ABSTRACT
A course of treatment with narrow-band ultraviolet B (NB-UVB) improves psoriasis and increases serum 25-hydroxyvitamin D (25(OH)D). In this study 12 patients with psoriasis who were supplemented with oral cholecalciferol, 20 µg daily, were given a course of NB-UVB and their response measured. At baseline, serum 25(OH)D was 74.14 ± 22.9 nmol/l. At the 9th exposure to NB-UVB 25(OH)D had increased by 13.2 nmol/l (95% confidence interval (95% CI) 7.2-18.4) and at the 18th exposure by 49.4 nmol/l (95% CI 35.9-64.6) above baseline. Psoriasis Area Severity Index score improved from 8.7 ± 3.5 to 4.5 ± 2.0 (p < 0.001). At baseline, psoriasis lesions showed low vitamin D metabolizing enzyme (CYP27A1, CYP27B1) and high human ß-defensin-2 mRNA expression levels compared with those of the healthy subjects. In conclusion, NB-UVB treatment significantly increases serum 25(OH)D in patients with psoriasis who are taking oral vitamin D supplementation, and the concentrations remain far from the toxicity level. Healing psoriasis lesions show similar mRNA expression of vitamin D metabolizing enzymes, but higher antimicrobial peptide levels than NB-UVB-treated skin in healthy subjects.
Subject(s)
Psoriasis/blood , Psoriasis/therapy , Ultraviolet Therapy , Vitamin D/analogs & derivatives , 25-Hydroxyvitamin D3 1-alpha-Hydroxylase/genetics , 25-Hydroxyvitamin D3 1-alpha-Hydroxylase/metabolism , Administration, Oral , Adult , Biopsy , Cholecalciferol/therapeutic use , Cholestanetriol 26-Monooxygenase/genetics , Cholestanetriol 26-Monooxygenase/metabolism , Female , Humans , Male , Middle Aged , Psoriasis/metabolism , RNA, Messenger/metabolism , Real-Time Polymerase Chain Reaction , Skin/metabolism , Skin/pathology , Vitamin D/blood , Vitamin D Deficiency/therapy , Vitamins/therapeutic use , beta-Defensins/genetics , beta-Defensins/metabolismABSTRACT
BACKGROUND/AIMS: Chronic kidney disease (CKD) patients on dialysis are prone to vitamin D insufficiency despite oral vitamin D supplementation. Here, we studied whether narrow-band ultraviolet B (NB-UVB) exposures improve vitamin D balance. METHODS: 14 haemodialysis patients and 15 healthy subjects receiving oral cholecalciferol 20 µg daily got nine NB-UVB exposures on the entire body. Serum 25-hydroxyvitamin D (25(OH)D) was measured by radioimmunoassay. Cutaneous mRNA expression levels of CYP27A1 and CYP27B1, two enzymes required for hydroxylation of vitamin D into its active metabolite, were also measured. RESULTS: The baseline serum 25(OH)D concentration was 57.6 ± 18.2 nmol/l in the CKD patients and 74.3 ± 14.8 nmol/l in the healthy subjects. The NB-UVB course increased serum 25(OH)D by 14.0 nmol/l (95% CI 8.7-19.5) and 17.0 nmol/l (CI 13.7-20.2), respectively. At baseline the CKD patients showed significantly increased CYP27B1 levels compared to the healthy subjects. CONCLUSIONS: A short NB-UVB course is an efficient way to improve vitamin D balance in CKD patients on dialysis who are receiving oral vitamin D supplementation. The increased cutaneous CYP27B1 levels in the CKD patients suggest that the loss of renal activity of this enzyme is at least partially compensated for by the skin.
Subject(s)
25-Hydroxyvitamin D3 1-alpha-Hydroxylase/metabolism , Cholestanetriol 26-Monooxygenase/metabolism , Renal Insufficiency, Chronic/metabolism , Renal Insufficiency, Chronic/therapy , Skin/metabolism , Vitamin D Deficiency/therapy , Vitamin D/administration & dosage , 25-Hydroxyvitamin D3 1-alpha-Hydroxylase/genetics , Administration, Oral , Adolescent , Aged , Cholestanetriol 26-Monooxygenase/genetics , Combined Modality Therapy/methods , Dietary Supplements , Female , Humans , Male , RNA, Messenger/metabolism , Renal Dialysis/adverse effects , Renal Insufficiency, Chronic/complications , Skin/radiation effects , Steroid Hydroxylases/genetics , Steroid Hydroxylases/metabolism , Treatment Outcome , Ultraviolet Therapy/methods , Vitamin D/blood , Vitamin D Deficiency/etiology , Vitamin D Deficiency/metabolism , Young AdultABSTRACT
BACKGROUND: Chronic kidney disease (CKD) patients are especially prone to vitamin D insufficiency. Narrow-band ultraviolet B (NB-UVB) treatment increases serum 25-hydroxyvitamin D [25(OH)D] in dermatological patients, and we studied whether it also improves vitamin D balance in CKD patients on haemodialysis. METHODS: Fifteen dialysis patients (mean age 48.3 years) and 12 healthy subjects (mean age 43.6 years) received nine NB-UVB exposures on the upper body. Serum 25(OH)D and 1,25(OH)(2)D were measured before and after the exposures. From skin biopsy specimen messenger RNA (mRNA) expression levels of CYP24A1 and CYP27B1, two enzymes needed for hydroxylation of vitamin D into its active metabolites, and of antimicrobial peptide cathelicidin, were examined. RESULTS: Before NB-UVB, mean serum 25(OH)D was 32.5 ± 10.2 nmol/L in the dialysis patients and 60.2 ± 18.0 nmol/L in the healthy subjects (P < 0.001). After eight NB-UVB exposures, serum 25(OH)D increased by 13.8 nmol/L (43%; P < 0.001) and serum 1,25(OH)(2)D by 3.3 pmol/L (27%; P = 0.002) in the dialysis patients. After NB-UVB exposures, CYP27B1 mRNA was increased (P = 0.04), whereas cathelicidin mRNA was decreased (P < 0.0001) compared to non-treated healthy subjects. One and 2 months after NB-UVB exposure, serum 25(OH)D was still 10% higher than initially in the dialysis patients. CONCLUSIONS: The present study shows that a short course of NB-UVB exposure increases significantly serum 25(OH)D and 1,25(OH)(2)D in dialysis patients. The effect is, however, short lasting suggesting that the patients need cyclic NB-UVB exposure to maintain their improved vitamin D concentration.
