Recommendations for rosacea diagnosis, classification and management: update from the global ROSacea COnsensus 2019 panel.

BACKGROUND: A transition from a subtyping to a phenotyping approach in rosacea is underway, allowing individual patient management according to presenting features instead of categorization by predefined subtypes. The ROSacea COnsensus (ROSCO) 2017 recommendations further support this transition and align with guidance from other working groups. OBJECTIVES: To update and extend previous global ROSCO recommendations in line with the latest research and continue supporting uptake of the phenotype approach in rosacea through clinical tool development. METHODS: Nineteen dermatologists and two ophthalmologists used a modified Delphi approach to reach consensus on statements pertaining to critical aspects of rosacea diagnosis, classification and management. Voting was electronic and blinded. RESULTS: Delphi statements on which the panel achieved consensus of ≥ 75% voting 'Agree' or 'Strongly agree' are presented. The panel recommends discussing disease burden with patients during consultations, using four questions to assist conversations. The primary treatment objective should be achievement of complete clearance, owing to previously established clinical benefits for patients. Cutaneous and ocular features are defined. Treatments have been reassessed in line with recent evidence and the prior treatment algorithm updated. Combination therapy is recommended to benefit patients with multiple features. Ongoing monitoring and dialogue should take place between physician and patients, covering defined factors to maximize outcomes. A prototype clinical tool (Rosacea Tracker) and patient case studies have been developed from consensus statements. CONCLUSIONS: The current survey updates previous recommendations as a basis for local guideline development and provides clinical tools to facilitate a phenotype approach in practice and improve rosacea patient management. What's already known about this topic? A transition to a phenotype approach in rosacea is underway and is being recommended by multiple working groups. New research has become available since the previous ROSCO consensus, necessitating an update and extension of recommendations. What does this study add? We offer updated global recommendations for clinical practice that account for recent research, to continue supporting the transition to a phenotype approach in rosacea. We present prototype clinical tools to facilitate use of the phenotype approach in practice and improve management of patients with rosacea.

Applying the phenotype approach for rosacea to practice and research.

BACKGROUND: Rosacea diagnosis and classification have evolved since the 2002 National Rosacea Society expert panel subtype approach. Several working groups are now aligned to a more patient-centric phenotype approach, based on an individual's presenting signs and symptoms. However, subtyping is still commonplace across the field and an integrated strategy is required to ensure widespread progression to the phenotype approach. OBJECTIVES: To provide practical recommendations that facilitate adoption of a phenotype approach across the rosacea field. METHODS: A review of the literature and consolidation of rosacea expert experience. RESULTS: We identify challenges to implementing a phenotype approach in rosacea and offer practical recommendations to overcome them across clinical practice, interventional research, epidemiological research and basic science. CONCLUSIONS: These practical recommendations are intended to indicate the next steps in the progression from subtyping to a phenotype approach in rosacea, with the goals of improving our understanding of the disease, facilitating treatment developments and ultimately improving care for patients with rosacea.

Cathelicidin suppresses lipid accumulation and hepatic steatosis by inhibition of the CD36 receptor.

BACKGROUND AND OBJECTIVES: Obesity is a global epidemic which increases the risk of the metabolic syndrome. Cathelicidin (LL-37 and mCRAMP) is an antimicrobial peptide with an unknown role in obesity. We hypothesize that cathelicidin expression correlates with obesity and modulates fat mass and hepatic steatosis. MATERIALS AND METHODS: Male C57BL/6 J mice were fed a high-fat diet. Streptozotocin was injected into mice to induce diabetes. Experimental groups were injected with cathelicidin and CD36 overexpressing lentiviruses. Human mesenteric fat adipocytes, mouse 3T3-L1 differentiated adipocytes and human HepG2 hepatocytes were used in the in vitro experiments. Cathelicidin levels in non-diabetic, prediabetic and type II diabetic patients were measured by enzyme-linked immunosorbent assay. RESULTS: Lentiviral cathelicidin overexpression reduced hepatic steatosis and decreased the fat mass of high-fat diet-treated diabetic mice. Cathelicidin overexpression reduced mesenteric fat and hepatic fatty acid translocase (CD36) expression that was reversed by lentiviral CD36 overexpression. Exposure of adipocytes and hepatocytes to cathelicidin significantly inhibited CD36 expression and reduced lipid accumulation. Serum cathelicidin protein levels were significantly increased in non-diabetic and prediabetic patients with obesity, compared with non-diabetic patients with normal body mass index (BMI) values. Prediabetic patients had lower serum cathelicidin protein levels than non-diabetic subjects. CONCLUSIONS: Cathelicidin inhibits the CD36 fat receptor and lipid accumulation in adipocytes and hepatocytes, leading to a reduction of fat mass and hepatic steatosis in vivo. Circulating cathelicidin levels are associated with increased BMI. Our results demonstrate that cathelicidin modulates the development of obesity.

