Health and economic effects of introducing single-dose or two-dose human papillomavirus vaccination in India

BACKGROUND

Cervical cancer is a major public health problem in India, where access to prevention programmes is low. The WHO-Strategic Advisory Group of Experts recently updated their recommendation for human papillomavirus (HPV) vaccination to include a single-dose option in addition to the two-dose option, which could make HPV vaccination programmes easier to implement and more affordable.

METHODS

We combined projections from a type-specific HPV transmission model and a cancer progression model to assess the health and economic effects of HPV vaccination at national and state level in India. The models used national and state-specific Indian demographic, epidemiological and cost data, and single-dose vaccine efficacy and immunogenicity data from the International Agency for Research on Cancer India vaccine trial with 10-year follow-up. We compared single-dose and two-dose HPV vaccination for a range of plausible scenarios regarding single-dose vaccine protection, coverage and catch-up. We used a healthcare sector payer perspective with a time horizon of 100 years.

RESULTS

Under the base-case scenario of lifelong protection of single-dose vaccination in 10-year-old girls with 90% coverage, the discounted incremental cost-effectiveness ratio (ICER) of nationwide vaccination relative to no vaccination was US$406 (₹INR30 000) per DALY (disability-adjusted life-years) averted. This lay below an opportunity-cost-based threshold of 30% Indian gross domestic product per capita in each Indian state (state-specific ICER range: US$67-US$593 per DALY averted). The ICER of two-dose vaccination versus no vaccination vaccination was US$1404 (₹INR104 000). The ICER of two-dose vaccination versus single-dose vaccination, assuming lower initial efficacy and waning of single-dose vaccination, was at least US$2282 (₹INR169 000) per DALY averted.

CONCLUSIONS

Nationwide introduction of single-dose HPV vaccination at age 10 in India is highly likely to be cost-effective whereas extending the number of doses from one to two would have a less favourable profile.

Reconstructing multi-strain pathogen interactions from cross-sectional survey data via statistical network inference

Infectious diseases often involve multiple pathogen species or multiple strains of the same pathogen. As such, knowledge of how different pathogens interact is key to understand and predict the outcome of interventions targeting only a subset of species or strains involved in disease. Population-level data may be useful to infer pathogen strain interactions, but most previously used inference methods only consider uniform interactions between all strains or focus on marginal pairwise interactions. As such, these methods are prone to bias induced by indirect interactions through other strains. Here, we evaluated statistical network inference for reconstructing heterogeneous interactions from cross-sectional surveys detecting joint presence/absence patterns of pathogen strains within hosts. We applied various network models to simulated survey data, representing endemic infection states of multiple pathogen strains with potential interactions in acquisition or clearance of infection. Satisfactory performance was demonstrated by the estimators converging to the true interactions. Accurate reconstruction of interaction networks was achieved by regularization or penalization for sample size. Although performance deteriorated in the presence of host heterogeneity, this was overcome by correcting for individual-level risk factors. Our work demonstrates how statistical network inference could prove useful for detecting multi-strain pathogen interactions and may have applications beyond epidemiology.

Building resilient cervical cancer prevention through gender-neutral HPV vaccination

The COVID-19 pandemic has disrupted HPV vaccination programmes worldwide. Using an agent-based model, EpiMetHeos, recently calibrated to Indian data, we illustrate how shifting from a girls-only (GO) to a gender-neutral (GN) vaccination strategy could improve the resilience of cervical cancer prevention against disruption of HPV vaccination. In the base case of 5-year disruption with no coverage, shifting from GO to GN strategy under 60% coverage (before disruption) would increase the resilience, in terms of cervical cancer cases still prevented in the disrupted birth cohorts per 100,000 girls born, by 2.8-fold from 107 to 302 cases, and by 2.2-fold from 209 to 464 cases under 90% coverage. Furthermore, shifting to GN vaccination helped in reaching the World Health Organization (WHO) elimination threshold. Under GO vaccination with 60% coverage, the age-standardised incidence rate of cervical cancer in India in the long term with vaccination decreased from 11.0 to 4.7 cases per 100,000 woman-years (above threshold), as compared to 2.8 cases (below threshold) under GN with 60% coverage and 2.4 cases (below threshold) under GN with 90% coverage. In conclusion, GN HPV vaccination is an effective strategy to improve the resilience to disruption of cancer prevention programmes and to enhance the progress towards cervical cancer elimination.

Approximating missing epidemiological data for cervical cancer through Footprinting: A case study in India

Local cervical cancer epidemiological data essential to project the context-specific impact of cervical cancer preventive measures are often missing. We developed a framework, hereafter named Footprinting, to approximate missing data on sexual behaviour, human papillomavirus (HPV) prevalence, or cervical cancer incidence, and applied it to an Indian case study. With our framework, we (1) identified clusters of Indian states with similar cervical cancer incidence patterns, (2) classified states without incidence data to the identified clusters based on similarity in sexual behaviour, (3) approximated missing cervical cancer incidence and HPV prevalence data based on available data within each cluster. Two main patterns of cervical cancer incidence, characterized by high and low incidence, were identified. Based on the patterns in the sexual behaviour data, all Indian states with missing data on cervical cancer incidence were classified to the low-incidence cluster. Finally, missing data on cervical cancer incidence and HPV prevalence were approximated based on the mean of the available data within each cluster. With the Footprinting framework, we approximated missing cervical cancer epidemiological data and made context-specific impact projections for cervical cancer preventive measures, to assist public health decisions on cervical cancer prevention in India and other countries.

