Lung Transplant Week

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General Information

Lung Transplant Week

Lung transplantation is an innovative therapy for persons with advanced lung disease, including pulmonary fibrosis, cystic fibrosis, chronic obstructive pulmonary disease, and pulmonary hypertension.  This procedure is usually considered the ultimate treatment after medical therapies for the underlying lung disease have been exhausted and the disease is having a significant impact on survival and quality of life. The number of lung transplants performed continues to climb, and currently there are over 4000 lung and heart-lung transplants performed annually worldwide.

The most common diseases considered for lung transplantation include:

  • chronic obstructive pulmonary disease
  • idiopathic pulmonary fibrosis
  • cystic fibrosis
  • idiopathic pulmonary arterial hypertension
  • Eisenmenger syndrome
  • emphysema due to alpha-1 antitrypsin deficiency

Other less common diseases include

  • Bronchiectasis
  • sarcoidosis
  • lymphangioleiomyomatosis (LAM)
  • pulmonary Langerhans cell histiocytosis

In general, patients with advanced pulmonary disease can be considered for lung transplantation if they meet the following guidelines:

  • Untreatable advanced pulmonary disease of any etiology
  • Absence of other significant medical diseases
  • Substantial limitation of daily activities
  • Limited life expectancy-usually less than 2 years
  • Ambulatory patient with rehabilitation potential
  • Acceptable nutritional status
  • Satisfactory psychosocial profile and emotional support system

HOW DOES THE EVALUATION AND LISTING PROCESS WORK?

When a person meets the general guidelines discussed above, he/she can be referred to a designated lung transplant center.  In the United States, there are approximately 70 centers that have approval for lung or heart-lung transplantation.

Each center has its own system for evaluation. The comprehensive transplant evaluation seeks to determine the ability of the patient to benefit from transplantation and to enjoy a successful outcome with long-term health.  While outside information can be screened for basic eligibility, the evaluation will require a visit to the lung transplant center. The evaluation is conducted in stages and is customized to efficiently address key issues that might preclude transplantation in a particular patient.

Objectives of Evaluation Procedures

  • To assess the patient's clinical, social and psychological suitability as a transplant recipient
  • To impart information to the patient and his/her family concerning all aspects of transplantation
  • To meet hospital staff and transplant patients
  • To provide an opportunity for the patient, and his or her family, to begin to come to terms with the prospect of transplantation, and to be informed about the procedure and its aftermath

Lung Allocation Score (LAS)

All patients listed for lung transplantation are assigned a Lung Allocation Score (LAS).  The LAS system of lung allocation was implemented in May of 2005. Patients who are listed for lung transplantation are ranked on the waiting list in order of their score; the higher the score, the greater the likelihood of being offered donor lungs.

The LAS is based on multiple clinical variables from each individual patient and is designed to reflect both the seriousness of the patient's medical condition before transplant and the likelihood of success after a transplant.  In prioritizing patients with the most urgent status, there has been an increased number of critically ill recipients, and it is not clear that this maximizes transplant benefit.  However despite this controversy, the LAS system is an improvement over the prior waiting time-based system. The variables used in the LAS include: diagnosis, age, body mass index (kg/m2), diabetes, New York Heart Association functional class, forced vital capacity (% predicted), six-minute walk distance, pulmonary arterial systolic pressure, oxygen requirements at rest, use of continuous mechanical ventilation, and creatinine. The score has recently been updated to include total bilirubin and cardiac index. 

Suitable candidates are placed on a waiting list.  A non-profit organization called the United Network of Organ Sharing (UNOS) oversees the transplant system and helps prioritize peoples' position on the wait list, depending on the LAS.  The limited number of available donor lungs is a key factor that limits the number of lung transplants performed.

WHAT ARE SOME OF THE COMMON COMPLICATIONS OF LUNG TRANSPLANTATION?

A variety of complications have been described following lung transplantation, including rejection, infection, neoplasms, phrenic nerve and diaphragm dysfunction, pneumothorax, and pulmonary embolism.

Rejection

Regardless of the maintenance therapy used, more than 40% of patients experience at least one episode of acute rejection during the first year, most commonly in the first several months after transplantation. Acute rejection is the host's immune response to recognizing the graft as foreign.  Acute rejection is diagnosed by bronchoscopy with transbronchial biopsies and is classified into 5 grades based on the severity and extent of the perivascular lymphocytic infiltration.  Fortunately most episodes of acute rejection are amenable to treatment with augmented immunosuppression. The mainstay of therapy for acute rejection is pulse intravenous methylprednisolone, followed by higher oral prednisone doses.

Chronic Lung Allograft Dysfunction continues to be the major limitation to long-term survival.  Its pathogenesis is complex and poorly understood.  There are several identified risk factors including acute damage to the allograft, episodes of acute rejection, cytomegalovirus, pneumonia, and gastro-esophageal reflux.  CLAD can be characterized by either obstruction or the bronchial tubes (BOS) or scarring of the lungs (RAS).   Unfortunately there are no good therapies for CLAD; the search for CLAD therapies remains the holy grail of long term survival after lung transplantation.

Infection

Infection is the leading cause of death in lung transplant recipients.  In addition to medication-related immunosuppression, the lung is particularly susceptible to infection because of reduced mucociliary clearance, decreased cough reflex resulting from denervation, and interruption of lymphatic drainage.

WHAT ARE THE EXPECTED OUTCOMES OF LUNG TRANSPLANTATION?

The outcome of lung transplantation can be assessed by survival and quality of life. 

Survival

For all transplant recipients, survival is approximately 85% at one year, 70% at 3 years and 50-60% at 5 years .  Survival is better for younger cohorts (<50 years of age) compared to the older cohorts, and recipients with cystic fibrosis have improved survival compared to other indications.  Survival also appears to be better in double lung transplant compared to single lung transplant.

Quality of life

Several studies have documented a significant improvement in both overall and health-related quality of life after lung transplantation. Almost 90 percent of surviving transplant recipients have expressed satisfaction with their decision to have a transplant and would encourage a friend with a similar problem to seek transplantation(25).  More than 80% of recipients have no limitations at 5 years, and 40% of these recipients are working(5).

WHERE CAN YOU GET MORE INFORMATION?

United Network for Organ Sharing — UNOS is a private, not-for-profit corporation that operates the national Organ Procurement and Transplantation Network (OPTN) and maintains the Scientific Registry for Organ Transplantation under a government contract. UNOS develops policies that regulate the transplant system, and all OPOs and transplant programs must be members of UNOS.

Organ procurement organizations — The OPOs are nongovernmental organizations that recover organs in their service area and allocate them according to UNOS guidelines. There are 60 OPOs.

 


 

Four Facts About Lung Transplant

  1. In 1987 there were 27 lung transplants performed in the US. At the end of 2015 there were 1511.

  2. From 1997 to 2015 there have been 26,476 lung transplants performed in the US.

  3. Lungs are the most difficult of all solid organs to transplant

  4. To date there are not any drugs developed specifically for lung transplant