Post Bone Marrow Transplant Lung Diseases

Introduction:

Bone marrow transplantation is done to treat various types of malignant and non-malignant conditions. It is considered the most life-saving treatment in more than 77 countries. Recent research says an increased death rate is associated with post-bone marrow transplantation due to infectious pulmonary diseases. Bone-marrow transplantation is of two types: one is the transplantation done from the marrow, which was earlier obtained from the patient. The other type is a transplant obtained from the donor. It is used to treat congenital (present by birth), autoimmune, and metabolic disorders.

What Are the Causes of Post-bone Marrow Transplant Lung Disease?

Lung diseases are present in one-third of the patients undergoing bone marrow transplants.

• Gender - Females are most commonly affected by post-bone marrow transplant lung disease.

• Smoking - Patients with a smoking history before bone marrow transplantation have long-term pulmonary complications that worsen the condition.

• Myeloablative Regimen - Myeloablative irradiation of the body is done during leukemia (cancer affecting the blood-forming tissues) treatment. It causes systemic diseases and infectious lung diseases in older patients aged more than 70 years. Myeloablative therapy is an increased dose of chemotherapy that destroys cancer cells.

• Chemotherapy - Intensive chemotherapy before transplantation produces inflammatory mediators in the lungs and causes lung diseases.

What Are the Lung Diseases Associated With Bone Marrow Transplantation?

The following are some types of lung diseases associated with bone marrow transplantation:

• Acute Lung Injury - The body reacts to the bone marrow transplant by producing excess tumor necrosis factor (TNF). This is released from the lungs. It causes cell injury and affects the immune system. The toxic effects of antibiotic regimens used to manage post-bone marrow complications injure the lungs. Exposure to toxins worsens acute lung injury.

• Idiopathic Pneumonia Syndrome - Idiopathic pneumonia syndrome is the most common acute complication due to bone marrow transplantation. The presence of bacteria in the long-term compromises the lung and causes idiopathic pneumopathy. In addition, it damages the air sacs or alveoli.

• Bronchiolitis Obliterans - Bronchiolitis obliterans due to bone marrow transplantation is the most severe chronic lung disease. It is a rare condition and develops many months after infection. There is an increased formation of granulation tissue which eventually affects the breathing mechanism.

• Interstitial Lung Disease - The blood vessel injury and respiratory failure due to infection after bone marrow transplantation causes interstitial lung disease, an irreversible condition. It also causes inflammation of air sacs and scarring in the lungs.

• Pleural Effusion - Pleural infections that develop post-transplant result in pleural effusion. However, bone marrow transplantation is the secondary cause of the pleural effusion. The fluid gets collected due to increased inflammation. Therefore, it indirectly causes cardiac and pulmonary dysfunction.

What Are the Symptoms of Post-bone Marrow Transplant Lung Disease?

Following are the symptoms of post-bone marrow transplant lung disease:

• Breathing Difficulty - The lack of oxygen due to the involvement of the lungs after bone marrow transplantation causes difficulty in breathing and shortness of breath.

• Fever - Infectious lung disease due to post-bone marrow transplant lung disease, syncytial respiratory virus, and parainfluenza virus results in fever.

• Cough - The upper respiratory tract damage produces a non-productive cough.

• Hemoptysis - Inflammation of the bronchi results in blood streaks in the mucus during cough.

• Wheezing - The narrowing of bronchial tubes due to infectious lung disease causes wheezing.

• Exertion - Physical exertion is present in older people with post-bone marrow transplant lung disease.

• Chest Pain - Infectious lung disease results in chest pain.

• Chills and Flushing - Respiratory syncytial viral infection leads to chills or flushing during the night.

How Is a Post-bone Marrow Transplant Lung Disease Diagnosed?

The post-bone marrow transplant lung disease can be diagnosed in the following ways:

• Pulmonary Function Test - The pulmonary function test is performed to analyze the lung capacity before bone marrow transplantation. The forced expiratory volume is primarily tested. Carbon monoxide diffusion in the lungs is measured to determine infectious lung disease. The lung shows an increased restrictive pattern in the pulmonary function test due to renal and cardiac dysfunction. Spirometry is taken once in three months as a screening test.

• Bronchoscopy - The bronchoscope is used to collect the lavage from the airways. It helps classify post-bone marrow lung disease as infectious and non-infectious. Bronchoalveolar lavage is present only in infectious lung diseases. A flexible bronchoscope also collects tissue from consolidated lungs for biopsy.

• Chest X-Rays - Since idiopathic pneumonia syndrome due to bone marrow transplant affects the lungs, it shows multilobular infiltration in the radiographic image. The infected areas show diffuse opacities in the lungs.

How Is Post-bone Marrow Transplant Lung Disease Treated?

There is no complete recovery for patients with post-bone marrow lung disease. However, palliative care is given to avoid complications.

• Medication - Antimicrobial prophylaxis helps prevent post-bone marrow transplant lung disease and effectively decreases infectious lung disease. Steroids like Prednisone and Etanercept are most commonly used to treat infectious lung diseases. Relapsing lung diseases is present if the medications are withdrawn. Azithromycin helps prevent sepsis in the lungs.

• Ventilatory Support - The hypoxic condition due to lung damage is managed by intubation or mechanical ventilation. It also includes supportive oxygen therapy. It is the rescue therapy for managing severe lung diseases. It prevents acute lung exacerbation due to post-bone marrow transplant lung disease.

• Pneumonectomy - The severely consolidated lung or a portion of the lobe is removed to save the patient's life and prevent further spread to other parts of the lung. It also eliminates the infection present in the chest. However, there are many different criteria to consider before pneumonectomy.

Conclusion:

Post-bone marrow transplant lung disease requires a multidisciplinary approach. The recent advancement in preventive measures for infectious lung disease has increased the consequence of noninfectious lung diseases. Post-bone marrow lung disease can be prevented by choosing the appropriate donor under unrelated or partially matching donors, conditioning regimens, human leukocyte antigen (HLA), and suitable sources. In recent days, the patients have been kept under observation and continuously monitored after transplantation. So it prevents major complications like graft versus host disease. Using a lower dose of myeloablative regimen in clinical practice reduces the potential of diseases.