A randomized controlled double-blind investigation of the effects of vitamin D dietary supplementation in subjects with atopic dermatitis.

BACKGROUND: Subjects with atopic dermatitis (AD) have defects in antimicrobial peptide (AMP) production possibly contributing to an increased risk of infections. In laboratory models, vitamin D can alter innate immunity by increasing AMP production. OBJECTIVE: To determine if AD severity correlates with baseline vitamin D levels, and to test whether supplementation with oral vitamin D alters AMP production in AD skin. METHODS: This was a multi-centre, placebo-controlled, double-blind study in 30 subjects with AD, 30 non-atopic subjects, and 16 subjects with psoriasis. Subjects were randomized to receive either 4000 IU of cholecalciferol or placebo for 21 days. At baseline and day 21, levels of 25-hydroxyvitamin D (25OHD), cathelicidin, HBD-3, IL-13, and Eczema Area and Severity Index (EASI) and Rajka-Langeland scores were obtained. RESULTS: At baseline, 20% of AD subjects had serum 25OHD below 20 ng/mL. Low serum 25OHD correlated with increased Fitzpatrick Skin Type and elevated BMI, but not AD severity. After 21 days of oral cholecalciferol, mean serum 25OHD increased, but there was no significant change in skin cathelicidin, HBD-3, IL-13 or EASI scores. CONCLUSIONS: This study illustrated that darker skin types and elevated BMI are important risk factors for vitamin D deficiency in subjects with AD, and highlighted the possibility that seasonality and locale may be potent contributors to cathelicidin induction through their effect on steady state 25OHD levels. Given the molecular links between vitamin D and immune function, further study of vitamin D supplementation in subjects with AD is warranted.

Intrarectal administration of mCRAMP-encoding plasmid reverses exacerbated colitis in Cnlp(-/-) mice.

Cathelicidin is a pleiotropic host defense peptide secreted by epithelial and immune cells. Whether endogenous cathelicidin is protective against ulcerative colitis, however, is unclear. Here we sought to delineate the role of endogenous murine cathelicidin (mCRAMP) and the therapeutic efficacy of intrarectal administration of mCRAMP-encoding plasmid in ulcerative colitis using dextran sulfate sodium (DSS)-challenged cathelicidin-knockout (Cnlp(-/-)) mice as a model. Cnlp(-/-) mice had more severe symptoms and mucosal disruption than the wild-type mice in response to DSS challenge. The tissue levels of interleukin-1ß and tumor necrosis factor-α, myeloperoxidase activity and the number of apoptotic cells were increased in the colon of DSS-challenged Cnlp(-/-) mice. Moreover, mucus secretion and mucin gene expression were impaired in Cnlp(-/-) mice. All these abnormalities were reversed by the intrarectal administration of mCRAMP or mCRAMP-encoding plasmid. Taken together, endogenous cathelicidin may protect against ulcerative colitis through modulation of inflammation and mucus secretion.

Cathelicidin protects against Helicobacter pylori colonization and the associated gastritis in mice.

