Serial QuantiFERON-TB Gold In-Tube assay and tuberculin skin test to diagnose latent tuberculosis in household Mexican contacts: conversion and reversion rates and associated factors using conventional and borderline zone definitions

A cohort of 123 adult contacts was followed for 18‐24 months (86 completed the follow-up) to compare conversion and reversion rates based on two serial measures of QuantiFERON (QFT) and tuberculin skin test (TST) (PPD from TUBERSOL, Aventis Pasteur, Canada) for diagnosing latent tuberculosis (TB) in household contacts of TB patients using conventional (C) and borderline zone (BZ) definitions. Questionnaires were used to obtain information regarding TB exposure, TB risk factors and socio-demographic data. QFT (IU/mL) conversion was defined as <0.35 to ≥0.35 (C) or <0.35 to >0.70 (BZ) and reversion was defined as ≥0.35 to <0.35 (C) or ≥0.35 to <0.20 (BZ); TST (mm) conversion was defined as <5 to ≥5 (C) or <5 to >10 (BZ) and reversion was defined as ≥5 to <5 (C). The QFT conversion and reversion rates were 10.5% and 7% with C and 8.1% and 4.7% with the BZ definitions, respectively. The TST rates were higher compared with QFT, especially with the C definitions (conversion 23.3%, reversion 9.3%). The QFT conversion and reversion rates were higher for TST ≥5; for TST, both rates were lower for QFT <0.35. No risk factors were associated with the probability of converting or reverting. The inconsistency and apparent randomness of serial testing is confusing and adds to the limitations of these tests and definitions to follow-up close TB contacts.

Mycobacterium tuberculosis epitope-specific interferon-g production in healthy Brazilians reactive and non-reactive to tuberculin skin test

The interferon (IFN)-γ response to peptides can be a useful diagnostic marker of Mycobacterium tuberculosis (MTB) latent infection. We identified promiscuous and potentially protective CD4+ T-cell epitopes from the most conserved regions of MTB antigenic proteins by scanning the MTB antigenic proteins GroEL2, phosphate-binding protein 1 precursor and 19 kDa antigen with the TEPITOPE algorithm. Seven peptide sequences predicted to bind to multiple human leukocyte antigen (HLA)-DR molecules were synthesised and tested with IFN-γ enzyme-linked immunospot (ELISPOT) assays using peripheral blood mononuclear cells (PBMCs) from 16 Mantoux tuberculin skin test (TST)-positive and 16 TST-negative healthy donors. Eighty-eight percent of TST-positive donors responded to at least one of the peptides, compared to 25% of TST-negative donors. Each individual peptide induced IFN-γ production by PBMCs from at least 31% of the TST-positive donors. The magnitude of the response against all peptides was 182 ± 230 x 106 IFN-γ spot forming cells (SFC) among TST-positive donors and 36 ± 62 x 106 SFC among TST-negative donors (p = 0.007). The response to GroEL2 (463-477) was only observed in the TST-positive group. This combination of novel MTB CD4 T-cell epitopes should be tested in a larger cohort of individuals with latent tuberculosis (TB) to evaluate its potential to diagnose latent TB and it may be included in ELISPOT-based IFN-γ assays to identify individuals with this condition.

PAR2 absence completely rescues inflammation and ichthyosis caused by altered CAP1/Prss8 expression in mouse skin.

Altered serine protease activity is associated with skin disorders in humans and in mice. The serine protease channel-activating protease-1 (CAP1; also termed protease serine S1 family member 8 (Prss8)) is important for epidermal homeostasis and is thus indispensable for postnatal survival in mice, but its roles and effectors in skin pathology are poorly defined. In this paper, we report that transgenic expression in mouse skin of either CAP1/Prss8 (K14-CAP1/Prss8) or protease-activated receptor-2 (PAR2; Grhl3(PAR2/+)), one candidate downstream target, causes epidermal hyperplasia, ichthyosis and itching. K14-CAP1/Prss8 ectopic expression impairs epidermal barrier function and causes skin inflammation characterized by an increase in thymic stromal lymphopoietin levels and immune cell infiltrations. Strikingly, both gross and functional K14-CAP1/Prss8-induced phenotypes are completely negated when superimposed on a PAR2-null background, establishing PAR2 as a pivotal mediator of pathogenesis. Our data provide genetic evidence for PAR2 as a downstream effector of CAP1/Prss8 in a signalling cascade that may provide novel therapeutic targets for ichthyoses, pruritus and inflammatory skin diseases.

