The utility of immunoglobulin A/complement 3 and immunoglobulin G/immunoglobulin M ratios in the assessment of disease activation in patients with Behçet disease.

OBJECTIVE

Pathogenesis of Behçet disease (BD) has not yet been clearly revealed and there is no ideal test for the estimation of disease activation at present. This study aimed to assess the efficiencies of IgG/IgM and IgA/C3 ratios in determining activation of BD.

METHOD

This retrospective cohort study consisted of 140 patients with BD. Patients were divided into two groups: (1) active BD ( = 89) and (2) inactive BD ( = 51) and were compared in terms of  demographic features, clinical characteristics and laboratory test results. IgA/C3 and IgG/IgM ratios were compared according to organ system involvement; receiver operating characteristic (ROC) curve analysis was performed in order to assess the performance of IgA/C3 and IgG/IgM ratios in determining patient disease status.

RESULTS

Significantly higher levels of erythrocyte sedimentation rate, C-reactive protein, IgA, G, C4, IgA/C3, IgG/IgM ratios ( = .007 for IgA and  < .001 for others) and significantly lower levels of IgM and C3 were observed in patients with active BD ( < .001). The IgG/IgM ratio was significantly higher in patients with vascular involvement ( = .017) and the IgA/C3 ratio was significantly higher in patients with arthritis ( = .007). Cut-off values of 0.019 (70.8% sensitivity, 62% specificity) and 7.08 (84.3% sensitivity, 80% specificity) were determined for IgA/C3 and IgG/IgM ratios, respectively.

CONCLUSION

IgA/C3 and IgG/IgM ratios may be used as additional parameters for the assessment of BD status.