Evidence-based impact projections of single-dose human papillomavirus vaccination in India: a modelling study

BACKGROUND

Despite the high burden of cervical cancer, access to preventive measures remains low in India. A single-dose immunisation schedule could facilitate the scale-up of human papillomavirus (HPV) vaccination, contributing to global elimination of cervical cancer. We projected the effect of single-dose quadrivalent HPV vaccination in India in comparison with no vaccination or to a two-dose schedule.

METHODS

In this modelling study, we adapted an HPV transmission model (EpiMetHeos) to Indian data on sexual behaviour (from the Demographic and Health Survey and the Indian National AIDS Control Organisation), HPV prevalence data (from two local surveys, from the states of Tamil Nadu and West Bengal), and cervical cancer incidence data (from Cancer Incidence in Five Continents for the period 2008-12 [volume XI], and the Indian National Centre for Disease Informatics and Research for the period 2012-16). Using the model, we projected the nationwide and state-specific effect of HPV vaccination on HPV prevalence and cervical cancer incidence, and lifetime risk of cervical cancer, for 100 years after the introduction of vaccination or in the first 50 vaccinated birth cohorts. Projections were derived under a two-dose vaccination scenario assuming life-long protection and under a single-dose vaccination scenario with protection duration assumptions derived from International Agency for Research on Cancer (IARC) India vaccine trial data, in combination with different vaccination coverages and catch-up vaccination age ranges. We used two thresholds to define cervical cancer elimination: an age-standardised incidence rate of less than 4 cases per 100 000 woman-years, and standardised lifetime risk of less than 250 cases per 100 000 women born.

FINDINGS

Assuming vaccination in girls aged 10 years, with 90% coverage, and life-long protection by two-dose or single-dose schedule, HPV vaccination could reduce the prevalence of HPV16 and HPV18 infection by 97% (80% UI 96-99) in 50 years, and the lifetime risk of cervical cancer by 71-78% from 1067 cases per 100 000 women born under a no vaccination scenario to 311 (80% UI 284-339) cases per 100 000 women born in the short term and 233 (219-252) cases per 100 000 women born in the long term in vaccinated cohorts. Under this scenario, we projected that the age-standardised incidence rate threshold for elimination could be met across India (range across Indian states: 1·6 cases [80% UI 1·5-1·7] to 4·0 cases [3·8-4·4] per 100 000 woman-years), while the complementary threshold based on standardised lifetime risk was attainable in 17 (68%) of 25 states, but not nationwide (range across Indian states: 207 cases [80% UI 194-223] to 477 cases [447-514] per 100 000 women born). Under the considered assumptions of waning vaccine protection, single-dose vaccination was projected to have a 21-100% higher per-dose efficiency than two-dose vaccination. Single-dose vaccination with catch-up for girls and women aged 11-20 years was more impactful than two-dose vaccination without catch-up, with reduction of 39-65% versus 38% in lifetime risk of cervical cancer across the ten catch-up birth cohorts and the first ten routine vaccination birth cohorts.

INTERPRETATION

Our evidence-based projections suggest that scaling up cervical cancer prevention through single-dose HPV vaccination could substantially reduce cervical cancer burden in India.

FUNDING

The Bill & Melinda Gates Foundation.

Approximate likelihood-based estimation method of multiple-type pathogen interactions: An application to longitudinal pneumococcal carriage data

While the serotypes of Streptococcus pneumoniae are known to compete during colonization in human hosts, our knowledge of how competition occurs is still incomplete. New insights of pneumococcal between‐type competition could be generated from carriage data obtained by molecular‐based detection methods, which record more complete sets of serotypes involved in co‐carriage than when detection is done by culture. Here, we develop a Bayesian estimation method for inferring between‐type interactions from longitudinal data recording the presence/absence of the types at discrete observation times. It allows inference from data containing co‐carriage of two or more serotypes, which is often the case when pneumococcal presence is determined by molecular‐based methods. The computational burden posed by the increased number of types detected in co‐carriage is addressed by approximating the likelihood under a multi‐state model with the likelihood of only those trajectories with minimum number of acquisition and clearance events between observation times. The proposed method's performance was validated on simulated data. The estimates of the interaction parameters of acquisition and clearance were unbiased in settings with short sampling intervals between observation times. With less frequent sampling, the estimates of the interaction parameters became more biased, but their ratio, which summarizes the total interaction, remained unbiased. Confounding due to unobserved heterogeneity in exposure could be corrected by including individual‐level random effects. In an application to empirical data about pneumococcal carriage in infants, we found new evidence for between‐serotype competition in clearance, although the effect size was small.