Cathelicidin, an antimicrobial peptide of the innate immune system, has been shown to modulate microbial growth, wound healing and inflammation. However, whether cathelicidin controls Helicobacter pylori infection in vivo remains unexplored. This study sought to elucidate the role of endogenous and exogenous mouse cathelicidin (CRAMP) in the protection against H. pylori infection and the associated gastritis in mice. Results showed that genetic ablation of CRAMP in mice significantly increased the susceptibility of H. pylori colonization and the associated gastritis as compared with the wild-type control. Furthermore, replenishment with exogenous CRAMP, delivered via a bioengineered CRAMP-secreting strain of Lactococcus lactis, reduced H. pylori density in the stomach as well as the associated inflammatory cell infiltration and cytokine production. Collectively, these findings indicate that cathelicidin protects against H. pylori infection and its associated gastritis in vivo. Our study also demonstrates the feasibility of using the transformed food-grade bacteria to deliver cathelicidin, which may have potential clinical applications in the treatment of H. pylori infection in humans.

Induction and exacerbation of psoriasis with Interferon-alpha therapy for hepatitis C: a review and analysis of 36 cases.

BACKGROUND: Interferon-alpha (IFN-α) therapy is used to treat hepatitis C infection. The exacerbation and occurrence of psoriasis in hepatitis C patients treated with IFN-α is increasingly recognized, but the distinct associated features, aetiology and management have not been reviewed. OBJECTIVE: To review all published cases of hepatitis C patients who developed psoriasis while receiving IFN-α therapy. METHODS: The review was conducted by searching the PubMed database using the keywords 'hepatitis C' AND 'psoriasis.' In addition, references to additional publications not indexed for PubMed were followed to obtain a complete record of published data. RESULTS: We identified 32 publications describing 36 subjects who developed a psoriatic eruption while receiving IFN-α therapy for hepatitis C. Topical therapies were a commonly employed treatment modality, but led to resolution in only 30% of cases in which they were employed solely. Cessation of IFN-α therapy led to resolution in 93% of cases. Hundred per cent of those who developed psoriasis while on IFN-α therapy responded to systemic therapy and were able to continue the drug. CONCLUSION: Further studies and analysis of IFN-α-induced lesions are necessary to clarify the role of IFN-α and the hepatitis C virus in the development of psoriatic lesions.

Dermatan sulfate activates nuclear factor-kappab and induces endothelial and circulating intercellular adhesion molecule-1.

Proteoglycans (PGs) can influence cell behaviors through binding events mediated by their glycosaminoglycan (GAG) chains. This report demonstrates that chondroitin sulfate B, also known as dermatan sulfate (DS), a major GAG released during the inflammatory phase of wound repair, directly activates cells at the physiologic concentrations of DS found in wounds. Cultured human dermal microvascular endothelial cells exposed to DS responded with rapid nuclear translocation of nuclear factor-kappaB (NF-kappaB), increased expression of intercellular adhesion molecule-1 (ICAM-1) mRNA, and increased ICAM-1 cell surface protein. Heparan sulfate and chondroitin sulfates A and C had no effect on activation of NF-kappaB or induction of ICAM-1. Inhibition of NF-kappaB activation blocked the effect of DS. The increase in cell surface ICAM-1 did not involve TNF-alpha or IL-1 release by endothelial cells, but it was facilitated by autocrine factors whose release was initiated by DS. The ICAM-1-inductive activity of DS was confirmed in vivo. Injection of DS, but not heparin or other chondroitin sulfates, into mice greatly increased circulating levels of soluble ICAM. These data provide evidence that DS, but not other GAGs, initiates a previously unrecognized cell signaling event that can act during the response to injury.

Antimicrobial peptides: an essential component of the skin defensive barrier.

The skin is positioned at the interface between an organism's internal milieu and an external environment characterized by constant assault with potential microbial pathogens. While the skin was formerly considered an inactive physical protective barrier that participates in host immune defense merely by blocking entry of microbial pathogens, it is now apparent that a major role of the skin is to defend the body by rapidly mounting an innate immune response to injury and microbial insult. In the skin, both resident and infiltrating cells synthesize and secrete small peptides that demonstrate broad-spectrum antimicrobial activity against bacteria, fungi, and enveloped viruses. Antimicrobial peptides also act as multifunctional immune effectors by stimulating cytokine and chemokine production, angiogenesis, and wound healing. Cathelicidins and defensins comprise two major families of skin-derived antimicrobial peptides, although numerous others have been described. Many such immune defense molecules are currently being developed therapeutically in an attempt to combat growing bacterial resistance to conventional antibiotics.

