Homocysteinylated alpha 1 antitrypsin as an antigenic target of autoantibodies in seronegative rheumatoid arthritis patients

Tania Colasanti; Danilo Sabatinelli; Carmine Mancone; Alessandra Giorgi; Arbi Pecani; Francesca Romana Spinelli; Alessandra Di Giamberardino; Luca Navarini; Mariangela Speziali; Marta Vomero; Cristiana Barbati; Carlo Perricone; Fulvia Ceccarelli; Annacarla Finucci; Alessandra Ida Celia; Damiano Currado; Antonella Afeltra; Maria Eugenia Schininà; Vincenzo Barnaba; Fabrizio Conti; Guido Valesini; Cristiano Alessandri

doi:10.1016/j.jaut.2020.102470

Homocysteinylated alpha 1 antitrypsin as an antigenic target of autoantibodies in seronegative rheumatoid arthritis patients

J Autoimmun. 2020 Sep:113:102470. doi: 10.1016/j.jaut.2020.102470. Epub 2020 May 28.

Authors

Tania Colasanti¹, Danilo Sabatinelli², Carmine Mancone³, Alessandra Giorgi⁴, Arbi Pecani⁵, Francesca Romana Spinelli⁶, Alessandra Di Giamberardino⁷, Luca Navarini⁸, Mariangela Speziali⁹, Marta Vomero¹⁰, Cristiana Barbati¹¹, Carlo Perricone¹², Fulvia Ceccarelli¹³, Annacarla Finucci¹⁴, Alessandra Ida Celia¹⁵, Damiano Currado¹⁶, Antonella Afeltra¹⁷, Maria Eugenia Schininà¹⁸, Vincenzo Barnaba¹⁹, Fabrizio Conti²⁰, Guido Valesini²¹, Cristiano Alessandri²²

Affiliations

¹ Rheumatology Unit, Department of Clinical Internal, Anesthetic and Cardiovascular Sciences, Sapienza University of Rome, Rome, Italy. Electronic address: tania.colasanti@gmail.com.
² Rheumatology Unit, Department of Clinical Internal, Anesthetic and Cardiovascular Sciences, Sapienza University of Rome, Rome, Italy. Electronic address: danilo.sabatinelli@gmail.com.
³ Department of Molecular Medicine, Proteomics Laboratory, Sapienza University of Rome, Rome, Italy. Electronic address: carmine.mancone@uniroma1.it.
⁴ Department of Biochemical Sciences "A. Rossi Fanelli", Sapienza University of Rome, Rome, Italy. Electronic address: alessandra.giorgi@uniroma1.it.
⁵ University Hospital "Shefqet Ndroqi", Tirana, Albania. Electronic address: arbipecani@gmail.com.
⁶ Rheumatology Unit, Department of Clinical Internal, Anesthetic and Cardiovascular Sciences, Sapienza University of Rome, Rome, Italy. Electronic address: francescaromana.spinelli@uniroma1.it.
⁷ Department of Molecular Medicine, Proteomics Laboratory, Sapienza University of Rome, Rome, Italy. Electronic address: alessandra.digiamberardino@uniroma1.it.
⁸ Unit of Allergology, Immunology and Rheumatology, Department of Medicine, Campus Bio-Medico University of Rome, Rome, Italy. Electronic address: l.navarini@unicampus.it.
⁹ Rheumatology Unit, Department of Clinical Internal, Anesthetic and Cardiovascular Sciences, Sapienza University of Rome, Rome, Italy. Electronic address: mariangela.speziali@uniroma1.it.
¹⁰ Rheumatology Unit, Department of Clinical Internal, Anesthetic and Cardiovascular Sciences, Sapienza University of Rome, Rome, Italy. Electronic address: marta.vomero@gmail.com.
¹¹ Rheumatology Unit, Department of Clinical Internal, Anesthetic and Cardiovascular Sciences, Sapienza University of Rome, Rome, Italy. Electronic address: cristiana.barbati1@gmail.com.
¹² Rheumatology Unit, Department of Clinical Internal, Anesthetic and Cardiovascular Sciences, Sapienza University of Rome, Rome, Italy. Electronic address: carlo.perricone@gmail.com.
¹³ Rheumatology Unit, Department of Clinical Internal, Anesthetic and Cardiovascular Sciences, Sapienza University of Rome, Rome, Italy. Electronic address: fulvia.ceccarelli@uniroma1.it.
¹⁴ Rheumatology Unit, Department of Clinical Internal, Anesthetic and Cardiovascular Sciences, Sapienza University of Rome, Rome, Italy. Electronic address: finini@hotmail.it.
¹⁵ Rheumatology Unit, Department of Clinical Internal, Anesthetic and Cardiovascular Sciences, Sapienza University of Rome, Rome, Italy. Electronic address: celiaalessandraida@gmail.com.
¹⁶ Unit of Allergology, Immunology and Rheumatology, Department of Medicine, Campus Bio-Medico University of Rome, Rome, Italy. Electronic address: d.currado@unicampus.it.
¹⁷ Unit of Allergology, Immunology and Rheumatology, Department of Medicine, Campus Bio-Medico University of Rome, Rome, Italy. Electronic address: a.afeltra@unicampus.it.
¹⁸ Department of Biochemical Sciences "A. Rossi Fanelli", Sapienza University of Rome, Rome, Italy. Electronic address: eugenia.schinina@uniroma1.it.
¹⁹ Department of Clinical Internal, Anesthetic and Cardiovascular Sciences, Sapienza University of Rome, Rome, Italy; Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Rome, Italy. Electronic address: vincenzo.barnaba@uniroma1.it.
²⁰ Rheumatology Unit, Department of Clinical Internal, Anesthetic and Cardiovascular Sciences, Sapienza University of Rome, Rome, Italy. Electronic address: fabrizio.conti@uniroma1.it.
²¹ Rheumatology Unit, Department of Clinical Internal, Anesthetic and Cardiovascular Sciences, Sapienza University of Rome, Rome, Italy. Electronic address: guido.valesini@uniroma1.it.
²² Rheumatology Unit, Department of Clinical Internal, Anesthetic and Cardiovascular Sciences, Sapienza University of Rome, Rome, Italy. Electronic address: cristiano.alessandri@uniroma1.it.

