Comparison of a multiplexed bead-based assay with an immunofluorescence and an enzyme-immuno assay for the assessment of Epstein-Barr virus serologic status

Dans cette étude, nous avons testé la performance diagnostique d'une nouvelle technique d'analyse multiplexée qui permet la détection d'anticorps de différentes spécificités dans la même réaction. En l'absence de gold standard, nous avons choisi de comparer la performance diagnostique de l'analyse avec deux méthodes de référance que sont l'IF et EIA, et avec un consensus déterminé selon une règle de majorité entre les trois méthodes.¦393 sérums analysés par IF, conservés par congélation, ont été décongelés pour être analysés par EIA et BBA. Pour chaque sérum, les anticorps recherchés ont été les anti-VCA (Viral Capsid Antigen) IgM, anti-VCA IgG et anti-EBNA (Epstein-Barr Nuclear Associated) IgG. Les échantillons ont été classés en cinq groupes selon les résultats de l'IF : séronégatifs, infections aiguës, infections anciennes et deux types d'indéterminés.¦Pour chaque méthode, le résultat numérique (index ou titre) des analyses est converti en termes de positif, négatif ou douteux. Pour le résultat de chaque type d'anticorps, un consensus est établi selon une règle de majorité entre les trois méthodes, permettant une interprétation du stade de l'infection. Puis l'interprétation de chacune des méthodes a été comparée au consensus. Nous avons également comparé les trois méthodes les unes aux autres concernant la détection des anticorps.¦Globalement, nous observons une bonne corrélation qualitative entre les trois approches pour détecter les anti-VCA IgG et IgM. Pour pour les anti-EBNA IgG, il y a une divergence notable entre l'IF et les deux autres méthodes, l'IF apparaissant moins sensible que les autres méthodes, résultant en un nombre accru d'interprétations indéterminées du stade de l'infection.¦L'origine de cette divergence ne peut être due à une perte d'anticorps liée au stockage de longue durée des échantillons. En effet, EIA et BBA restent plus sensibles que IF, dont l'analyse a été faite sur des sérums frais.¦Cette divergence ne semble pas non plus être due aux différents antigènes utilisés par les trois méthodes. EIA et BBA utilisent le même antigène recombinant EBNA-1, alors que l'IF utilise des "cellules lymphoïdes choisies pour leur production sélective d'antigènes EBNA". Ces cellules sont probablement des cellules infectées par EBV qui devraient exprimer plus d'antigènes de latence que seul EBNA-1. Cette différence devrait donc plutôt en principe résulter en une meilleure sensibilité de l'IF par rapport aux deux autres méthodes.¦Les anti-EBNA IgG peuvent disparaître chez les patients immunocompromis chez qui se produit une réactivation d'EBV. Nous avons donc recherché le status immunitaire des patients du groupe dont les sérums étaient négatifs pour anti-EBNA IgG en IF et positifs par les autres méthodes: seulement 28 des 70 patients étaient immunocompromis.¦Par conséquent, il est probable que dans la majorité de ces résultats discordants, les anticorps anti-EBNA IgG détectés par BBA et EIA sont de vrais positifs non décelés par l'IF.¦En conclusion, BBA est meilleur que la méthode de référance qu'est l'IF, et est égal à EIA en ce qui concerne la performance diagnostique. En outre, ces deux nouvelles méthodes offrent une économie de temps en raison de manipulations moindres, et ne requièrent aucune formation en microscopie à fluorescence. Elles sont également plus économes en échantillons que IF. BBA a l'avantage de n'avoir besoin que de deux analyses pour donner un diagnostique, alors que IF et EIA ont en besoin d'une par anticorps. Enfin, BBA dispose de contrôles internes permettant de reconnaître les liaisons non antigène-spécifiques des anticorps. Par contre, BBA nécessite l'achat d'un lecteur par cytométrie de flux assez coûteux.

Characterization of the Aspergillus nidulans biotin biosynthetic gene cluster and use of the bioDA gene as a new transformation marker.

