Relations Between Serum IgA Level and Cartilage Erosion in 436 Cases of Rheumatoid Arthritis

Abstract

More patients with X-ray grading as cartilage erosion (slight, medium or severe) showed abnormal IgA comparing to those in X-ray grading as normal (p<0.05-0.01) both in preliminary investigation and after 6 months' follow-up. The serum IgA level in RA with X-ray grading as slight, medium or severe cartilage erosion was elevated remarkably comparing with in grading as normal (p<0.05-0.01). The Spearman Analysis showed that the level of serum IgA presents positive correlation with X-ray grading both in preliminary investigation (p=0.003, rIgA=0.143) and after 6 months follow-up (p=0.001, rIgA=0.173). IgG and IgM, however, have no correlation with X-ray image outcomes. The increase of serum IgA shows positive correlation with the grade of cartilage damage in active RA. IgA seems to be involved in the mechanism of joint cartilage erosion in active RA.

The era of the immunoglobulin A Fc receptor FcαRI; its function and potential as target in disease

“…The involvement of IgA RF in extra‐articular manifestations in RA was also reported . In a large patient cohort study, a positive correlation was found between the increase in serum IgA and the grade of cartilage destruction in active RA . Furthermore, clinical studies showed that anti‐TNF‐α treatment of RA patients reduced IgM, IgG, and IgA RF levels.…”

“…Interestingly, several studies reported a correlation between the presence of IgA RF or IgA ACPA in blood or synovial fluid and worse disease prognosis as well as severe bone erosions . This raises the hypothesis that IgA can contribute to pathology, as cross‐linking of FcαRI by immune complexes triggers neutrophil‐induced inflammation.…”

Immunoglobulin A: magic bullet or Trojan horse?

“…It was demonstrated that IgA1 immune complexes contain soluble FcaRI, which may block the binding between IgA and membrane-bound FcaRI [37,38], which could explain why neutrophils are not activated in IgA nephropathy. Patients with rheumatoid arthritis have IgA autoantibodies against the Fc domain of IgG (rheumatoid factor, RF), and a correlation between IgA RF and worse disease prognosis as well as severe bone erosion has been reported [39,40]. As the synovial fluid of patients with RA contains high numbers of neutrophils, it is conceivable that neutrophils induce inflammatory responses via FcaRI, ultimately leading to destruction of joint tissue.…”

An integrative approach of linking traditional Chinese medicine pattern classification and biomedicine diagnosis

“…Thus it is reasonable to make the hypothesis that there is a positive correlation among IgA (reflecting immune response), platelet and cartilage erosion (severe in late stage) in RA. The changes in peripheral IgA level and platelet number positively correlated with the grade of cartilage damage in active RA patients, thus supporting the hypothesis (Zha et al, 2006;He et al, 2007b). In the clinical practice, the CMMs with activating blood stasis pattern, and those reinforcing deficiency pattern and containing polysacharides or animal proteins were used for the treatment (Yang et al, 2003;Zhang et al, 2010).…”