Capturing multiple-type interactions into practical predictors of type replacement following human papillomavirus vaccination

Current HPV vaccines target a subset of the oncogenic human papillomavirus (HPV) types. If HPV types compete during infection, vaccination may trigger replacement by the non-targeted types. Existing approaches to assess the risk of type replacement have focused on detecting competitive interactions between pairs of vaccine and non-vaccine types. However, methods to translate any inferred pairwise interactions into predictors of replacement have been lacking. In this paper, we develop practical predictors of type replacement in a multi-type setting, readily estimable from pre-vaccination longitudinal or cross-sectional prevalence data. The predictors we propose for replacement by individual non-targeted types take the form of weighted cross-hazard ratios of acquisition versus clearance, or aggregate odds ratios of coinfection with the vaccine types. We elucidate how the hazard-based predictors incorporate potentially heterogeneous direct and indirect type interactions by appropriately weighting type-specific hazards and show when they are equivalent to the odds-based predictors. Additionally, pooling type-specific predictors proves to be useful for predicting increase in the overall non-vaccine-type prevalence. Using simulations, we demonstrate good performance of the predictors under different interaction structures. We discuss potential applications and limitations of the proposed methodology in predicting type replacement, as compared to existing approaches. This article is part of the theme issue 'Silent cancer agents: multi-disciplinary modelling of human DNA oncoviruses'.

Human Papillomavirus Genotype Replacement: Still Too Early to Tell?

Background

Although human papillomavirus (HPV) vaccines are highly efficacious in protecting against HPV infections and related diseases, vaccination may trigger replacement by nontargeted genotypes if these compete with the vaccine-targeted types. HPV genotype replacement has been deemed unlikely, based on the lack of systematic increases in the prevalence of nonvaccine-type (NVT) infection in the first decade after vaccination, and on the presence of cross-protection for some NVTs.

Methods

To investigate whether type replacement can be inferred from early postvaccination surveillance, we constructed a transmission model in which a vaccine type and an NVT compete through infection-induced cross-immunity. We simulated scenarios of different levels of cross-immunity and vaccine-induced cross-protection to the NVT. We validated whether commonly used measures correctly indicate type replacement in the long run.

Results

Type replacement is a trade-off between cross-immunity and cross-protection; cross-immunity leads to type replacement unless cross-protection is strong enough. With weak cross-protection, NVT prevalence may initially decrease before rebounding into type replacement, exhibiting a honeymoon period. Importantly, vaccine effectiveness for NVTs is inadequate for indicating type replacement.

Conclusions

Although postvaccination surveillance thus far is reassuring, it is still too early to preclude type replacement. Monitoring of NVTs remains pivotal in gauging population-level impacts of HPV vaccination.

Occurrence of human papillomavirus (HPV) type replacement by sexual risk-taking behaviour group: Post-hoc analysis of a community randomized clinical trial up to 9 years after vaccination (IV)

Oncogenic non-vaccine human papillomavirus (HPV) types may conceivably fill the vacated ecological niche of the vaccine types. The likelihood of this may differ by the risk of acquiring HPV infections. We examined occurrence of HPV types among vaccinated and unvaccinated subgroups of 1992-1994 birth cohorts with differing acquisition risks up to 9 years post-implementation of HPV vaccination in 33 Finnish communities randomized to: Arm A (gender-neutral HPV16/18 vaccination), Arm B (girls-only HPV16/18 vaccination and hepatitis B-virus (HBV) vaccination of boys), and Arm C (gender-neutral HBV vaccination). Out of 1992-1994 born resident boys (31,117) and girls (30,139), 8,618 boys and 15,615 girls were vaccinated, respectively, with 20-30% and 50% coverage in 2007-2009. In 2010-2013, 8,868 HPV16/18 and non-HPV vaccinated females, and in 2014-2016, 5,574 originally or later (2010-2013) HPV16/18 vaccinated females attended two cervical sampling visits, aged 18.5 and 22-years. The samples were typed for HPV6/11/16/18/31/33/35/39/45/51/52/56/58/59/66/68 using PCR followed by MALDI-TOF MS. HPV prevalence ratios (PR) between Arms A/B vs. C were calculated for Chlamydia trachomatis positives (core-group), and negatives (general population minus core group). At both visits the vaccine-protected HPV type PRs did not significantly differ between the core-group and non-core group. Among the vaccinated 18-year-olds, HPV51 occurrence was overall somewhat increased (PR_core = 1.4, PR_non-core. = 1.4) whereas the HPV52 occurrence was increased in the core-group only (PR_core = 2.5, PR_non-core = 0.8). Among the non-HPV vaccinated 18-year-olds, the HPV51/52 PRs were higher in the core-group (PR_core = 3.8/1.8, PR_non-core = 1.2/1.1). The 22-year-olds yielded no corresponding observations. Monitoring of the sexual risk-taking core-group may detect early tendencies for HPV type replacement.

