Extracorporeal photopheresis

Introduction

Extracorporeal photopheresis, also known as extracorporeal photochemotherapy, is a safe immunomodulatory treatment used to treat a growing number of conditions. Originally used to treat Sézary syndrome, a leukemic form of primary cutaneous T cell lymphoma, its use has now been expanded to include acute and chronic graft againsthost disease and other conditions.

There are about 200 eextracorporeal photopheresis units around the world. Treatment protocols vary and optimal treatment protocols have yet to be established.

That thisextracorporeal photopheresis?

meextracorporeal photopheresis use a closed system (where the device performs the entire procedure) or use separate devices for each step. Anticoagulation with heparin or citrate prevents coagulation within the tubing system.

The treatment is often carried out on two consecutive days each month. Response to treatment is evaluated at 3-month intervals. meextracorporeal photopheresis discontinued at 6 months if response is inadequate. The process involves 3 steps and takes 2-4 hours to complete.

Step 1: leukapheresis

This involves drawing blood from the patient, followed by centrifugation to separate and collect the white blood cells (leukocytes)

Step 2: photoactivation

The collected white blood cells are mixed with methoxypsoralen (see PUVA), causing T-lymphocyte cells sensitive to ultraviolet A (UVA) radiation. They are then exposed to UVA rays, which damage diseased cells.

Step 3: reinfusion

The treated white blood cells are infused back into the patient.

How does it work andextracorporeal photopheresis worked?

The mechanism of action of eextracorporeal photopheresis It is not fully understood. Theories on how it may work are:

• The combination of psoralen and UVA radiation causes apoptosis (programmed cell death) of some of those affected T cells.
• When it returns to the body, the damaged white blood cells trigger the immune system to recognize antigens on T cells and kill them.
• less damaged monocytes phagocytize apoptotic T cells, which is an anti-normaltumor reply.
• Monocytes exposed to radiation convert to dendritic cells that dampen the immune response [1,2].

What are the clinical applications for eextracorporeal photopheresis?

Cutaneous T-cell lymphoma

Cutaneous T-cell lymphoma was the first approved indication for eextracorporeal photopheresis.

Extracorporeal photopheresis it is a first-line treatment for the erythrodermic and leukemic forms of cutaneous T-cell lymphoma, Sézary syndrome.[3] Without treatment, Sézary syndrome has a bad forecast with a median survival of 4 years. The published overall response rate aeextracorporeal photopheresis it is approximately the 43% with a full response of the 10%.[4] The results depend on many factors, including the treatment protocol.

meextracorporeal photopheresis it can also be used in mycosis fungoides, particularly in erythrodermic disease or in advanced stage (Stage III).

Graft-versus-host disease

Acute and chronic forms of graft-versus-host disease are potentially serious complications of allogeneic hematopoietic stem cell transplants. First-line treatment is with systemic corticosteroids

meextracorporeal photopheresis it can be considered in approximately 50% of patients with acute graft-versus-host disease unresponsive to corticosteroids. meextracorporeal photopheresis it has been more successful when it started early. The skin has similar response rates to other affected organs.[5] The complete response rate is approximately 80% when skin alone is involved and 60% when hepatic or gastrointestinal involvement is also present.[6] Higher response rates are reported with more frequent treatments.

meextracorporeal photopheresis It is a second-line treatment for chronic graft-versus-host disease. It is used in patients refractory or intolerant to corticosteroids. meextracorporeal photopheresis it does not seem to interfere with the antileukemic effect of the grafted cells. The risk of infection It is also lower than with other immunosuppressive treatments.

Systemic sclerosis

When used early in systemic sclerosis, eextracorporeal photopheresis has been reported to reduce dermal thickness. Internal organ involvement is not helpful.[7]

Other uses for eextracorporeal photopheresis

meextracorporeal photopheresis Benefits have been reported in some patients with:

• Crohn's disease [8]

• Solid Organ transplant rejection, particularly heart [9]
• Systemic lupus erythematosus [10]
• Atopic dermatitis [11]

• Pemphigus [12]

• Type 1 diabetes [13]

• nephrogenic fibrous dermopathy.

What are the possible side effects of eextracorporeal photopheresis?

meextracorporeal photopheresis it is well tolerated and does not increase the risks of infection. Side effects are rare and mild. These include:

• Transient drop in blood pressure, causing dizziness during leukapheresis.
• low grade storm fever 2 to 12 hours after treatment
• Increased redness or itching of the skin 6 to 8 hours after treatment.
• Possibly some sensitivity to light after treatment.
• Thrombocytopenia and anemia.

During the procedure, the medical team must carefully monitor the patient's blood pressure and blood count. From time to time saline It can be given to maintain blood pressure.

Patients taking blood pressure lowering medications should be advised not to take them until after eextracorporeal photopheresis process. Patients with hypertriglyceridemia should be advised to fast before the procedure, as treatment is less effective with high circulation. lipid– Rich blood.

challenges of eextracorporeal photopheresis

Challenges include the availability of eextracorporeal photopheresis, Okay venous access, anticoagulation, low hematocrit and the cost of treatment. Optimal treatment protocols have yet to be established.