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Procedure · Immunomodulatory

Extracorporeal photopheresis (ECP)

Extracorporeal photochemotherapy; photopheresis. Sometimes “extracorporeal PUVA”.

Extracorporeal photopheresis is a closed-circuit apheresis-based immunotherapy in which the patient's mononuclear cells are collected, exposed ex vivo to 8-methoxypsoralen and UVA light, and reinfused. It produces apoptosis of the targeted lymphocytes and drives a broader immunomodulatory effect (dendritic-cell activation, regulatory T-cell expansion). It is the first-line systemic therapy for erythrodermic CTCL (Sézary syndrome and mycosis fungoides T4) and a key option for steroid-refractory chronic graft-versus-host disease. UK ECP services are commissioned by NHS England.

UK supraregional CTCL practice and NHS England specialised commissioning service specifications are the primary frame of reference; see about the author.

CurrentLast reviewed 27 April 2026

Mechanism

ECP combines apheresis with PUVA exposure of the leucocyte fraction ex vivo. The pleiotropic mechanism is not fully understood but the central effects are:

  • Apoptosis of irradiated lymphocytes — UVA-activated 8-methoxypsoralen forms covalent DNA crosslinks; cells undergo apoptosis over 24–48 hours after reinfusion.
  • Activation of monocytes → dendritic cells on passage through the photopheresis circuit.
  • Cross-presentation of apoptotic-cell-derived antigens on the resulting dendritic cells, with induction of antigen-specific cytotoxic and regulatory T-cells.
  • Expansion of regulatory T-cells (Tregs) — central to the benefit in GvHD.
  • Pro-tolerogenic shift in the overall T-cell compartment.

The clinical effect is therefore more than a simple reduction in circulating Sézary cells; ECP is best regarded as cellular immunotherapy rather than cytoreductive therapy.

Indications (UK)

  • Guideline Erythrodermic CTCL: Sézary syndrome (B2 blood involvement) and mycosis fungoides T4 / stage III. NHS England commissioned therapy for this indication.
  • Guideline Chronic graft-versus-host disease, particularly cutaneous, oral and hepatic GvHD refractory to or steroid-dependent on first-line therapy.
  • Acute GvHD (selected refractory cases).
  • Cardiac, lung and other solid-organ transplant rejection (selected, supraregional).
  • Other immune-mediated dermatoses (severe atopic dermatitis, scleroderma) — off-pathway, occasional use.

Contraindications and cautions

  • Inadequate peripheral venous access without central line (relative).
  • Active uncontrolled infection.
  • Severe cardiac failure / haemodynamic instability (apheresis fluid shifts).
  • Photosensitivity disorders (porphyria, SLE, xeroderma pigmentosum).
  • Aphakia / pseudophakia without UV-protective lens implants — cataract risk from psoralen photoactivation.
  • Pregnancy (8-MOP is teratogenic).

Technique

  1. Vascular access: peripheral venous (preferred) or central; some closed-system devices need only a single peripheral line.
  2. Leucapheresis: continuous- or intermittent-flow apheresis collects ~200–500 mL of mononuclear-cell-enriched buffy coat (around 5–10% of the patient's total lymphocyte mass per procedure).
  3. Photoactivation: 8-methoxypsoralen (8-MOP) added to the cell bag at 200 ng/mL final concentration; the bag passes through a UVA chamber delivering a calibrated dose (typically 2 J/cm²).
  4. Reinfusion: the treated cells are returned to the patient via the same access. Whole-procedure duration ~2–3 hours.

Schedule

  • Induction: two consecutive days every 2–4 weeks. Most UK centres use 2-weekly cycles initially.
  • Response assessment at 3 and 6 months.
  • If responding, continue with progressive interval extension to 4–6 weekly; long-term maintenance is common in CTCL.
  • If no response by 6 months in CTCL, consider escalation (combination with interferon-α, bexarotene, mogamulizumab; or transition to systemic chemotherapy / allogeneic SCT).

Outcomes

  • Trial Sézary syndrome: overall response rate 40–75% across published series; complete response 15–25%. Best results in earlier-stage Sézary with high circulating tumour burden and limited skin tumour burden. Edelson 1987 was the first formal report.
  • Erythrodermic MF (T4): response rates similar to Sézary; benefit on quality of life and pruritus often disproportionate to the percentage skin reduction.
  • Trial Chronic GvHD: response rates 50–70% with steroid-sparing effect; randomised data (Flowers 2008, blood; UK STOC trial) support its use as second-line.
  • ECP is rarely curative alone but is well tolerated and often used as part of a combination regimen (with interferon-α, bexarotene, mogamulizumab or topical / systemic agents) where it provides immunological benefit while limiting toxicity.

Adverse events

  • Generally well tolerated — the major attraction over systemic chemotherapy.
  • Apheresis-related: hypotension, vasovagal reactions, transient citrate-related paraesthesia (paraesthesia, perioral tingling), hypocalcaemia if not pre-empted.
  • Photosensitivity: skin and ocular photosensitivity for ~24 hours after each session; eye and skin protection mandatory.
  • Nausea, fatigue, headache after the procedure.
  • Anaemia and lymphopenia — mild, transient, programmable to the apheresis volume.
  • Catheter-related infection (if central line used).
  • No conclusive long-term association with secondary malignancy.

Practical considerations

  • Provided in the UK at NHS England commissioned ECP centres (a small number of supraregional services); referrals via the CTCL or GvHD MDT.
  • Baseline workup: vascular access assessment, FBC, U&Es, LFTs, calcium, eye assessment, pregnancy test in childbearing potential.
  • Patient education: photoprotection (UVA-blocking glasses, full-cover clothing) for 24 hours after each session; sunscreen.
  • Monitoring: skin response (mSWAT), peripheral blood Sézary cell count (B0/B1/B2), quality-of-life metrics, and time on treatment.
  • ECP and concurrent therapy: works well alongside topical steroids, interferon-α, bexarotene and mogamulizumab; sequencing with TSEB and brentuximab vedotin is an MDT decision.

References

  1. Edelson R, Berger C, Gasparro F et al. Treatment of cutaneous T-cell lymphoma by extracorporeal photochemotherapy. Preliminary results. N Engl J Med 1987;316:297–303.
  2. Knobler R, Berlin G, Calzavara-Pinton P et al. Guidelines on the use of extracorporeal photopheresis. J Eur Acad Dermatol Venereol 2014;28(suppl 1):1–37.
  3. Trautinger F, Eder J, Assaf C et al. European Organisation for Research and Treatment of Cancer consensus recommendations for the treatment of mycosis fungoides / Sézary syndrome — Update 2017. Eur J Cancer 2017;77:57–74.
  4. Flowers MED, Apperley JF, van Besien K et al. A multicenter prospective phase 2 randomized study of extracorporeal photopheresis for treatment of chronic graft-versus-host disease. Blood 2008;112:2667–74.
  5. NHS England. Service Specification 170103S: Extracorporeal photopheresis for adults and children. Accessed 18 May 2026.

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