Abstract 2102: Increased Th2 Cytokine Response In Pulmonary Arterial Hypertension Associated With Congenital Heart Disease
BACKGROUND AND PURPOSE: Proinflammatory responses have been largely investigated in idiopathic pulmonary arterial hypertension, but less extensively in the congenital heart disease-associated form (CHDPAH). We therefore decided to analyse the circulating levels of C-reactive protein (CRP), TNF-alpha and IL-6 in a specific group of CHDPAH subjects. Because in clinical practice some PAH patients present with associated inflammatory conditions such as asthma and thyroid disease, we also included determinations of circulating IL-10 and IL-10/TNF-alpha ratio.
METHODS: Measurements were performed at admittance and in the absence of any vasodilator therapy. Forty-six consecutive patients were enrolled, with ages ranging from 15 to 60 years (median 33 yrs). The mean pulmonary arterial pressure was 52±17 mmHg and peripheral oxygen saturation ranged from 79 to 96% (median 89%). Determinations were carried out in plasma, using high-sensitivity enzyme-linked immunoassays.
RESULTS: Levels of CRP and TNF-alpha, were within the normal range in patients, while IL-6 and IL-10 were significantly increased in comparison with controls (Table⇓). In addition, the IL-10/TNF-alpha ratio was higher in patients as compared with normals (respectively, 3.18 and 2.01, median values, p=0.0414). No significant differences in the levels of inflammatory mediators were observed in patients with peripheral oxygen saturation <90% versus >90%.
CONCLUSIONS: Proinflammatory mechanisms seem to be present not only in idiopathic PAH, but also in CHDPAH. Furthermore, heightened circulating level of IL-10 associated with increased IL-10/TNF-alpha ratio suggests involvement of Th2 response at least in some patients. If so, CHDPAH may be close, in some aspects, to conditions such as asthma, thyroid disease, autoimmune disorders and tumor developments, an interesting field for further studies.