Which of the following is not classified as an autoimmune disease
Which of the following is not classified as an autoimmune disease Autoimmune diseases are a diverse group of disorders characterized by the immune system mistakenly attacking the body’s own tissues. Normally, the immune system defends us against pathogens like bacteria and viruses, but in autoimmune conditions, this defense system becomes dysregulated, leading to chronic inflammation, tissue damage, and a range of clinical symptoms. Conditions such as rheumatoid arthritis, lupus erythematosus, multiple sclerosis, and type 1 diabetes are classic examples of autoimmune diseases, each targeting specific organs or tissues.
Understanding what classifies a disease as autoimmune involves recognizing the hallmark features: the presence of autoantibodies, immune cell infiltration into tissues, and evidence of immune-mediated tissue destruction. These diseases often have complex etiologies involving genetic predisposition, environmental triggers, and immune dysregulation. Diagnosis typically involves clinical evaluation, laboratory tests for autoantibodies, and imaging studies.
However, not all diseases that involve immune system activity are classified as autoimmune. For instance, infectious diseases like bacterial or viral infections primarily involve the immune system fighting external pathogens, not attacking self-tissues. Similarly, allergic reactions represent hypersensitivity responses where the immune system overreacts to harmless substances such as pollen or food proteins, but they are not autoimmune because they do not involve an attack on the body’s own tissues.
To clarify, let’s consider some specific examples. Rheumatoid arthritis, which causes joint inflammation, is a clear autoimmune disease because it involves autoantibodies like rheumatoid factor and anti-CCP antibodies, along with immune cell infiltration in synovial tissues. Multiple sclerosis involves immune-mediated damage to the myelin sheath of nerve fibers in the central nervous system, driven by autoreactive immune cells. Conversely, a common cold caused by a viral infection is not autoimmune—it’s an infectious disease triggered by external pathogens.
Another key distinction lies in diseases like gout, which results from the deposition of uric acid crystals in joints, causing inflammation. Although gout involves immune response to these crystals, it is not classified as an autoimmune disease because the primary cause is metabolic, not immune dysregulation against self-antigens. Similarly, diseases like psoriasis involve immune activity but are often categorized as immune-mediated inflammatory diseases rather than classic autoimmune diseases.
In essence, the classification depends on whether the immune system’s attack is directed against the body’s own tissues due to immune tolerance breakdown (autoimmune) or is a reaction to external agents or metabolic disturbances. Recognizing this distinction helps in diagnosis, treatment, and understanding the underlying mechanisms.
Therefore, when asked which of the following is not classified as an autoimmune disease, the answer hinges on identifying diseases primarily caused by external pathogens, metabolic disturbances, or hypersensitivity reactions rather than immune system self-attack. For example, a viral infection such as influenza, a metabolic disorder like gout, or allergic reactions are not autoimmune diseases, unlike conditions such as lupus or multiple sclerosis.
