# immunoglobulin

CEFR C2 · Noun

Source: https://englishreference.com/word/immunoglobulin
Updated: 2026-10-15

## Definition

a protein in your blood that fights germs and helps keep you from getting sick. Your body makes different types to fight different infections.

For teachers: a class of proteins produced by plasma cells that function as antibodies, binding to specific antigens to neutralize pathogens. Includes five major classes (IgA, IgD, IgE, IgG, IgM) distinguished by structure and immune role.

## Examples

- Immunoglobulin helps your body fight infections.
- After the blood test, the doctor said low immunoglobulin levels might explain his frequent infections.
- Researchers isolated a novel immunoglobulin variant that binds the viral spike protein with unusual strength, opening new paths for targeted therapy.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.