SARCOIDOSIS AND THE LUNGS
Function of the Lungs and Sarcoidosis
Your lungs transfer oxygen from the air to the blood. At the same time carbon dioxide leaves the blood through the lungs. This happens in lung tissue called lung parenchyma.
In sarcoidosis of the lung the parenchyma becomes inflamed. The white blood cells which gather disrupt the oxygen uptake and carbon dioxide release. In addition, accumulations of white blood cells (also known as granulomas) may develop in the lymph system (the lymph system is an important part of the immune system) of the lungs.
These granulomas adversely affect the operation of the lungs and can cause scarring. This inhibits the stretching, and therefore capacity, of the lungs. This in turn leads to a shortness of breath.
Common Symptoms of Lung Sarcoidosis
Sometimes, the symptoms of pulmonary sarcoidosis start suddenly and don’t last long. In other patients, the symptoms may develop gradually and last for many years.
Some people don’t have any symptoms at all and are told they have sarcoidosis after having a routine chest x-ray or other investigations.
Common symptoms of pulmonary sarcoidosis include:
shortness of breath, especially with exercise
You may read that consultants classify sarcoidosis into the 'Stages of Sarcoidosis'. In reality this is a rarely used technique by clinicians in the UK.
Living with Pulmonary Sarcoidosis
Sarcoidosis affects people very differently - each case is unique. However there are some shared experiences for those living with sarcoidosis.
It is common that patients with sarcoidosis may feel tired and lethargic (fatigued), lose weight or suffer with fevers and night sweats.
Sometimes symptoms may suddenly get worse - this is known as a ‘flare-up’. This may be triggered by stress, illness or nothing recognisable.
It is important to make sure you eat healthily, pace yourself and talk to friends and family about your sarcoidosis. You should discuss your condition early on with your employer - use the SarcoidosisUK Leaflet ‘Information for Employers’.
Sarcoidosis can leave patients feeling scared and isolated - recognise mental health problems early and seek support. Please contact SarcoidosisUK or your GP for professional support.
Techniques to Understand your Condition
X-rays can give you a picture of lung abnormalities. If abnormalities are found, then generally additional tests are performed to confirm any diagnosis.
Lung Function Test: Spirometry tests how well you breathe in and out. Lung volume tests measure the total size of your lungs. Gas transfer tests measure the amount of oxygen that passes from your lungs into your blood.
CT scan (also called CAT scan or computed tomography) combines x-rays and computer technology to create detailed images of the inside of your body.
MRI scans use magnetic fields and radio waves. They show abnormal tissue clearer than CT scans. MRI is rarely used with the lungs but may be useful to check other organs.
Nuclear scans, for example PET scans and the octreotide scan. The patient swallows a radioactive tracer before images are taken with a special (gamma) camera. These techniques can sometimes be combined with CT scans or MRI scans to provide even more detailed images.
Bronchoscopy involves your consultant inserting a thin tubular viewing device to examine your lungs. Lavage is a technique sometimes used with bronchoscopy that uses salt water to extract cells for study under a microscope.
Biopsy: During bronchoscopy your consultant takes a piece of lung tissue (biopsy) to examine under the microscope. They may also take cells from an inflamed lymph node. In a few cases surgery is required to obtain a biopsy. This technique is often used when doctors want to confirm the disease as sarcoidosis. The most common technique for this is called VATS (video-assisted thoracoscopic surgery).
Course of the Disease
Sarcoidosis affects people differently and often follows an unpredictable course. Most patients with pulmonary sarcoidosis recover spontaneously within a few years; sometimes no treatment is needed.
When treatment is required, it is designed to help relieve the symptoms as the disease runs its course. A consultant may prescribe drugs if, for example, the lungs malfunction or there is scarring in the lung tissue.
There is no cure for sarcoidosis. The goal of the treatments below is to suppress the lung inflammation and scarring while the disease is active. You will discuss with your doctor the best treatment regime for you - regular check-ups may be necessary.
Corticosteroids (commonly prednisolone) may be used for a year or more. These drugs act to suppress the symptoms of the disease. A high dose is usually prescribed at the start of the treatment, before being reduced to a ‘maintenance dose’.
NsAIDS (Non-steroidal Anti-Inflammatory Drugs) are anti-inflammatory drugs similar to aspirin; they are also mild pain-killers.
Methotrexate is usually given in combination with corticosteroids - in tablet form or administered by repeated injections.
Other treatments: New drugs such as infliximab and adalimumab are sometimes used to treat difficult and severe forms of sarcoidosis.