Impact of anti-human IgG hinge peptide antibodies on identification of patients with early seronegative rheumatoid arthritis

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CER17653
2024 Vol.42, N°11
PI 2238, PF 2247
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PMID: 38976292 [PubMed]

Received: 07/03/2024
Accepted : 20/05/2024
In Press: 05/07/2024
Published: 04/11/2024

Abstract

OBJECTIVES:
The early diagnosis of seronegative rheumatoid arthritis (SNRA), characterised by the absence of rheumatoid factor and anti-citrullinated antibody, involves a greater challenge compared to seropositive RA (SPRA). This study aimed to assess the discriminatory potential of anti-human IgG hinge antibodies (AHAs) for patients with early SNRA.
METHODS:
DMARDs-naive patients with SPRA (n=43), SNRA (n=21), and non-RA (n=49), with disease duration < 2 years, were included. Antigens comprised IgG1 or IgG4 F(ab’)2 cleaved by pepsin or MMP-3 and their hinge peptide analogues. Eight IgG anti-hinge antibodies (AHAs) against these antigens were measured in sera from the patients and 58 healthy controls (HCs) using ELISA. Serum CRP and MMP-3 levels, and clinical disease activity index (CDAI), were obtained from medical records. The area under the curve (AUC) obtained from logistic regression and receiver operating characteristic curve analyses were used as a discriminant indicator.
RESULTS:
The levels of the IgG AHAs were as follows: SPRA≥SNRA≈non-RA>HC. None of the AHAs were effective in discriminating SNRA from non-RA. However, the combination of MMP-3 and AHAs against IgG4 hinge peptide analogues demonstrated the utility (AUC=0.94). Furthermore, combination of MMP-3, AHAs against IgG1 hinge peptide analogues and CDAI maximally exerted discriminatory power (AUC=0.997).
CONCLUSIONS:
Specific AHAs in combination with MMP-3 and CDAI are potentially useful to discriminate SNRA from non-RA.

DOI: https://doi.org/10.55563/clinexprheumatol/sp1d13