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Gastroenterologie
a hepatologie

Gastroenterology and Hepatology

Gastroent Hepatol 2012; 66(3): 187-190.

The serological positivity of immunoglobulin IgG4 in patients with pancreatic carcinoma

Zdeněk Dítě Orcid.org  1, Ivan Novotný Orcid.org  2, Zdeněk Kala Orcid.org  3, Markéta Hermanová Orcid.org  4, Hana Nechutová Orcid.org  5, Jana Dvořáčková Orcid.org  , Arnošt Martínek Orcid.org  6,7, Jan Trna Orcid.org  8

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Summary

The group of illnesses marked by high level of immunoglobulin G4 (IgG4) in blood serum are designated as IgG4-associated diseases. The most common disease in this group is an autoimmune form of pancreatitis. In its initial stage, this is characterised by mild, subjective complaints, which more resemble stomach discomfort. The first symptom, however, may be a painless, obstructive icterus. Imaging methods can be used to view the diffuse or segmental enlargement of the pancreas, which can cause difficulties in distinguishing it from a pancreatic carcinoma. A characteristic feature of the autoimmune form of pancreatitis, and in particular first type, is an increased level of IgG4 of the blood serum, where a 97% specificity and 95% sensitivity predict a diagnosis of the autoimmune form of pancreatitis. Case studies have also appeared in specialist literature showing a high level of IgG4 in patients with a pancreatic carcinoma. In our prospective study, we therefore examined a set of patients with histologically verified pancreatic carcinomas and determined the level of IgG4 in their blood serum.

Materials and methods: Over the course of a 52-month period, the level of IgG4 in blood serum was analysed using the nephelometric method in 81 patients with histologically verified pancreatic carcinomas. According to standards set in literature, the borderline IgG4 value is higher than 135 mg/dl.

Results: In the observed group an IgG4 level exceeding 135 mg/dl was demonstrated in 8 patients (9.8). The average IgG4 level was 173 mg/dl, i.e. 12.9% higher against the borderline value. Amongst the patients showing a greater IgG4 value were five in whom the creation of a carcinoma during the course of chronic pancreatitis could be anticipated, as the diagnosis of chronic pancreatitis was determined more than 5 years before the determination of the diagnosis of the pancreatic carcinoma. None of the 8 patients with a higher IgG4 value showed any diagnostic signs of the autoimmune form of pancreatitis.

Conclusion: A higher level of IgG4 can accompany the finding of a pancreatic carcinoma; however, the IgG4 value is increased by no more than 20% above the so-called serum IgG4 limit value. Determination of IgG4 is not a suitable marker for differential diagnostics between the autoimmune form of pancreatitis and a pancreatic carcinoma, as was originally assumed, and it is possible to agree with opinions that an at least twofold increase in IgG4 of the blood serum is a significant diagnostic sign for the autoimmune form of pancreatitis and the entire group of diseases designated as IgG4-associated diseases.

Keywords

IgG4, autoimmune pancreatitis, pancreatic carcinoma

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