Ankylosing spondylitis (AS) is a chronic inflammatory arthritis of unknown origin. Its autoimmune origin has been suggested but never proven. Several reports have implicated Klebsiella pneumoniae as a triggering or perpetuating factor in AS; however, its role in the disease pathogenesis remains debated. Moreover, despite extensive investigations, a biomarker for AS has not yet been identified. To clarify these issues, we screened a random peptide library with pooled IgGs obtained from 40 patients with AS. A peptide (AS peptide) selected from the library was recognized by serum IgGs from 170 of 200 (85%) patients with AS but not by serum specimens from 100 healthy controls. Interestingly, the AS peptide shows a sequence similarity with several molecules expressed at the fibrocartilaginous sites that are primarily involved in the AS inflammatory process. Moreover, the peptide is highly homologous to a Klebsiella pneumoniae dipeptidase (DPP) protein. The antibody affinity purified against the AS peptide recognizes the autoantigens and the DPP protein. Furthermore, serum IgG antibodies against the Klebsiella DPP121-145peptide epitope were detected in 190 of 200 patients with AS (95%), 3 of 200 patients with rheumatoid arthritis (1.5%) and only 1 of 100 (1%) patients with psoriatic arthritis. Such reactivity was not detected in healthy control donors. Our results show that antibodies directed against an epitope of a Klebsiella pneumoniae-derived protein are present in nearly all patients with AS. In the absence of serological biomarkers for AS, such antibodies may represent a useful tool in the diagnosis of the disease. Copyright:

Antibodies directed against a peptide epitope of a Klebsiella pneumoniae-derived protein are present in ankylosing spondylitis

Puccetti, Antonio;Dolcino, Marzia;
2017

Abstract

Ankylosing spondylitis (AS) is a chronic inflammatory arthritis of unknown origin. Its autoimmune origin has been suggested but never proven. Several reports have implicated Klebsiella pneumoniae as a triggering or perpetuating factor in AS; however, its role in the disease pathogenesis remains debated. Moreover, despite extensive investigations, a biomarker for AS has not yet been identified. To clarify these issues, we screened a random peptide library with pooled IgGs obtained from 40 patients with AS. A peptide (AS peptide) selected from the library was recognized by serum IgGs from 170 of 200 (85%) patients with AS but not by serum specimens from 100 healthy controls. Interestingly, the AS peptide shows a sequence similarity with several molecules expressed at the fibrocartilaginous sites that are primarily involved in the AS inflammatory process. Moreover, the peptide is highly homologous to a Klebsiella pneumoniae dipeptidase (DPP) protein. The antibody affinity purified against the AS peptide recognizes the autoantigens and the DPP protein. Furthermore, serum IgG antibodies against the Klebsiella DPP121-145peptide epitope were detected in 190 of 200 patients with AS (95%), 3 of 200 patients with rheumatoid arthritis (1.5%) and only 1 of 100 (1%) patients with psoriatic arthritis. Such reactivity was not detected in healthy control donors. Our results show that antibodies directed against an epitope of a Klebsiella pneumoniae-derived protein are present in nearly all patients with AS. In the absence of serological biomarkers for AS, such antibodies may represent a useful tool in the diagnosis of the disease. Copyright:
File in questo prodotto:
File Dimensione Formato  
Puccetti et al. PLoS One 2017.pdf

accesso aperto

Tipologia: Documento in versione editoriale
Dimensione 2.19 MB
Formato Adobe PDF
2.19 MB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11567/882940
Citazioni
  • ???jsp.display-item.citation.pmc??? 2
  • Scopus 10
  • ???jsp.display-item.citation.isi??? 10
social impact