Extracorporeal Photopheresis

Question 1

What is the product volume and typical capture percentage of ECP?

Answer 1

Process 1500mL WB to yield about 270mL of product. About 10% of circulating MNCs are captured.

Question 2

What is the source of 8-MOP, and how is it administered?

Answer 2

Ammi Majus plant

Can be given orally (2hr peak, light sensitivity) or directly spiked into the bag (0.017mL per mL of product)

Question 3

What are the contraindications to 8-MOP use?

Answer 3

Conditions with sun sensitivity (porphyria cutanea tarda, xeroderma pigmentosum, albinism), aphakia

Question 4

What is the activation wavelength of 8-MOP?

Answer 4

320-400nm (UV-A).

Question 5

What are the best indications for ECP?

Answer 5

Erythodermic CTCLs
GVHD (especially involving skin rather than visceral organs)
Rejection (heart and lung, not liver)
*Benefit in autoimmune disorders is questionable.

Question 6

What are the downstream effects of ECP?

Answer 6

Infusion of apoptotic T-cells enhances monocyte maturation into CD83+ dendritic cells, reduces antigen-dependent T-cell activation, and promotes T-regs. Th1 cytokine profiles decrease.