No major impact of skin aging on the response of skin blood flow to a submaximal local thermal stimulus

La peau est sujette à un vieillissement intrinsèque (processus naturel et chronologique) et extrinsèque (processus induit par l'environnement et notamment les rayons UV). Plusieurs études ont montré que le vieillissement cutané s'accompagne d'une réduction de la densité capillaire au sein du derme et d'une dégradation de plusieurs protéines de la matrice extracellulaire. Cette atteinte morphologique est associée à une diminution de la capacité vasodilatatrice maximale de la microcirculation dermique et en particulier, de la réponse maximale du flux sanguin cutané à un échauffement local de la surface cutanée à des températures avoisinant les 43-44°C. Cette réponse, appelée hyperémie locale induite par la chaleur (local thermal hyperemia), est facilement mesurable par des investigations non invasives, telles que le laser Doppler. Nous avons entrepris cette étude afin d'investiguer les effets de l'âge sur la réactivité de la microcirculation dermique dans des zones cutanées exposées différemment aux rayons UV. Pour ce faire, nous avons étudié, chez des patients jeunes (18 à 30 ans, n=13) et des patients âgés (> 60 ans, n=13), la vasodilatation cutanée induite par réchauffement local de la peau, au niveau de 3 sites anatomiques différents (la cuisse, l'avant- bras et le front). Les mesures ont été effectuées au moyen d'un laser Doppler. Pour chaque sujet et chaque site, la température cutanée fut tout d'abord amenée à 34°C par 2 corps de chauffe (A et B), disposés de manière adjacente sur la peau. La température fut ensuite augmentée à 39°C (corps de chauffe A) et à 41°C (corps de chauffe B) pour une durée de 30 minutes, dans l'optique d'induire une vasodilatation sous- maximale. Ensuite, la température fut augmentée à 43 °C (corps de chauffe A et B) pour 15 minutes supplémentaires. Enfin, la vasodilatation maximale a été induite par un échauffement local à 44°C pour 15 minutes supplémentaires (corps de chauffe A et B). L'enregistrement séquentiel du flux sanguin cutané, effectué chaque minute par laser Doppler imager, donne des images sur lesquelles peut être calculé le flux sanguin cutané (unités de perfusion, PU). Par la suite, nous avons calculé les conductances vasculaires cutanées (CVC), en divisant le flux sanguin (PU) par la tension artérielle moyenne (mmHg), afin de permettre une normalisation entre les différents sujets. Les CVC, évaluées au temps de départ (température 34°C) et après vasodilatation maximale (température 44°C), étaient plus hautes au niveau du front qu'au niveau des 2 autres sites anatomiques. Sur les 3 sites, la CVC maximale (température 44°C) diminuait avec l'âge mais de façon moins importante au niveau du front, en comparaison avec les 2 autres sites. La réponse aux températures sous-maximales (température 39 et 41°C), exprimée en pourcentage de la CVC maximale, ne variait pas avec l'âge ni en fonction du site anatomique étudié. En conclusion, cette étude est la première à étudier simultanément l'hyperémie locale induite par la chaleur sur 3 sites ayant une exposition différente aux rayons UV. Le processus utilisé (laser Doppler imager) est également unique dans la littérature concernant les altérations de la microcirculation cutanée en lien avec l'âge. Cette étude confirme ainsi que le vieillissement cutané intrinsèque et/ou extrinsèque réduit la capacité vasodilatatrice maximale de la microcirculation dermique. Par contre, la réactivité à réchauffement local à des températures moindres ne semble pas être affectée.

Comparison of skin microvascular reactivity with hemostatic markers of endothelial dysfunction and damage in type 2 diabetes.

