HLA association with the susceptibility to anti-synthetase syndrome.

OBJECTIVE: To investigate the human leukocyte antigen (HLA) association with anti-synthetase syndrome (ASSD). METHODS: We conducted the largest immunogenetic HLA-DRB1 and HLA-B study to date in a homogeneous cohort of 168 Caucasian patients with ASSD and 486 ethnically matched healthy controls by sequencing-based-typing. RESULTS: A statistically significant increase of HLA-DRB1*03:01 and HLA-B*08:01 alleles in patients with ASSD compared to healthy controls was disclosed (26.2% versus 12.2%, P=1.56E-09, odds ratio-OR [95% confidence interval-CI]=2.54 [1.84-3.50] and 21.4% versus 5.5%, P=18.95E-18, OR [95% CI]=4.73 [3.18-7.05]; respectively). Additionally, HLA-DRB1*07:01 allele was significantly decreased in patients with ASSD compared to controls (9.2% versus 17.5%, P=0.0003, OR [95% CI]=0.48 [0.31-0.72]). Moreover, a statistically significant increase of HLA-DRB1*03:01 allele in anti-Jo-1 positive compared to anti-Jo-1 negative patients with ASSD was observed (31.8% versus 15.5%, P=0.001, OR [95% CI]=2.54 [1.39-4.81]). Similar findings were observed when HLA carrier frequencies were assessed. The HLA-DRB1*03:01 association with anti-Jo-1 was unrelated to smoking history. No HLA differences in patients with ASSD stratified according to the presence/absence of the most representative non-anti-Jo-1 anti-synthetase autoantibodies (anti-PL-12 and anti-PL-7), arthritis, myositis or interstitial lung disease were observed. CONCLUSIONS: Our results support the association of the HLA complex with the susceptibility to ASSD.

Influence of MUC5B gene on antisynthetase syndrome.

MUC5B rs35705950 (G/T) is strongly associated with idiopathic pulmonary fibrosis (IPF) and also contributes to the risk of interstitial lung disease (ILD) in rheumatoid arthritis (RA-ILD) and chronic hypersensitivity pneumonitis (CHP). Due to this, we evaluated the implication of MUC5B rs35705950 in antisynthetase syndrome (ASSD), a pathology characterised by a high ILD incidence. 160 patients with ASSD (142 with ILD associated with ASSD [ASSD-ILD+]), 232 with ILD unrelated to ASSD (comprising 161 IPF, 27 RA-ILD and 44 CHP) and 534 healthy controls were genotyped. MUC5B rs35705950 frequency did not significantly differ between ASSD-ILD+ patients and healthy controls nor when ASSD patients were stratified according to the presence/absence of anti Jo-1 antibodies or ILD. No significant differences in MUC5B rs35705950 were also observed in ASSD-ILD+ patients with a usual interstitial pneumonia (UIP) pattern when compared to those with a non-UIP pattern. However, a statistically significant decrease of MUC5B rs35705950 GT, TT and T frequencies in ASSD-ILD+ patients compared to patients with ILD unrelated to ASSD was observed. In summary, our study does not support a role of MUC5B rs35705950 in ASSD. It also indicates that there are genetic differences between ILD associated with and that unrelated to ASSD.

[Key features in the management of diffuse interstitial pulmonary disease]. / Aspectos relevantes en el manejo de la enfermedad pulmonar intersticial difusa.

Diffuse interstitial lung disease is a heterogeneous group of diseases in which the common denominator is involvement of the area between the basement membrane of the alveolar epithelium and the capillary endothelium, known as the interstitial space. Diffuse interstitial lung disease poses a tremendous challenge to the clinician due to the diagnostic approach, the complications that can appear in the natural history of these entities, and the scarcity of available therapeutic resources. This brief review discusses key features of the management of diffuse interstitial pulmonary disease, such as prognostic factors, the therapeutic options -including the role of lung transplantation- and the diagnosis and treatment of two complications with crucial impact on the clinical course of the disease: exacerbations and associated pulmonary hypertension.