Selective decrease of serum immunoglobulin G1 as marker for early stages of invasive breast cancer.

The diagnostic value of the decrease in percentage of immunoglobulin G1 (%lgG1) in breast cancer was analyzed with special emphasis on early tumor stages. IgG1 and total IgG were preoperatively measured in the sera of a total of 801 individuals using a modified quantitative affinity chromatography. Group A consisted of 174 healthy individuals of both sexes, group B of 324 female patients with benign breast disease, and group C of 303 patients with invasive and non-invasive breast cancer.

The tumor-associated shift in immunoglobulin G1/G2 is expressed at the messenger RNA level of peripheral blood B lymphocytes in patients with gynecologic malignancies.

Background: Previously, it could be demonstrated that human patients with malignant diseases of various tissues exhibited characteristic and highly significant changes in the serum patterns of immunoglobulin (Ig)G subclasses, consisting of a decrease in IgG1 and an increase in IgG2 relative to total IgG. The aim of the current study was to determine whether this phenomenon was detectable at the level of IgG-producing B lymphocytes.

Methods: Using a competitive reverse transcriptase polymerase chain reaction specific to IgG1 and IgG2, the gene expression of these 2 IgG subclasses in peripheral B cells from 10 patients with carcinomas of various sites within the female reproductive tract and 10 healthy controls was quantitatively determined, in parallel with the concentrations of the respective serum proteins.

The IgG1/G2 subclass shift--a sensitive, tissue non-specific marker for malignancy. Diagnostic performance with squamous cell carcinoma of the head and neck.

A significant decrease in %IgG1 accompanied by an increase in %IgG2 in total serum IgG has been previously reported as a highly sensitive marker for detecting early stages of carcinomas of various localizations. Here we investigated the question as to whether this phenomenon is also observed in sera of patients with squamous cell carcinoma of the head-neck region (SCC-HN), and to evaluate its diagnostic performance in the post-operative monitoring. Using quantitative affinity chromatography, serum concentrations of IgG1, IgG2 and total IgG were determined in 81 patients with different stages of primary and untreated SCC-HN, in 51 SCC-HN patients in post-therapeutical follow up, and in 33 patients with organ matched benign diseases.

[Quantitative changes in the immunoglobulin G subclass system--a reliable tumor marker in squamous epithelial carcinoma in the area of the head-neck].

Aim: Until now no serological markers were available towards the diagnosis of squamous-cell carcinomas of the head and neck (HNSCC) particularly in the detection of posttherapeutic recurrent diseases and metastases. Previous reports described patients with malignant diseases of various tissues exhibiting a characteristic and highly significant alteration in the subclass composition of serum IgG, consisting of a reduction in %IgG1 and an increase of %IgG2. In this study we present for the first time results of this IgG-shift in patients suffering from HNSCC.

Interheavy disulfide bridge in immunoglobulin G (IgG) reacting with dithionitrobenzoate. A unique feature in serum proteins.

Immunoglobulin G (IgG) of many species contains 'labile' disulfide bonds (SS*), which within 24 h undergo a disulfide exchange with dithionitrobenzoic acid (NBSSBN). Aims of the present study were to detect directly this type of SS* groups by means of 14C-labelled NBSSBN, and to investigate its possible presence in other serum proteins. NBSSBN reacts during the first 30 min of incubation with free SH groups, and thereafter with the sulfur atoms of SS* groups.

Selective decrease of serum immunoglobulin G1 as a marker of malignant transformation in colorectal tissue.

Background: Malignant diseases of various origins were previously shown to be associated with a characteristic and highly significant change in the serum pattern of immunoglobulin (Ig)G subclasses, comprised of a decrease in %IgG1 and an increase in %IgG2 relative to and independent of the absolute concentration of total IgG. The goal of the current study was to evaluate this phenomenon as an indirect marker in the primary diagnosis of colorectal carcinoma.

Methods: Using affinity chromatography, IgG1, IgG2, and total IgG were determined in 36 patients with colorectal carcinoma of different stages and compared with 162 apparently healthy controls.

Reactive disulfide bonds in immunoglobulin G. A unique feature in serum proteins of different species.

A reactive disulfide bond (SS)* was detected and characterized in IgG of humans, rats and mice by virtue of disulfide interchange with dithionitrobenzoate. (SS)* was found exclusively in human IgG1 and rat IgG2b. In human IgG1 (SS)* was identified as the upper one of the two interheavy bridges in the hinge, where it appears to take part in complement activation.

Selective decrease in serum immunoglobulin G1. A tissue nonspecific tumor marker detecting early stages of gynecologic malignant disease with high efficiency.

Background: Malignant diseases of various tissue origin have previously been found to be associated with a characteristic shift in the serum pattern of IgG subclasses, i.e., a highly significant reduction of the percent of IgG1 and an increase of the percentage of IgG2 relative to the total IgG.