Obstructive jaundice caused by IgG4-related disease with multiorgan involvement.

Abstract

Immunoglobulin G4-related disease (IgG4-RD) is an immune-mediated disease with multiorgan involvement. The variable clinical manifestations and image findings of this disease often present a diagnostic dilemma for physicians. Herein, we describe a patient with IgG4-RD involving the kidney, retroperitoneum, pancreas, and biliary tracts, successfully treated with steroids. A 68-year-old man presented to our emergency room with a 2-week history of jaundice, tea-color urine, and poor appetite. He denied presence of fever, dyspnea, abdominal pain, or dysuria recently. Relevant laboratory data showed elevated liver enzymes and bilirubinemia (SGOT = 82 IU/L, SGPT = 174 IU/L, ALP = 196 IU/L, GGT = 340 IU/L, total bilirubin = 12 mg/dl, direct bilirubin = 7.51 mg/dl) with normal C-Reactive protein (CRP), blood cell counts and renal function. Abdominal computed tomography (CT) showed enhancing soft tissue lesions at bilateral renal pelvises (Figure 1A, arrow) and para-aortic regions (Figure 1B, arrow), diffuse swelling of the pancreas with a peripheral poorly enhanced halo (Figure C, short arrow) and dilatation of intra-hepatic and extra-hepatic bile ducts associated with enhancing wall thickenings (Figure 1 D, arrow). Urine cytology, performed twice, was negative for malignant cells. Ureterorenoscopy biopsy was suggested; however, the patient refused. Biopsy using endoscopic retrograde cholangiopancreatography revealed a dense lymphoplasmacytic infiltration in a fibrotic background (Figure 1E), and increased IgG4-positive plasma cells with IgG4+/IgG+ plasma cell ratio about 50%. The density of IgG4+ plasma cells is 20 per high-power field (Figure 1F). The subsequent serum IgG4 was >1300 mg/dl (normal <135 mg/dl) and the diagnosis of IgG4-RD was confirmed. Prednisolone was administered at 40 mg/day with subsequent tapering. His symptoms improved rapidly. The soft tissue masses at the bilateral renal pelvises and paraaortic regions showed shrinkage at 4-month follow-up CT, and he was asymptomatic at the 6-month outpatient department (OPD) follow-up. IgG4-RD is characterized by lymphoplasmacytic infiltrate rich in IgG4-positive plasma cells. It has a predilection for middle-aged or elderly males. While almost every organ system may be affected by IgG4-RD, those most commonly involved are the major salivary gland, pancreas, lymph node and retroperitoneum.1, 2 The diagnosis of IgG4-RD is challenging, the appearance of a capsule-like rim of low attenuation surrounding the pancreas is a specific finding on CT, but it present in only 12%–48% of cases.2 The 2019 ACR/EULAR classification criteria for IgG4-RD provide a useful diagnostic tool that provides weighted criteria considering the clinical, serologic, radiologic, and pathologic domains, with scores ≥20 points and absence of exclusion criteria having 82% sensitivity and 97% specificity.3 Our patient's cumulative score was 65 points (Table 1). Another challenge was the differentiation between IgG4-RD and tumors, as both of can present as mass-like lesions in involved organs or painless obstructive jaundice. Unlike patients with IgG4-RD who usually have elevated serum IgG4 concentration, patients with cancer may have elevated tumor marker levels. Another indicator of IgG4-RD is the rapid improvement of clinical symptoms and imaging findings after steroid treatment.4 Glucocorticoids are the first-line treatment for active IgG4-RD, the recommended dose being 0.6 mg/kg/day initially. Rituximab is also useful and effective for patients with recurrent or refractory disease.1, 5 For patients undergoing treatment, continual monitoring of clinical symptoms, follow-up of relevant laboratory data, and periodic imaging studies are suggested. This case emphasizes the diversity of IgG4-RD due to variable clinical presentation and multiorgan involvement. Early recognition with adequate treatment may have excellent outcomes and prevent irreversible organ damage. All authors declare no conflict of interest.