AIM: Patients with non-insulin-dependent diabetes mellitus (NIDDM) are at increased cardiovascular risk due to an accelerated atherosclerotic process. The present study aimed to compare skin microvascular function, pulse wave velocity (PWV), and a variety of hemostatic markers of endothelium injury [von Willebrand factor (vWF), plasminogen activator inhibitor-1 (PAI-1), tissue plasminogen activator (t-PA), tissue factor pathway inhibitor (TFPI), and the soluble form of thrombomodulin (s-TM)] in patients with NIDDM. METHODS: 54 patients with NIDDM and 38 sex- and age-matched controls were studied. 27 diabetics had no overt micro- and/or macrovascular complications, while the remainder had either or both. The forearm skin blood flow was assessed by laser-Doppler imaging, which allowed the measurement of the response to iontophoretically applied acetylcholine (endothelium-dependent vasodilation) and sodium nitroprusside (endothelium-independent vasodilation), as well as the reactive hyperemia triggered by the transient occlusion of the circulation. RESULTS: Both endothelial and non-endothelial reactivity were significantly blunted in diabetics, regardless of the presence or the absence of vascular complications. Plasma vWF, TFPI and s-TM levels were significantly increased compared with controls only in patients exhibiting vascular complications. Concentrations of t-PA and PAI-1 were significantly increased in the two groups of diabetics versus controls. CONCLUSION: In NIDDM, both endothelium-dependent and -independent microvascular skin reactivity are impaired, whether or not underlying vascular complications exist. It also appears that microvascular endothelial dysfunction is not necessarily associated in NIDDM with increased circulating levels of hemostatic markers of endothelial damage known to reflect a hypercoagulable state.

No implication of thromboxane prostanoid receptors in reactive hyperemia of skin and skeletal muscle in human forearm.

There is evidence that reactive hyperemia (ie, the transient increase of blood flow above resting level after a short period of ischemia) could be negatively modulated by vasoconstrictor prostanoids. The present study tested whether pharmacological blockade of the thromboxane prostanoid receptors with the specific antagonist S18886 (terutroban) would amplify reactive hyperemia in human skin and skeletal muscle. Twenty healthy young male volunteers were enrolled in a randomized, blinded, crossover trial of oral S18886 30 mg/d for 5 days versus placebo. Reactive hyperemia was evaluated in forearm skin and skeletal muscle, after occlusion of the brachial artery with a pneumatic cuff inflated at suprasystolic pressure. Blood flow was measured with laser Doppler imaging (skin) and strain gauge venous occlusion plethysmography (muscle). On the first and last day of each treatment period, recordings of reactive hyperemia were obtained immediately before and 2 hours after drug intake. Whether in forearm muscle or skin, S18886 had no discernible effect on peak postocclusion blood flow, nor on the global hyperemic response as quantified by the area under curve. These results do not support that thromboxane prostanoid receptor activation could exert a moderating influence on reactive hyperemia in human skin and skeletal muscle, at least in young subjects.

Diagnosis of latent tuberculosis in patients with systemic lupus erythematosus: T.SPOT.TB versus tuberculin skin test.

Early studies in patients with systemic lupus erythematosus (SLE) reported increased incidence of tuberculosis. The tuberculin skin test (TST) is the technique of choice to detect latent tuberculosis infection (LTBI) but has several limitations. OBJECTIVES We compared TST and the newer T.SPOT.TB test to diagnose LTBI in SLE patients. METHODS In this observational cohort study conducted between August 2009 and February 2012, we recruited 92 patients from those attending the SLE clinic of our university hospital. Data recorded were epidemiological and sociodemographic characteristics. Laboratory analyses included TST and T.SPOT.TB tests. RESULTS Of the patients studied, 92% were women with an average age of 42.7 years. Overall, the degree of correlation between the two tests was low (Kappa index = 0.324) but was better in patients not receiving corticosteroids (CTC)/immunosuppressive (IS) therapy (Kappa = 0.436) and in those receiving hydroxychloroquine (Kappa = 0.473). While TST results were adversely affected by those receiving CTC and/or IS drugs (P = 0.021), the T.SPOT.TB results were not. CONCLUSION Although the TST test remains a useful tool for diagnosing LTBI in SLE patients, the T.SPOT.TB test is perhaps better employed when the patient is receiving CTC and/or IS drugs.

