Background. The cutaneous T-cell lymphomas (CTCL) are diseases characterised by cutaneous infiltrates of malignant, clonally expanded T-cells. Because individual genetic determination of angiogenetic and antioxidant properties of blood vessels could take part in responsibility to phototherapy in CTCL patients, the association of two frequent polymorphisms in endothelin-1 gene with phototherapy was tested. Methods and Results. 77 patients with CTCL, diagnosed and treated at the First Dermatological Clinic of St. Ann’s Faculty Hospital Brno (46 men and 31 women, median age 62, range 28-82 years) were included in the study. Diagnosis of CTCL according to the clinical picture was verified histologically. The genotype distributions and allelic frequencies between CTCL with phototherapy and those without phototherapy were compared. The 4A4A variant of -3A/-4A EDN1 is more frequent in patients treated with phototherapy (8/30 vs. 1/38, OR=10.13; P=0.01). The GA and AA genotypes of G8002A EDN1 polymorphism are more frequent in CTCL patients treated with phototherapy compared to those without it (15/23 vs. 7/32, OR=2.98; P=0.03). Conclusions. Some polymorphic variants in EDN1 genes, a homozygote -4A-4A in -3A /-4A EDN1 and genotypes GA and GG in G8002A EDN1) seem to carry an advantage for phototherapy effectiveness in patients with CTCL.

        Key words: endothelin-1, genetic polymorphism, therapy, phototherapy, steroids, cutaneous T-cell lymphoma.