PMID: 32473759
DOI: 10.1016/j.jaut.2020.102470

Abstract

Rheumatoid arthritis (RA) is a chronic autoimmune disease and rheumatoid factor (RF) and anti-citrullinated protein antibodies (ACPA) are the most frequently detected autoantibodies (autoAbs). To date, more than 20% of RA cases are still defined as seronegative forms (seronegative RA, SN-RA). The aim of this study was to identify new antigenic targets of autoAbs in RA patients, which can also be recognized in SN-RA. Using a proteomic approach, we tested sera from SN-RA patients by analyzing synovial fluid (SF) proteins from these patients. Sera from SN-RA patients revealed a strong reactive spot, corresponding to alpha 1 antitrypsin (A1AT). Reverse-phase nanoliquid chromatography and tandem mass spectrometry (Matrix Assisted Laser Desorption/Ionization-Time Of Flight, MALDI-TOF/TOF) confirmed the presence of A1AT in SF and showed that homocysteinylation was one of the post-translational modifications of A1AT. Homocysteinylated (Hcy)-A1AT immunoprecipitated from SN-RA patients' SFs and in vitro modified Hcy-A1AT were used as antigens by Enzyme-Linked ImmunoSorbent Assay (ELISA) to test the presence of specific autoAbs in sera from 111 SN-RA patients, 132 seropositive (SP)-RA patients, and from 95 patients with psoriatic arthritis, 40 patients with osteoarthritis, and 41 healthy subjects as control populations. We observed that a large portion of SN-RA patients (75.7%), and also most of SP-RA patients' sera (87.1%) displayed anti-Hcy-A1AT autoAbs (anti-HATA). Native A1AT was targeted at a lower rate by SP-RA patients autoAbs, while virtually no SN-RA patients' sera showed the presence of anti-native A1AT autoAbs. In conclusion, anti-HATA can be considered potential biomarkers for RA, also in the SN forms. The discovery of novel autoAbs targeting specific autoantigens can represent higher clinic significance for all RA patients' population.

Keywords: Alpha 1 antitrypsin; Autoantibodies; Homocysteine; Post-translational modifications; Rheumatoid arthritis; Seronegative rheumatoid arthritis.

Publication types

Observational Study
Research Support, Non-U.S. Gov't

MeSH terms

Aged
Arthritis, Rheumatoid / blood
Arthritis, Rheumatoid / diagnosis*
Arthritis, Rheumatoid / immunology
Autoantibodies / blood*
Autoantibodies / immunology
Autoantibodies / metabolism
Autoantigens / immunology*
Autoantigens / metabolism
Biomarkers / blood
Biomarkers / metabolism
Case-Control Studies
Enzyme-Linked Immunosorbent Assay
Female
Healthy Volunteers
Homocysteine / metabolism
Humans
Male
Middle Aged
Protein Processing, Post-Translational
Serologic Tests
alpha 1-Antitrypsin / immunology*
alpha 1-Antitrypsin / metabolism

Substances

Autoantibodies
Autoantigens
Biomarkers
SERPINA1 protein, human
alpha 1-Antitrypsin
Homocysteine

Grants and funding

26813/CRUK_/Cancer Research UK/United Kingdom