Serum B cell–activating factor (BAFF) level in connective tissue disease associated interstitial lung disease

Abstract

BackgroundInterstitial lung diseases (ILDs) are common in patients with connective tissue diseases (CTDs). Although the diagnosis of an underlying CTD in ILD (CTD-ILD) affects both prognosis and treatment, it is sometimes difficult to distinguish CTD-ILD from chronic fibrosing interstitial pneumonia (CFIP). B cell–activating factor belonging to the tumour necrosis factor family (BAFF) plays a crucial role in B cell development, survival, and antibody production.MethodsWe examined serum levels of BAFF, surfactant protein D (SP-D), and Krebs von den Lungen-6 (KL-6) in 33 patients with CTD-ILD, 16 patients with undifferentiated CTD-ILD, 19 patients with CFIP, and 26 healthy volunteers. And we analysed the relationship between serum BAFF levels and pulmonary function, as well as the expression of BAFF in the lung tissue of patients with CTD-ILD.ResultsSerum levels of BAFF were significantly higher in CTD-ILD patients compared to healthy subjects and CFIP patients. However, there were no significant differences in serum levels of SP-D and KL-6. Furthermore, serum BAFF levels in CTD-ILD patients were inversely correlated with pulmonary function. BAFF was strongly expressed in the lungs of CTD-ILD patients, but weakly in normal lungs.DiscussionThis is the first study to demonstrate that serum BAFF levels were significantly higher in CTD-ILD patients compared to healthy subjects and CFIP patients. Furthermore, serum BAFF levels were correlated with pulmonary function. We consider that serum BAFF levels in patients with CTD-ILD reflect the presence of ILDs disease activity and severity.ConclusionThese finding suggest that BAFF may be a useful marker for distinguishing CTD-ILD from CFIP.

Aberrant activation of the type I interferon system may contribute to the pathogenesis of anti‐melanoma differentiation‐associated gene 5 dermatomyositis

“…Elevated levels of BAFF have been seen in patients with myositis and ILD . Recently, in patients with connective tissue disease (CTD)–ILD, overexpression of BAFF was found not only in the blood but also in lung specimens, mainly in alveolar macrophages and infiltrating lymphoid cells . Serum BAFF levels were shown to be inversely correlated with pulmonary function in these patients with CTD‐ILD.…”

Circulatory levels of B‐cell activating factor of the TNF family in patients with diabetic foot ulcer: Association with disease progression

“…Furthermore, it was shown that BAFF levels were increased in patients with asthma . Hamada et al demonstrated that the BAFF levels were significantly higher in connective tissue disease associated interstitial lung disease and inversely correlated with pulmonary function . It has been well documented that one of the most important BAFF‐induced mechanism is an activation of nuclear factors of kappa light polypeptide in B‐cells (NF‐kB) signaling cascades.…”

Interstitial Score and Concentrations of IL-4Rα, PAR-2, and MMP-7 in Bronchoalveolar Lavage Fluid Could Be Useful Markers for Distinguishing Idiopathic Interstitial Pneumonias

“…Inhibition of BAFF led to IPF attenuation and a reduction in IL-1β levels [49,50]. Higher levels of BAFF were also found in the serum of patients with IPF and CTD-ILD in comparison with healthy controls [48,[51][52][53]. Francois et al showed that patients with systemic sclerosis (a CTD) and higher serum BAFF levels had a significantly higher incidence of pulmonary fibrosis and thus determined that BAFF was a potential therapeutic target [48].…”

“…Francois et al showed that patients with systemic sclerosis (a CTD) and higher serum BAFF levels had a significantly higher incidence of pulmonary fibrosis and thus determined that BAFF was a potential therapeutic target [48]. In another work, Hamada et al [51] found significantly higher serum BAFF levels in patients with CTD-ILD compared to patients with IPF. Additionally, they found a negative correlation between serum BAFF levels and lung function.…”