SESSION TITLE: Pulmonary Vascular Diseases Student/Resident Cases
SESSION TYPE: Student/Resident Case Report Slide
PRESENTED ON: Tuesday, October 27, 2015 at 04:30 PM - 05:30 PM
INTRODUCTION: Castleman’s disease is a rare group of lymphoproliferative disorders characterized by abnormal production of interleukin 6 (IL-6) by CD20+ polyclonal lymphocytes, and it is often associated with HHV-8 or HIV infection. Castleman’s disease has been associated with pulmonary arterial hypertension (PAH), but little is known about the natural course and optimal treatment of PAH associated with Castleman’s disease (PAH-CD) . While toculizumab, an IL-6 receptor antagonist, has been associated with clinical improvement in patients with PAH-CD, we herein report the first case of sustained clinical response to rituximab in a patient with PAH-CD .
CASE PRESENTATION: A 42 year old female was diagnosed with Castleman's disease by mediastinal biopsy in 1987. She was managed with steroids and mediastinal radiation until 2008, when clinical progression led to mediastinal and liver biopsies confirming CD20+ multicentric Castleman’s disease (MCD). A diagnosis of idiopathic MCD was confirmed after negative testing for HIV and HHV-8. Progressive exertional dyspnea (functional class III) was evaluated, and PAH was confirmed after right heart catheterization and exclusion of other etiologies. Ambrisentan was initiated for PAH, and rituximab was initiated as treatment of Castleman’s disease. On this regimen functional class improved (III to II), 6 minute walk distance improved (480m to 553m), and normal RV function was maintained on serial echocardiogram. Her MCD responded to rituximab, with radiographic stabilization of mediastinal and hepatic disease.
DISCUSSION: Association between clinical improvement and rituximab treatment in a patient with PAH-CD is possible, although not confirmed in this case report. As the driving force for our patient’s PAH is presumed to be CD20+ MCD, and rituximab depletes CD20+ lymphocytes, it is possible that rituximab has contributed or caused the clinical improvement. Because the rarity of this condition will prevent large-scale evaluation, it’s important that additional cases be followed closely as medications are used to target CD20+ cells or to inhibit the effects or IL-6.
CONCLUSIONS: We present a case of PAH-CD with sustained clinical improvement over 7 years after initiation of ambrisentan and rituximab. While concurrent initiation of ambrisentan and rituximab prevents an accurate assessment of the cause of her improvement, we feel that her sustained improvement is impressive and unexpected.
Reference #1: Montani D, Achouh L, Marcelin AG, et al. Reversibility of pulmonary arterial hypertension in HIV/HHV8-associated Castleman’s disease. Eur Respir J. 2005; 26:969-972.
Reference #2: Arita Y, Sakata Y, Sudo T, et al. The efficacy of toclizumab in a patient with pulmonary arterial hypertension associated with Castleman’s disease. Heart vessels 2010; 25:444-447.
DISCLOSURE: The following authors have nothing to disclose: Adam Fox, Grant Farr, Dan Grinnan
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