Pulmonary-Renal Syndrome - Causes, Symptoms, Diagnosis, and Treatment

Introduction

A pulmonary-renal syndrome is a group of diseases due to autoimmune disorders. It occurs due to the damage to small blood vessels present in the lungs. It results in bleeding of the small air sacs or alveoli. It destroys the alveoli and interrupts the gaseous exchange. It also causes inflammation of the blood vessels in the kidneys. This medical condition is known as glomerulonephritis. It affects both the kidneys and may eventually end in renal failure.

What Are the Causes of Pulmonary-Renal Syndrome?

The pulmonary-renal syndrome occurs due to other preexisting disorders. They are as follows;

1. Rheumatoid Arthritis - The synovial layer in the affected joint thickens and proliferates into many folds. It leads to the inflammation of the joint and the destruction of the cartilage. Chronic rheumatoid arthritis causes renal dysfunction.

2. Systemic Lupus Erythematosus - Systemic lupus erythematosus is a long-standing autoimmune disorder. It leads to deformity of the joints and skin lesions on the face. It produces proteins, which destroy vital organs like kidneys and lungs. This eventually leads to inflammation of the kidneys and causes glomerulonephritis.

3. Systemic Sclerosis - Systemic sclerosis is a connective tissue disorder. Sclerosis results in excess deposition of the collagen fibers in the skin and blood vessels. It affects the pulmonary artery and increases the pressure inside the blood vessel. This condition is known as pulmonary hypertension.

4. Granulomatosis - The chronic inflammation of glomeruli results in necrosis of the tissue. It also affects the small blood vessels present in the kidneys. It ruptures the upper respiratory tract and induces pus discharge. It affects the bronchial tubes or air passages and causes inflammation. Severe granulomatosis results in the rupture of tiny air sacs or alveoli in the lungs and causes bleeding. This condition is called alveolar hemorrhage.

5. Goodpasture Syndrome - The characteristic diseases of good pasture syndrome are inflammation of the glomeruli and alveolar hemorrhage. There is an increase in circulating antibodies anti-GBM (anti-glomerular basement membrane). It causes renal impairment and bleeding in the pulmonary blood vessels.

6. Nephropathy - It is the most common cause of glomerulonephritis (inflammation in the kidneys) but is rarely seen in pulmonary-renal syndrome. There is an increased production of immunoglobulin IgA1. These immunoglobulins get deposited in the glomeruli of the kidneys and cause inflammation. It affects the pulmonary artery and causes profuse bleeding. Eventually, this leads to pulmonary-renal syndrome.

7. Glomerulonephritis - Glomerulonephritis occurs due to an autoimmune reaction. It also occurs due to a connective tissue disorder. It leads to increased production of anti-collagen antibodies. It triggers the inflammatory response in vital organs like kidneys and lungs and results in pulmonary-renal syndrome. Severe glomerulonephritis progresses rapidly and affects the cardiac tissue resulting in heart failure.

8. Behcet Disease - It causes inflammation in the oral mucosa and mucosa of the genital organs. Serious disorders include neurologic disorders, thrombus formation in the veins and pulmonary arteries along with internal bleeding. It can also rupture the pulmonary artery and induce pulmonary-renal syndrome.

9. Drug-Induced Vasculitis - Certain drugs cause inflammation of the blood vessels in the lungs and kidneys. This condition is known as vasculitis. The drugs that cause pulmonary-renal syndrome are Hydralazine and Propylthiouracil. Hydralazine is used to treat cardiac patients with hypertension. It causes aggressive vasculitis. Propylthiouracil is used as an antithyroid drug. It results in diffuse bleeding of the alveoli or air sacs.

What Are the Symptoms of Pulmonary-Renal Syndrome?

The symptoms of pulmonary-renal syndrome are as follows;

• Cough - The inflammatory cells rupture the bronchial tubes or air passages. It irritates the throat and expels cough with mucus. This is called a productive cough.

• Dyspnea - Severe pulmonary-renal syndrome results in respiratory failure. There is a lack of oxygen supply to the body tissues. So the individual has difficulty breathing. Extreme oxygen insufficiency eventually leads to discoloration of the skin. The skin turns blue, and this condition is known as cyanosis.

• Fever - The viral infection increases the body temperature and causes fever.

• Hematuria - Since pulmonary-renal syndrome involves the kidney, there is a bloody discharge during urination. The blood discharge is minimal and cannot be visualized. It is usually determined by diagnostic tests.

• Hemoptysis - Severe inflammation of the bronchial tubes results in sputum with blood discharge while coughing. It appears bright red. The individual has shortness of breath.

• Peripheral Oedema - The damage to the tiny blood vessels in the kidneys causes fluid accumulation in the legs. This is known as peripheral edema.

What Are the Different Types of Diagnostic Procedures for Pulmonary-Renal Syndrome?

• Chest X-Rays - Diffuse bleeding in the tiny air sacs can be visualized in the X-rays. It appears as abnormal white patches in the radiographic image.

• Blood and Urine Test - Since there is an oxygen insufficiency, a blood test is done to determine the count of red cells. It is also used to determine the autoantibodies in the blood. The urine test is used to investigate the presence of blood in the urine.

• Bronchoscopy - A thin, flexible tube is used to observe the abnormality of the air passages. The presence of pus formation can be detected with the help of bronchoscopy. It is inserted into the mouth for visualization of the bronchial tubes.

• Biopsy - A small portion of the tissue is removed from the kidneys or lungs for analysis. The physician interprets the results after the lab examination.

What Are the Various Treatment Methods for Pulmonary-Renal Syndrome?

• Medication - Corticosteroids are used to treat autoimmune disorders. It leads to the suppression of autoantibodies. The commonly used steroid to treat pulmonary-renal syndrome is Prednisone.

• Plasma Exchange - The autoantibodies must be removed from the body to prevent the progression of the pulmonary-renal syndrome. The abnormal red cells are discarded, and the individual is transfused with plasma from the donor.

• Dialysis - In severe cases of pulmonary-renal syndrome, there is a functional impairment of the kidneys. So the excess fluid and waste content from the body is removed with a procedure called dialysis.

Conclusion

The systemic manifestations of the lungs and kidneys occur for several weeks or months apart. There will be a good prognosis in the individual with pulmonary-renal syndrome if the underlying autoimmune disease is treated earlier. There is a high recovery rate for the patients who are treated with steroid therapy, especially for patients with Goodpasture syndrome. However, patients with end-stage renal disease have a life expectancy of four to five years. As it involves the major organs like kidneys and lungs, the patient must be monitored periodically under the supervision of the medical professional. It has an acute onset due to the infection, so consult the physician without any delay to avoid refractory disease in the future.