Prognostic value of N-terminal natriuretic peptides in systemic sclerosis: a single centre study.

OBJECTIVES: Cardiac involvement is an important determinant of prognosis in systemic sclerosis (SSc). The identification of patients with high risk is of great importance. Our aim was to investigate the diagnostic and prognostic value of circulating concentrations of N-terminal fragments of A- and B-type natriuretic peptides (NT-proANP and NT-proBNP) in patients with SSc. METHODS: We prospectively studied 144 patients with SSc and followed them up for five years. Blood was collected for natriuretic peptide measurement at the time of the yearly scheduled cardiological check-up. The occurrence of clinically significant cardiac disease was measured as the composite of pulmonary arterial hypertension, cardiac revascularisation, development of left ventricular dysfunction or death. RESULTS: Patients diagnosed with heart involvement during the study had significantly higher levels of NT-proANP and NT-proBNP (791.4 ± 379.9 pmol/l vs. 608.0 ± 375.8 pmol/l, p<0.05 and 183.1 ± 162.6 vs. 125.7 ± 117.5 pmol/l, p<0.05, respectively). Receiver-operator-characteristic analysis identified <822.5 pmol/l as the best NT-proANP and <154.5 pmol/l as the best NT-proBNP threshold (sensitivity 56.3%, specificity 79.5%, negative predictive value: 86.4% and sensitivity 50.0%, specificity 76.8%, negative predictive value: 83.7%, respectively). During the follow-up, lower NT-proANP levels were significantly associated with a longer event-free survival (p<0.05), similar but a non-significant trend regarding NT-proBNP levels was also shown (p=0.052). CONCLUSIONS: In our cohort, NT-proANP had a supplementary prognostic value for cardiac involvement in systemic sclerosis. In addition, the high negative predictive value of natriuretic peptides supports the more extensive use in identifying SSc patients with high risk of future cardiac involvement.

A three-year follow-up study of the development of joint contractures in 131 patients with systemic sclerosis.

OBJECTIVES: To analyse the correlation between the number of joint-contractures and other major clinical findings in a follow-up study of 131 patients with systemic sclerosis (SSc). METHODS: The range of motion of joints (ROM), HAQ-DI, and the major clinical characteristics were assessed. RESULTS: A high frequency of contractures (ROM<75% of the normal) were present at baseline in small joints of the hand (82%), wrists (75%), and shoulders (50%). ROM of the dominant side hand was significantly more decreased compared to the non-dominant side. The number of the upper extremity contractures correlated positively with ESR (p<0.01), CRP (p<0.01), HAQ-DI (p<0.01), and negatively with forced vital capacity (FVC) (p<0.05). The number of contractures was not significantly different in cases with early (≤ 4 years) and late disease duration in both the limited and diffuse subgroups. During the three-year follow-up period, an increase in the number of joint contractures (ROM<75%) was associated with an increase of ESR, modified Rodnan's skin score, and the European Scleroderma Study Group Activity Index by multiple linear regression analysis. Univariate analysis over a six-year period demonstrated poor outcome in patients with more than ten contractures, or more than four contractures of unilateral hand-joints. CONCLUSIONS: Contractures predominantly develop during the early years following disease onset in both SSc subgroups. Inflammation and skin-involvement are significant contributing factors for the development of contractures. The dominant hand may be more pronouncedly impaired compared to the non-dominant side. A high number of joint-contractures might be an unfavourable prognostic factor in SSc.

Follow-up of serum KL-6 lung fibrosis biomarker levels in 173 patients with systemic sclerosis.