The genes involved in the biosynthesis of biotin were identified in the hyphal fungus Aspergillus nidulans through homology searches and complementation of Escherichia coli biotin-auxotrophic mutants. Whereas the 7,8-diaminopelargonic acid synthase and dethiobiotin synthetase are encoded by distinct genes in bacteria and the yeast Saccharomyces cerevisiae, both activities are performed in A. nidulans by a single enzyme, encoded by the bifunctional gene bioDA. Such a bifunctional bioDA gene is a genetic feature common to numerous members of the ascomycete filamentous fungi and basidiomycetes, as well as in plants and oömycota. However, unlike in other eukaryota, the three bio genes contributing to the four enzymatic steps from pimeloyl-CoA to biotin are organized in a gene cluster in pezizomycotina. The A. nidulans auxotrophic mutants biA1, biA2 and biA3 were all found to have mutations in the 7,8-diaminopelargonic acid synthase domain of the bioDA gene. Although biotin auxotrophy is an inconvenient marker in classical genetic manipulations due to cross-feeding of biotin, transformation of the biA1 mutant with the bioDA gene from either A. nidulans or Aspergillus fumigatus led to the recovery of well-defined biotin-prototrophic colonies. The usefulness of bioDA gene as a novel and robust transformation marker was demonstrated in co-transformation experiments with a green fluorescent protein reporter, and in the efficient deletion of the laccase (yA) gene via homologous recombination in a mutant lacking non-homologous end-joining activity.

Optimal 3-T MRI for depiction of the finger A2 pulley: comparison between T1-weighted, fat-saturated T2-weighted and gadolinium-enhanced fat-saturated T1-weighted sequences

OBJECTIVE: To compare three spin-echo sequences, transverse T1-weighted (T1WI), transverse fat-saturated (FS) T2-weighted (T2WI), and transverse gadolinium-enhanced (Gd) FS T1WI, for the visualisation of normal and abnormal finger A2 pulley with magnetic resonance (MR) imaging at 3 tesla (T). MATERIALS AND METHODS: Sixty-three fingers from 21 patients were consecutively investigated. Two musculoskeletal radiologists retrospectively compared all sequences to assess the visibility of normal and abnormal A2 pulleys and the presence of motion or ghost artefacts. RESULTS: Normal and abnormal A2 pulleys were visible in 94% (59/63) and 95% (60/63) on T1WI sequences, in 63% (40/63) and 60% (38/63) on FS T2WI sequences, and in 87% (55/63) and 73% (46/63) on Gd FS T1WI sequences when read by the first and second observer, respectively. Motion and ghost artefacts were higher on FS T2WI sequences. Seven among eight abnormal A2 pulleys were detected, and were best depicted with Gd FS T1WI sequences in 71% (5/7) and 86% (6/7) by the first and the second observer, respectively. CONCLUSION: In 3-T MRI, the comparison between transverse T1WI, FS T2WI, and Gd FS T1WI sequences shows that transverse T1WI allows excellent depiction of the A2 pulley, that FS T2WI suffers from a higher rate of motion and ghost artefacts, and transverse Gd FS T1WI is the best sequence for the depiction of abnormal A2 pulley.

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Musculoskeletal disorders (MSD) are the most prevalent pain disorders in industrialized countries, and their costs can represent up to 2% of gross national product. MSD are often work associated and recurrent and may lead to disability. In occupational health we are interested in the opposite process : in the return to work (RTW). Different models of disability and RTW exist with different conceptions of psychosocial factors. We therefore propose to analyze the influence of factors from work, patient, health care providers, and broader societal domains along the different phases of the MSD process, adopting a biopsychosocial approach. The analysis of risk factors for the different phases of MSD indicate that work stress factors have an impact on the occurrence of MSD and RTW with MSD, but their effect is low to moderate and nonspecific. Physical work demands, work place adaptation, and pain experience are much stronger predictors of RTW. Lack of modified or adapted work is one of the major factors that hinder RTW. The longer the pain lasts, the longer the patient is out of work, the more personal factors and broader context factors become dominant. There is a clear lack of RTW studies concerning neck and upper limb pain. MSD and especially chronic MSD should be viewed as public health concerns, implying a wider socio-economic and insurance and disability problem. Adequate medical support tailored to the different dimensions and phases of MSD must be on offer, and work accommodations must be promoted and supported.

Destruction of conditional insulinoma cell lines in NOD mice: a role for autoimmunity.