Polymerase chain reaction detection of LeishmaniaDNA in skin biopsy samples in Sri Lanka where the causative agent of cutaneous leishmaniasis is Leishmania donovani

Leishmania donovani is the known causative agent of both cutaneous (CL) and visceral leishmaniasis in Sri Lanka. CL is considered to be under-reported partly due to relatively poor sensitivity and specificity of microscopic diagnosis. We compared robustness of three previously described polymerase chain reaction (PCR) based methods to detectLeishmania DNA in 38 punch biopsy samples from patients presented with suspected lesions in 2010. Both, Leishmaniagenus-specific JW11/JW12 KDNA and LITSR/L5.8S internal transcribed spacer (ITS)1 PCR assays detected 92% (35/38) of the samples whereas a KDNA assay specific forL. donovani (LdF/LdR) detected only 71% (27/38) of samples. All positive samples showed a L. donovani banding pattern upon HaeIII ITS1 PCR-restriction fragment length polymorphism analysis. PCR assay specificity was evaluated in samples containing Mycobacterium tuberculosis, Mycobacterium leprae, and human DNA, and there was no cross-amplification in JW11/JW12 and LITSR/L5.8S PCR assays. The LdF/LdR PCR assay did not amplify M. leprae or human DNA although 500 bp and 700 bp bands were observed in M. tuberculosis samples. In conclusion, it was successfully shown in this study that it is possible to diagnose Sri Lankan CL with high accuracy, to genus and species identification, using Leishmania DNA PCR assays.

Preserved capillary density of dorsal finger skin in treated hypertensive patients with or without type 2 diabetes

RESUME : La raréfaction des vaisseaux capillaires est une caractéristique de l'hypertension artérielle non traitée. Des données récentes indiquent que cette raréfaction peut être renversée par un traitement antihypertenseur chez les patients hypertendus non diabétiques. Malgré la fréquente association du diabète et de l'hypertension, on ne sait rien de la densité capillaire de patients diabétiques traités, souffrant d'hypertension artérielle. Nous avons dès lors recruté 21 patients normotendus (groupe contrôle), 25 patients souffrant uniquement d'hypertension artérielle , et 21 patients diabétiques (Diabète de type 2) souffrant également d'hypertension artérielle. Tous les patients hypertendus ont été traités avec un inhibiteur du système rénine-angiotensine, et une majorité présentait une tension artérielle moyenne en auto-contrôle à domicile de 135/85 mmHg ou moins. La densité capillaire a été évaluée par vidéomicroscopie sur la peau du dos des doigts et avec laser Doppler sur la peau de l'avant-bras (vasodilatation maximale induite par le chauffage local). Au final, il n'y avait pas de différence entre les groupes de l'étude, que ce soit lors des mesures de la densité capillaire sur le dos du doigt (groupe contrôle 101 ±11 capillaires, groupe des patients non- diabétiques hypertendus 99 ± 16, groupe des patients hypertendus et diabétiques 96 ± 18, p>0,5) ou lors des mesures de débit sanguin maximal sur la peau de l'avant-bras, un témoin indirect de la densité capillaire dans ce territoire (contrôles 666 ±114 unités de perfusion, non diabétique hypertendu 612 ± 126, hypertendus diabétiques 620 ±103, p> 0,5). En conclusion, notre étude est la première à démontrer que indépendamment de la présence ou non d'un diabète de type 2, la densité capillaire est normale chez les patients hypertendus présentant un contrôle raisonnable de la pression artérielle obtenue avec un bloqueur du système rénine-angiotensine.

The Euromelanoma skin cancer prevention campaign in Europe: characteristics and results of 2009 and 2010.