OBJECTIVES: A single-centre retrospective longitudinal study to investigate the predictive value of KL-6 serum levels for the outcome of interstitial lung fibrosis in a large systemic sclerosis (SSc) patient cohort. METHODS: ELISA tests for the mucin like glycoprotein KL-6 were performed in sera of 173 SSc patients. The clinical and laboratory data were evaluated by a standardised protocol of chest x-ray, lung function tests, echocardiography and high-resolution computed tomography. 158 patients were 29 ± 22 months later reinvestigated, 9 patients (2 lcSSc, 7 dcSSc) died from SSc-related causes, and 6 patients were lost to follow-up. RESULTS: Serum titer of KL-6 was negatively correlated with lung function parameters, independent of the time of investigation. There was a significantly higher probability of death among patients with high level of baseline KL-6. There was no statistically significant difference in the deterioration and improvement rates between groups with normal and elevated KL-6 level at study entry, even in patients in early phase of disease (disease duration <3 years). Serum levels of KL-6 significantly decreased in patients receiving cyclophosphamide treatment in spite of the fact that the spirometry results (FVC and DLCO) did not show a significant change. CONCLUSIONS: KL-6 can be used as a lung fibrosis severity marker, but its role as a marker for disease activity is questionable. Furthermore, following cyclophosphamide treatment serum KL-6 levels may decrease independently of the lung function parameters.

Overlap of coronary disease and pulmonary arterial hypertension in systemic sclerosis.

OBJECTIVES: Pulmonary arterial hypertension (PAH) is a common complication of systemic sclerosis (SSc). Symptoms of coronary artery disease (CAD) and PAH are closely related and cardiac catheterisation is needed to confirm their diagnosis. The aim of the present work was to investigate of the extent of overlap between CAD and PAH in patients with SSc. METHODS: Based on non-invasive investigations, 20 patients out of 120 were suspected to have PAH ("suspected PAH" group). Another 10 patients showed signs of coronary disease ("suspected CAD" Group). In these 30 patients, right heart catheterisation and coronary angiography were performed, and the coronary flow reserve (CFR) was assessed by thermodilution technique. RESULTS: In the "suspected PAH" and the "suspected CAD" groups, PAH was found in 12/20 and 2/10 cases, and coronary artery stenosis in 9/20 and 6/10 cases, respectively. Severely reduced CFR was revealed in 7/20 and 3/10 cases, respectively. CONCLUSIONS: PAH, CAD and reduced CFR all show a considerable overlap in symptomatic patients with SSc. The current non-invasive investigations are neither sensitive nor specific enough to make an appropriate distinction between these different disease manifestations. A more invasive approach, such as coronary angiography at the initial catheterisation, is required to properly characterise and treat the different forms of cardiac involvement in SSc.

Comprehensive investigation of novel serum markers of pulmonary fibrosis associated with systemic sclerosis and dermato/polymyositis.

OBJECTIVE: To investigate the association between serum levels and clinical signs of lung fibrosis in patients with systemic sclerosis and inflammatory myopathies. METHODS: ELISA tests for a mucin-like glycoprotein KL-6, von Willebrandt factor (vWF), soluble E-selectin (sES) and surfactant protein D (SP-D) were performed in sera of 104 patients with systemic sclerosis, 31 patients with poly/dermatomyositis) and 24 patients with Raynaud's phenomenon as controls. The clinical and laboratory data were evaluated by a simple standard protocol including chest x-ray, lung function tests, echocardiography and, in selected cases, high resolution computer tomography (HRCT). Clinically significant pulmonary fibrosis (PF) defined as a simultaneous presence of radiological sign of pulmonary fibrosis and restrictive impairment. Severe PF was established if HRCT scans showed diffuse interstitial lung disease with low diffusing capacity. End stage PF was determined as severe PF with very low diffusing capacity. RESULTS: Patients with pulmonary fibrosis on chest x-ray showed significantly elevated serum levels of KL-6, SP-D and vWF. Inverse correlation was found between serum levels of KL-6/SP-D and lung function parameters, such as DLCO% and FVC. With regard to HRCT findings, patients with elevated serum level of KL-6 showed significantly more frequently ground glass opacity, diffuse and honeycombing fibrosis than patients with normal level of KL-6. The sensitivity of KL-6 for PF in SSc is increased with the severity of PF (PF on chest x-ray < severe PF < end stage of PF). Lung fibrosis occurred more frequently in patients with simultaneously elevated KL-6 and sES compared to cases with a single positivity of either KL-6 or sES. CONCLUSION: KL-6, SP-D, vWF and ES are good surrogate factors of pulmonary fibrosis but can not replace conventional diagnostic procedures. However, these markers are suitable for the assessment of progression and severity of pulmonary fibrosis in systemic autoimmune disorders once the diagnosis is established.