Members of the syndecan family of heparan sulfate proteoglycans are expressed in distinct cell-, tissue-, and development-specific patterns.

The syndecans are a gene family of four transmembrane heparan sulfate proteoglycans that bind, via their HS chains, diverse components of the cellular microenvironment. To evaluate the expression of the individual syndecans, we prepared cDNA probes to compare mRNA levels in various adult mouse tissues and cultured mouse cells representing various epithelial, fibroblastic, endothelial, and neural cell types and B cells at various stages of differentiation. We also prepared antibody probes to assess whether the extracellular domains of the individual syndecans are shed into the conditioned media of cultured cells. Our results show that all cells and tissues studied, except B-stem cells, express at least one syndecan family member; most cells and tissues express multiple syndecans. However, each syndecan family member is expressed selectively in cell-, tissue-, and development-specific patterns. The extracellular domain of all syndecan family members is shed as an intact proteoglycan. Thus, most, if not all, cells acquire a distinctive repertoire of the four syndecan family members as they differentiate, resulting in selective patterns of expression that likely reflect distinct functions.

Characterization of the plasma and mitochondrial membrane potentials of alveolar type II cells by the use of ionic probes.

The lipophilic cation triphenylmethylphosphonium (TPMP+) and the potassium analog Rb+, were used to monitor the membrane potential (delta psi) of freshly isolated rabbit type II alveolar epithelial cells. Type II cells were found to accumulate TPMP+ rapidly at 37 degrees C in Hanks' balanced-salt solution with 5 microM tetraphenyl boron, but this accumulation was partially due to non-membrane potential dependent binding of TPMP+ to the cell. Lysophosphatidylcholine (lysoPC) was found to abolish delta psi and permitted correction for bound TPMP+ or Rb+. TPMP+ remaining in the cell following correction for binding represents the sum of mitochondrial and plasma membrane potential dependent accumulation. The accumulation of Rb+ by the type II cell was found to be independent of the mitochondrial membrane potential and indicated a trans-plasma membrane Rb+ distribution potential of -62.9 +/- 4 mV. A similar value was obtained by estimating the plasma membrane potential dependent accumulation of TPMP+ in type II cells whose mitochondria were depolarized with carbonylcyanide m-chlorophenylhydrazone (CCCP). The release of TPMP+ due to CCCP treatment also permitted an estimation for the trans-mitochondrial membrane potential of -141.8 +/- 10 mV. These techniques of membrane potential measurements were found to be sensitive to changes in delta psi induced by a number of inhibitors and ionophores. The ability to measure the membrane potential of the type II pneumocyte, and the changes caused by various agents, should be useful in characterizing the functional responses of this pulmonary surfactant producing cell.

Antimicrobial peptides: an emerging concept in cutaneous biology.

Antimicrobial peptides are part of the host defense systems of plants, insects, fish, amphibia, birds, and mammals. These small proteins were previously thought of as an evolutionarily ancient system of immune protection with little relevance to the normal function of human skin. Recent developments have found that mammalian skin expresses these gene-encoded peptide antibiotics during inflammatory events such as wound repair, contact dermatitis, and psoriasis. The presence of these peptides in the skin forms a barrier for innate host protection against microbial pathogenesis. Furthermore, antimicrobial peptides also act on animal cells by stimulating them to change behaviors such as syndecan expression, chemotaxis, and chloride secretion. The combination of effects on host cells with antimicrobial action in a single molecule represents an efficient defense and response system against injury. Understanding the action of antimicrobial peptides in skin may yield further insight into the mechanism of innate cutaneous disease control and provide new approaches to therapy of wounds and inflammatory dermatitis.

Anti-microbial activity and cell binding are controlled by sequence determinants in the anti-microbial peptide PR-39.

