The potential use of antibacterial peptide antibody indices in the diagnosis of rheumatoid arthritis and ankylosing spondylitis.

Background: Both rheumatoid arthritis (RA) and ankylosing spondylitis (AS) are potentially disabling arthritic disorders for which as yet no highly sensitive and reliable diagnostic laboratory markers are available.

Objective: The objective of this study was to evaluate the levels of antibodies against Proteus and Klebsiella antigenic peptides in an endeavor to develop diagnostic indices for the identification of patients with RA and AS, respectively.

Methods: Sera from 50 patients with RA, 34 patients with AS, and 38 healthy subjects were screened for antibodies against "ESRRAL" and "IRRET" synthetic amino acid peptides obtained from Proteus hemolysin and urease (HU) as well as against "QTDRED" and "DRDE" peptides from Klebsiella nitrogenase and pullulanase (NP) proteins, respectively.

Cytotoxicity responses to peptide antigens in rheumatoid arthritis and ankylosing spondylitis.

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.

Rapid solid phase synthesis and biodistribution of 18F-labelled linear peptides.

A rapid method for radiolabelling short peptides with 18F ( t(1/2)=109.7 min) for use in positron emission tomography (PET) was developed. Linear peptides (13mers) were synthesised using solid phase peptide synthesis and 9-fluorenylmethoxycarbonyl (Fmoc) chemistry.