AIMS/HYPOTHESIS: betaTC-tet (H2(k)) is a conditional insulinoma cell line derived from transgenic mice expressing a tetracycline-regulated oncogene. Transgenic expression of several proteins implicated in the apoptotic pathways increase the resistance of betaTC-tet cells in vitro. We tested in vivo the sensitivity of the cells to rejection and the protective effect of genetic alterations in NOD mice. METHODS: betaTC-tet cells and genetically engineered lines expressing Bcl-2 (CDM3D), a dominant negative mutant of MyD88 or SOCS-1 were transplanted in diabetic female NOD mice or in male NOD mice with diabetes induced by high-dose streptozotocin. Survival of functional cell grafts in NOD-scid mice was also analyzed after transfer of splenocytes from diabetic NOD mice. Autoreactive T-cell hybridomas and splenocytes from diabetic NOD mice were stimulated by betaTC-tet cells. RESULTS: betaTC-tet cells and genetically engineered cell lines were all similarly rejected in diabetic NOD mice and in NOD-scid mice after splenocyte transfer. In 3- to 6-week-old male NOD mice treated with high-dose streptozotocin, the cells temporarily survived, in contrast with C57BL/6 mice treated with high-dose streptozotocin (indefinite survival) and untreated 3- to 6-week-old male NOD mice (rejection). The protective effect of high-dose streptozotocin was lost in older male NOD mice. betaTC-tet cells did not stimulate autoreactive T-cell hybridomas, but induced IL-2 secretion by splenocytes from diabetic NOD mice. CONCLUSION/INTERPRETATION: The autoimmune process seems to play an important role in the destruction of betaTC-tet cells in NOD mice. Genetic manipulations intended at increasing the resistance of beta cells were inefficient. Similar approaches should be tested in vivo as well as in vitro. High dose streptozotocin influences immune rejection and should be used with caution.

Subclinical peripheral synovitis detected by echography in patients with axial Spondyloarthritis

Background: patients with axial Spondyloarthritis (SD), even withoutany obvious peripheral joint synovitis, often complain of pain in thejoints of arms and legs. Several musculoskeletal ultrasound (US)scores developed in rheumatoid arthritis have demonstrated theircapacity of discovering subclinical synovitis which were relevant interm of disease activity and for treatment strategies. None of thesescores however have been, to our knowledge, applied tospondyloarthritis patients.Objectives: to determine if subclinical synovitis can be detected byechography in patients with SD and if these synovitis are relevantcompared with RA and controls.Methods: the Swiss Sonography in Arthritis and Rheumatism(SONAR) group has developed a reproducible semi-quantitative scorefor RA using OMERACT criteria for synovitis. The score includes Bmode and Doppler mode. 35 out of 40 enrolled SD patients fulfillingthe 2010 diagnostic criteria were evaluated according to the SONARscore. In none of them, peripheral synovitis was clearly demonstrated,although some have or reported recurrent peripheral joint pain. Thescore was also applied to 20 matched controls and 40 consecutive RApatients (RA). 19 of them were in remission (DAS: <2.6), 10 with alow activity (DAS: 2.6 <>3.4) and 11 with a moderate activity disease(DAS: 3.5 <>5.1). All the patients and the controls had a completeclinical, biological and auto-evaluation assessment (joint pain andswelling counts, DAS28, HAQ, BASDAI BASMI, BASFI, m-SACRAH).The ultra-sonographer was blind to all these parameters.Results: a B mode score >8, was set up as a cut-off value forsignificant synovitis as only 10% of the controls (median: 5.9 ± 2.2)and 90% of active RA had a higher score .34% of SD had significantsynovitis which remained mostly mild. Their median B mode score(12 ± 1.6) was higher but not significantly than in remission Ra (7.1 ±3.4). Only active RA (DAS >3.5) had significant higher echographicscores: B mode (17 ± 11), Doppler score and cumulative score forsynovitis grade >1. BASDAI, BASFI, BASMI, m-SACRAH, DAS28 andCRP were not significantly different in SD patients with or withoutsynovitis.Conclusions: some patients with axial Spondyloarthritis havesubclinical but significant peripheral synovitis detected by echography.The impact of these synovitis remains uncertain as their presencedoes not seem to significantly influence disease activity and functionevaluation tools.

Manual therapy followed by specific active exercises versus a placebo followed by specific active exercises on the improvement of functional disability in patients with chronic non specific low back pain: a randomized controlled trial.

