Peptides are short chains of amino acids, the building blocks of proteins. They are smaller than proteins and typically consist of fewer than 50 amino acids. In immunodiagnosis, peptides are utilised as specific markers or targets to detect the presence of certain diseases or conditions in a patient’s body.

Here’s how peptides are used in immunodiagnosis:

Biomarkers: Peptides can act as biomarkers, which are substances in the body that indicate the presence of a disease or condition. Specific peptides may be associated with certain diseases, such as cancer or autoimmune disorders. By detecting the presence or concentration of these peptides in biological samples like blood or urine, healthcare professionals can diagnose or monitor the progression of diseases.

Antigens: Peptides can be designed to mimic parts of disease-causing agents, such as viruses or bacteria. These synthetic peptides, known as antigens, can trigger an immune response in the body. Immunodiagnostic tests can detect the antibodies produced by the immune system in response to these antigens. The presence of these antibodies can indicate a current or past infection, aiding in the diagnosis of infectious diseases.

Diagnostic Assays: Peptides are incorporated into diagnostic assays, such as enzyme-linked immunosorbent assays (ELISAs) or lateral flow assays, to detect specific antibodies or antigens in patient samples. These assays utilise the specific binding affinity between peptides and antibodies to accurately detect and quantify the target molecules present in the sample.

Point-of-care Testing: Peptide-based immunodiagnostic tests are often designed for rapid and convenient detection of diseases at the point of care, such as in a doctor’s office or clinic. These tests are commonly used for detecting infectious diseases like HIV, malaria, or influenza.

Personalised Medicine: Peptides can also be used in immunodiagnosis for personalised medicine approaches. By targeting specific peptides associated with a patient’s disease subtype or genetic profile, healthcare providers can tailor treatment plans to individual patients, optimise therapeutic outcomes.