Sarcoidosis is a disease of the immune system that is typically characterized by specific small masses of cells, also called non-necrotizing granulomas.
The big problem is that virtually any organ can be affected, but the granulomas appear most frequently in the lungs and surrounding lymph nodes. There is no rule on the progress of this disease, because symptoms can appear suddenly, but more often appear gradually. These tiny granulomas can grow and clump together, making many large and small groups of lumps. If many granulomas form in an organ, they can affect the latter’s functions. Sarcoidosis rarely affects other organs, including the thyroid, breast, kidneys, reproductive organs.
It has an active and non-active phase
During the active phase, the granulomas form and grow. At this stage, symptoms may develop, and scar tissue can form in the organs where the granulomas occur. In the non-active phase, inflammation and granulomas disappears maintain the same size or contract. However, scars may remain and cause symptoms.
Although anyone can develop sarcoidosis, the disease mainly affects adults between the ages of 20 and 40 years. The prevalence of sarcoidosis in the adult population ranges from 1 case to 40 cases per 100,000 population, with an annual incidence of 10.9 per 100,000 age for Caucasians and 35.5 per 100,000 for African Americans. There is no clear predominance of sex in this disorder.
Signs and symptoms of sarcoidosis
Sarcoidosis sometimes gradually develops and produces signs and symptoms that last for years, but can also appear suddenly and disappear just as quickly. Research has shown that there is no rule about the signs and symptoms, as they may vary depending on the organs affected and the time the patient has the disease.
The most common symptoms include the lungs, skin, eyes and liver.
Light – It is estimated that the lungs are affected in about 88% of people with sarcoidosis. The most common symptoms are cough or chest pain. Some people have breathing problems, but most people do not.
Skin – Very often people with sarcoidosis have some symptoms of the skin, which mostly include rashes or nodules (small bumps on the skin). They can be placed across the face, arms or buttocks, and are more common in African Americans.
Eyes – It is shown that about 25% of people who have sarcoidosis have eye symptoms. Although these symptoms can affect vision, rarely cause blindness. Eye symptoms usually include dry eyes, but can also include swelling of the lacrimal gland that makes the eyes water.
Liver – Sarcoidosis affects the liver in about 20% of people who have the disease. The most common symptom is hepatomegaly – liver enlargement.
Heart – The most common cardiac abnormalities include conduction abnormalities and arrhythmias due to granulomatous infiltration of the heart. Half of patients with sarcoidosis have electrocardiographic heart rhythm abnormalities, conduction and repolarization.
Other signs and symptoms of sarcoidosis include:
- A vague feeling of discomfort and fatigue
- Red and watery eyes
- Arthritis in the ankles, elbows, wrists and hands, commonly associated with bumps on the skin over the shins
Possible causes of sarcoidosis
Although many experts speculate about possible causes of sarcoidosis, no one really knows the exact cause of the disease. The most common theory is that can occur when a person’s immune system overreacts to some unknown toxin, drug or pathogen that enters the body through the airways and lungs. Some experts say this could be caused by some kind of bacteria, especially some non-tuberculous mycobacteria, a member of the family of bacteria that cause tuberculosis. It is also important to note that only a small part of sarcoidosis people may have a genetic component, so that heredity may play a role.
What is the purpose of the immune system? The immune system helps protect the body from foreign substances and invading microorganisms such as bacteria and viruses, but in sarcoidosis, T helper cells seem to respond too strongly to a perceived threat. This means that the immune response is doing more harm than the microorganism itself. This triggers small areas of inflammation called granulomas.
We have concluded that sarcoidosis is a chronic inflammatory disease characterized by a highly focused to an unknown antigen in the target organs exaggerated immune response. The most common histologic signs of disease, sarcoidosis granulomas, probably formed in response to a persistent stimulus, not degrade, antigenic.
As a result of these various immunological interactions, specific inflammation cascade occurs and is characterized by changes in tissue permeability, cell influx and the local cell proliferation, resulting in a granuloma.
