Does the effectiveness of biological medications in the treatment for psoriasis depend on the moment of starting therapy? A preliminary study.

Introduction: It is well known that biological medications acting on selected elements of the immune response are highly effective in psoriasis treatment. It is a common perception that psoriasis is a seasonal disorder with improvement in warmer months, however it has not been unequivocally confirmed. It is not known whether the time of year of starting systematic therapy for psoriasis influences treatment outcomes. Material and methods: Changes in psoriasis severity scores during treatment with biologics were investigated. The scores were recorded for 62 patients with moderate to severe psoriasis at the beginning, after 1, 4 and 7 months of the therapy. Patients were divided into two groups: those beginning the treatment in the cold period of the year (November-March) and in the warm period (May-September). The seasonal groups were also divided into subgroups according to the type of biologics used: interleukin inhibitors and tumor necrosis factor α (TNF-α) inhibitors. Results of the treatment were analysed using standard statistical tests of differences between samples. Results: After 1 and 4 months of the therapy, better efficacy of interleukin inhibitors was found in patients starting treatment in summer. The course of psoriasis improvement in patients taking TNF-α inhibitors resulted in consistent improvement regardless of the season. The outcome of the treatment after 7 months was similar for both seasonal groups and types of biologics used. Conclusions: Our understanding of the effectiveness of the treatments depending on the time of the year combined with the type of biologics used, may further improve results of the therapy.

Measurements of biologically effective solar radiation using erythemal weighted broadband meters.

In this paper, we describe conversion factors (CF) for the calculation of biologically effective irradiances (BEI) from erythemal irradiance for three effects: photosynthesis of previtamin D3, psoriasis healing, and inactivation of the SARS-Cov-2 virions. CFs were empirically derived from measurements of spectral solar ultraviolet (UV) radiation during all sky conditions at four mid-latitude sites in the Northern Hemisphere, namely Aosta, Belsk, Reading, and San Diego. These CFs were found to depend on solar zenith angle (SZA) and total column ozone, but are largely independent (within ± 5% for SZA < 60°) of local conditions such as surface albedo, visibility and other local atmospheric patterns. The values of these empirical CFs are consistent with analytical CFs derived with radiative transfer calculations (model FastRT) for clear-sky and overcast conditions. To validate these analytical CFs, one-hour radiant exposures for the three biological effects were calculated from erythemal measurements at Reading between 2012 and 2021 and compared with similar exposures calculated directly from the spectral UV measurements. The two datasets agreed within 10% for SZA < 65°, demonstrating the utility of the conversion method. These results suggest that the proposed analytical CFs can be used with confidence to estimate radiant exposures for the three biological effects from measurements of the UV Index at any northern mid-latitude site.

A Priori Estimation of the Narrow-Band UVB Phototherapy Outcome for Moderate-to-Severe Psoriasis Based on the Patients' Questionnaire and Blood Tests Using Random Forest Classifier.

BACKGROUND: Nowadays, patients with moderate-to-severe psoriasis are treated with conventional immunosuppressants or with new biological agents. Phototherapy is the first-line treatment for patients in whom topical therapy is insufficient. Although numerous studies have been carried out, it is still difficult to predict the outcome of phototherapy in individual patients. METHODS: Prior to standard narrow band (NB) ultraviolet B (UVB) phototherapy, the patients filled out a questionnaire about personal life and health status. Several standard blood tests, including selected cytokine levels, were performed before and after a course of 20 NB-UVB treatments. The questionnaire answers, results of the blood tests, and treatment outcomes were analyzed using an artificial intelligence approach-the random forest (RF) classification tool. RESULTS: A total of 82 participants with moderate-to-severe psoriasis were enrolled. Prior to starting phototherapy, the patients with expected good outcome from the phototherapy, shorter remission, and quitting a possible second course of the NB-UVB treatment could be identified by the RF classifier with sensitivity over 84%, and accuracy of 75%, 85%, and 79%, respectively. The inclusion of cytokine data did not improve the performance of the RF classifier. CONCLUSION: This approach offers help in making clinical decisions by identifying psoriatic patients in whom phototherapy will significantly improve their skin, or those in whom other therapies should be recommended beforehand.

