IgG4-related sclerosing cholangitis

Differentiation of benign and malignant hilar bile duct stenosis

BACKGROUND

Failure to differentiate benign and malignant hilar bile duct stenosis may lead to inappropriate treatment. We retrospectively analyzed the methods for differentiation.

MATERIALS AND METHODS

A total of 53 patients with hilar bile duct stenosis were included, comprising 41 malignant cases (hilar cholangiocarcinoma) and 12 benign cases (six primary sclerosing cholangitis and six IgG4-associated sclerosing cholangitis). Data of clinical histories, laboratory tests, imaging studies, and liver pathologies were collected, and comparison was made between benign and malignant groups.

RESULTS

Compared with malignant group, patients in the benign group were more likely to have multiorgan involvement of clinical histories (P < 0.001). There was no difference on bilirubin, liver enzyme, and serum tumor marker between the two groups, whereas serum IgG4 levels were higher in the benign group (P = 0.003). Patients in the benign group were more likely to have pancreatic changes (P < 0.001) and multiple-segmental bile duct stenosis (P < 0.001) on imaging. Compared with the malignant group, patients in the benign group were more likely to show severe periportal inflammation in noninvolved liver (P < 0.001), fibrosis around intrahepatic bile duct (P < 0.001), and more IgG4-positive plasma cells (P < 0.001) on liver pathology.

CONCLUSIONS

Benign lesion should be considered for patients with history of multiorgan involvement, pancreas changes, or multiple-segmental bile duct stenosis on imaging. Liver biopsy could be helpful for differential diagnosis before surgery.

The role of peroral video cholangioscopy in patients with IgG4-related sclerosing cholangitis

BACKGROUND

The cholangioscopic features of IgG4-related sclerosing cholangitis (IgG4-SC) remain undefined. The aim of this study was to clarify these endoscopic features using peroral video cholangioscopy (PVCS) in IgG4-SC patients.

METHODS

PVCS was performed in 33 patients: IgG4-SC (n = 13); primary sclerosing cholangitis (PSC; n = 5); and cholangiocarcinoma (n = 15), which included hilar cholangiocarcinoma (HCCA; n = 5) and distal cholangiocarcinoma (DCCA; n = 10).

RESULTS

The most frequent findings on PVCS in the IgG4-SC patients were dilated (62 %) and tortuous (69 %) vessels, and absence of partially enlarged vessels. The incidence of dilated and tortuous vessels was significantly higher in IgG4-SC patients than in PSC patients (p = 0.015). Scarring and pseudodiverticula were found significantly more often in PSC patients than in IgG4-SC patients (p = 0.001 and p = 0.0007, respectively). The incidence of partially enlarged vessels was significantly higher in DCCA patients than in IgG4-SC patients (p = 0.004). In contrast, the incidence of dilated vessels was significantly higher in IgG4-SC patients than in HCCA patients (p = 0.015). PVCS performed after corticosteroid therapy showed resolution of bile duct stenosis and dilated, tortuous, or partially enlarged vessels, as well as resolution of friability in all patients with IgG4-SC.

CONCLUSION

Cholangioscopy was useful in differentiating IgG4-SC from PSC. In addition, monitoring the patterns of proliferative vessels on PVCS may be useful to differentiate IgG4-SC from cholangiocarcinoma.

IgG4-related tubulointerstitial nephritis with plasma cell-rich renal arteritis

Immunoglobulin G4 (IgG4)-related tubulointerstitial nephritis is a newly recognized clinicopathologic entity that may occur as an isolated renal lesion or as part of a multisystem disorder. It is characterized by plasma cell-rich interstitial nephritis with abundant IgG4-positive plasma cells and IgG-dominant tubulointerstitial immune deposits. We report the first case of IgG4-related tubulointerstitial nephritis with multifocal plasma cell-rich renal arteritis presenting as acute kidney injury in a 72-year-old man. Seven weeks of prednisone therapy led to nearly complete recovery of kidney function. This case enlarges the morphologic spectrum of this disorder and emphasizes the need to distinguish it from other causes of renal vasculitis.