Experimental validation of specificity of the squamous cell carcinoma antigen-immunoglobulin M (SCCA-IgM) assay in patients with cirrhosis

Background: Squamous cell carcinoma antigen-immunoglobulin M (SCCA-IgM) is a useful biomarker for the risk of development of hepatocellular carcinoma (HCC) in patients with cirrhosis due to its progressive increase associated to HCC evolution. In patients with cirrhosis, other assays have been affected by interfering reactivities of IgM. In this study, the analytical specificity of the SCCA-IgM assay was assessed by evaluating SCCA-IgM measurement dependence on different capture phases, and by measuring the recovery of SCCA-IgM reactivity following serum fractionation. Methods: Serum samples from 82 patients with cirrhosis were analyzed. SCCA-IgM was measured using the reference test (Hepa-IC, Xeptagen, Italy) that is based on rabbit oligoclonal anti-squamous cell carcinoma antigen (SCCA) and a dedicated ELISA with a mouse monoclonal anti-SCCA as the capture antibody. Results: SCCA-IgM concentrations measured with the reference assay (median value=87 AU/mL) were higher than those measured with the mouse monoclonal test (median value=78 AU/mL). However, the differences in the SCCA-IgM distribution were not statistically significant (p>0.05). When SCCA-IgM concentrations measured with both tests were compared, a linear correlation was found (r=0.77, p<0.05). Fractionation of the most reactive sera by gel-filtration chromatography showed that total recovery of SCCA-IgM reactivity was seen only in the fractions corresponding to components with a molecular weight higher than IgM and SCCA (>2000 kDa) with both tests. Conclusions: The equivalence of both SCCA-IgM assays and the absence of reactivity not related to immune complexes support the analytical specificity of SCCA-IgM measurements. The results validate the assessment of SCCA-IgM for prognostic purposes in patients with cirrhosis. Clin Chem Lab Med 2010;48:217–23.Peer Reviewe

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

SERPINB3 is a serine protease inhibitor with pleiotropic functions. It is involved in several physiological and pathological processes, where it appears to exert antiapoptotic effects. Little is known about its expression on immune system cells, the major players in mechanisms of viral defense and autoimmune disorders. The aim of this study was to characterize the expression of SERPINB3 on the surface of peripheral blood mononuclear cell subsets in both normal subjects and in patients with chronic viral infections and autoimmune diseases. Sixty-two patients were analyzed by flow cytometric analysis, including 45 with hepatitis C virus (HCV)-related chronic liver disease and 17 with systemic lupus erythematosus (SLE). SERPINB3 was expressed on B lymphocytes in 79% of the controls, in 32% of the HCV-infected patients and in none of the SLE patients. Surface localization of SERPINB3 was confirmed by confocal microscopy. SERPINB3 positivity was associated with CD27 reactivity (r = 0.98), but not to other activation molecules (CD69, CD71, CD86 and CXCR3). SERPINB3 is physiologically expressed on the surface of CD27(+) B lymphocytes, but its expression is reduced in HCV viral infection and not detectable in SLE patients. These results may suggest a role for SERPINB3 in B-cell defects typically found in viral infections and autoimmune disorders

IgM-linked SerpinB3 and SerpinB4 in sera of patients with chronic liver disease.

Epidemiological 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.To ascertain whether IgM-linked SCCA isoforms circulate in patients with chronic liver disease, compared to total SCCA-IgM levels.79 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).IgM-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

Hepatic progenitor cells overexpress SERPINB3 in a mouse model of fulminant hepatitis

none12noneQUARTA S; VILLANO G; TURATO C; BIASIOLO A; VIDALINO L; RUVOLETTO MG; TONO M; CALABRESE F; NICOLOSI L; BERNARDI P; GATTA A; P. PONTISSOQuarta, SANTINA MARIA; Villano, Gianmarco; Turato, Cristian; Biasiolo, Alessandra; Vidalino, Laura; Ruvoletto, Mariagrazia; Tono, M; Calabrese, Fiorella; Nicolosi, Luca; Bernardi, Paolo; Gatta, Angelo; Pontisso, Patrizi

SERPINB3 is associated with longer survival in transgenic mice

The physiological roles of the protease inhibitor SERPINB3 (SB3) are still largely unknown. The study was addressed to assess the biological effects of this serpin in vivo using a SB3 transgenic mouse model. Two colonies of mice (123 transgenic for SB3 and 148 C57BL/6J controls) have been studied. Transgenic (TG) mice showed longer survival than controls and the difference was more remarkable in males than in females (18.5% vs 12.7% life span increase). In TG mice decreased IL-6 in serum and lower p66shc in the liver were observed. In addition, TG males showed higher expression of mTOR in the liver. Liver histology showed age-dependent increase of steatosis and decrease of glycogen storage in both groups and none of the animals developed neoplastic lesions. In conclusion, the gain in life span observed in SB3-transgenic mice could be determined by multiple mechanisms, including the decrease of circulating IL-6 and the modulation of ageing genes in the liver

Role of squamous cell carcinoma antigen-1 on liver cells after partial hepatectomy in transgenic mice.

Squamous Cell Carcinoma Antigen-1 (SCCA1) overexpression has been observed in tumours of epithelial origin and in hepatocellular carcinoma. Previous data indicate that this serpin inhibits apoptosis, while its proliferative activity was only recently proposed. The aim of this study was to evaluate the effect of SCCA1 on liver cells in a transgenic mouse model after partial hepatectomy. Twenty-one C57BL/6J mice (11 transgenic for human SCCA1, 10 wild-type) underwent partial hepatectomy and were sacrified after one week. Apoptosis and proliferation markers were determined in the liver at sacrifice, while a cytokine panel was measured in serum. Transgenic mice showed a relative liver weight significantly higher than wild-type mice at sacrifice (mean +/- SD, 5.38 +/- 0.50% vs 4.84 +/- 0.29%, p=0.0221), while no difference (p=0.2403) was observed in two untreated control groups (6 transgenic, 6 wild-type mice). Active caspase-3 was significantly lower in transgenic mice than in wild-type mice (p=0.0047). The transgenic mouse group showed overall higher proliferative activity at sacrifice, compared to wild-type mice, with increased proliferation parameters. Cytokine analysis revealed a remarkable and opposite sex-dependent behaviour of interleukin (IL)-6 after hepatectomy. At variance with wild-type mice, a significant IL-6 increase was documented only in transgenic females (p=0.0313), even more relevant than that observed in wild-type males. In conclusion, transgenic mice expressing SCCA1 showed higher liver regenerative potential compared to wild-type mice, supporting, the dual role of this serpin as an anti-apoptotic and pro-proliferative stimulus for liver cells in vivo

Distribution of serpinB4-IgM(SCC103)/serpinB3-IgM ratios.

<p>Scatter plot displays the distribution of serpinB4-IgM(SCC103)/serpinB3-IgM ratios detected in patients with chronic hepatitis, cirrhosis and HCC. Horizontal bars represent median value for each group.</p