WBR0870

Author	[[PageAuthor::Serge Korjian M.D. (Reviewed by Serge Korjian)]]
Exam Type	ExamType::USMLE Step 1
Main Category	MainCategory::Immunology, MainCategory::Pathology
Sub Category	SubCategory::Pulmonology
Prompt	[[Prompt::A 65-year-old lung transplant patient presents to the transplant clinic for several months of gradually worsening shortness of breath. He had been out of the country and was not able to see a physician until now. After proper examination, the physician orders a set of pulmonary function tests and a high resolution chest CT. The results obtained raise the suspicion for chronic transplant rejection. If the physician was to order a transbronchial lung biopsy, what findings would confirm his suspicion?]]
Answer A	AnswerA::Bronchiolitis obliterans
Answer A Explanation	AnswerAExp::A form of fibrotic lung changes seen in patients with chronic lung transplant rejection.
Answer B	AnswerB::Vascular fibrosis
Answer B Explanation	AnswerBExp::Usually seen in chronic rejection of kidney and liver transplants.
Answer C	AnswerC::Graft vessel occlusion
Answer C Explanation	AnswerCExp::Usually seen in hyperacute rejection due to preformed antibodies, not in chronic rejection.
Answer D	AnswerD::Graft vessel vasculitis
Answer D Explanation	AnswerDExp::Usually seen in acute rejection, not in chronic rejection.
Answer E	AnswerE::Giant cell formation
Answer E Explanation	AnswerEExp::Not a characteristic of transplant rejection.
Right Answer	RightAnswer::A
Explanation	[[Explanation::Bronchiolitis obliterans, a manifestation of chronic transplant rejection, is a fibrotic process that leads to progressive narrowing of bronchiolar lumens with eventual airflow obstruction. It is a pattern seen on histologic examination that typically represents transplant rejection with transplant failure within 5 years of initial diagnosis. Bronchiolitis obliterans is a form of chronic rejection similar to other organ transplants; however, it does not involve the blood vessels typically seen in chronic rejection of renal and liver transplants. Approximately half of lung transplant patients have bronchiolitis obliterans by five years following transplantation, and as high as three quarters of the population has some manifestation by ten years. Risk factors include prior episodes of acute rejection, as well as viral, bacterial, and fungal infections of the lung. Classical findings include shortness of breath and an obstructive pattern on pulmonary function testing (PFT). Diagnosis is by physical exam, PFT, and transbronchial lung biopsy for confirmation. Educational Objective: Chronic rejection of lung transplants manifests as fibrosis with narrowing of the bronchilar lumens known as bronchiolitis obliterans. References: Belperio JA, Lake K, Tazelaar H, Keane MP, Strieter RM, Lynch JP. Bronchiolitis obliterans syndrome complicating lung or heart-lung transplantation. Semin Respir Crit Care Med. 2003;24(5):499-530. First Aid 2015 page 217]]
Approved	Approved::Yes
Keyword	WBRKeyword::Chronic rejection, WBRKeyword::Bronchiolitis obliterans, WBRKeyword::Lung transplant
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Order in Linked Questions	LinkedOrder::