PR-39 is a member of the proline-rich group of cathelicidin peptides, a class of anti-microbial peptides found in skin and in leukocytes. In addition to their innate defense function, these proline-rich peptides influence a number of mammalian cell processes, including inflammation, development, differentiation, and metastatic transformation. To characterize the mechanism further, through which proline-rich cathelicidin peptides may exert their numerous effects, we altered various conserved peptide sequence motifs using a biologically active fragment of PR-39 [PR-39(15)] as the template: We altered the N-terminal charge of its SH3 binding motif, substituted tryptophan for a conserved intervening leucine, and modified a proline-arginine stretch (residues 10-13). These peptide variants were tested for binding known targets of PR-39 and for biologic activity in mammalian and bacterial systems. We found that the N-terminal arginines are crucial for protein binding and that modification in this domain results in loss of affinity and specificity in binding to generalized and SH3-containing targets. The N-terminal charged residues are also required for NIH 3T3 syndecan induction and anti-microbial activity. In addition, modification of more C-terminal residues eliminates anti-bacterial activity while having less of an effect on peptide interactions in mammalian cell assays. This study shows that the presence of a charged N-terminus is important for peptide activity in both mammalian and bacterial systems whereas the C-terminal alterations of PR-39(15) more definitively affect anti-bacterial activity.

Structure-function relations in the inhibition of murine contact hypersensitivity by amiloride.

Topical application of amiloride, a potent inhibitor of the Na+/H+ antiport, inhibits cutaneous inflammation induced by ultraviolet radiation or contact hypersensitivity in mice. Amiloride analogues with greater and lesser inhibition of the Na+/H+ exchange were tested to determine whether anti-inflammatory effects correlate with this activity. Structural analogues of amiloride without significant activity at the Na+/H+ antiport (pyrazine, pyrazinamide, and chloropyrazine) failed to inhibit contact hypersensitivity. N-amidino-3-amino-5-dimethyl amino-6-chloropyrazinecarboxamide (DMA) has a 23-fold greater affinity for the Na+/H+ antiport compared to amiloride, but failed to inhibit contact hypersensitivity in this assay. 3,5-diamino-6-chloropyrazine-amido-guanidine (DCG), which has only 7% of the affinity of amiloride for the antiport, suppressed contact hypersensitivity as well as amiloride. Experiments examining the ability of these agents to diffuse through mouse skin revealed amiloride to be superior to both DCG and DMA, which were approximately equal. DMA, with greater inhibition of the Na+/H+ antiport but lesser ability to inhibit contact hypersensitivity, inhibited protein synthesis and induced cell death more than amiloride or DCG. Amiloride and DCG hold promise as topical anti-inflammatory agents. Their anti-inflammatory properties do not correlate with affinity for the Na+/H+ antiport, ability to penetrate murine skin, or inhibition of protein synthesis.

Cyclosporin increases granulocyte/macrophage colony-stimulating factor (GM-CSF) activity and gene expression in murine keratinocytes.

Keratinocytes produce multiple cytokines in response to a variety of stimuli. The release of interleukin 1 (IL-1) from keratinocytes may be significant in initiation of cutaneous inflammation, and the presence of granulocyte/macrophage colony-stimulating factor (GM-CSF) is thought to be important in the regulation of antigen-presenting function by epidermal Langerhans cells. Because cyclosporin inhibits interleukin 2 release from T cells, it has been suggested that cyclosporin may function as an anti-inflammatory agent within the epidermis through inhibition of keratinocyte cytokine release. This investigation examined the direct effect of cyclosporin on the production of GM-CSF by murine keratinocytes and the keratinocyte cell line PAM 212. GM-CSF bioactivity increased in cell supernatants from keratinocytes exposed in vitro to 1 microgram/ml cyclosporin for up to 24 h. GM-CSF and IL-1 mRNA levels in keratinocytes cultured under similar conditions or in the presence of lipopolysaccharide also increased. The lack of inhibition of GM-CSF expression following cyclosporin treatment is consistent with recent observations in T cells and is opposite to the effect of cyclosporin on interleukin 2.

Endothelial cell surface alkaline phosphatase activity is induced by IL-6 released during wound repair.

