Background The ELF test and its components (PIIINP, TIMP-1 and HA) have been shown to correlate with skin, lung and overall fibrosis and not with any vascular manifestation of Systemic Sclerosis (SSc)1. On the contrary, NT-proBNP has been suggested to be useful for stratification of SSc patients, especially to identify those at risk of pulmonary hypertension2.
Objectives Aims of this study were: a) to validate ELF score and its single analytes on an independent cohort of scleroderma patients; b) to evaluate whether NT-proBNP could provide additional value to the development of an SSc-specific algorithm.
Methods 250 sera from SSc patients from a single UK centre were analysed employing a high-throughput in vitro diagnostic of a routine NHS pathology lab to measure ELF score, its analytes and NT-proBNP levels. All patients fulfilled 2013 ACR/EULAR classification criteria for SSc. Clinical, laboratory and instrumental data were collected at time of sampling. Statistical analysis was performed using SPSS. P<0.05 was considered statistically significant.
Results Multivariate analysis of ELF score (including the variables found statistically significant in univariate analysis) identified age, mRSS and DLCO% as independently associated with ELF score (p<0.0001 for all), confirming results previously published on an independent Italian cohort. As previously shown, ELF score and single analytes were not associated with heart and vascular manifestations of the disease. On the contrary NT-proBNP significantly correlated with heart severity (p<0.0001) and peripheral vasculopathy (p=0.005). Its levels were higher in patients with current digital ulcers (p=0.001), digital pitting scars (p=0.01), telangiectasias (p=0.01), systemic arterial hypertension (p=0.004), pulmonary artery hypertension (PAH) (p=0.01), diastolic dysfuction (p=0.002), reduced ejection fraction (p=0.0002), arrhythmias (p<0.0001) and dyspnoea (p=0.003) compared to those without the manifestation. Multivariate analysis identified presence of arrhythmias (p<0.0001), age (p<0.0001), PAH (p<0.001) and DLCO% (p=0.006) as independently associated with NT-proBNP. All the biomarkers significantly correlated with total Medsger's severity scale and EScSGactivity index (p<0.0001).
Conclusions Our findings validate the value of ELF score in a second independent cohort of 250 SSc sera and suggest that NT-proBNP has a complementary value correlating with other aspects of the disease such as PAH and heart severity. Longitudinal multicentres studies are warranted to determine the sensitivity to change and the predictive value of these biomarkers in SSc patients and to build up a new combined scleroderma specific algorithm including markers of fibrosis and vasculopathy.
Abignano G et al. Ann Rheum Dis 2014
Avouac J et al. Arthritis Care Res 2015
Disclosure of Interest None declared