Numerical estimations of the daily amount of skin-synthesized vitamin D by pre-school children in Poland.

According to Polish guidelines, children need a daily dose of 600-1000 I·U. vitamin D, which could be skin-synthesized in the period May to September, after at least 15 min solar exposure between 10 am and 3 pm with uncovered forearms and lower legs. In Poland, doctors only prescribe oral supplementation to infants and small children up to 2 years old, rarely for the older children. Numerical estimates of the daily amount of vitamin D (expressed in I.U. vitamin D taken orally) due to the solar exposure for preschoolers have been made on the basis of an observation campaign in Warsaw, Poland. In the period from April to September, the observations of children's clothing of age 4-6 years and the measurements of UV index were carried out in the kindergarten playground and a nearby park (52.31oN, 21.06°E). It appears, that longer exposures (~45 min) are needed to gain the recommended dose. However, the estimation is burden with large uncertainties. The alternative scenario is to allow children to play outside for as long as possible without getting sunburn, i.e. until the personal erythemal threshold is reached. Then, sunscreens should be applied.

Perspectives of UV nowcasting to monitor personal pro-health outdoor activities.

Nowcasting model for online monitoring of personal outdoor behaviour is proposed. It is envisaged that it will provide an effective e-tool used by smartphone users. The model could estimate maximum duration of safe (without erythema risk) outdoor activity. Moreover, there are options to estimate duration of sunbathing to get adequate amount of vitamin D3 and doses necessary for the antipsoriatic heliotherapy. The application requires information of starting time of sunbathing and the user's phototype. At the beginning the user will be informed of the approximate duration of sunbathing required to get the minimum erythemal dose, adequate amount of vitamin D3, and the dose necessary for the antipsoriatic heliotherapy. After every 20-min the application will recalculate the remaining duration of sunbathing based on the UVI measured in the preceding 20 min. If the estimate of remaining duration is <20 min the user will be informed that the deadline of sunbathing is approaching. Finally, a warning signal will be sent to stop sunbathing if the measured dose reaches the required dose. The proposed model is verified using the data collected at two measuring sites for the warm period of 2017 (1st April-30th September) in large Polish cities (Warsaw and Lodz). First instrument represents the UVI monitoring station. The information concerning sunbathing duration, which is sent to a remote user, is evaluated on the basis of the UVI measurements collected by the second measuring unit in a distance of ~7 km and 10 km for Warsaw and Lodz, respectively. The statistical analysis of the differences between sunbathing duration by nowcasting model and observation shows that the model provides reliable doses received by the users during outdoor activities in proximity (~10 km) to the UVI source site. Standard 24 h UVI forecast based on prognostic values of total ozone and cloudiness appears to only be valid for sunny days.

Adequate vitamin D3 skin synthesis versus erythema risk in the Northern Hemisphere midlatitudes.

