Also known as cryptogenic organizing pneumonia, bronchiolitis obliterans organizing pneumonia, or BOOP, is a fairly uncommon but serious condition that affects the lungs. When the bronchioles or small airways of the lungs, and the alveoli or tiny air-exchange sacs, get inflamed or clogged with connective tissue, the diagnosis is most likely going to be BOOP.
Symptoms, which are not always immediately present in BOOP, are typically pretty mild, ranging from an unproductive cough to shortness of breath.
There are several reasons a patient may develop BOOP, but for the purposes of this entry we will look at BOOP as a consequence of anti-cancer treatment. Specifically, BOOP sometimes develops as a complication following bone marrow transplantation.
BOOP in bone marrow transplantation
Bronchiolitis obliterans organizing pneumonia occurs to between 2-14 % of all allogeneic bone marrow transplantation patients. There are two known factors that raise one's risk of developing BOOP after a bone marrow transplantation.
1- Chronic graft versus host disease (cGVHD)
2- Low levels of immunoglobulin
In general, BOOP can be successfully treated with corticosteroid therapy, but this is not the case in bone marrow transplant patients, in whom response to such therapy is low and prognosis, rather poor. Neither the corticosteroids nor bronchodilators can reliably improve the airflow through the lungs in these patients.
For this reason, an immediate response to suspicions of BOOP becomes critical for the patient's prognosis. Furthermore, there is no telling what kind of clinical course BOOP may take, and in some rare cases, when the disease reaches advanced stages, a lung transplantation may become necessary.
Sources
Boyiadzis, Michael M. et al. Hematology-Oncology Therapy. 2007. New York: McGraw Hill, Medical Publishing Division.
Epler, Gary R MD. Bronchiolitis obliterans organizing pneumonia. Arch Intern Med. Vol 161 Jan22 2001.
