SESSION TITLE: Pulmonary Vascular Disease Student/Resident Case Report Posters
SESSION TYPE: Student/Resident Case Report Poster
PRESENTED ON: Tuesday, October 27, 2015 at 01:30 PM - 02:30 PM
INTRODUCTION: Schimke immuno-osseous dysplasia (SIOD) is rare, fatal autosomal recessive disorder causing a variety of systemic complications. Pulmonary manifestations are attributed to faulty production of elastin and include emphysema and tracheobronchomalacia. Because elastin degredation in the matrix of pulmonary arteries is implicated in the development of pulmonary arterial hypertension (PAH) , previous investigators have proposed a link between SIOD and PAH . We present a patient with SIOD and pulmonary hypertension (PH).
CASE PRESENTATION: A 24 year old female presented for evaluation of worsening hypoxemia. She had multiple ischemic strokes resulting in expressive aphasia and end stage renal disease from focal segmental glomerulonephritis. Despite remaining euvolemic on hemodialysis, she had insidious onset of exertional dyspnea and hypoxemia. On exam, she had blood pressure 122/78, pulse of 90 bpm, respiratory rate of 16, and oxygen saturation of 96% on 2 L of nasal cannula. Exam was significant only for a loud second heart sound with a systolic murmur at the right upper sternal border. Electrocardiogram and chest X-ray were normal. Transthoracic echocardiogram (TTE) noted a normal left ventricular size/function and right ventricular peak systolic pressure of 57 mmHg. Computed tomography angiography of the chest showed no areas of emphysematous changes or chronic pulmonary embolism. Right heart catheterization showed pulmonary arterial pressures of 63/28/43, a pulmonary capillary wedge pressure (PCWP) of 20, and a measured pulmonary vascular resistance of 4.5 wood units. Despite the elevation in her PCWP, she was treated with sildenafil monotherapy with significant improvement in symptoms and hypoxemia. Due to clinical suspicion, specific testing for the SMARCAL1 gene revealed two previously described changes (c.1190delT and c.2114C>T) which confirmed SIOM. Soon thereafter, she developed a fatal intracranial hemorrhage.
DISCUSSION: We present a patient with SIOD in association with PH. While her right heart catheterization showed elevated PCWP that would prohibit labeling her as ‘group I PAH,’ the significant elevation of PVR suggests an underlying pulmonary vascular disease. While such changes are often seen in patients on hemodialysis, it is remarkable that this occurred in an adult patient with SIOD.
CONCLUSIONS: SIOD is a rare disorder, and patients rarely survive into adulthood. Pulmonary complications of SIOD include emphysema and tracheobronchomalacia. PAH is not well established in patients with SIOD, but there is a physiologic rationale for developing PAH. We hope our case report improves awareness of this potential association and recommend intermittent screening for PAH with TTE.
Reference #1: Humbert M et al., Cellular and molecular pathobiology of pulmonary arterial hypertension, J Am Coll Cardiol. 2004. 43(12s1):13S-24S.
Reference #2: Clewing JM et al., Schimke immune-osseous dysplasia: a clinicopathologic correlation. J Med Genet. 2007. 44(2): 122-130.
DISCLOSURE: The following authors have nothing to disclose: Adam Fox, Grant Farr, Dan Grinnan
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