IgG4-related disease: features and treatment response in a multi-ethnic cohort in Singapore

OBJECTIVES: To describe the features and treatment outcomes of IgG4-RD in multi-ethnic patients in Singapore.
METHODS: Retrospective study was performed on IgG4-RD patients identified from patient databases in a tertiary hospital.
RESULTS: Fourty-two patients (76% male) were included; 79% fulfilled the 2011 comprehensive diagnostic criteria for IgG4-RD for definite IgG4-RD. 81% were Chinese and 19% were Malays. Common initial manifestations included jaundice (52%), abdominal pain (36%) and swollen salivary glands (26%). Only 36% had a history of allergy. 83% had ≥ 1 organ involvement. Erythrocyte sedimentation rate, immunoglobulin E, IgG2 and IgG4 levels were elevated in 84%, 100%, 70% and 44% of patients, respectively. The most common histopathological feature was >10 IgG4+ cells per high power field (66%). 94% (34/36) of patients were treated with moderate to high doses of glucocorticoids, including 17 patients with combination immunosuppressants. Of these, all patients responded to therapy by 3 months. With a median (range) follow-up of 4.1 (0.4-13.8) years, 69% (25/36) needed low dose of glucocorticoids to maintain disease remission. Twenty-six per cent had relapse of disease, of which 82% had disease recurrence in the same organs.
CONCLUSIONS: Pancreatitis, lymphoadenopathy and cholangitis were the commonest manifestations in Asians with IgG4-RD. All patients responded to glucocorticoid therapy by 3 months, two-thirds required maintenance therapy with glucocorticoids, and one-quarter developed relapse of disease.