IgM-Linked SerpinB3 and SerpinB4 in Sera of Patients with Chronic Liver Disease

Abstract

BackgroundEpidemiological studies indicate that a growing number of cirrhotic patients will develop hepatocellular carcinoma (HCC) in the next decade. Recent findings have demonstrated that Squamous cell carcinoma antigen 1 (SCCA1) and 2 (SCCA2) isoforms, now classified as serpinB3 and serpinB4, are over-expressed in HCC, but not in normal liver. As reported, high levels of circulating SCCA-IgM immunocomplexes in patients with cirrhosis are significantly associated with HCC development.AimTo ascertain whether IgM-linked SCCA isoforms circulate in patients with chronic liver disease, compared to total SCCA-IgM levels.Methodology and Findings79 patients with chronic liver disease were studied, including 17 patients with chronic hepatitis, 36 patients with cirrhosis and 26 with HCC. 28 blood donors were used as control. Monoclonal antibodies against serpinB3 and serpinB4 were used as catcher antibodies to set up specific ELISA assays, while total SCCA-IgM immunocomplexes were detected by commercially available ELISA assay. Overall, the results revealed a better diagnostic sensitivity of total SCCA-IgM assay, compared to both serpinB3 and serpinB4 IgM-linked assays. SerpinB4-IgM median values obtained with SCC103 antibody were moderately higher in patients with cirrhosis than in those with HCC, median values: 0.168 (IQR 0.140–0.427) vs. 0.140 (IQR 0.140–0.278), (p = 0.177). A trend toward decreasing serpinB4-IgM/serpinB3-IgM median ratio was observed in patients with advanced liver disease, being 1.08 in patients with HCC, 1.10 in patients with cirrhosis and 1.40 in patients with chronic hepatitis (p = 0.079).ConclusionsIgM-linked SCCA isoforms in serum of patients with chronic liver diseases were quantified for the first time. Although the number of patients was limited, this preliminary study reveals that the relative balance of the two serpin isoforms is altered in HCC and it is characterized by a lower serpinB4-IgM/serpinB3-IgM ratio, determined by lower serpinB4 levels.

SERPINB3 is associated with longer survival in transgenic mice

“…It is also overexpressed in neoplastic cells of epithelial origin1112. Normal liver does not contain detectable amounts of this serpin, while it is over-expressed in primary liver cancer and in preneoplastic lesions131415, where remarkable levels have been found also in serum as IgM-linked immunocomplex161718. Several data indicate that SB3 induces cellular protection from apoptotic death caused by different kinds of stimuli and the suggested molecular target is located upstream to caspase-31920, with supporting evidence of cytochrome c release inhibition by mithocondria21.…”

Squamous cell carcinoma antigen 1 and 2 mRNA and a new variant expressed in hepatocellular carcinoma

“…Recently Pontisso et al [17] detected SCCA expression in HCC by immunohistochemistry for the first time but the expression pattern of SCCA1 and SCCA2 in cancer pathogenesis is not fully defined. Biasiolo et al [18] quantified IgM-linked SCCA1, 2 isoforms in serum of patients with chronic liver diseases, however, their result could not represent the expression of SCCA isoforms in HCC since no correlation was found between serum and tissue levels of SCCA antigen [19]. Furthermore, to date no information is available on the clinical and prognostic significance of SCCA variants.…”

Diagnostic accuracy of SCCA and SCCA‐IgM for hepatocellular carcinoma: A meta‐analysis

“…(Table ) The major bias identified in the studies was in “patient selection” and the “index test”. Four studies selected cirrhosis patients as the control group; seven studies included patients with hepatitis, chronic liver disease, or cirrhosis or healthy donors as the control group . Three studies did not included tumour biopsies to confirm HCC, and we marked one study as “unclear” …”

“…However, the results are controversial because of the different cut‐off values used in each study. Sensitivities ranged from 42% to 89% and specificities from 27% to 89%, with a wide range for the area under the curve (AUC) values, from 0.66 to 0.86 …”

“…Previous meta‐analysis included both English and Chinese language papers and compared the pooled diagnostic accuracies between SCCA and SCCA‐IgM; these data need to be updated . Several limitations of the most recent meta‐analysis include the following: (a) the data collection ended in September 2015; (b) the heterogeneity between studies was not explored; (c) one study published in 2012 by Biasiolo et al was omitted; (d) a study published by Crescenzi et al was included, but the recorded sensitivity of 51% and specificity of 49% might have been inappropriately extracted from the combination of AFP‐IgM and SCCA‐IgM; moreover, if one biomarker is insufficient to precisely diagnostic HCC, combinations of currently available biomarkers should be assessed by meta‐analysis; (e) to the best of our knowledge, the investigation of reasons for heterogeneity among studies beyond the computation of a single summary measure is an important purpose of meta‐analysis . Previous studies failed to assess heterogeneity because of the limited number of publications at the time.…”