Lung involvement in scleroderma

Reactivity of pulmonary circulation and right ventricle function to inhaled nitric oxide in systemic sclerosis patients

Systemic sclerosis (SSc) is complicated by pulmonary hypertension and right ventricle (RV) failure in approximately 10% of the patients. Factors influencing the reactivity of pulmonary circulation to vasodilators are not established, while the examination of vasoreactivity is important in determining the treatment, because systemic administration of oral vasodilators can induce severe adverse events in nonresponders. The mechanism of RV failure in SSc is unclear and may result either from increased RV afterload or intrinsic myocardial disease. The aim of the study was to assess the reactivity of pulmonary circulation to inhaled nitric oxide (iNO) and to evaluate its influence on RV function in SSc patients with elevated right ventricle systolic pressure (RVSP). In 60 SSc patients aged 24-73 (58 females, two males; 33 patients with limited SSc and 27 with diffuse SSc), echocardiographic examination with tissue Doppler echocardiography (TDE) was performed. RV function was measured by systolic (S) and early diastolic (E) velocity of tricuspid annulus by TDE. In patients with RVSP >45 mmHg, the reactivity of pulmonary circulation was assessed by iNO test. High-resolution computerized tomography (HRCT) was performed to assess the extent of pulmonary fibrosis. Of 14 SSc subjects with elevated RVSP (13 females, one male; RVSP 47-62 mmHg), positive reaction to iNO was observed in five (RVSP decreased from 51.6 ± 3.7 to 32.24 ± 2.3 mmHg); nine patients were not reactive (RVSP 53.5 ± 5.7 mmHg before iNO vs. 49.6 ± 6.7 mmHg). RV systolic function was decreased in patients with elevated RVSP as compared to the patients with normal pulmonary pressure (S velocity 13.2 ± 1.3 vs. 14.4 ± 1.6 cm/s, respectively, p < 0.05). Significant increase of RV systolic function during iNO test was found in reactive patients only (S velocity before iNO 12.8 ± 1.2 cm/s, during iNO 14.5 ± 1.5 cm/s, p < 0.01). RVSP decrease strongly correlated with S velocity increase (r = 0.95, p < 0.0001). Response to iNO was found only in limited form of SSc; diffuse SSc patients showed no response. Pulmonary fibrosis on HRCT was more frequent in subjects nonreactive to iNO (67% of patients) than in the reactive group (40% of patients). The reactivity of pulmonary circulation to iNO in SSc patients with elevated RVSP was found predominantly in limited form of the disease. Pulmonary fibrosis typical for diffuse SSc was more frequent in nonreactive subjects. Elevated pulmonary pressure plays an important role in RV systolic dysfunction. Pulmonary pressure decrease during iNO test leads to the improvement of RV systolic function. Therapy for right-heart failure in reactive SSc patients should be directed, if possible, at the decrease in pulmonary resistance.

Scleroderma: it has been a long hard journey

Progress in the understanding of the aetiopathogenesis of scleroderma (systemic sclerosis) has been painfully slow and this has greatly impeded the application of specific disease modifying treatments. This article provides a brief historical overview of scleroderma (including the important Australian contribution of Dr Alfred Barnett and colleagues--see accompanying article in this issue on pages 513-18), highlights some recent pathogenic developments and summarises some exciting new therapies. Cautious optimism can now be offered to scleroderma sufferers.

Manifestations of scleroderma pulmonary disease

Scleroderma is a multisystem disease of unknown cause characterized by synthesis and deposition of excessive extracellular matrix and vascular anti-GBM antibodies, leading to pulmonary hemorrhage and glomerulonephritis with rapidly progressive renal insufficiency. Recent advances in the understanding of disease pathogenesis and diagnosis and treatment have significantly improved our ability to recognize the syndrome, distinguish it from other similar disorders, and offer successful treatment. This article focuses on the pathogenetic features, clinical manifestations, diagnostic strategies, and therapeutic principles of anti-GBM disease.

Acute hemodynamic responses to inhaled nitric oxide in patients with limited scleroderma and isolated pulmonary hypertension

BACKGROUND

Inhaled nitric oxide (NO) is a selective pulmonary vasodilator that reduces pulmonary vascular resistance (PVR) in patients with primary pulmonary hypertension. Their responses to inhaled NO predict their responses to other vasodilators, such as prostacyclin, and provide an estimate of the "fixed" component of their increased PVR. Some patients with limited cutaneous systemic sclerosis develop isolated pulmonary hypertension with a similar clinical course. Therefore, we have measured the acute hemodynamic response to inhaled NO in such patients.

METHODS AND RESULTS

Seven patients were studied during inhalation of increasing concentrations of NO (0 to 80 ppm). Complete hemodynamic data were collected on five patients. They demonstrated a selective, dose-dependent, and rapidly reversible fall in PVR (34%) and mean pulmonary artery pressure (17%). There was a nonsignificant increase in cardiac index but no change in mean arterial pressure or systemic vascular resistance. The mean right atrial pressure fell (27%), but there was no change in pulmonary artery occlusion pressure. Of the seven patients, five responded to inhaled NO ( < or = 40 ppm) with a decrease in total pulmonary resistance of at least 20%.

CONCLUSIONS

Inhaled NO is an effective and selective pulmonary vasodilator in a significant number of patients with pulmonary hypertension associated with limited cutaneous systemic sclerosis. It may be useful in determining the potentially reversible contribution to the increased PVR and should be considered for patients with acute pulmonary vascular crisis.