Question

What percentage of IgE constitutes of all antibodies in the human blood?

• A. $\ge 0.001\%$
• B. $\ge 10\%$
• C. $\ge 0.1\%$
• D. $\ge 0.5\%$

Answer 1

The correct option is A $\ge 0.001\%$

• An antibody (Ab) or immunoglobulin (Ig), is a large, Y-shaped protein produced mainly by plasma cells that are used by the immune system to neutralize pathogens such as pathogenic bacteria and viruses.
• In humans, antibodies are classified into 5 types. They are IgG(75%), IgM(10%), IgA(15%), IgE(0.002%), and IgD(0.2%).
• IgE antibodies are only found in mammals.
  
• Hence the percentage of IgE constitutes of all antibodies in the human blood is ≥ 0.001%.
• So, the correct answer is '≥0.001%'.