Antibodies as predictors of autoimmune diseases and cancer

Elevated levels of antibodies against xenobiotics in a subgroup of healthy subjects

In spite of numerous research efforts, the exact etiology of autoimmune diseases remains largely unknown. Genetics and environmental factors, including xenobiotics, are believed to be involved in the induction of autoimmune disease. Some environmental chemicals, acting as haptens, can bind to a high-molecular-weight carrier protein such as human serum albumin (HSA), causing the immune system to misidentify self-tissue as an invader and launch an immune response against it, leading to autoimmunity. This study aimed to examine the percentage of blood samples from healthy donors in which chemical agents mounted immune challenges and produced antibodies against HSA-bound chemicals. The levels of specific antibodies against 12 different chemicals bound to HSA were measured by ELISA in serum from 400 blood donors. We found that 10% (IgG) and 17% (IgM) of tested individuals showed significant antibody elevation against aflatoxin-HSA adduct. The percentage of elevation against the other 11 chemicals ranged from 8% to 22% (IgG) and 13% to 18% (IgM). Performance of serial dilution and inhibition of the chemical–antibody reaction by specific antigens but not by non-specific antigens were indicative of the specificity of these antibodies. Although we lack information about chemical exposure in the tested individuals, detection of antibodies against various protein adducts may indicate chronic exposure to these chemical haptens in about 20% of the tested individuals. Currently the pathological significance of these antibodies in human blood is still unclear, and this protein adduct formation could be one of the mechanisms by which environmental chemicals induce autoimmune reactivity in a significant percentage of the population.

Chronic exposure to oral pathogens and autoimmune reactivity in acute coronary atherothrombosis

Background. It has been hypothesized that various infective agents may activate immune reactions as part of the atherosclerotic process. We aimed to investigate the interrelationship between chronic exposure to oral pathogens and immune-inflammatory response in patients with acute coronary atherothrombosis. Patients and Methods. The study included 200 participants from Serbia: 100 patients with acute myocardial infarction (MI), and 100 age- and sex-matched controls. Antibodies to oral anaerobes and aerobes were determined as well as autoantibodies to endothelial cells, beta-2 glycoprotein I, platelet glycoprotein IIb/IIIa and anticardiolipin. Interleukin-6 (IL-6) and C-reactive protein (CRP) were measured. Results. The mean serum antibodies to oral anaerobes tended to be higher among subjects with MI (0.876 ± 0.303 versus 0.685 ± 0.172 OD, P < 0.001). Similarly, antibody levels against oral aerobes in patients were significantly different from controls. Antibodies against endothelial cell, beta-2 glycoprotein I, platelet glycoprotein IIb/IIIa, anticardiolipin along with CRP and IL-6 were highly elevated in patients. The levels of antibodies to oral bacteria showed linear correlation with tissue antibodies, CRP and IL-6. Conclusion. Antibody response to chronic oral bacterial infections and host immune response against them may be responsible for the elevation of tissue antibodies and biomarkers of inflammation which are involved in acute coronary thrombosis development.

Cytokines: monitors of disease severity for the clinic

BACKGROUND

Cytokines communicate between the cells of the immune system and its targets to maintain homeostasis after injury or pathogenic events. They are involved in almost any pathological situation imaginable.

OBJECTIVE

To verify the importance of cytokines as biomarkers in current preclinical (aetiopathogenic, development of new therapies) and clinical studies (diagnosis, disease severity, prognosis and response to therapy).

METHOD/RESULTS

A Medline search with the query 'cytokine' AND 'biomarker' AND a variable for a variety of biomedical fields, followed by deeper-level searches, demonstrated the immense popularity of cytokines as biomarkers in almost any biomedical field.

CONCLUSION

As cytokines are not disease-specific they do not serve as single diagnostic biomarkers. The strength of the cytokines resides in monitoring disease severity, prognosis and response to treatment.

The characterization of the repertoire of wheat antigens and peptides involved in the humoral immune responses in patients with gluten sensitivity and Crohn's disease

Intestinal T cells from gluten sensitivity/celiac disease patients respond to a heterogeneous array of peptides. Our study extended this heterogeneity to humoral immune response to various wheat proteins and peptides in patients with gluten sensitivity or Crohn's disease. IgG and IgA antibodies in sera from those patients and healthy control subjects were measured against an array of wheat antigens and peptides. In gluten-sensitive patients, IgG reacted most against transglutaminase, prodynorphin, wheat extract, and α-, γ-, and ω-gliadin; IgA reacted most against wheat then transglutaminase, glutenin, and other peptides. In the sera of Crohn's disease patients, IgG reacted most against wheat and wheat germ agglutinin then transglutaminase, prodynorphin, α-, and γ-gliadin; IgA reacted foremost against prodynorphin then transglutaminase and α-gliadin. These results showed a substantial heterogeneity in the magnitude of IgG and IgA response against various wheat antigens and peptides. Measurements of IgG and IgA antibodies against such an array of wheat peptides and antigens can enhance the sensitivity and specificity of serological assays for gluten sensitivity and celiac disease and may also detect silent celiac disease or its overlap with inflammatory bowel disease.