Leukocyte Adhesion Deficiencies

Question 1

Process of Leukocyte Adhesion

Answer 1

1. Margination: increased contact of neutrophils with endothelial lining following increased intravascular leakage
2. Rolling: Neutrophils/endothelium bind the others selections (Neuts- L selectin, endothelium P/E selectins)
3. Activation: slow rolling allows for chemokine sampling –> integrin expression
4. Tight adhesion & Crawling: neuts attach via LFA-1 and MAC-1 (CD-18) to ICAM-1 on endothelium
5. Transmigration: PECAM-1

Question 2

absence of CD18

Answer 2

LAD type 1: failure of “Tight adhesion and crawling”: everything downstream is reduced (MAC-1 and LFA-1 decreased);

NO PUS FORMATION + DELAYED DETACHMENT OF UMBILICUS are key features

Question 3

Delayed separation of umbilicus

Answer 3

all the LADs