Late presentation of erythropoietic protoporphyria: case report and genetic analysis of family members

Erythropoietic protoporphyria (EPP) is an inherited disorder of haem biosynthesis caused by decreased activity of the enzyme ferrochelatase (FECH), which catalyses the insertion of iron into protoporphyrin, the last step in haem biosynthesis. Development of clinically overt EPP usually requires inheritance of a severe FECH mutation trans to a low-expression FECH variant (FECH IVS3-48C), which is present in 13% of the U.K. population. Reduced FECH activity leads to accumulation of protoporphyrin in various tissues. An excess amount of free protoporphyrin in the skin causes photosensitivity. EPP usually presents in early childhood or infancy, with painful burning and pruritus within minutes of light exposure. Onset of symptoms in adults is rare and often associated with acquired somatic mutation of the FECH gene secondary to haematological malignancy. Here we describe a patient with EPP, in whom the presenting clinical symptom, night-time itch, did not appear until middle age and who had an asymptomatic sister with the same FECH genotype.

The photocarcinogenic risk of narrowband UVB (TL-01) phototherapy: early follow-up data

BACKGROUND

Limited information is available on the carcinogenic risk associated with narrowband TL-01 UVB phototherapy in humans.

OBJECTIVES

To determine the skin cancer incidence in a population treated with TL-01 phototherapy.

PATIENTS AND METHODS

All TL-01-treated patients were identified from the departmental computerized database. Patients with malignant melanoma (MM), squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) were identified by record linkage with the Scottish Cancer Registry. The incidence of each was compared with the normal Scottish population matched for age and sex.

RESULTS

Data were obtained from 1908 patients. The median follow-up duration was 4 years (range 0.04-13). The median cumulative number of TL-01 treatments and dose were 23 (1-199) and 13 337 (30-284 415) mJ cm(-2), respectively. No increased incidence of SCC or MM was observed. Ten patients developed BCC compared with an expected 4.7 in the Scottish population [standardized rate ratio 213 (95% confidence interval 102-391); P < 0.05].

CONCLUSIONS

A small but significant increase of BCC was detected in the TL-01 group. This could be explained by a number of factors, including ascertainment bias. To determine the true carcinogenic risk of TL-01 phototherapy, longer follow-up is essential.

The optimal time to determine the minimal phototoxic dose in skin photosensitized by topical 8 methoxypsoralen

BACKGROUND

We recently investigated the characteristics of psoralen plus ultraviolet (UV) A erythema in skin photosensitized by topical 8-methoxypsoralen (8-MOP) in three independent studies.

OBJECTIVES

In order to determine the optimal time to read the minimal phototoxic dose (MPD) after treatment with topical 8-MOP and irradiation with UVA, we assessed the overall data.

METHODS

One forearm of each subject was immersed in 8-MOP solution for 15 min and test sites on the flexor surface of the forearm were immediately exposed to a UVA dose series. Erythema was assessed visually and objectively using a reflectance instrument at 24-h intervals for 7 days.

RESULTS

Results were obtained from 44 subjects (predominantly Fitzpatrick skin phototype II). A broad erythemal plateau was evident beyond 72 h and the visual MPD was significantly lower at 96, 120 and 144 h than at 72 h (P < 0.01). Only 30% of subjects were at peak erythema at the conventional MPD assessment time of 72 h. The median time to reach maximal erythema was 96 h (range 48-144). Objectively, 85% of subjects were at peak erythema at or beyond 96 h.

CONCLUSIONS

We recommend that (i) the optimal time to read the topical 8-MOP MPD is 4 days after UVA exposure as readings beyond this time may be difficult to interpret because of the development of pigmentation, and (ii) 40% of the topical 8-MOP MPD should be considered for the first treatment.

Whole-body UVB (TL-01) or UVA-1 irradiation does not alter the levels of immunomodulatory cytokines in the serum of human volunteers

BACKGROUND/PURPOSE

Ultraviolet (UV) exposure of mammalian skin induces local and systemic immunosuppression. In mice it has been proposed that systemic immunosuppression is mediated by an UV-induced cytokine cascade involving systemic interleukin (IL)-4 and IL-10 and a reduction in IL-12 activity. To investigate whether there was a parallel mechanism in humans we examined the effect of whole-body narrowband ultraviolet B (UVB) (311-313 nm; TL-01) and ultraviolet A (UVA)-1 (340-400 nm) on serum cytokine levels.

METHODS/RESULTS

In a first study, five male psoriatic subjects were whole-body irradiated with three sessions of a standard UVB (TL-01) phototherapy regimen previously shown to cause downregulation of natural killer cell activity and T helper 1 (Th1) and Th2 cytokine production by peripheral blood mononuclear cells. Enzyme-linked immunoabsorbent assay (ELISA) of sera taken before and after the third session showed no effect of phototherapy on IL-10 and tumour necrosis factor-alpha (TNF-alpha). In a second study, five healthy subjects received three whole-body exposures of UVB (TL-01) and five other healthy subjects received three exposures of UVA-1 on alternate days (total 22 J/cm(2)). Blood samples were taken before the first irradiation and at 0, 4, 8, 12, 14, 24 and 48 h after the third irradiation. The sera were subsequently analysed for IL-10, IL-12, IL-8, IL-1beta and TNF-alpha, by ELISA. The levels of IL-1beta and TNF-alpha were below detection limits (<5 pg/ml), while no significant change in the levels of IL-10, IL-12 or IL-8 was detected as a result of either TL-01 or UVA-1.

