Immunoglobulin G4-related disease with multi-organ involvement: A case report

Immunoglobulin G4-related disease (IgG4-RD) is a rare, chronic, and progressive clinical condition characterized by elevated serum IgG4 levels and significant infiltration of IgG4-positive plasma cells, can affect various organs and tissues. However, multi-organ involvement, particularly in the gastrointestinal tract, has rarely been reported. This case report presents a rare instance of multi-organ IgG4-RD, aiming to raise clinicians' awareness of the diverse manifestations of this condition, thereby mitigating its potential for misdiagnosis and subsequent unnecessary surgical interventions.

This case report describes a 76-year-old female presented with a chief complaint of intermittent abdominal pain over the past decade and a 20-day history of jaundice. The laboratory findings revealed elevated serum IgG4 levels 21.5 g/L. Liver function test results show significant abnormalities. Magnetic resonance imaging and contrast-enhanced computed tomography of the upper abdomen indicated biliary duct dilation and narrowing of the pancreatic segment of the common bile duct. Gastroscopy revealed inflammatory changes in the cardia. Gastric fundus elevation indicated gastric antrum elevation in external gallbladder pressure. Histopathological analysis of biopsies from the stomach, pancreas, and liver revealed infiltration by plasma cells, eosinophils, and lymphocytes, with a plasma cell IgG4(+) to IgG(+) cell ratio exceeding 40%.

Based on the clinical, laboratory, and pathological findings, the patient was diagnosed with IgG4-RD, including IgG4-related pancreatitis (autoimmune pancreatitis), immunoglobulin G4-related sclerosing cholangitis, immunoglobulin G4-related autoimmune hepatitis, and immunoglobulin G4-related gastrointestinal disease.

Therapy was initiated on March 8, 2022, with oral prednisone acetate (30 mg once daily) in conjunction with acid suppression and calcium supplementation.

Following glucocorticoid administration, the skin and scleral jaundice showed significant improvement compared to previous assessments. Liver function tests and serum IgG4 levels also demonstrated notable improvement, and subsequent magnetic resonance imaging and gastroscopy examinations revealed further amelioration.

IgG4-RD is a rare condition with unclear pathogenesis. Given its diverse clinical presentations and propensity for multi-organ involvement, IgG4-RD is frequently subject to missed or incorrect diagnoses, potentially leading to unnecessary surgical interventions or other therapeutic approaches. The diagnosis and management of this case involving multiple organs aim to enhance clinicians' understanding of IgG4-RD, thereby facilitating timely administration of the most effective treatment.