Features of vitamin D synthesis during PUVA therapy in patients with psoriasis
Authors:   Peoples' Friendship University of Russia (RUDN), Moscow, Russian Federation, Samburskaya O.V. ,   Professor Kalinchenko Clinic, Moscow, Russian Federation,   Psoriasis Center, Moscow, Russian Federation, Batkaeva N.V. ,   Peoples' Friendship University of Russia (RUDN), Moscow, Russian Federation, Kalinchenko S.Yu. ,   Peoples' Friendship University of Russia (RUDN), Moscow, Russian Federation,   Professor Kalinchenko Clinic, Moscow, Russian Federation, Moshnin M.V. ,   Psoriasis Center, Moscow, Russian Federation, Batkaev E.A. ,   Peoples' Friendship University of Russia (RUDN), Moscow, Russian Federation, Moshnina Z.I. 
Published: September 2024

The possibility of combining the inhibition of keratinocyte proliferation during PUVA therapy with the immunomodulatory effect of vitamin D. Objective. To evaluate the possibility of vitamin D synthesis during PUVA therapy and the clinical efficacy of treatment (CET) of the combined use of PUVA therapy and vitamin D in patients with psoriasis. Patients and methods. The study included 25 male and female patients with psoriasis of any severity, aged 18 years and older, undergoing PUVA therapy. The patients were divided into two groups: group 1 (n = 15) did not take vitamin D; group 2 (n = 10) took cholecalciferol 4,000 IU per day for the entire course of treatment. The course of treatment ranged from 5 to 20 sessions, the exposure was carried out three hours after taking the photosensitizer, the procedures were performed every other day. Before the beginning and at the end of treatment, the severity of psoriasis was assessed by the PASI index, CET was evaluated, and the level of vitamin D in the blood was determined by chemiluminescent immunoassay (ECLIA) according to the level of its metabolite calcidiol (25(OH)D). Statistical data processing was performed using the IBM SPSS Statistics 23.0 software (USA). Results. Before treatment: in group 1, vitamin D ranged from 8.0 to 24.0 ng/mL, mean value – 15.933 ± 4.0622 ng/mL, PASI ranged from 4.6 to 26.8, mean value – 12.23 ± 7.85; in group 2, vitamin D ranged from 10.0 to 30.0 ng/mL, mean value – 18.000 ± 4.400 ng/mL, PASI ranged from 4.60 to 16.01, mean value – 7.840 ± 3.691. In all patients, calcidiol began to increase after the 5th PUVA therapy procedure. After treatment: in group 1, vitamin D ranged from 16 to 30 ng/mL, mean value – 22.267 ± 4.284 ng/mL (p < 0.01), PASI ranged from 2.100 to 5.600, mean value – 2.801 ± 1.252 (p < 0.01), CET ranged from 62.056 to 92.120%, mean value – 78.132 ± 10.843% (p < 0.01); in group 2, vitamin D ranged from 25 to 58 ng/mL, mean value – 36.800 ± 9.360 ng/mL (p < 0.01), PASI ranged from 0.0 to 4.600, mean value – 2.231 ± 1.452 (p < 0.01), CET ranged from 79.432 to 99.764%, mean value – 87.724 ± 9.684% (p < 0.01). Discussion. Photochemical reactions during PUVA therapy result in double bond interactions in biomolecules and a hydroxylation process, which may be a method of synthesis of cholecalciferol and calcidiol. Conclusion. The increase in calcidiol during PUVA therapy allows using this method both for the regulation of keratinocyte proliferation and for the synthesis of vitamin D to enhance immunomodulation. Key words: vitamin D, calcidiol, calcitriol, previtamin D, psoralenes, psoriasis, PUVA therapy