How do Lung nodules form from RA?

Thanks Peggy for asking this question!  I was curious myself as to if RA could affect our lungs, and how. I figured I'd make this blog on RA in the lungs, and all the complications it could possibly cause, not just nodules.  I read that although RA primarily affects our joints, it can also affect our lungs.  There are four common complications to lungs, due to RA.  They include:






- Painful breathing. Rheumatoid arthritis can cause inflammation of the lining of the lungs (pleurisy). The inflammation can cause sharp pain while breathing.

- Shortness of breath. Fluid due to inflammation of the lining of the lungs may accumulate around the lungs (pleural effusion). This accumulation can cause shortness of breath.

- Lung nodules. Small lumps may form in the lungs (rheumatoid nodules), as well as in other parts of the body. Lung nodules usually cause no signs or symptoms, and they don't pose a risk of lung cancer. In some cases, however, a nodule can rupture and cause a collapsed lung.

- Scarring of the lungs. Rheumatoid arthritis can lead to scarring within the lungs. Signs and symptoms may include shortness of breath, chronic dry cough, fatigue, weakness and loss of appetite.

Now let's take a look at each complication. In the last blog I wrote about rib pain and RA and I explained pleurisy, so instead of repeating myself, I will skip that one.  If you'd like to read more about pleurisy, please look back at the previous blog "Can you get RA in your Ribs?!"  It includes an email from my Rheumatologist explaining this very question, and information about pleurisy as well as Costochondritis.

A Pleural effusion is an accumulation of fluid between the layers of tissue that line the lungs and chest cavity.  Your body produces pleural fluid in small amounts to lubricate the surfaces of the pleura, the thin tissue that lines the chest cavity and surrounds the lungs. A pleural effusion is an abnormal, excessive collection of this fluid.  Transudative pleural effusions are caused by fluid leaking into the pleural space. This is caused by elevated pressure in, or low protein content in, the blood vessels. Congestive heart failure is the most common cause.   Exudative effusions usually result from leaky blood vessels caused by inflammation (irritation and swelling) of the pleura. This is often caused by lung disease. Examples include lung cancer, lung infections such as tuberculosis and pneumonia, drug reactions, and asbestosis.  Symptoms include sharp chest pain that is usually worse with a cough or deep breaths, cough, fever, hiccups, rapid breathing, shortness of breath and sometimes there are no symptoms at all.  Call your health care provider if you have symptoms of pleural effusion.

Lung nodules are small round growth on the lung that should be considered serious because it could be a type of early stage cancer. As precaution, every doctor will observe these growths as malignant (cancerous), until they have sufficient proof that it is benign (not cancerous).  People will usually not experience any specific symptoms that suggest that a lung nodule might be present. The majority of cases are discovered by chance during chest x-rays or CT scans.  Lung nodules can form from:

-Hamartomas (the abnormal formation of normal tissue is the most common – 75% of benign nodule cases). 
-Bacterial infections (Tuberculosis, round pneumonia, atypical mycobacteria). 
-Fungal infection (coccidioidomycosis known as Valley fever, histoplasmosis known as darling’s disease)
-Anthracosilicosis (Accumulation of carbon and silica in the lungs from inhaled coal dust)
-Fibrosing alveolitis ( a chronic, progressive form of lung disease characterized by fibrosis of the supporting framework (interstitium) of the lungs)
-Rheumatoid arthritis
-Bronchogenic cysts (rare) (Bronchogenic cysts are small, solitary cysts or sinuses, most typically located in the region of the suprasternal notch or over the manubrium)
-Hemangiomas of the lung (benign tumour)
-Lymph node hyperplasia (Known as Castleman’s disease - rare benign tumour)
-Wegener’s granulomatosis (rare)
-Parasitic infection (prevalent in temperate, tropical and subtropical regions of the world)

Since this is an RA blog, and it's the question that Peggy asked, let's take a further look into how RA can cause lung nodules.  Roughly one percent of RA patients show signs of pulmonary rheumatoid nodules in conventional X-rays, according to the Johns Hopkins Arthritis Center. However, high resolution computed tomography (CT) scans reveal signs of nodules in roughly 22 to 28 percent of patients.  Rheumatoid lung nodules appear most frequently in men with active RA who also have high blood levels of the autoimmune antibody called rheumatoid factor, Johns Hopkins reports. Women and individuals with low blood levels of rheumatoid factor may also be affected. Smoking may be a risk factor for these nodules. Typically, rheumatoid lung nodules do not cause symptoms and do not develop into lung cancer, the Mayo Clinic reports. Potential complications include erosion of a nodule through the lung, infection and pneumothorax (collapsed lung).  Additional potential effects of rheumatoid lung disease include pulmonary fibrosis (lung scarring), pulmonary hypertension (localized high blood pressure) and pleural effusion (fluid buildup inside the chest). Nodules are usually found in patients who have been suffering from RA for quite some time. Cigarette smoking in patients who have RA increases the chance that nodules will form. Methotrexate, a medication used to manage the symptoms of RA, has been found to increase chances that nodules will form.

Scarring of the lungs Chronic inflammation can lead to scarring of lung tissue, swelling of the tissue lining the lungs, constriction of arteries that feed blood to the lungs, airway restriction and pulmonary fluid buildup. Though some of these effects are treatable, others can cause irreversible damage.  Rheumatoid arthritis can lead to scarring of lung tissue and a group of conditions referred to as interstitial lung disease (ILD) that make breathing difficult and prevent sufficient oxygen from reaching the bloodstream. It's estimated that clinical significant ILD occurs in about 3 percent to 5 percent of RA patients. Interstitial lung disease can cause dyspnea (breathlessness), dry cough, wheezing, chest pain and clubbed fingernails (nails that curl over the ends of the fingers). Scarring is usually irreversible, and symptoms are typically progressive. Scarring can also occur in the connective tissue of the alveoli (air sacs) of the lungs, causing a condition called pulmonary fibrosis. Pulmonary fibrosis leads to symptoms such as chronic dry cough, shortness of breath, fatigue, weakness, loss of appetite and rapid weight loss.  Some arthritis medications can also lead to scarring of the small airways in the lungs, leading to shortness of breath or other breathing problems.

In the future, I plan on writing a blog all about RA nodules, because that can form anywhere on the body.  It seems that RA can affect just about anything.  If you are having any complications with your lungs, please be sure to tell your Rheumatologist in case there is something going on.  Never be afraid to tell your doctor of any symptoms you are experiencing, even if you think it's something small.