Extracorporeal photochemotherapy in patients with cutaneous T-cell lymphoma: is clinical response predictable?

Background: Extracorporeal photochemotherapy (ECP) has been accepted as a standard therapy in cutaneous T-cell lymphomas (CTCL), a category of lymphomas mainly resistant to conventional therapies. Approximately one half of patients demonstrate a reduction in skin affliction by at least 50% within 12 months of therapy and are categorized as responders to ECP. Predictive criteria for selecting patients who will respond to ECP are lacking. Such criteria would however, be of great benefit.

Objectives: This study compared T-cell clonality and serum levels of soluble interleukin-2 receptor (sIL-2R), lactate dehydrogenase (LD), neopterin, beta2-microglobulin (beta(2)-M) and granzyme B in CTCL patients in order to evaluate their potential usefulness as predictive markers.

Patients/methods: Serum and T lymphocytes obtained from 16 patients with CTCL receiving ECP treatment were evaluated in an open retrospective study.

Results: We found no evident correlation between detected T-cell clonality and response to ECP. The non-responding group had on average a higher level of serum sIL-2R. This difference was significant after 6 and 12 months of therapy, but not pretreatment. An individual reduction in serum sIL-2R, neopterin and beta(2)-M during a 6-month course of ECP was well correlated to clinical remission.

Conclusions: Seven out of 16 patients were classified as responders. Neither T-cell clonality nor any of the serum markers assessed pretreatment could reliably predict the response to ECP treatment. However, the individual relative changes in sIL-2R, neopterin and beta(2)-M during 6 months of ECP treatment coherently displayed correlation to the clinical response, as assessed after 12 months of ECP treatment.