[1597] The Presence of IGG4 Positive Plasma Cells in PSC/AIH as Compared to Other Autoimmune Liver Diseases.

Maria Westerhoff, John Hart. University of Chicago, IL

Background: It has recently been recognized that some patients with autoimmune pancreatitis develop a hepatic IgG4 associated disease which clinically and histologically resembles sclerosing cholangitis. It is not clear whether this disease, termed IgG4-associated cholangitis, can also occur in patients without autoimmune pancreatitis.
Design: In order to determine whether IgG4 positive plasma cells are present in a variety of autoimmune liver disease, we performed immunohistochemical staining for IgG4 on needle core biopsies from 47 patients diagnosed by standard histologic and clinical criteria as autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC), AMA negative PBC, AIH/PBC overlap, primary sclerosing cholangitis (PSC), and PSC/AIH overlap. No patients had autoimmune pancreatitis or any other IgG4 related disorder. The total number of IgG4 reactive plasma cells was counted, and the highest number per portal tract was scored as: 0 (none), 1 (1-3), and 2 (greater than 3).
Results: Absent or rare scattered single IgG4 reactive plasma cells were present in portal tracts (score 0 or 1) in the patients with PBC (n=12), AMA negative PBC (n=7), PBC/AIH overlap (n=7), AIH, (n=7), and PSC (n=6). In contrast, biopsies from six of eight patients with PSC/AIH overlap contained numerous IgG4 reactive cells (see chart).

PSC/ AIH	Total # of IgG4 cells	IgG4 score	Colonoscopy	ANA	Alk phos	AST/ALT	MRCP/ ERCP
48 F	44	2+	No IBD	1:320	472	37/39	Negative
54 F	20	2+	Not done	1:640	68	77/161	Not done
28 F	82	2+	Not done	1:640	236	182/263	Not done
28 M	68	2+	IBD	1:640	366	502/692	Negative
19 M	65	2+	Not done	Not done	N/A	N/A	Negative
27 M	34	2+	IBD	1:2560	190	1083/1300	Negative
5 M	1	1+	No IBD	1:640	3415	325/358	Not done
16 M	3	1+	IBD	1:320	3415	17/13	Negative

Conclusions: IgG4 reactive plasma cells are not present in the liver biopsies of patients with AIH, PBC, AMA negative PBC, AIH/PBC overlap or PSC. In contrast, a majority of patients with PSC/AIH overlap have significant infiltrates of IgG4 plasma cells. These patients appear to have a small duct form of PSC (ERCP negative) with fibrotic biliary changes that may be an IgG4-associated feature. Serum levels of IgG4 should be obtained from PSC/AIH patients to further characterize this overlap syndrome.
Category: Liver & Pancreas

Monday, February 28, 2011 9:30 AM

Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 205, Monday Morning