BACKGROUND: Recent clinical recommendations still propose active exercises (AE) for CNSLBP. However, acceptance of exercises by patients may be limited by pain-related manifestations. Current evidences suggest that manual therapy (MT) induces an immediate analgesic effect through neurophysiologic mechanisms at peripheral, spinal and cortical levels. The aim of this pilot study was first, to assess whether MT has an immediate analgesic effect, and second, to compare the lasting effect on functional disability of MT plus AE to sham therapy (ST) plus AE. METHODS: Forty-two CNSLBP patients without co-morbidities, randomly distributed into 2 treatment groups, received either spinal manipulation/mobilization (first intervention) plus AE (MT group; n = 22), or detuned ultrasound (first intervention) plus AE (ST group; n = 20). Eight therapeutic sessions were delivered over 4 to 8 weeks. Immediate analgesic effect was obtained by measuring pain intensity (Visual Analogue Scale) before and immediately after the first intervention of each therapeutic session. Pain intensity, disability (Oswestry Disability Index), fear-avoidance beliefs (Fear-Avoidance Beliefs Questionnaire), erector spinae and abdominal muscles endurance (Sorensen and Shirado tests) were assessed before treatment, after the 8th therapeutic session, and at 3- and 6-month follow-ups. RESULTS: Thirty-seven subjects completed the study. MT intervention induced a better immediate analgesic effect that was independent from the therapeutic session (VAS mean difference between interventions: -0.8; 95% CI: -1.2 to -0.3). Independently from time after treatment, MT + AE induced lower disability (ODI mean group difference: -7.1; 95% CI: -12.8 to -1.5) and a trend to lower pain (VAS mean group difference: -1.2; 95% CI: -2.4 to -0.30). Six months after treatment, Shirado test was better for the ST group (Shirado mean group difference: -61.6; 95% CI: -117.5 to -5.7). Insufficient evidence for group differences was found in remaining outcomes. CONCLUSIONS: This study confirmed the immediate analgesic effect of MT over ST. Followed by specific active exercises, it reduces significantly functional disability and tends to induce a larger decrease in pain intensity, compared to a control group. These results confirm the clinical relevance of MT as an appropriate treatment for CNSLBP. Its neurophysiologic mechanisms at cortical level should be investigated more thoroughly. TRIAL REGISTRATION: Trial registration number: NCT01496144.

Multiple non-ossifying fibromas as a cause of pathological femoral fracture in Jaffe-Campanacci syndrome.

BACKGROUND: Jaffe-Campanacci is a rare syndrome characterised by the association of café-au-lait spots, axillary freckles, multiple non-ossifying fibromas of the long bones and jaw, as well as some features of type 1 neurofibromatosis. There are less than 30 reported cases, and a genetic profile has not yet been determined. Furthermore, it has not been clarified whether it is a subtype of type 1 neurofibromatosis or a separate syndrome. The risk of pathological fracture is over 50%, due to substantial cortical thinning of the weight-bearing bones. CASE PRESENTATION: A 17-year-old female patient, known for type 1 neurofibromatosis, presented with a low-energy distal femoral fracture due to disseminated large non-ossifying fibromas. Investigations revealed all of the distinctive signs of Jaffe-Campanacci syndrome. Both her distal femurs and proximal tibias exhibited multiple non-ossifying fibromas. The fracture was treated by open reduction and internal plate fixation. Some of the bony lesions were biopsied to confirm the diagnosis. The fracture healed eventless, as did the lesions biopsied or involved in the fracture. The other ones healed after curettage and bone grafting performed at the time of plate removal. CONCLUSION: Jaffe-Campanacci is a rare syndrome having unclear interactions with type 1 neurofibromatosis, which still needs to be characterised genetically. It is associated with a high risk of pathological fracture, due to the presence of multiple large non-ossifying fibromas of the long bones, with an expected normal healing time. Curettage and bone grafting promote healing of the lesions and should be considered to prevent pathological fracture. We agree with other authors that all patients with newly-diagnosed type 1 neurofibromatosis should undergo an osseous screening to detect disseminated non-ossifying fibromas, and evaluate the inherent risk of pathological fracture.

Stimulation-induced increases of astrocytic oxidative metabolism in rats and humans investigated with 1-11C-acetate

The purpose of this study was to investigate astrocytic oxidative metabolism using 1-(11)C-acetate. 1-(11)C-acetate kinetics were evaluated in the rat somatosensory cortex using a beta-scintillator during different manipulations (test-retest, infraorbital nerve stimulation, and administration of acetazolamide or dichloroacetate). In humans a visual activation paradigm was used and kinetics were measured with positron emission tomography. Data were analyzed using a one-tissue compartment model. The following features supported the hypothesis that washout of radiolabel (k(2)) is because of (11)C-CO(2) and therefore related to oxygen consumption (CMRO(2)): (1) the onset of (11)C washout was delayed; (2)k(2) was not affected by acetazolamide-induced blood flow increase; (3)k(2) demonstrated a significant increase during stimulation in rats (from 0.014+/-0.007 to 0.027+/-0.006 per minute) and humans (from 0.016+/-0.010 to 0.026+/-0.006 per minute); and (4) dichloroacetate led to a substantial decrease of k(2). In the test-retest experiments K(1) and k(2) were very stable. In summary, 1-(11)C-acetate seems a promising tracer to investigate astrocytic oxidative metabolism in vivo. If the washout rate indeed represents the production of (11)C-CO(2), then its increase during stimulation would point to a substantially higher astrocytic oxidative metabolism during brain activation. However, the quantitative relationship between k(2) and CMRO(2) needs to be determined in future experiments.

