We have previously demonstrated that peripheral blood mononuclear cells from patients with Sézary syndrome, the leukemic form of
cutaneous T-cell lymphoma which is accompanied by
erythroderma and
lymphadenopathy, have a Th2 cell
cytokine [
interleukin 4 (IL-4) and
interleukin 5] production pattern. In this study, we extend these observations to demonstrate a correlation of the presence of a Th2
cytokine pattern with a malignant T-cell clone in different stages of cutaneous involvement among patients with
cutaneous T-cell lymphoma (CTCL). Skin biopsies were obtained from 12 CTCL patients with various disease stages (three patch, three plaque, six
tumor), three patients with
parapsoriasis, four patients with inflammatory
dermatoses, including two
psoriasis and two
lichen planus, and 12 normal controls. Total
RNA was extracted, reverse transcribed, and PCR amplified with
IL-2,
IL-4,
IL-5,
interferon gamma (IFN-gamma), and
beta-actin oligonucleotide primers. Although all skin specimens tested had detectable
IL-2 and IFN-gamma
mRNA, only specimens from patients with CTCL or
parapsoriasis had demonstrable
IL-4 and/or
IL-5 mRNA. Specifically,
IL-5 mRNA was detected in skin biopsies from five of six
tumor-stage CTCL, two of three plaque-stage CTCL, one of three patch-stage CTCL, and 1 of 3
parapsoriasis patients, whereas
IL-4 mRNA was demonstrated to be present in five of six
tumor-stage, one of three plaque stage, none of three patch-stage CTCL, and none of three
parapsoriasis patients. These results indicate that in all stages of cutaneous involvement of CTCL, encompassing patch stage through
tumor stage,
IL-4 and
IL-5 mRNA is variably detectable. In
tumor-stage skin lesions, typically characterized by a dense dermal infiltrate of malignant T cells, Th2
cytokine mRNA is virtually always detectable. The ability to detect Th2
cytokine mRNA in the skin of patients with CTCL supports our previous findings that the malignant T cells in CTCL possess a Th2-helper cell phenotype.