IgA

noun

ˌī-(ˌ)jē-ˈā 

1

: a class of immunoglobulins including antibodies found in external bodily secretions (such as saliva, tears, and sweat)

2

: an antibody of the class IgA

Examples of IgA in a Sentence

Recent Examples on the Web

But when delivered at mucosal sites, vaccines can also produce local antibodies, such as IgA, which coat mucosal membranes in the nose, throat, and lungs; creating a first line of defense. —New Atlas, 9 Aug. 2025

Both prebiotics and probiotics can increase immunoglobulin A (IgA). —Jessica Swirble, Verywell Health, 5 Aug. 2025

In the blood, two types of antibodies (IgA and IgG) increased by several fold after vaccination compared with the placebo group. —Ars Technica, 6 Mar. 2025

Living With IgA Nephropathy In terms of overall prognosis, individual cases of IgA nephropathy vary. —Mark Gurarie, Health, 30 Sep. 2024

What about the company Vertex didn’t buy? Vertex Pharmaceuticals’ decision to pay $4.9 billion for Alpine Immune Sciences cast a spotlight on the severe kidney disease IgA nephropathy — and, by extension, a company called Vera Therapeutics. —Damian Garde, STAT, 12 Apr. 2024

Word History

Etymology

immunoglobulin

First Known Use

1969, in the meaning defined at sense 1

Medical Definition

IgA

noun

ˌī-ˌjē-ˈā 

1

: a class of immunoglobulins that include antibodies found in external bodily secretions (as saliva, tears, and sweat)

2

: an immunoglobulin of the class IgA