A clinical trial and molecular study of photoadaptation in vitiligo

Phototherapy for vitiligo: A narrative review on the clinical and molecular aspects, and recent literature

BACKGROUND

Vitiligo is characterized by depigmented patches resulting from loss of melanocytes. Phototherapy has emerged as a prominent treatment option for vitiligo, utilizing various light modalities to induce disease stability and repigmentation.

AIMS AND METHODS

This narrative review aims to explore the clinical applications and molecular mechanisms of phototherapy in vitiligo.

RESULTS AND DISCUSSION

The review evaluates existing literature on phototherapy for vitiligo, analyzing studies on hospital-based and home-based phototherapy, as well as outcomes related to stabilization and repigmentation. Narrowband ultra-violet B, that is, NBUVB remains the most commonly employed, studied and effective phototherapy modality for vitiligo. Special attention is given to assessing different types of lamps, dosimetry, published guidelines, and the utilization of targeted phototherapy modalities. Additionally, the integration of phototherapy with other treatment modalities, including its use as a depigmenting therapy in generalized/universal vitiligo, is discussed. Screening for anti-nuclear antibodies and tailoring approaches for non-photo-adapters are also examined.

CONCLUSION

In conclusion, this review provides a comprehensive overview of phototherapy for vitiligo treatment. It underscores the evolving landscape of phototherapy and offers insights into optimizing therapeutic outcomes and addressing the challenges ahead. By integrating clinical evidence with molecular understanding, phototherapy emerges as a valuable therapeutic option for managing vitiligo, with potential for further advancements in the field.

Evaluation of Biological Effects and Transcriptome Changes Induced by LED Based Narrow Band UVB Phototherapy

Ultraviolet (UV), particularly UVB, is widely used in the treatment of skin diseases including psoriasis, atopic dermatitis, vitiligo, mycosis fungoides, and pruritus. Recently, there has been a trend of replacing broad band UVB (BB-UVB) units with narrow band UVB (NB-UVB), as studies have demonstrated that NB-UVB is more efficacious in the treatment of psoriasis. The purpose of this study is to evaluate the biological effects and transcriptome changes induced by light emitting diode based NB-UVB (NB-UVB LED) phototherapy. Cell viability and the cell migration ability was significantly decreased post treatment, as well as apoptosis and ROS levels were remarkably increased. NB-UVB induced S phase arrest was observed 12 hours post irradiation. Bioinformatics analysis of transcriptome sequencing data revealed that NB-UVB LED irradiation induced dose-depended changes in multiple key signaling pathways, such as PI3K and cytoskeletal-related pathways. The depolymerization of cytoskeleton induced by NB-UVB was observed 24 hours post treatment. In addition, the expression levels of cytoskeleton related proteins FN1, ITGB4, ITGA1, RAC2 and DOCK1 decreased significantly 12 hours after irradiation. Our results indicated that NB-UVB LED may serve as a novel option for the development of NB-UVB phototherapy devices.

The necessity of antinuclear antibody investigation in pre-phototherapy vitiligo patients: A retrospective study

BACKGROUND

Narrowband UVB (NBUVB) phototherapy is the cornerstone treatment for vitiligo. Before its initiation, some experts recommend antinuclear antibody (ANA) screening out of concern for either photosensitivity to NBUVB or autoimmune disease exacerbation during treatment. As vitiligo is considered an autoimmune disorder, ANAs can be positively found in the disease without any clinical importance. The necessity for ANA investigations for pre-phototherapy vitiligo patients is therefore questioned.

METHODS

We conducted a retrospective study to investigate vitiligo patients who had been checked for ANA before commencing NBUVB phototherapy. Demographic data-including vitiligo type and age of onset-were collected. Samples of ANA, anti-thyroglobulin, and anti-thyroid peroxidase were obtained. The phototherapy treatment protocol and cutaneous reactions to the phototherapy were also recorded.

RESULTS

Among 85 Thai vitiligo patients, the ANA prevalence was 35.3%. The speckled ANA pattern was the most common, and the large majority of patients (80%) had a titer of ≤1:100. Factors associated with positive ANA were female gender and positive anti-thyroglobulin. There were no statistical differences between the phototoxic reactions or phototoxic doses of NBUVB of the ANA-positive vitiligo and ANA-negative vitiligo groups. No cases of SLE were detected in ANA-positive group.

CONCLUSIONS

ANA positivity was not correlated with the incidence or dose of phototoxic reaction in phototherapy treated vitiligo, and it may not a predictive factor for SLE diagnosis in vitiligo. ANA might therefore not need to be routinely checked in pre-phototherapy in vitiligo, unless there are clinical suspicions of an autoimmune disease. However, ANA might be involved in part of the cutaneous photoadaptation response to phototherapy.

Clinical and Spectrophotometric Evaluation of Skin Photoadaptation in Vitiligo Patients after a Short Cycle of NB-UVB Phototherapy

BACKGROUND

The phenomenon of photoadaptation to narrow-band ultraviolet B (NB-UVB) radiation has been previously described in vitiligo and has usually been clinically measured by the assessment of the minimal erythema dose (MED) after phototesting.

OBJECTIVES

To assess the photoadaptive response in vitiligo and healthy skin after NB-UVB phototherapy not only clinically, but also by spectrophotometry.

MATERIALS AND METHODS

Fourteen patients affected by generalized vitiligo underwent NB-UVB phototherapy twice weekly for 12 weeks. Before and after phototherapy, a phototesting procedure was administered on vitiligo patches and adjacent healthy skin with a solar simulated radiation (SSR). Visual assessment of the MED took place after 24 h. A spectrophotometer was used to assess the a* value and the melanin index (MI*), as signs of skin erythema and pigmentation. The photoadaptation factor (MED-PF) and the a* photoadaptation factor (a*-PF) were calculated.

