Idiopathic Pulmonary Artery Hypertension (IPAH) is a fatal disease in which progressive pulmonary arterial hypertension leads to right heart failure and death. Recent advances in the medical management of this disease has successfully delayed the necessity of lung transplant but has not resulted in remissions. This case report details an unusual remission of IPAH.
A 40 year-old African-American female with a prior history of IPAH s/p single lung transplant 10 years ago presents to her new pulmonologist after discharge from her transplant center with a diagnosis of chronic rejection of her lung. She was initially diagnosed with IPAH 12 years earlier after presenting with recurrent syncope and progressive dyspnea. Elevated pulmonary artery systolic pressure (PASP) 80mmHg on echocardiogram was confirmed with right heart catheterization (RHC). After developing profound fatigue with overt right heart failure she underwent successful left single lung transplant with normalization of right heart function and was maintained on tacrolimus and mycophenolate mofetil. The next ten years were complicated by episodes of acute rejection, pneumonia and development of severe hypertension with chronic kidney disease. Renal biopsy showed Focal Segmental Glomerulosclerosis (FSGS) presumed to be secondary to tacrolimus. Spring 2004 she developed a persistent non-productive cough with mild but progressive dyspnea and eventually presented to her pulmonologist. Her chest radiograph revealed complete atelectasis of her left lung with proximal air-bronchograms and was immediately referred to her transplant center for further evaluation. Bronchoscopy was performed with unsuccessful transbronchial biopsies due to obliteration of her small airways. Laser ablation of her left mainstem anastomosis site with wire stent placement was performed without improvement. She was discharged with presumed chronic rejection of her transplanted lung and tapering of her immunosuppressive regimen. Complete functional loss of her transplanted lung was confirmed by V/Q scan and an echocardiogram with follow-up RHC revealing only mild pulmonary hypertension with PASP 44mmHg. An evaluation for secondary pulmonary artery hypertension was unremarkable. Persistent fatigue and malaise with worsening chronic cough and no clinical utility of preserving her rejected lung prompted the decision to recommend resecting the source of her symptoms. She underwent a successful resection of her transplanted lung January 2005 after discontinuing her tacrolimus with immediate resolution of her symptoms. Follow-up echocardiography 2 months after resection revealed stable mild pulmonary hypertension without treatment.
This unique case of IPAH that resolved after an astounding 10 year survival of a single lung transplant presents a glimpse into the role of pressure and the abnormal response of the pulmonary artery endothelium in the pathogenesis of this disease. Our patient was near death when her right pulmonary vasculature was unloaded by the shunted flow through the transplanted lung. 10 years later as my patient lost her transplanted lung to bronchiolitis obliterans, a sentinel event for most transplant recipients, resulting in only modest symptoms. Whether the remodeling of her native pulmonary vasculature was directly due to hemodynamic offloading, an unknown process or an inadvertently treated occult secondary pulmonary artery hypertension (SPAH) has yet to be discovered. The SPAH candidates that may have responded to her immunosuppressive regimen include vasculitides such as Takayasu Arteritis, collagen vascular diseases as well as Sarcoidosis. Without a clinical suspicion for these entities or supporting laboratory/radiographic evidence the working diagnosis is still IPAH.
This case report details the remission of IPAH in a long term survivor of a single lung transplant. Many patients have benefited from new therapies for PAH such as epoprostenol and bosentan limiting the number of patients that progress on to surgical intervention. The option of lung transplant still has a role and in this intriguing patient may have assisted in a remission.
Joon Yun, None.