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The diagnosis of sarcoidosis
Physical exam – To find out if a patient has sarcoidosis, most doctors will perform a physical examination for the common signs.
Laboratory studies – Thereno definitive test laboratory diagnosis of sarcoidosis. Inabsence of a known etiological agent, sarcoidosis often remains in diagnosis of exclusion. Doctors usually order a blood test to determine the level of a certain chemical called angiotensin converting enzyme in the patient’s blood. ACE is produced by granuloma epithelioid cells and, therefore, may be elevated in the serum of patients with sarcoidosis. When the doctor finds that the level of angiotensin converting enzyme, can help you track the course of the disease and test the response to treatment.
Imaging studies – The most effective noninvasive test to support the diagnosis of sarcoidosis is a chest radiograph, which usually shows bilateral enlargement of the lymph nodes. It is also very useful if doctors wantexclude other diseases such as tuberculosis, histoplasmosis or other fungal infections or lymphoma can also show swollen lymph nodes similar to sarcoidosis.
The high resolution CT is also considered a diagnostic tool very useful and effective. Feature to scan findings include smooth or nodular interstitial thickening of structures such as bronchi and surrounding blood vessels.
Pulmonary function tests – These tests measure the amount of air the lungs can hold and the airflow in and out of the lungs. They can also measure the amount of gases exchanged through the membrane wall between the lung and the capillary membrane.
Biopsy – Results tissue biopsy to confirm the diagnosis of sarcoidosis in childhood, have been documented in many cases. The biopsy is obtained from the most easily accessible body with the least invasive method.
Histological findings – The diagnosis of sarcoidosis was confirmed by demonstrating a typicalof a biopsy sample using a microscope granuloma. An experienced pathologist must review the pathologic changes characteristic.
Stages of sarcoidosis
- Stage 0 – normal findings on chest radiograph
- Stage I – hilar lymphadenopathy bilateral, which may be accompanied by lymphadenopathy
- Stage II – bilateral hilar lymphadenopathy with pulmonary infiltrates
- Stage III – parenchymal infiltrates without hilar lymphadenopathy
- Stage IV – the evidence advanced fibrosis with honey combing, hilar retraction, bullae, cysts, and emphysema
Risk factors for development of sarcoidosis
Although literally anyone can develop sarcoidosis, there are some factors that can make a person more likely to get this disease:
Race – African Americans are more likely to develop sarcoidosis than Caucasians.
The real cause of this still remains unknown. Although sarcoidosis affects men and women almost equally white, African American women contract the disease twiceoften as African American men.
Ethnicity – People Scandinavian, German or Irish origin have a higher risk.
Years – Sarcoidosis usually occurs between the ages of 20 and 40 years. Rarely it affects children, but can occur in adults over 50 years.
Treatment of sarcoidosis
What are the most important goals of therapy? The goals of treatment are:
- Improve the shape of the organs affected by the work of sarcoidosis
- Relieve symptoms
- Reduce the size of granulomas
The main treatment for sarcoidosis is a corticosteroid drug called Prednisone.
Prednisone is a very strong anti-inflammatory drug. Almost always relieves the symptoms of inflammation. Prednisone is usually given for many months, sometimes for a year or more.
Low doses of Prednisone often can relieve symptoms without causing major side effects.
There are also some other drugs, mostly immune system suppressants, which can prevent the immune system to fight against things like bacteria and viruses
The most used are:
- Hydroxychloroquine (Plaquenil, Quineprox®)
- Methotrexate (Rheumatrex, Trexall®)
- Azathioprine (Imuran)
- Cyclophosphamide (Neosar, Revimmune, Cytoxan)
Avoidance of food disciplined sunlight and vitamin D is needed in patients who are prone to develop hypercalcemia and will help relieve symptoms in all patients with sarcoidosis.
Antibiotic therapy has been reported to be effective in the lung, lymph and cutaneous manifestations of sarcoidosis.