Health-optimum-exposure index (HOEI) is proposed to assess if the prescribed amount of vitamin D3 (target value) could be synthesized in the human skin without erythema appearance. It is defined as the ratio between the vitamin D3 quantity received during the maximum allowed outdoor exposure without erythema risk and the target value. Sunbathing is safe for HOEI>1 and 1/HOEI represents a part of minimal erythema dose (MED) necessary to obtain the target value. We examine the following targets: a vitamin D3 quantity equivalent to 1000 IU vitamin D3 taken orally, and an optimal vitamin D3 quantity defined by Krzyscin et al. (2016). The biologically weighted (previtamin D3 and erythemal) doses from the Northern Hemisphere midlatitudinal stations are analyzed to find HOEI dependence on personal and meteorological factors. HOEI depends mostly on the exposed skin area, person's age, and sun elevation at noon but not on the Fitzpatrick skin phototype. We found that only young adults (<21 yr) could safely obtain vitamin D3 quantity, which is equivalent to 1000 IU taken orally, almost throughout the whole year. Duration of such exposures appears <1 h only in the warm subperiods of the year (April-September) for a person with minimal erythema dose of 330 J m-2. Exposing larger part of the body (~30%) enables the oldest persons (>59 yr) to reach 1000 IU target during warm days in spring and summer. The optimal daily vitamin D3 quantity could only be synthesized only by young adults for about 40-60% of days in the May-August period if they expose at least 1/3 part of their body surface area. Vitamin D3 supplementation seems to be necessary over the whole year for the oldest persons with daily dosage of ~2000 IU but reduced to ~1000 IU in summer for sunseekers exposing significant part of the body.

UV Index monitoring in Europe.

The UV Index was established more than 20 years ago as a tool for sun protection and health care. Shortly after its introduction, UV Index monitoring started in several countries either by newly acquired instruments or by converting measurements from existing instruments into the UV Index. The number of stations and networks has increased over the years. Currently, 160 stations in 25 European countries deliver online values to the public via the Internet. In this paper an overview of these UV Index monitoring sites in Europe is given. The overview includes instruments as well as quality assurance and quality control procedures. Furthermore, some examples are given about how UV Index values are presented to the public. Through these efforts, 57% of the European population is supplied with high quality information, enabling them to adapt behaviour. Although health care, including skin cancer prevention, is cost-effective, a proportion of the European population still doesn't have access to UV Index information.

Controlling sunbathing safety during the summer holidays - The solar UV campaign at Baltic Sea coast in 2015.

Information regarding the intensity of surface UV radiation, provided for the public, is frequently given in terms of a daily maximum UV Index (UVI), based on a prognostic model. The quality of the UV forecast depends on the accuracy of column amount of ozone and cloudiness prediction. Daily variability of UVI is needed to determine the risk of the UV overexposure during outdoor activities. Various methods of estimating the temporary UVI and the maximum duration of UV exposures (received a dose equal to minimal erythemal dose - MED), at the site of sunbathing, were compared. The UV indices were obtained during a field experiment at the Baltic Sea coast in the period from 13th to 24th July 2015. The following UVI calculation models were considered: UVI measurements by simple hand-held biometers (Silver Crest, Oregon Scientific, or more advanced Solarmeter 6.5), our smartphone models based on cloud cover observations at the site and the cloudless-sky UVI forecast (available for any site for all smartphone users) or measured UVI, and the 24h weather predictions by the ensemble set of 10 models (with various cloud parameterizations). The direct UV measurements, even by a simple biometer, provided useful UVI estimates. The smartphone applications yielded a good agreement with the UV measurements. The weather prediction models for cloudless-sky conditions could provide valuable information if almost cloudless-sky conditions (cloudless-sky or slightly scattered clouds) were observed at the sunbathing site.

Optimal vitamin D3 daily intake of 2000IU inferred from modeled solar exposure of ancestral humans in Northern Tanzania.

Recently, high serum 25-hydroxyvitamin D concentration (~110nmol/L) was found in the Hadza tribe still keeping ancient hunter-gather life style. This level could serve as optimal vitamin D level that was built during millennia of human evolution. The personal vitamin D3 effective solar exposures of the Hadza adults are estimated using radiative model simulations with input from the satellite observations over lake Eyasi (3.7°S, 35.0°E). The calculations are carried out assuming the Hadza typical clothing habits and specific scenarios of the out-door activity comprising early morning and late afternoon working time in sun and prolonged midday siesta in the shade. The modeled doses received by the Hadza are converted to the vitamin D3 effective daily doses pertaining to the lighter skinned persons. We propose a novel formula to get adequate vitamin D level - exposure of 1/3 MED around local noon to 1/3 part of the whole body during warm sub-period of the year in the low- and mid-latitude regions. Such daily solar exposure is equivalent to ~2000IU of vitamin D3 taken orally. For many contemporary humans with limited out-door activity habit achieving such daily norm requires vitamin D3 supplementation of 2000IU throughout the whole year.

