Clinical implications of serum IgG4 levels in patients with IgG4-related ophthalmic disease

Abstract

AIMS: The present study aimed to investigate the clinical implications of serum IgG4 levels in patients with IgG4-related ophthalmic disease (ROD).

METHODS: The medical records of 31 patients who met the diagnostic criteria for IgG4-ROD were retrospectively reviewed. Twenty-five patients whose serum IgG4 levels could be identified were included. Clinical manifestations and serum IgG4 levels before and after corticosteroid treatment were obtained. Factors associated with relapse were evaluated by comparing the features of patients with disease relapse with those of patients without relapse.

RESULTS: Twenty-four patients were 'definite' and one was 'probable' for IgG4-ROD according to the diagnostic criteria. Serum IgG4 levels were higher in patients with systemic involvement (p=0.046). All patients improved clinically after corticosteroid treatment. Serum IgG4 levels decreased after steroid treatment (p=0.005) and normalised in nine patients. In cases of relapse, serum IgG4 levels increased along with the aggravation of symptoms (p=0.047). Serum IgG4 levels that were still elevated (≥135 mg/dL) after steroid treatment (p=0.034) and cessation of steroid treatment during disease remission (p=0.043) were predictive factors for IgG4-ROD relapse.

CONCLUSIONS: Serum IgG4 level can be considered an adjunctive marker for treatment response in IgG4-ROD. Patients with serum IgG4 levels that remain elevated after steroid treatment should be carefully observed for relapse. A continuing maintenance dose of oral steroid is recommended to prevent relapse, even when clinical remission is achieved.