to ascertain that it is indeed MPA and not another form of localized disorder or vasculitis variant.
Treatment for MPA can involve combination therapy that could include steroids, cytotoxic agents glucocorticoids, and/or immunosuppresive class of drugs such as methotrexate, azathioprine etc, for various stages of the disease.
Since MPA can be chronic (long lasting), early detection can help bring about faster suppression of the symptoms and therefore reduce the chances of organ failure in future. However, there have been cases of remission (resurfacing of the disease) and therefore constant contact with your doctor is essential if you are diagnosed with MPA.