Background  Euromelanoma is a skin cancer education and prevention campaign that started in 1999 in Belgium as 'Melanoma day'. Since 2000, it is active in a large and growing number of European countries under the name Euromelanoma. Objective  To evaluate results of Euromelanoma in 2009 and 2010 in 20 countries, describing characteristics of screenees, rates of clinically suspicious lesions for skin cancer and detection rates of melanomas. Methods  Euromelanoma questionnaires were used by 20 countries providing their data in a standardized database (Belgium, Croatia, Cyprus, Czech Republic, FYRO Macedonia, Germany, Greece, Hungary, Italy, Lithuania, Luxembourg, Malta, Moldavia, Portugal, Serbia, Slovenia, Spain, Sweden, Switzerland and Ukraine). Results  In total, 59 858 subjects were screened in 20 countries. Most screenees were female (64%), median ages were 43 (female) and 46 (male) and 33% had phototype I or II. The suspicion rates ranged from 1.1% to 19.4% for melanoma (average 2.8%), from 0.0% to 10.7% for basal cell carcinoma (average 3.1%) and from 0.0% to 1.8% for squamous cell carcinoma (average 0.4%). The overall positive predictive value of countries where (estimation of) positive predictive value could be determined was 13.0%, melanoma detection rates varied from 0.1% to 1.9%. Dermoscopy was used in 78% of examinations with clinically suspected melanoma; full body skin examination was performed in 72% of the screenees. Conclusion  Although the population screened during Euromelanoma was relatively young, high rates of clinically suspected melanoma were found. The efficacy of Euromelanoma could be improved by targeting high-risk populations and by better use of dermoscopy and full body skin examination.

The microbiological signature of human cutaneous leishmaniasis lesions exhibits restricted bacterial diversity compared to healthy skin

Localised cutaneous leishmaniasis (LCL) is the most common form of cutaneous leishmaniasis characterised by single or multiple painless chronic ulcers, which commonly presents with secondary bacterial infection. Previous culture-based studies have found staphylococci, streptococci, and opportunistic pathogenic bacteria in LCL lesions, but there have been no comparisons to normal skin. In addition, this approach has strong bias for determining bacterial composition. The present study tested the hypothesis that bacterial communities in LCL lesions differ from those found on healthy skin (HS). Using a high throughput amplicon sequencing approach, which allows for better populational evaluation due to greater depth coverage and the Quantitative Insights Into Microbial Ecology pipeline, we compared the microbiological signature of LCL lesions with that of contralateral HS from the same individuals.Streptococcus, Staphylococcus,Fusobacterium and other strict or facultative anaerobic bacteria composed the LCL microbiome. Aerobic and facultative anaerobic bacteria found in HS, including environmental bacteria, were significantly decreased in LCL lesions (p < 0.01). This paper presents the first comprehensive microbiome identification from LCL lesions with next generation sequence methodology and shows a marked reduction of bacterial diversity in the lesions.

A positive FGFR3/FOXN1 feedback loop underlies benign skin keratosis versus squamous cell carcinoma formation in humans.

Seborrheic keratoses (SKs) are common, benign epithelial tumors of the skin that do not, or very rarely, progress into malignancy, for reasons that are not understood. We investigated this by gene expression profiling of human SKs and cutaneous squamous cell carcinomas (SCCs) and found that several genes previously connected with keratinocyte tumor development were similarly modulated in SKs and SCCs, whereas the expression of others differed by only a few fold. In contrast, the tyrosine kinase receptor FGF receptor-3 (FGFR3) and the transcription factor forkhead box N1 (FOXN1) were highly expressed in SKs, and close to undetectable in SCCs. We also showed that increased FGFR3 activity was sufficient to induce FOXN1 expression, counteract the inhibitory effect of EGFR signaling on FOXN1 expression and differentiation, and induce differentiation in a FOXN1-dependent manner. Knockdown of FOXN1 expression in primary human keratinocytes cooperated with oncogenic RAS in the induction of SCC-like tumors, whereas increased FOXN1 expression triggered the SCC cells to shift to a benign SK-like tumor phenotype, which included increased FGFR3 expression. Thus,we have uncovered a positive regulatory loop between FGFR3 and FOXN1 that underlies a benign versus malignant skin tumor phenotype.

Biological treatments in Behçet's disease: beyond anti-TNF therapy.