CONCLUSIONS

It seems unlikely that a modulation in these circulating cytokines assessed in this study accounts for systemic UV-induced immunosuppression in human subjects.

Photoinduced pompholyx: a report of 5 cases

We describe 5 patients whose histories and investigation findings point toward a diagnosis of photo-induced hand pompholyx, a previously unreported condition. Several factors have been associated with the exacerbation of pompholyx, but no direct relationship with sunlight exposure has been reported.

An intraindividual comparative study of psoralen-UVA erythema induced by bath 8-methoxypsoralen and 4, 5', 8-trimethylpsoralen

BACKGROUND

Limited work has been conducted on the characteristics of topical trimethylpsoralen (TMP) psoralen-UVA (PUVA) erythema.

OBJECTIVE

We sought to determine the time-course and dose-response characteristics of erythema induced by topical TMP, and to compare these parameters with those for topical 8-methoxypsoralen (MOP) within patients.

METHODS

After photosensitization of one forearm with topical TMP, test sites were exposed to a UVA dose series. The procedure was repeated on the other forearm using 8-MOP solution. Erythema was assessed visually and with a reflectance instrument every 24 hours for 7 days.

RESULTS

TMP PUVA erythema followed a similar time course to 8-MOP PUVA erythema. The majority of patients were at maximal erythema at or beyond 96 hours. TMP PUVA had a significantly steeper dose-response curve at 48, 72, and 96 hours compared with 8-MOP PUVA.

CONCLUSION

On the basis of these data, the optimal time to read the TMP minimal phototoxic dose is 96 hours. In view of the steeper dose-response curve for TMP PUVA, a lower UVA incremental regimen should be considered compared with that for 8-MOP PUVA.

An intraindividual study of the characteristics of erythema induced by bath and oral methoxsalen photochemotherapy and narrowband ultraviolet B

We compared the characteristics of psoralen and ultraviolet A (PUVA) erythema in skin photosensitized by bath or oral methoxsalen in 20 subjects. Erythema was assessed visually and with a reflectance instrument at 24 h intervals for 7 days. In addition, narrowband ultraviolet B (TL-01 UVB) erythema was examined in 19 of these subjects at 4, 8, 12, 24, 48 and 72 h and in another nine subjects at 12, 15, 18, 21 and 24 h. Both bath and oral PUVA exhibited broad erythemal peaks beyond 72 h. For topical PUVA the lowest minimal phototoxic dose (MPD) occurred at 120 and 144 h (P = 0.01 and 0.03 compared with 72 h). Oral PUVA erythema peaked earlier at 96 h: the MPD was significantly lower at 96, 120 and 144 h compared with 72 h (P = 0.001, 0.01 and 0.02, respectively). At 120 h, bath PUVA had a significantly steeper slope compared with oral PUVA. The TL-01 UVB minimal erythema dose was significantly lower at 12 h compared with 24 h (P = 0.019). The majority of subjects were at maximal erythema at 12 h (22 of 28) and 15 h (eight of nine). Our results suggest that peak erythema for bath PUVA, oral PUVA and TL-01 UVB occurs at 120, 96 and 12-15 h, respectively.

A randomized controlled trial of narrowband ultraviolet B vs bath-psoralen plus ultraviolet A photochemotherapy for psoriasis

BACKGROUND

In 1991, consensus guidelines recommended psoralen plus ultraviolet A photochemotherapy (PUVA) for those requiring second-line therapy for psoriasis. Narrowband (TL-01) UVB has since become more widely available, replacing the less effective broadband sources. Objectives To compare the efficacy of TL-01 UVB phototherapy and trimethoxypsoralen (TMP) bath-PUVA for chronic plaque psoriasis.

PARTICIPANTS AND METHODS

A randomized, observer-masked, intraindividually controlled, paired (half-body) study was done in the Photo(chemo)therapy Unit in Ninewells Hospital and Medical School, Dundee. The study comprised 28 patients (skin phototypes I-III) with chronic plaque psoriasis. Each patient's body halves (sagittal plane) were treated independently, one-half with TL-01 UVB, the other with bath-PUVA. Both treatments were administered according to standard, optimized regimens. Treatment was continued until clearance or minimal residual activity (MRA), or a maximum of 30 treatments. The main outcome measures were treatments and time to clearance/MRA, the proportion reaching clearance/MRA, change in psoriasis severity score (scaling, erythema and induration) and remission durations.

RESULTS

Of 18 who completed the study, all reached clearance/MRA with TL-01, but three were still not clear after 30 PUVA exposures. TL-01 achieved clearance/MRA a median of 11 (6.5-25; P = 0.001) days more quickly than PUVA, but required a median of 24.5 compared with 19 exposures [95% confidence interval (CI) for difference 1.5-5.5; P = 0.01]. Ten patients were withdrawn (four because of inadequate response of PUVA-treated halves). Analysed on an intention-to-treat basis, 21 of 28 (75%) of all participants reached clearance/MRA with TL-01 compared with 15 of 28 (54%) with PUVA (95% CI for difference 4-37%; P = 0.03). Remission durations did not differ.