Controlling adverse and beneficial effects of solar UV radiation by wearing suitable clothes - spectral transmission of different kinds of fabrics.

Humans should avoid prolonged exposure to the Sun during the warm subperiod of the year with naturally high solar UV level. One of the known recommendations to avoid excessive UV radiation is wearing clothes with UV protection additives. However there is an important question: how do we get an adequate solar UV radiation, which maintains a healthy status of vitamin D, without facing overexposure risks? It is found that some kind of 100% cotton knitted fabric, used in the production of normal daily clothing, has ∼15% transmittance of solar UV. Model studies show that a garment made of this fabric allows larger synthesis of vitamin D3 in human body without the erythema risks (skin redness). Thus the adequate level of vitamin D could be attained safely by a person exposing only small part of the body (face, palms) during the period (May-August) of the year.

System for monitoring UV radiation level in phototherapy cabins in Poland.

INTRODUCTION: Ultraviolet phototherapy (UVP) is widely used in dermatological practice for the treatment of various skin diseases. Numerous studies support its beneficial curing effectiveness; however, overexposure to ultraviolet radiation can cause adverse health effects, such as sunburn reaction, erythema response, cataract, skin aging, etc. For these reasons, it is of special importance to monitor performance of UVP cabins using a calibration system to evaluate the UV doses incident upon the patient. MATERIAL AND METHODS: A mechanized cabin control system (CCS) is proposed. It consists of radiometers with a wide and narrow field of view to estimate the body irradiation and to identify malfunctioning cabin tubes. Quality control and quality assurance procedures are developed to keep high accuracy of the calibration procedure. The CCS has been used in the examination of two different types of UVP cabins routinely working in Poland. RESULTS: It allows precise calculation of UV doses and spatial variability of UV radiance inside the cabin, thus providing uncertainties of the doses assigned by medical staff. The CCS could potentially serve as a primary standard for monitoring various UVP cabins working in Poland. CONCLUSIONS: The methodology developed to quantify UV doses in UVP cabins may be easily extended to any UV radiation source.

Vitamin D serum level changes in psoriatic patients treated with narrowband ultraviolet B phototherapy are related to the season of the irradiation.

BACKGROUND: Vitamin D is produced in the human skin by short wavelength (290-315 nm) ultraviolet (UV) radiation. PURPOSE: The aim of the study was to investigate how outdoor conditions may influence the serum levels of 25(OH) vitamin D in psoriasis patients under narrowband ultraviolet B (UVB) phototherapy. METHODS: The winter and summer groups of patients received almost the same narrowband UV (nUVB) doses during whole-body phototherapy. The 25(OH)D serum concentration was measured before and after two series of 10 exposures. The cabinet doses were compared with potentially available cumulative solar doses. The solar doses (unweighted UVB and vitamin D effective dose) and duration of solar intensity sufficient to produce vitamin D were calculated using a model based on local atmospheric data. RESULTS: After an initial 10 nUVB treatments, 25(OH)D serum concentration increased by 68% for winter patients in relation to the level before therapy, whereas a 20% increase was found for the summer patients. The next 10 treatments caused a much lower increase in 25(OH)D concentration: 5% and 3.5% for the winter and summer patients, respectively. No statistically significant relationship was observed between post-therapy 25(OH)D serum concentration and solar radiation variability. CONCLUSIONS: The different baseline values of 25(OH)D serum levels in winter and summer patients result from seasonal variability in solar irradiance. Thus, outdoor solar radiation affects the patients over a much longer period, and artificial UV light is the main factor responsible for increase in 25(OH)D serum level over a 30-day period of cabinet therapy.