IgA

American  

Immunology.

1. immunoglobulin A: a class of antibodies predominant in respiratory and alimentary tract secretions and in saliva and tears, functioning as the body's first line of defense against invading foreign substances especially by neutralizing viral antigens and by preventing the adherence of bacteria to mucous membrane surfaces.

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Etymology

Origin of IgA

First recorded in 1960–65

Example Sentences

Povetacicept, for IgA nephropathy, achieved a 52% reduction in urine protein in its late-stage trial.

From Barron's • Mar. 10, 2026

Vertex acquired the drug, which treats the kidney condition known as IgA nephropathy, when it bought Alpine Immune Sciences for $4.9 billion in the second quarter of 2024.

From Barron's • Mar. 10, 2026

Absence or low levels of mucosal IgA is known to be associated with an increased risk of SARS-CoV-2 breakthrough infections.

From Science Daily • Jan. 10, 2024

In September 2022, she and her colleagues reported that people who were infected early in the pandemic, before they were vaccinated, had detectable levels of SARS-CoV-2–specific antibodies of a type named IgA in their noses.

From Science Magazine • Jan. 24, 2023

IgA and other antibodies are secreted into the intestinal lumen.

From Textbooks • Jun. 9, 2022