Immune disorder

Did You Know?

• Cytokine storms are suspected as the cause of deaths in the 1918 'Spanish Flu' pandemic, acute pancreatitis, and COVID-19.
• Cytokine storm syndrome has multiple undesirable symptoms.

Autoimmune diseases

An autoimmune disease arises from an abnormal immune response to a normal body part. Nearly any body part can be involved. Common symptoms include low-grade fever and feeling tired, and symptoms often come and go. Examples include alopecia areata, celiac disease, Graves' disease, lupus, multiple sclerosis (thought to be an immune-mediated process), rheumatoid arthritis, scleroderma, type 1 diabetes, and vasculitis.

Immunodeficiencies

Primary immune deficiency diseases are caused by inherited genetic mutations, while secondary or acquired immune deficiencies result from external factors such as a virus or immune suppressing drugs. Primary immune diseases increase susceptibility to recurrent ear infections, pneumonia, bronchitis, sinusitis, or skin infections; less frequently, patients may develop abscesses of internal organs, autoimmune or rheumatologic problems, and gastrointestinal issues. Examples include ataxia–telangiectasia, chronic granulomatous disease (a deficiency in NADPH oxidase enzyme causing failure to generate oxygen radicals, with classical recurrent infection from catalase positive bacteria and fungi), common variable immunodeficiency (the only primary immune disorder with onset in the late teens, featuring normal B cell levels but decreased IgG production), DiGeorge syndrome, hyper IgM syndrome (an X-linked deficiency in CD40 ligand production on activated T cells, increasing IgM in circulation with normal B and T cell numbers, and susceptibility to extracellular bacteria and opportunistic infections), selective immunoglobulin A deficiency (the most common humoral immunity defect, characterized by IgA deficiency and repeating sino-pulmonary and gastrointestinal infections), severe combined immunodeficiency, Wiskott–Aldrich syndrome, X-linked agammaglobulinemia (a deficiency in tyrosine kinase enzyme blocking B cell maturation, with no B cells or immunoglobulin classes but normal cell-mediated immunity), and AIDS as a secondary immune deficiency.