C-ANCA and p-ANCA are two tests used in the diagnosis and evaluation of rheumatologic diseases. These conditions often result from a dysfunction in the immune system, which triggers an attack on certain tissues in the body that it mistakes as foreign or invading microorganisms or poisons. These autoimmune conditions can be debilitating and cause significant health complications and disability. The c-ANCA and p-ANCA tests in particular help diagnose conditions that cause vasculitis.
What are the Vasculitides?
Vasculitides are medical conditions that cause vasculitis, an inflammation of the blood vessels. According to MayoClinic.com, the inflammation of vasculitis causes scarring and narrowing of the blood vessels. This results in decreased blood flow to the organs supplied by those blood vessels. Vasculitis also causes weakening of the wall of the blood vessels, causing an aneurysm, or an out-pouching of the tissue covering the blood vessels that predisposes to rupture and bleeding.
According to Lab Tests Online, ANCA stands for antineutrophil cytoplasmic antibodies. These antibodies are mistakenly produced by the body to attack its own neutrophils, the white blood cells that help fight off bacterial infections. When seen under the microscope after staining, the c-ANCA tests shows the presence of these antibodies in the cytoplasm, the internal microscopic compound that holds cells together, of neutrophils. The p-ANCA test shows the presence of antineutrophil antibodies around the nucleus of cells. P-ANCA and c-ANCA are usually seen in conditions like Wegener's granulomatosis, and other vasculitides.
The symptoms of the vasculitides vary depending on the vessels and organs affected. According to the National Institute of Allergy and Infectious Diseases, Wegener's granulomatosis usually affects the lungs and the kidneys. Symptoms include sinus pain, bloody fluid from the nose, nasal ulcers and symptoms of upper respiratory infections that do not go away with proper treatment. If the lungs are affected, cough, shortness of breath and bloody sputum can also occur. Kidney involvement usually does not cause obvious symptoms, but can cause long-term damage. Another vasculitis detected by the ANCA tests, microscopic polyangiitis, causes kidney inflammation, weight loss, skin lesions and nerve damage.
Treatment of the vasculitides usually requires a multidisciplinary approach to deal with the multiple organs affected. Medications include steroids, to decrease the inflammation surrounding the blood vessels; and immunosuppressants, including drugs like azathioprine and cyclophosphamide, that aim to control the body's autoimmune reaction while sparing the patient from the side effects of steroids. Other medicines include drugs to prevent steroid-associated bone loss, and antibiotics to prevent pneumonia.