IgG4-related disease - a clinical case

Abstract

Immunoglobulin G4-related disease (IgG4-RD) is a systemic disease affecting one or more organs. Pathomorphologically, a dense infiltrate of lymphocytes and IgG4 plasmocytes, and subsequent fibrosis is detected. Despite the many hypotheses of genetic predisposition, molecular mimicry and autoimmune nature of the disease, the etiology still remains unclear. Both innate and acquired immunity are believed to play a key role in disease pathogenesis. The involvement of occupational risk factors is also discussed. The possible involvement of multiple organs and systems (most often lacrimal and salivary glands, kidneys, lungs, aorta, pancreas, hepatobiliary duct, lymph nodes, as well as retroperitoneal fibrosis) is the reason for the multidisciplinary approach in this disease. In pulmonary involvement, clinical manifestations are nonspecific (cough, dyspnea, chest or back pain, hemoptysis, low-grade fever, weight loss) or patients are asymptomatic and pulmonary changes are an incidental finding on imaging. Up to 60% of cases of autoimmune pancreatitis represent a pancreatic manifestation of IgG4-related disease, with the majority of patients being elderly men. The most common differential diagnosis is a malignant process due to the tumor-like changes of the affected organ. Treatment with corticosteroids, immunosuppressors and symptomatic agents in most cases has a good effect, although relapses of the disease are also observed. We present a clinical case of a 72-year-old patient whose first complaints were nonspecific, for which a chest computed tomography was performed with visualization of four solid nodules in the right lung. After antibiotic therapy, without effect and deterioration of the patient's condition, video-assisted thoracoscopy, biopsy, histology and immunohistochemistry were performed. A diagnosis of IgG4-RD with pleural and lung involvement was confirmed. Anemic syndrome, increased values ​​of amylase, lipase, and acute phase parameters were found from the laboratory tests. Through endoscopic retrograde cholangio-pancreatography, autoimmune pancreatitis was diagnosed in the course of IgG4-RD. A plastic stent was placed on the common bile duct. Treatment with Prednisolone 40 mg/day was started with a subsequent dose reduction. Follow-up computed tomography of the lung after 9 months demonstrated a reduction of the described changes in the lungs, but with persistent lymphadenopathy and fibrotic changes. Azathioprine 100 mg daily was added to prednisone therapy. Against the background of the combined treatment, an improvement of the clinical condition and laboratory parameters was established.