Pruritus in psoriasis: An update Szepietowski, J.C.; Reich, A.
European journal of pain,
January 2016, Volume:
20, Issue:
1
Journal Article
Peer reviewed
Background and objective
Psoriasis is one of the most common chronic inflammatory skin diseases, found in about 1–3% of the general population. Pruritus affects about 60–90% of patients with ...psoriasis. The aim of this review was to summarize current knowledge about the pathogenesis and treatment of this symptom in psoriasis patients.
Results
Majority of psoriatic patients consider pruritus as the most bothersome symptom. The pathogenesis of pruritus is still unknown but the major concept of its origin is focused on neurogenic inflammation. Possible itch mediators include neuropeptides released from dermal nerve endings upon various stimuli, which were found to be abnormally expressed in itchy psoriatic plaques. Another important phenomenon supporting the idea of neurogenic inflammation as a key player in pruritus accompanying psoriasis is abnormal innervations of psoriatic skin. Possibly increased innervation density in psoriasis may decrease the threshold for pruritic stimuli. It is also suggested that pruritus in psoriasis might be related to abnormal functioning of the peripheral opioid system. Despite the high frequency of pruritus in psoriasis, to date there is no single antipruritic therapy dedicated specifically to treat itch in this disease.
Conclusions
Neurogenic inflammation seems to be important for itchiness in psoriasis. Treatment of pruritus in patients with psoriasis should be directed towards the resolution of skin lesions, as disease remission usually is linked with pruritus relief.
Patients with moderate to severe psoriasis are undertreated. To solve this persistent problem, the consensus programme was performed to define goals for treatment of plaque psoriasis with systemic ...therapy and to improve patient care. An expert consensus meeting and a collaborative Delphi procedure were carried out. Nineteen dermatologists from different European countries met for a face-to-face discussion and defined items through a four-round Delphi process. Severity of plaque psoriasis was graded into mild and moderate to severe disease. Mild disease was defined as body surface area (BSA) ≤10 and psoriasis area and severity index (PASI) ≤10 and dermatology life quality index (DLQI) ≤10 and moderate to severe psoriasis as (BSA > 10 or PASI > 10) and DLQI > 10. Special clinical situations may change mild psoriasis to moderate to severe including involvement of visible areas or severe nail involvement. For systemic therapy of plaque psoriasis two treatment phases were defined: (1) induction phase as the treatment period until week 16; however, depending on the type of drug and dose regimen used, this phase may be extended until week 24 and (2) maintenance phase for all drugs was defined as the treatment period after the induction phase. For the definition of treatment goals in plaque psoriasis, the change of PASI from baseline until the time of evaluation (ΔPASI) and the absolute DLQI were used. After induction and during maintenance therapy, treatment can be continued if reduction in PASI is ≥75%. The treatment regimen should be modified if improvement of PASI is <50%. In a situation where the therapeutic response improved ≥50% but <75%, as assessed by PASI, therapy should be modified if the DLQI is >5 but can be continued if the DLQI is ≤5. This programme defines the severity of plaque psoriasis for the first time using a formal consensus of 19 European experts. In addition, treatment goals for moderate to severe disease were established. Implementation of treatment goals in the daily management of psoriasis will improve patient care and mitigate the problem of undertreatment. It is planned to evaluate the implementation of these treatment goals in a subsequent programme involving patients and physicians.
Mitochondria can be incorporated into mammalian cells by simple co-incubation of isolated mitochondria with cells, without the need of transfection reagents or any other type of intervention. This ...phenomenon was termed mitochondrial transformation, and although it was discovered in 1982, currently little is known regarding its mechanism(s). Here we demonstrate that mitochondria can be transformed into recipient cells very quickly, and co-localize with endogenous mitochondria. The isolated mitochondria interact directly with cells, which engulf the mitochondria with cellular extensions in a way, which may suggest the involvement of macropinocytosis or macropinocytosis-like mechanisms in mitochondrial transformation. Indeed, macropinocytosis inhibitors but not clathrin-mediated endocytosis inhibition-treatments, blocks mitochondria transformation. The integrity of the mitochondrial outer membrane and its proteins is essential for the transformation of the mitochondria into cells; cells can distinguish mitochondria from similar particles and transform only intact mitochondria. Mitochondrial transformation is blocked in the presence of the heparan sulfate molecules pentosan polysulfate and heparin, which indicate crucial involvement of cellular heparan sulfate proteoglycans in the mitochondrial transformation process.