Behçet's disease (BD) is universally recognized as a multisystemic inflammatory disease of unknown etiology with chronic course and unpredictable exacerbations: its clinical spectrum varies from pure vasculitic manifestations with thrombotic complications to protean inflammatory involvement of multiple organs and tissues. Treatment has been revolutionized by the progressed knowledge in the pathogenetic mechanisms of BD, involving dysfunction and oversecretion of multiple proinflammatory molecules, chiefly tumor necrosis factor- (TNF-) α, interleukin- (IL-) 1β, and IL-6. However, although biological treatment with anti-TNF-α agents has been largely demonstrated to be effective in BD, not all patients are definite responders, and this beneficial response might drop off over time. Therefore, additional therapies for a subset of refractory patients with BD are inevitably needed. Different agents targeting various cytokines and their receptors or cell surface molecules have been studied: the IL-1 receptor has been targeted by anakinra, the IL-1 by canakinumab and gevokizumab, the IL-6 receptor by tocilizumab, the IL12/23 receptor by ustekinumab, and the B-lymphocyte antigen CD-20 by rituximab. The aim of this review is to summarize all current experiences and the most recent evidence regarding these novel approaches with biological drugs other than TNF-α blockers in BD, providing a valuable addition to the actually available therapeutic armamentarium.

Assessment of melanocytic skin lesions with a high-definition laser Doppler imaging system.

BACKGROUND: Early detection is a major goal in the management of malignant melanoma. Besides clinical assessment many noninvasive technologies such as dermoscopy, digital dermoscopy and in vivo laser scanner microscopy are used as additional methods. Herein we tested a system to assess lesional perfusion as a tool for early melanoma detection.¦METHODS: Laser Doppler flow (FluxExplorer) and mole analyser (MA) score (FotoFinder) were applied to histologically verified melanocytic nevi (33) and malignant melanomas (12).¦RESULTS: Mean perfusion and MA scores were significantly increased in melanoma compared to nevi. However, applying an empirically determined threshold of 16% perfusion increase only 42% of the melanomas fulfilled the criterion of malignancy, whereas with the mole analyzer score 82% of the melanomas fulfilled the criterion of malignancy.¦CONCLUSION: Laser Doppler imaging is a highly sensitive technology to assess skin and skin tumor perfusion in vivo. Although mean perfusion is higher in melanomas compared to nevi the high numbers of false negative results hamper the use of this technology for early melanoma detection.

International survey on skin patch test procedures, attitudes and interpretation.

BACKGROUND Skin patch test is the gold standard method in diagnosing contact allergy. Although used for more than 100 years, the patch test procedure is performed with variability around the world. A number of factors can influence the test results, namely the quality of reagents used, the timing of the application, the patch test series (allergens/haptens) that have been used for testing, the appropriate interpretation of the skin reactions or the evaluation of the patient's benefit. METHODS We performed an Internet -based survey with 38 questions covering the educational background of respondents, patch test methods and interpretation. The questionnaire was distributed among all representatives of national member societies of the World Allergy Organization (WAO), and the WAO Junior Members Group. RESULTS One hundred sixty-nine completed surveys were received from 47 countries. The majority of participants had more than 5 years of clinical practice (61 %) and routinely carried out patch tests (70 %). Both allergists and dermatologists were responsible for carrying out the patch tests. We could observe the use of many different guidelines regardless the geographical distribution. The use of home-made preparations was indicated by 47 % of participants and 73 % of the respondents performed 2 or 3 readings. Most of the responders indicated having patients with adverse reactions, including erythroderma (12 %); however, only 30 % of members completed a consent form before conducting the patch test. DISCUSSION The heterogeneity of patch test practices may be influenced by the level of awareness of clinical guidelines, different training backgrounds, accessibility to various types of devices, the patch test series (allergens/haptens) used for testing, type of clinical practice (public or private practice, clinical or research-based institution), infrastructure availability, financial/commercial implications and regulations among others. CONCLUSION There is a lack of a worldwide homogeneity of patch test procedures, and this raises concerns about the need for standardization and harmonization of this important diagnostic procedure.