Phosphatase activity on endothelial cell surfaces is responsible, in part, for the conversion of adenosine nucleotides to adenosine, a potent vasodilator and anti-inflammatory mediator that can protect tissues from the ischemic damage that results from injury. To evaluate whether phosphatases are actively induced by a soluble factor released following injury, the effect of tissue fluids collected from porcine or human skin wounds was tested on primary cultures of endothelial cells. Phosphatase activity increased approximately 50-fold following 48-h culture in the presence of wound fluid. Inductive activity was present only in fluids collected during the inflammatory phase of wound repair. The phosphatase activity metabolized adenosine monophosphate to free phosphate and was the liver/bone/kidney alkaline phosphatase isoenzyme: activity was temperature- and levamisole-sensitive, 1-phenylalanine-resistant, and linked to the cell surface via phospholipid, and migrated at a size identical to this isozyme. interleukin-6 was identified as the phosphatase-inducing factor in wound fluid and the related cytokines, leukaemia inhibiting factor, and oncostatin M, caused a similar degree of alkaline phosphatase induction. Therefore, following injury, accumulation of interleukin-6 can lead to production by alkaline phosphatase of adenosine and subsequent protection from ischemic injury.

Regulation of GM-CSF and IL-3 production from the murine keratinocyte cell line PAM 212 following exposure to ultraviolet radiation.

Ultraviolet radiation (UVR) exposure induces profound changes in the synthesis and secretion of various cytokines both in vivo and in vitro. Little is known regarding the mechanism of these responses. This investigation evaluated the effects of UVR on the ability of a murine keratinocyte line (PAM 212) to produce interleukin 3 (IL-3) and granulocyte-macrophage colony stimulating factor (GM-CSF). Subconfluent rapidly dividing PAM 212 cells were shown by RNA slot-blot hybridization studies to have increased levels of mRNA for both IL-3 and GM-CSF within 1 h of UVR exposure. However, only GM-CSF-specific bioactivity, as determined by antibody neutralization studies, was shown to increase above baseline in cell supernatants. Cells grown to confluence responded differently to UVR. Under these culture conditions an apparent decrease in bioactivity was detected after UVR exposure for both growth factors, and no change in mRNA levels was detected. In addition to culture density, removal of extracellular calcium or sodium during irradiation, treatment with amiloride, or inhibition of new mRNA synthesis with cordycepin was shown to influence the UVR-induced alteration in release of IL-3 or GM-CSF bioactivity from both confluent and subconfluent PAM 212 cells. These results demonstrate that UVR influences the release of the colony stimulating factors GM-CSF and IL-3 from keratinocyte, and suggests that the state of cell growth and conditions of membrane ion transport influence the mechanisms regulating secretion of those factors.

Cutaneous injury induces the release of cathelicidin anti-microbial peptides active against group A Streptococcus.

Cathelicidins are a family of peptides thought to provide an innate defensive barrier against a variety of potential microbial pathogens. The human and mouse cathelicidins (LL-37 and CRAMP, respectively) are expressed at select epithelial interfaces where they have been proposed to kill a number of gram-negative and gram-positive bacteria. To determine if these peptides play a part in the protection of skin against wound infections, the anti-microbial activity of LL-37 and CRAMP was determined against the common wound pathogen group A Streptococcus, and their expression was examined after cutaneous injury. We observed a large increase in the expression of cathelicidins in human and murine skin after sterile incision, or in mouse following infection by group A Streptococcus. The appearance of cathelicidins in skin was due to both synthesis within epidermal keratinocytes and deposition from granulocyctes that migrate to the site of injury. Synthesis and deposition in the wound was accompanied by processing from the inactive prostorage form to the mature C-terminal peptide. Analysis of anti-microbial activity of this C-terminal peptide against group A Streptococcus revealed that both LL-37 and CRAMP potently inhibited bacterial growth. Action against group A Streptococcus occurred in conditions that typically abolish the activity of anti-microbial peptides against other organisms. Thus, cathelicidins are well suited to provide defense against infections due to group A Streptococcus, and represent an important element of cutaneous innate immunity.