CD138 immunohistochemistry identifies more plasma cells compared with hematoxylin and eosin staining in autoimmune hepatitis. An observational study.

INTRODUCTION: Autoimmune hepatitis (AIH) is associated with periportal infiltration by plasma cells. Plasma cell detection is routinely performed through hematoxylin and eosin (H&E) staining. The present study aimed to assess the utility of CD138, an immunohistochemical plasma cell marker, in the evaluation of AIH.

MATERIALS AND METHODS: A retrospective study was conducted, in which cases consistent with AIH, within the time frame of 2001 and 2011, were collected. Routine H&E-stained sections were used for evaluation. CD138 immunohistochemistry (IHC) was performed to detect plasma cells.

RESULTS: Sixty biopsies were included. In the H&E group, the median and interquartile range (IQR) was 6 (4-9) plasma cells/high power field (HPF) and was 10 (IQR 6-20) plasma cells/HPF in the CD138 group (p < 0.001). There was a significant correlation between the number of plasma cells determined by H&E and CD138 (p = 0.31, p = 0.01). No significant correlation was found between the number of plasma cells determined by CD138 and IgG level (p = 0.21, p = 0.09) or stage of fibrosis (p = 0.12, p = 0.35), or between IgG level and stage of fibrosis (p = 0.17, p = 0.17). No significant correlation was found between the treatment response and the number of plasma cells determined by H&E (p = 0.11, p = 0.38), CD138 (p = 0.07, p = 0.55), or stage of fibrosis (p = 0.16, p = 0.20). CD138 expression was different between the treatment response groups (p = 0.04).

CONCLUSION: CD138 increased the detection of plasma cells in liver biopsies of patients with AIH, when compared with routine H&E staining. However, there was no correlation between the number of plasma cells determined by CD138 and serum IgG levels, stage of fibrosis, or response to treatment.