CONCLUSIONS

When administered according to these regimens in a skin phototype I-III population, TL-01 UVB is more efficacious than TMP bath-PUVA in the treatment of chronic plaque psoriasis.

The time course of topical PUVA erythema following 15- and 5-minute methoxsalen immersion

BACKGROUND

Limited data exist in the literature concerning the characteristics of erythema following psoralen UV-A (PUVA) treatment using topical methoxsalen. To optimize the phototherapeutic regimen and reduce short- and long-term risks, knowledge of such basic information is essential.

OBSERVATIONS

The characteristics of PUVA erythema following 15- and 5-minute immersion in methoxsalen was determined. The PUVA erythema after 15-minute methoxsalen immersion exhibited a broad peak, with the lowest median minimal phototoxic dose (MPD) at 96, 120, and 144 hours after UV-A irradiation. Seventy-three percent of subjects experienced peak erythema at 120 hours compared with only 45% at 72 hours. From the dose-response data, an increase in the erythema index of 0.025 (equivalent to the MPD) was significantly lower when determined at 120 hours after UV-A irradiation than at 72 hours (P =.03). The median maximum slope of the dose-response curve occurred at 144 hours. After 5-minute immersion, PUVA erythema displayed a broad peak from 72 hours. Erythema summation scores followed a trend similar to that of 15-minute immersion, but the intensity was significantly reduced.

CONCLUSIONS

Methoxsalen-UV-A erythema exhibited a broad plateau between 96 and 144 hours, with most subjects at peak erythema at 120 hours. Reduction of methoxsalen immersion time significantly lowered the erythemal intensity. Minimum phototoxic dose reading at 72 hours underestimates the phototoxic effect of topical methoxsalen PUVA, and a change in the MPD assessment time should be considered.

The Children's Dermatology Life Quality Index: validation of the cartoon version

BACKGROUND

In 1995 the Children's Dermatology Life Quality Index (CDLQI) was developed as a tool to allow quality of life assessment of children with skin conditions. This initial questionnaire was in a written format.

OBJECTIVES

Using the same validated questions, a full-colour cartoon version has been developed. The aim of this study was to validate this against the initial written questionnaire in a three-part study.

METHODS

The first part of the study piloted the use of both versions in an outpatient setting. One hundred and one children completed both versions of the CDLQI in a random order. A further 66 children completed the cartoon CDLQI in outpatients, and subsequently completed the cartoon version on the same day at home, which was returned by post. The scores were compared. In the second part, in more controlled conditions to eliminate parental and investigator bias, 107 children with current dermatological problems were administered both versions of the CDLQI in a random order. The scores were analysed, and time to complete each version, and the child and parental preferences, were recorded. The third part assessed compliance by asking 546 children recently reviewed in dermatology clinics to return a single completed postal CDLQI. Half of the children were given the text, and half the cartoon version.

RESULTS

The median age of participating children was 11 years. There was no significant difference in scores between the two versions in both parts 1 and 2, but the cartoon version was completed faster (median 90 s) than the written version (median 120 s) (P < 0.0001). Both children and their parents significantly preferred the cartoon version and found it easier to use. Forty-six per cent of the postal CDLQI questionnaires were returned; there was no difference in compliance between the two versions.

CONCLUSIONS

The cartoon CDLQI is equivalent to the previously validated written CDLQI version, but is faster and easier for children to use, and is preferred by both children and parents.

Time course of PUVA erythema

Optimization of the PUVA regime requires knowledge of the time-course and dose-response characteristics of PUVA erythema. Although existing guidelines recommend determination of the minimal phototoxic dose (MPD) 72 hours after UVA exposure and treatment administered 72 hours apart, recent evidence suggests that maximal PUVA erythema occurs beyond this time point, and hence the current assessment time underestimates the phototoxic effect of PUVA. This report reviews the current literature, including the authors' own experience of the characteristics of PUVA erythema, and recommends that the optimal time to read the PUVA MPD is 96 h.

UV-B phototherapy clears psoriasis through local effects

OBJECTIVE

To determine if UV-B phototherapy clears psoriasis through systemic effects.

DESIGN

Randomized, within-subject comparison of change in psoriasis in 3 plaques in patients attending for whole-body UV-B therapy. Change in patients' psoriasis plaques covered during UV-B treatment was compared with plaques in an untreated control group.

SETTING

University hospital phototherapy unit.

PATIENTS

The study population comprised 17 patients with chronic plaque psoriasis treated with UV-B and 24 psoriasis control patients awaiting UV-B phototherapy.

INTERVENTIONS

Treatment with a standard 3-times weekly narrowband TL-01 UV-B regimen. Three similar plaques were randomly allocated to be covered every treatment, covered for 2 of 3 weekly treatments, and exposed to local UV-B every treatment. Similar plaques were selected in control patients (awaiting but not yet started UV-B therapy). Severity of psoriasis plaques was assessed using a scaling, erythema, and induration (SEI) scoring system.

MAIN OUTCOME MEASURES

Change in SEI score of the selected plaques over the complete treatment course for UV-B-treated patients and change over 3 weeks in SEI score of plaques covered during UV-B treatment compared with that of plaques in controls.