Multimorbidity in the older population: CARDI research brief

New research funded by the Centre for Ageing Research and Development in Ireland (CARDI) finds that people suffering from two or more chronic conditions are 20 times more likely to report disability than those with none. The study examines the prevalence of two or more chronic conditions, known as multimorbidity, and its impact on quality of life and disability in older people. The research Multimorbidity and Disability in the Older Population of Ireland, studied eight chronic conditions: cancer; heart attack; angina; stroke; diabetes; asthma; chronic obstructive pulmonary disease (COPD) and musculoskeletal pain (including rheumatism, arthritis and back pain). Musculoskeletal pain was the most widely reported condition across the island with a prevalence of 40%, followed by diabetes (7%) and angina (6%). Asthma and COPD have the same levels of prevalence, 5%, while cancer and stroke were reported less frequently (1-2%). The study also revealed some clear differences in the prevalence of chronic diseases between ROI and NI. Angina was reported far more frequently in NI, 10% compared to 4% in ROI. So too was musculoskeletal pain, 55% compared to 35% in ROI while asthma was reported more frequently in ROI, 6% compared to 3% in NI.

Strength and limitations of regulatory T Cells for immunotherapy in transplantation.

In many experimental models, CD4+CD25+Foxp3+ regulatory T cells (nTreg) have been identifi ed as key players in promoting peripheral transplantation (Tx) tolerance. We have been focusing on therapies based on antigen-specifi c nTreg that can control effector T cells (Teff) and prevent allograft rejection. The use of nTreg in immunotherapeutic protocols for solid organ Tx is however limited by their overall low numbers as well as the low precursor frequency of alloantigen cross-reactive nTreg expected to be found in a normal individual. Moreover, although we previously described robust protocols to generate and expand antigen-specifi c nTreg in vitro, the process requires careful selection of highly pure nTreg and cumbersome ex-vivo manipulations, rendering this strategy not easily applicable in clinical solid organ Tx. In this study, we aimed to expand Treg directly in vivo and determine their suppressive function, effi cacy and stability in promoting donor-specifi c tolerance in a stringent murine Tx model. Our data suggest that IL-2-based therapies lead to a signifi cant increase of Treg in vivo. The expanded Treg suppressed Teff proliferation (albeit slightly less effi ciently than nTreg isolated from control mice) and allowed prolonged graft survival of major MHC-mismatched skin grafts in wild-type non-lymphopenic recipients. The expanded Treg alone were however not suffi cient to induce tolerance in stringent experimental conditions. Rapamycin reduced the frequency of Teff but did not impede expansion of Treg. Pro-infl ammatory stimuli hindered the expansion of Treg and resulted in an increase in the frequency of CD4+IFN-γ+ and CD4+IL17+ T cells. We propose that IL-2-based treatments would be an effi cient method for expanding functional Treg in vivo without affecting other immune cell populations, thereby favorably shifting the pool of alloreactive T cells towards regulation in response to an allograft. However, we also highlight some potential limitations of Treg expansion such as concomitant infl ammatory events.

