ELISA Kits for Autoantibody Research

1. Autoantibody

Autoantibodies, also known as AAB, are antibodies produced by the human immune system that target self-tissues. They typically include natural autoantibodies and pathological autoantibodies. Natural autoantibodies are predominantly of the IgM class and are encoded by unmutated V(D)J genes, with low affinity for self-antigens. Natural autoantibodies provide the first line of defense against infections and have certain physiological functions, such as maintaining cell function and regulating immune system homeostasis. In contrast, IgG class autoantibodies, which are generated through somatic cell mutations and exhibit high affinity for self-antigens, reflect a pathological process. They may lead to the clearance of normal cells, disruption of antigen-receptor signaling or cellular effector functions, and consequently result in pathological damage to self-tissues.

2. Autoimmune Diseases and Their Types

Autoimmune Disease (AID) refers to a pathological condition in which the immune system mounts an immune response against self-cells or components, leading to disease. The exact causes of autoimmune diseases are not fully understood, but they are believed to involve multiple factors such as genetic predisposition, environmental factors, and abnormal immune system reactions. Currently, over 100 types of autoimmune diseases have been identified, which can be broadly categorized into two types: organ-specific autoimmune diseases and systemic autoimmune diseases.

● Organ-Specific Autoimmune Diseases: These diseases involve immune responses primarily targeting specific organs or tissues. Common examples of organ-specific autoimmune diseases include autoimmune thyroid diseases, psoriasis, multiple sclerosis, autoimmune hepatitis, myasthenia gravis, pemphigus vulgaris, type I diabetes, etc.

● Systemic Autoimmune Diseases: In contrast, systemic autoimmune diseases involve multiple organs and tissues, with immune responses affecting various systems throughout the body. Some common examples of systemic autoimmune diseases include systemic lupus erythematosus, Behçet's disease, rheumatoid arthritis, inflammatory bowel disease, scleroderma, systemic vasculitis, etc.

Fig. 1 Causes and common symptoms of autoimmune diseases ^[1]

3. Autoantibodies and Autoimmune Diseases

In certain autoimmune diseases, self-antibodies may exist prior to disease onset and exhibit significant specificity, making them key biomarkers to aid in related disease treatment research. In organ-specific autoimmune diseases such as myasthenia gravis or pemphigus vulgaris, self-antibodies directly bind and damage target organs ^[2]. In systemic autoimmune diseases such as vasculitis, glomerulonephritis, and systemic lupus erythematosus, self-antibodies react with free molecules (such as phospholipids) as well as cell surface and nuclear protein antigens, forming pathogenic antigen-antibody (immune) complexes. These self-antibodies damage tissues and organs through participation in complement FcγR activation and Toll-like receptor internalization and activation ^[3].

4. Autoantibodies and Tumors

In the early stages of tumor development, although tumor antigens are difficult to detect in serum, the human immune system produces tumor-associated autoantibodies, which hold promise as potential biomarkers for early cancer diagnosis. P. Budde et al. ^[4] conducted autoantibody analysis on prostate cancer patients treated with prostvac and ipilimumab, and the study found that certain autoantibodies were associated with the occurrence of immune-related adverse events (irAEs) following treatment, while others may help counteract the effects of inflammatory molecules, thereby reducing the occurrence of irAEs. Additionally, several anti-tumor-associated antigen (TAA) autoantibodies have been validated as potential biomarkers for early detection of cancers such as lung cancer and hepatocellular carcinoma ^[5,6].

5. The List of CUSABIO's Autoantibody ELISA Kits