Immunohematology - Complement System

Complement system

A defense mechanism that destroy pathogen it helps to remove infected or foreign cells by breaking their membranesAn antibody (IgG or IgM) binds to an antigen (foreign substance).

Step 1

An antibody (IgG or IgM) binds to an antigen (foreign substance).

Step 2

This activates C1 complex, which starts the complement cascade.

Step 3

C2 and C4 split into fragments → C3 convertase is formed.

Step 4

C3 is hydrolyzed (split) into C3b (binds to the target) and C3a (signals inflammation

Step 5

C3b helps split C5 into C5a and C5b.

Step 6

MAC punches holes in the cell, causing water to rush in → Cell swells and bursts (lysis).

Lectins

Antibody like substance that derived from plants

Delichos biflorus

Anti-A1 plant source

Bandaraea simplicifolia

Anti-B plant source

Ulex europaeus

Anti-H plant source

Iberis amara, Iberis umbella, Iberis sempervirens and Madura aurantica

Anti-M plant source

Vicia graminea, Bauhinia variegate, Bauhinia candicans

Anti-N plant source

Prolectins

Antibody like substance derived from snail

Helix pomatia, Helix aspersa, Cepaea nemoralis

Anti-A snail source

Euphrada periompala

Anti-A1 snail source

Salmo irideus

Anti-B snail source

Eel

Anti-H snail source