RESULTS

There was a significant (P<.001) difference in how much the SEI score changed in the 3 plaques in UV-B-treated patients. It fell by a mean of 7.6 for uncovered plaques compared with 3.2 for plaques covered during each UV-B exposure (95% confidence interval for difference, 3.0 to 5.8). In patients awaiting UV-B, SEI score of plaques fell by a mean of 0.4 over 3 weeks, compared with a mean fall of 1.4 for covered plaques in UV-B-treated patients (95% confidence interval for difference in means, 0.1 to 2.0).

CONCLUSIONS

If UV-B therapy has any systemic effect capable of improving psoriasis, this effect is small and unlikely to be of clinical importance. It is insufficient to alter interpretation of findings of within-subject comparative phototherapy studies. UV-B phototherapy works for chronic plaque psoriasis through local effects.

Time course of skin photosensitivity following trimethylpsoralen bath PUVA

One aspect of bath photochemotherapy (PUVA) that requires clarification is the duration of psoralen-induced cutaneous photosensitisation under conditions simulating clinical use. Using a half back comparison study technique, we investigated the persistence of trimethylpsoralen (TMP)-induced photosensitivity in skin irradiated to simulate a first PUVA exposure compared with un-irradiated skin. Baseline UVA minimal erythema dose and minimal phototoxic dose (MPD) were determined in 13 healthy volunteers. After readings at 72 h, subjects were bathed in TMP bath water for 15 min and one half of the back was immediately exposed to 40% of the MPD. Test sites (1.5 cm2) on both halves of the back were then irradiated with a UVA dose series at 15 min, 5, 10, 24, 34, 48 and 72 h after the bath. MPD readings were recorded visually at 72 h after each UVA exposure. The UVA MED was >25 J/cm2 in all the subjects. At each time point, a phototoxic index (PI) was calculated as UVA MED/MPD. In un-irradiated skin, photosensitivity returned to normal (PI=1) within 24 h after the TMP bath. In contrast, skin pre-irradiated to simulate the first PUVA treatment was still significantly photosensitive (PI=2.3; P=0.002) at 48 h. Contrary to previous recommendations, these data suggest that patients should be advised to avoid ambient or artificial sources of UVA throughout their course of TMP bath PUVA to reduce the risk of phototoxic erythema.

Hydroa vacciniforme: A clinical and follow-up study of 17 cases

BACKGROUND

Hydroa vacciniforme (HV) is a rare, sporadic, idiopathic photodermatosis characterized by vesicles and crust formation after sunlight exposure. The lesions typically heal with vacciniform scarring.

OBJECTIVE

We identify and review the clinical features and follow-up data of Scottish patients with HV and report on the prevalence of this condition. This is the largest recent study of HV patients from a single center.

METHODS

In this retrospective study, patients with HV were identified by means of the diagnostic database from the Photobiology Unit, Dundee. Patients were contacted and details of clinical features, duration of disease, results of investigations, and treatment were recorded. At review, disease progress was assessed.

RESULTS

Between 1973 and 1997, 17 patients (9 males and 8 females) with a diagnosis of HV were investigated. Data from 15 patients showed a mean age at onset of 7.9 years (range, 1 to 16 years), with females (mean, 6.7 years; range, 2 to 12 years) having an earlier onset than males (mean, 8.7 years; range, 1 to 16 years). A bimodal age distribution was also identified with onsets between the ages of 1 and 7 years and 12 and 16 years. At review, spontaneous clearing had occurred in 9 patients (60%) with mean duration of disease being 9 years (range, 4 to 17 years). Males had longer disease duration (mean, 11 years; range, 5 to 17 years) than females (mean, 5 years; range, 4 to 7 years). Eight patients (53%) were sensitive in the UVA wave-band on monochromator phototesting, and 6 (40%) experienced papulovesicular lesions on repetitive broad-spectrum UVA irradiation. All patients received broad-spectrum sunscreens with variable results. Of the 5 patients treated with narrow-band UVB (TL-01) phototherapy, 3 reported beneficial results with an increase in tolerance to sunlight exposure and associated reduction in disease severity.

CONCLUSION

The estimated prevalence of HV was at least 0.34 cases per 100,000 with an approximately equal sex ratio. Males had a later onset and longer duration of disease than females. Phototesting showed abnormal responses in the UVA wavebands in 53% of cases, whereas 60% of patients treated with prophylactic TL-01 phototherapy found it beneficial.

