A case of non-cardiogenic acute pulmonary edema in a patient with POEMS syndrome-associated pulmonary arterial hypertension

Abstract

Dear Editor,POEMS syndrome is a monoclonal plasma cell disordercharacterized by polyneuropathy, organomegaly, endocrin-opathy, monoclonal protein, and skin changes [1]. It is alsoassociated with pulmonary arterial hypertension (PAH) orCastleman’s disease [1, 2]. However, there is no reportabout non-cardiogenic acute pulmonary edema (NCAPE).In this article, we describe a rare case of transient NCAPEin a patient with POEMS syndrome.A 55-year-old male with POEMS syndrome and Castle-man’s disease was referred to our institution because ofpulmonary hypertension (PH). Since no apparent causes ofPH were revealed, we reached the diagnosis of PAHconfirmed by right heart catheterization showing 49 mmHgof mean pulmonary artery pressure, 10 mmHg of meanpulmonary capillary wedge pressure, and 4.11 L/min ofcardiac output [3]. His complication included old myocar-dial infarction of distal part of left anterior descendingartery with mildly reduced left ventricular ejection fractionof 55%. Before the treatment of PAH, he acutely developeddyspnea without volume loading. Chest radiograph dem-onstrated bilateral alveolar infiltrates, and a ratio of arterialoxygen tension to fraction of inspired oxygen was89.8 mmHg. There were no changes in electrocardiographicand echocardiographic findings, and no elevations ofcardiac enzymes. Besides, no apparent causes of acuterespiratory distress syndrome such as bacteremia wereidentified [4]. We diagnosed that he developed NCAPE.He was treated with oxygen administration, nitroglycerin,and low-dose dobutamine as supportive measures. Hissymptoms diminished promptly over the next couple ofhours without ventilator support, accompanied by decreas-ing alveolar infiltrates.Since several cytokines such as vascular endothelialgrowth factor (VEGF) which act in conjunction withangiopoietin-1/2 are associated with exacerbations ofPOEMS syndrome, we evaluated these cytokines toelucidate possible mechanisms of NCAPE (Table 1)[1, 5,6]. There were acute increases in interleukin (IL)-6 andVEGF. However, no significant differences in othercytokines were revealed. Considering the Starling equation[7], we speculated that acute elevation of vascular perme-ability following VEGF elevation contributed to the onsetof NCAPE [4, 8]. It is also possible that elevated pre-capillary hydraulic pressure due to advanced PAH made thepatient susceptible to the change of vascular permeability[7]. We also speculated that acute elevation of IL-6provides essential stimulatory cues to acute VEGF eleva-tion, which may imply the risk of complication of Castle-man’s disease [8, 9].