RESULTS

After NB-UVB phototherapy, both vitiligo and healthy skin showed an increase in MED and MI* values and a reduction of skin erythema compared to baseline (p < 0.05). MED-PF data showed a photoadaptation in 10 (71.4%) vitiligo lesions and in 12 (85.7%) healthy skin areas. The assessment of the a*-PF showed a negative mean percentage value in all affected and unaffected skin areas.

CONCLUSIONS

A short cycle of NB-UVB phototherapy can induce photoadaptation in vitiligo by increasing the MED and reducing skin erythema after stimulation with SSR. This is most likely due to the physical filter function induced by ultraviolet radiation.

Effect of combination NSAID and NBUVB treatment in non-photoadapters-A pilot study

BACKGROUND

Vitiligo is a disorder of dyspigmentation that can impact quality of life. While narrow-band ultraviolet B (NBUVB) is an effective treatment for vitiligo, a subset of patients are unable to respond to phototherapy as they cannot photoadapt. However, nonsteroidal anti-inflammatory drugs (NSAIDs) have been shown to increase the minimal erythema dose.

PURPOSE

To determine whether ibuprofen allows non-photoadapters to respond to therapeutic doses of NBUVB and maintain photoadaptation.

METHOD

Four patients unable to tolerate NBUVB or excimer past a dose of 1000 mJ/cm² were enrolled in the study and given ibuprofen 400 mg prior to phototherapy, which was performed 2-3 times a week. Patients were followed up to 72 treatments to demonstrate photoadaptation and maintenance of response to phototherapy. Patients were clinically monitored by serial photographs approximately every 12 treatments. Response to phototherapy was monitored by tracking the dose of NBUVB received at each session. Maintenance of response was monitored for six treatments after discontinuing the ibuprofen. Percent change in pigmentation was also recorded.

RESULTS

Three out of four subjects enrolled in the study were able to increase their doses of phototherapy to a therapeutic range, and subjects continued to photoadapt for six treatments after discontinuing ibuprofen. Two subjects achieved repigmentation during their course of phototherapy.

CONCLUSION

Ibuprofen may be a safe alternative to corticosteroids for select patients with vitiligo that are unable to photoadapt. It appears that the ability to photoadapt continues once ibuprofen is discontinued, negating the need for chronic use. Enabling photoadaptation allows patients to achieve therapeutic doses of NBUVB phototherapy, leading to repigmentation and improved outcomes.

TRIAL REGISTRATION

The trial was registered through Henry Ford Hospital IRB-No. 9744.

The impact of oral Polypodium leucotomos extract on ultraviolet B response: A human clinical study

BACKGROUND

There is a rationale for adding systemic photoprotective agents to the current photoprotection regimen.

OBJECTIVE

This study was designed to objectively evaluate the molecular and photobiologic effects of oral administration of Polypodium leucotomos extract (PLE).

METHODS

In all, 22 subjects with Fitzpatrick skin phototype I to III were enrolled. On day 1, subjects were irradiated with visible light, ultraviolet (UV) A1, and UVB (using 308-nm excimer laser). Evaluation was done immediately and 24 hours after irradiation. On days 3 and 4, irradiation and evaluation process was repeated after ingestion of PLE.

RESULTS

Clinical assessments and colorimetry data showed a decrease in UVB-induced changes in 17 of 22 subjects post-PLE administration; histology findings demonstrated such a decrease in all 22 subjects.

LIMITATIONS

Only 2 doses of PLE were given. Furthermore, subjects with skin phototypes I to III only were studied.

CONCLUSION

The results suggest that PLE can potentially be used as an adjunctive agent to lessen the negative photobiologic effects of UVB.

The Vitiligo Working Group recommendations for narrowband ultraviolet B light phototherapy treatment of vitiligo

BACKGROUND

Treatment of vitiligo with narrowband ultraviolet B light (NBUVB) is an important component of the current standard of care. However, there are no consistent guidelines regarding the dosing and administration of NBUVB in vitiligo, reflected by varied treatment practices around the world.

OBJECTIVE

To create phototherapy recommendations to facilitate clinical management and identify areas requiring future research.

METHODS

The Vitiligo Working Group (VWG) Phototherapy Committee addressed 19 questions regarding the administration of phototherapy over 3 conference calls. Members of the Photomedicine Society and a group of phototherapy experts were surveyed regarding their phototherapy practices.

RESULTS

Based on comparison and analysis of survey results, expert opinion, and discussion held during conference calls, expert recommendations for the administration of NBUVB phototherapy in vitiligo were created.

LIMITATIONS

There were several areas that required further research before final recommendations could be made. In addition, no standardized methodology was used during literature review and to assess the strength of evidence during the development of these recommendations.

CONCLUSION

This set of expert recommendations by the VWG is based on the prescribing practices of phototherapy experts from around the world to create a unified, broadly applicable set of recommendations on the use of NBUVB in vitiligo.

Squamous Cell Carcinoma in a Patient with Vitiligo of Photo-covered Skin

Ultraviolet radiation is an important risk factor for the development of skin cancers. Melanin is known to protect the skin against harmful effects of ultraviolet radiation. Hence, vitiligo patients are at higher risk of developing such malignancies. But few reports of occurrence of skin cancers in vitiligo lesions suggest that their occurrence in vitiligo is rare. There are reports of development of Squamous cell carcinoma (SCC) in vitiligo lesions, following long-term Psoralen and Ultraviolet-A (PUVA) therapy. But there are no reports of occurrence of SCC in a vitiligo patch located in photo-covered area. We describe a patient with SCC in a vitiligo patch present in photo-covered skin.