Out-patient parenteral antimicrobial therapy--a viable option for the management of cutaneous leishmaniasis

Cutaneous infection with Leishmania braziliensis complex requires treatment with parenteral pentavalent antimonials to prevent development of mucocutaneous leishmaniasis. Patients with imported disease are usually managed in hospital because of concerns over drug toxicity. This study describes the clinical features and outcome of infection treated in the UK in an out-patient setting. Thirteen marines (aged 19-35 years) who acquired leishmaniasis in Belize were studied prospectively. Three had at least two lesions (0. 6-3 cm diameter), eight had regional lymphadenopathy and one had localized painless lymphatic thickening. Histology for amastigotes and PCR for Leishmania braziliensis complex was positive in all. Culture was positive in six. Patients received 1.5-2 g (mean 1.7 g) (20 mg/kg) sodium stibogluconate intravenously daily for 20 days. All developed transient musculoskeletal symptoms and asymptomatic hepatitis. Eleven developed biochemical pancreatitis, and one thrombocytopenia. Three developed transient ECG changes and one herpes zoster. There were four device-related infections, two requiring hospitalization (one required surgical drainage of an abscess). All lesions re-epithelialized. A total of 250 bed-days were saved over a 67-day period. These results indicate that in selected patients, out-patient therapy for cutaneous leishmaniasis with parenteral high-dose sodium stibogluconate may be appropriate, provided there is adequate monitoring of therapy.

Artificial hardening for polymorphic light eruption: practical points from ten years' experience

The conservative approach of sunlight avoidance and broad-spectrum sunscreen is often disappointing in patients with moderate to severe polymorphic light eruption. A springtime course of prophylactic artificial hardening with ultraviolet B (UVB) phototherapy or psoralen plus ultraviolet A (PUVA) photochemotherapy will often allow patients to tolerate more sunlight and give them greater freedom during the summer. In this retrospective study we describe ten years' experience of such "desensitization" treatment. Individualized therapy with attention to detail will maximize the effectiveness of this treatment.

Fluoroquinolone phototoxicity: a comparison of moxifloxacin and lomefloxacin in normal volunteers

Moxifloxacin, a broad-spectrum fluoroquinolone with the methoxy group at position 8 of the quinolone structure that is believed to confer reduced phototoxicity, was investigated in 32 healthy human male volunteers by a randomized double-blind placebo and positive control (lomefloxacin) phototest technique. A comparison of pre- and on-drug photosensitivity levels tested with an irradiation monochromator using relevant sunlight wavelengths, failed to demonstrate phototoxicity after administration of either placebo or moxifloxacin (200 mg or 400 mg/day) for 7 days. As expected, lomefloxacin (400 mg/day) phototoxicity was revealed at the UVA wavebands 335 +/- 30 nm and 365 +/- 30 nm (maximal at 24 h), with a phototoxic index of 3-4. The susceptibility to this effect rapidly normalized within 48 h of stopping the drug. No special protection from UVA wavelengths is necessary for those taking moxifloxacin.

The photosensitivity dermatitis and actinic reticuloid syndrome (chronic actinic dermatitis) occurring in seven young atopic dermatitis patients

Seven young patients with atopic dermatitis (AD) who presented with a marked photoexposed site dermatitis have been investigated in detail. The results of phototesting, patch testing and other investigations were compatible with the diagnosis of photosensitivity dermatitis/actinic reticuloid syndrome (PD/AR) (chronic actinic dermatitis). It is known that AD patients may have photoaggravation of their dermatitis or exacerbation secondary to a photodermatosis, such as polymorphic light eruption, actinic prurigo or drug-induced phototoxicity. The patients we describe, however, appear to be an uncommon AD subgroup affected by PD/AR. We recommend that all AD patients who have a history of sunlight-induced exacerbation or marked intolerance of PUVA or ultraviolet B phototherapy should have phototesting and patch testing conducted.

Lipidogram structure and the exercise capacity in obesity

30 women, aged between 21 and 52, with 2nd and 3rd grade obesity were investigated. Total lipids, total cholesterol, HDL cholesterol, tryglicerides and lipoprotein electrophoretic fractions from blood plasma were determined. The subjects were tested at a submaximal exercise intensity of a triangular type on the ergometric bicycle, starting from zero Watt to a progressive increasing load of 10 Watt/min., till the maximal optimal heart rate was reached. The heart rate, blood pressure, CO2 produced and O2 consumption were determined at rest, during exercise at each step, and in the recovery period, predicted the maximum oxygen consumption, evaluated by the Astrand method. The subjective sensation concerning the effort was taken into consideration, based on the modified Borg scale and adaptability to exercise was evaluated, expressed by the "adaptability coefficient" (AC). The index of correlation between the plasma lipid fractions and AC was also determined. Lipidograma showed modifications of 94.44 percent of which 27.77 percent belonged to type IV of H-LP. AC diminished to 50.2 percent as opposed to the ideal values; the maximum oxygen consumption was diminished as well, with an important functional aerobic impairment. There was not found a statistically significant correlation between plasma lipid fractions and AC.

Atherogenic risk in obese and in diabetic children

By a complex biochemical, immunologic, morphohistochemical and ultrastructural study, carried out on a group of 42 obese and 38 diabetic children, comparatively with 12 normal controls, the authors arrive at conclusions which prove that obesity and diabetes mellitus carry great atherogenic risk factors. Even though the intimate atherogenesis mechanism is not perfectly known, the abnormal values of insulinemia, lipidemia and cortisolemia are certainly involved in this process. In diabetes mellitus the immunologic factor is also involved. Microangiopathy in diabetes mellitus and capillary lesions in the adipose tissue of obese children may also represent atherogenic risk factors. An efficient prophylaxis in atherosclerosis must therefore begin in childhood.