Physical activity and pregnancy

SUMMARY : The traditional medical advice for pregnant women has been to reduce their physical activity (PA) levels. The advice was based on concerns that exercise could affect pregnancy outcomes by increasing core body temperature, by increasing the risk of maternal musculoskeletal injury and by altering the transplacental transport of oxygen and nutrients to maternal skeletal muscle rather than to the developing foetus. In the meantime, several studies have provided new information on adaptation of the pregnant woman and her foetus to moderate PA. New investigations have shown no adverse maternal or neonatal outcomes, abnormal foetal growth, increase in early pregnancy loss, or late pregnancy complications. Moreover, enrolment in moderate PA has proven to result in marked health benefits including improved maternal cardiovascular function, reduction of excessive weight gain and fat retention, less complicated labour, improved foetal stress tolerance and neurobehavioral maturation. In view of the beneficial effects, current recommendations encourage healthy pregnant women to engage in 30 minutes of moderate PA on most, if not all, days of the week. This thesis work addressed several questions. Firstly, it examined whether compliance with the recommended levels of PA during pregnancy results in better preparedness for the sudden physical exertion of labour and delivery. Secondly, it measured PA during pregnancy as compared to postpartum. Lastly, it assessed the influence of pre-pregnancy body mass index on gestational resting metabolic rate. Data collection was conducted on healthy women living in Switzerland during the third trimester of pregnancy and postpartum. Total and activity energy expenditure was assessed through 24-hour heart rate and accelerations recordings, and cardiovascular fitness through an individual step-test. Information related to pregnancy, labour and delivery was collected from medical records. The results indicate that a minimum 30 min of moderate PA per day during pregnancy are associated with better cardiovascular fitness and lower risk of operative delivery with no negative effects on maternal and foetal conditions (study 1). Despite these benefits, a substantial proportion of pregnant women (39%) living in Switzerland do not meet the PA recommendations. The decrease in activity related energy expenditure during pregnancy compared to postpartum was measured to be around 100 kcal/day (~13%), whereas the total energy expenditure was found to increase by 300 kcal/day (study 2). Thus, the energy cost of late pregnancy in Switzerland corresponds to 200 kca/day. These findings are based on average values of the study group. It should be noted, however, that large variations in individual energy expenditure may occur depending on the pre-pregnancy body mass index (study 3). When adjusted to body weight, gestational resting metabolic rate is significantly lower among women of high pre-pregnancy body mass index compared to women of normal or low pre-pregnancy body mass index. This can be explained by the fact that resting metabolic rate is primarily a function of fat-free mass, and when expressed per kg body weight, it decreases as the percentage of body fat increases. If energy intake is not modified appropriately in order to match lower energy cost per kg body weight in overweight and obese women it will result in positive energy balance, thus contributing to the current trend towards increasing adiposity in affluent society. The results of these studies go beyond the current state of knowledge on PA and pregnancy (study 4) and provide valid evidence to guide clinical practice. In view of the current epidemic of sedentary behaviour and obesity related pathology, the findings contribute new and reliable information to public health policies regarding the effects of PA in pregnancy, an important period of life for both mother and infant.

Implementació d'un esquema de proteccció del copyright per a imatges

En aquest treball s'ha implementat un sistema d'inserció i recuperació de marques que ha permès fer aquest procés amb un tipus específic d'imatges (imatges en format JPEG). La implementació correcta del sistema ha permès fer proves d'inserció i recuperació de marca en imatges JPEG. S'ha estudiat la robustesa del sistema enfront de manipulacions per compressió que pretenen eliminar la marca i s?ha comprovat que el sistema implementat ofereix més robustesa en imatges en escala de grisos que en imatges en color.

Expression of smoothelin and smooth muscle actin in the skin.

INTRODUCTION: Smoothelin is a cytoskeletal protein of differentiated smooth muscle cells with contractile capacity, distinguishing it from other smooth muscle proteins, such as smooth muscle actin (SMA). OBJECTIVE: To evaluate the expression of smoothelin and SMA in the skin in order to establish specific localizations of smoothelin in smooth muscle cells with high contractile capacity and in the epithelial component of cutaneous adnexal structures. Methods: Immunohistochemical analysis (smoothelin and SMA) was performed in 18 patients with normal skin. RESULTS: SMA was expressed by the vascular structures of superficial, deep, intermediate and adventitial plexuses, whereas smoothelin was specifically expressed in the cytoplasm of smooth muscle cells of the deepest vascular plexus and in no other plexus of the dermis. The hair erector muscle showed intense expression of smoothelin and SMA. Cells with nuclear expression of smoothelin and cytoplasmic expression of SMA were observed in the outer root sheath of the inferior portion of the hair follicles and intense cytoplasmic expression in cells of the dermal sheath to SMA. CONCLUSIONS: We report the first study of smoothelin expression in normal skin, which differentiates the superficial vascular plexus from the deep. The deep plexus comprises vessels with high contractile capacity, which is important for understanding dermal hemodynamics in normal skin and pathological processes. We suggest that the function of smoothelin in the outer root sheath may be to enhance the function of SMA, which has been related to mechanical stress. Smoothelin has not been studied in cutaneous pathology; however we believe it may be a marker specific for the diagnosis of leiomyomas and leiomyosarcomas of the skin. Also, smoothelin could differentiate arteriovenous malformations of cavernous hemangioma of the skin