Canonical microRNA biogenesis requires the Microprocessor components, Drosha and DGCR8, to generate precursor-miRNA, and Dicer to form mature miRNA. The Microprocessor is not required for processing ...of some miRNAs, including mirtrons, in which spliceosome-excised introns are direct Dicer substrates. In this study, we examine the processing of putative human mirtrons and demonstrate that although some are splicing-dependent, as expected, the predicted mirtrons, miR-1225 and miR-1228, are produced in the absence of splicing. Remarkably, knockout cell lines and knockdown experiments demonstrated that biogenesis of these splicing-independent mirtron-like miRNAs, termed 'simtrons', does not require the canonical miRNA biogenesis components, DGCR8, Dicer, Exportin-5 or Argonaute 2. However, simtron biogenesis was reduced by expression of a dominant negative form of Drosha. Simtrons are bound by Drosha and processed in vitro in a Drosha-dependent manner. Both simtrons and mirtrons function in silencing of target transcripts and are found in the RISC complex as demonstrated by their interaction with Argonaute proteins. These findings reveal a non-canonical miRNA biogenesis pathway that can produce functional regulatory RNAs.
Despite measurable benefits of childhood vaccines, mothers with high levels of social privilege are increasingly refusing some or all vaccines for their children. These mothers are often clustered ...geographically or networked socially, providing information, emotional support, and validation for each other. Mothers who reject vaccines may face disapproval from others, criticism in popular culture, negative interactions with healthcare providers, and conflicts with people they know, which serve to stigmatize them. This article uses qualitative data from in-depth interviews with parents who reject vaccines, ethnographic observations, and analyses of online discussions to examine the role of social capital in networks of vaccine-refusing mothers. Specifically, this article explores how mothers provide each other information critical of vaccines, encourage a sense of one's self as empowered to question social expectations around vaccination, provide strategies for managing stigma that results from refusing vaccines, and define a sense of obligation to extend social capital to other mothers. In examining these strategies and tensions, we see how social capital can powerfully support subcultural norms that contradict broader social norms and provide sources of social support. Even as these forces are experienced as positive, they work in ways that actively undermine community health, particularly for those who are the most socially vulnerable to negative health outcomes from infection.
•Many mothers who refuse vaccines access social capital through their networks of likeminded parents.•Networks of vaccine-refusing mothers share informational, emotional, and appraisal support.•Mothers who reject vaccines face stigma, but receive support on how to manage it from their networks.•Vaccine-refusing mothers aim to extend social capital to other mothers.•Social capital creates subcultural norms that contradict broader social norms around vaccines.
Chronic pruritus is a common symptom and there is an urgent need to test new anti-pruritic substances in high-quality clinical trials. However, no widely accepted standardized and validated method ...for objectively measuring pruritus is yet available. A special interest group of the International Forum for the Study of Itch has been established to assess scoring methods and questionnaires for use in clinical trials. This paper presents our current recommendations. The set of measures we recommend includes pruritus intensity scales, instruments for assessment of scratch lesions, chronic pruritus course, quality of life and patient benefits.
Retinoid X receptor (RXR) agonists, which activate the RXR nuclear receptor, are effective in multiple preclinical cancer models for both treatment and prevention. While RXR is the direct target of ...these compounds, the downstream changes in gene expression differ between compounds. RNA sequencing was used to elucidate the effects of the novel RXRα agonist MSU-42011 on the transcriptome in mammary tumors of HER2+ mouse mammary tumor virus (MMTV)-Neu mice. For comparison, mammary tumors treated with the FDA approved RXR agonist bexarotene were also analyzed. Each treatment differentially regulated cancer-relevant gene categories, including focal adhesion, extracellular matrix, and immune pathways. The most prominent genes altered by RXR agonists positively correlate with survival in breast cancer patients. While MSU-42011 and bexarotene act on many common pathways, these experiments highlight the differences in gene expression between these two RXR agonists. MSU-42011 targets immune regulatory and biosynthetic pathways, while bexarotene acts on several proteoglycan and matrix metalloproteinase pathways. Exploration of these differential effects on gene transcription may lead to an increased understanding of the complex biology behind RXR agonists and how the activities of this diverse class of compounds can be utilized to treat cancer.
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