Cytotoxicity Responses to Peptide Antigens in Rheumatoid Arthritis and Ankylosing Spondylitis

CLYDE WILSON, TAHA RASHID, HARMALE TIWANA, HURYIA BEYAN, LUCY HUGHES, SUKVINDER BANSAL, ALAN EBRINGER, and ALLEN BINDER

ABSTRACT.

Objective. To measure levels of IgG antibodies against structurally related synthetic peptides of HLA-DRB1*0404, type XI collagen, and Proteus mirabilis in patients with rheumatoid arthritis (RA) and HLA-B*2705 and Klebsiella pneumoniae in patients with ankylosing spondylitis (AS), and to determine whether sera from RA and AS patients are cytotoxic for sheep red blood cells (SRBC) coated with HLA-DRB1*0404, type XI collagen, or HLA-B*2705.

Methods. Sera from 51 patients with RA, 34 with AS, and 38 healthy controls were tested against synthetic EQRRAA, ESRRAL, LRREI, and IRRET peptides by ELISA. Sera from patients and controls were also tested for reactivity in complement mediated cytotoxicity with SRBC coated with EQRRAA and HLA-B*2705, LRREI peptides.

Results. Antibodies to synthetic peptides containing EQRRAA, ESRRAL, LRREI, and IRRET were significantly increased in RA patients compared with AS patients (p < 0.001) and controls (p < 0.001). The percentage lysis data for SRBC coated with EQRRAA and LRREI peptides were significantly higher for RA sera (p < 0.001) compared to control sera. Percentage lysis for SRBC coated with HLA-B*2705 peptide was significantly higher for AS sera (p < 0.001) compared to control sera.

Conclusion. Our results suggest that antibodies against antigenic determinants of P. mirabilis in RA and K. pneumoniae in AS have cytotoxic properties on structurally related host proteins. These cytotoxic antibodies together with T cell interactions could be relevant in the etiopathogenesis of RA and AS. (J Rheumatol 2003;30:972-8)

Key Indexing Terms:

CYTOTOXICITY
ANKYLOSING SPONDYLITIS
RHEUMATOID ARTHRITIS
PEPTIDE ANTIGENS

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From the Division of Life Sciences, Infection and Immunity Group, and Department of Pharmacy, King's College London, London; Department of Rheumatology, Middlesex Hospital, University College London, School of Medicine, London; and the Department of Rheumatology, Lister Hospital, Stevenage, England.

Supported by the Arthritis and Rheumatism Council and the Trustees of the Middlesex Hospital

C. Wilson, PhD; T. Rashid, MBChB; H. Tiwana, PhD; H. Beyan, BSc; L. Hughes, MSc, Division of Life Sciences, Infection and Immunity Group; A. Ebringer, MD, Division of Life Sciences, Infection and Immunity Group, Department of Rheumatology, Middlesex Hospital; S. Bansal, PhD, Department of Pharmacy, King's College London; A. Binder, MD, Department of Rheumatology, Lister Hospital.

Address reprint requests to Prof. A. Ebringer, Division of Life Sciences, Infection and Immunity Group, King's College London, 150 Stamford Street, London SE1 9NN, UK.

Submitted June 7, 2002; revision accepted October 10, 2002.

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