Comparison of the Immunohistochemical Staining Methods for the Diagnosis of Lymphoplasmacytic Sclerosing Pancreatitis
Katsuyuki Miyabe, Kenji Notohara, Takahiro Nakazawa, Kaduki Hayashi, Itaru Naitoh, Fumihiro Okumura, Shuya Shimizu, Michihiro Yoshida, Hiroaki Yamashita, Hirotaka Ohara, Takashi Joh. Nagoya City University, Nagoya, Japan; Kurashiki Central Hospital, Kurashiki, Japan
Background: Presence of abundant IgG4-positive plasma cells is a significant pathologic finding for the diagnosis of lymphoplasmacytic sclerosing pancreatitis (LPSP), or type 1 autoimmune pancreatitis. Various methods to evaluate the immunohistochemical stains have been proposed. However, these methods have not been compared so far.
Design: Resected or open biopsy specimens of LPSP (18 patients), chronic pancreatitis (CP; 24), and pancreatic ductal adenocarcinoma (PDA; 45) were evaluated. In each case, serial sections were made from a representative block for H&E stain and immunostaining for IgG, IgG1, IgG4, and CD138. The number of immunostaing-positive cells was counted in 10 high power fields (HPFs) by selecting fields with the most numerous positive cells (Method A), or by selecting fields randomly in the affected areas (Method B). We evaluated 1) mean number of IgG4-positive plasma cells/HPF, 2) number of fields with ≥11 IgG4-positive plasma cells, and 3) IgG4/ IgG1 ratio (total number of IgG4-positive plasma cells/ total number of IgG1-positive plasma cells), 4) IgG4/ IgG ratio, and 5) IgG4/ CD138 ratio. The best cutoff values and area under curve (AUC) to differentiate LPSP from CP and PDA were evaluated by receiver operator characteristic (ROC) curve and AUCs of these five groups were compared within each Method and between Method A and B.
|Method A||Method B|
|Cutoff value||Sensivity/ Specifity||AUC||Cutoff value||Sensivity/ Specificity||AUC|
|1) mean IgG4-positive plasma cells||54.6||94.4%/ 92.8%||0.9782||34.9||83.3%/ 100%||0.9744|
|2) number of fields with ≥11 IgG4-positive plasma cells||10||100%/ 79.7%||0.8929||6||94.4%/ 97.1%||0.9828|
|3) IgG4/ IgG1||1.082||88.9%/ 87.0%||0.9235||0.903||94.4%/ 90.3%||0.9370|
|4) IgG4/ IgG||0.197||88.9%/ 49.3%||0.6857||0.332||100%/ 81.2%||0.9143|
|5) IgG4/ CD138||0.487||100%/ 21.7%||0.4303||0.424||88.9%/ 76.8%||0.8534|