Infliximab in dermatological treatment: beyond psoriasis

Biologics for pityriasis rubra pilaris treatment: A review of the literature

Pityriasis rubra pilaris (PRP) is a rare inflammatory papulosquamous skin disease that is often refractory to conventional therapies. The off-label use of biologics, such as anti-tumor necrosis factor, anti-interleukin (IL) 12/IL-23, and anti-IL-17 agents, has been proven successful in the past 2 decades for PRP treatment. Our aim was to analyse the literature for the use of biologics in PRP treatment. We conducted a review by performing PubMed and ClinicalTrials.gov searches. Sixty-eight articles met our selection criteria and are herein discussed. Out of 86 PRP patients, the vast majority were treated with anti-tumor necrosis factor, anti-IL-12/IL-23, or anti-IL-17 biologics, either alone or in combination therapy. A marked-to-complete response was observed in 50%-78%, a partial response in 11%-25%, and no or poor response in 11%-25%. This review has several limitations, including small sample sizes and the lack of shared study design criteria. In some instances, PRP might have resolved spontaneously. Further, the presence of concomitant therapy or the lack of detailed data on previous treatments, makes it difficult to strictly define a therapeutic role per se of specific biologics in PRP. This review shows that biologics may be regarded as a tool for PRP treatment alone or in combination therapy although clinical trials are needed to better assess their efficacy and safety.

Role of Ceramide from Glycosphingolipids and Its Metabolites in Immunological and Inflammatory Responses in Humans

Glycosphingolipids (GSLs) are composed of hydrophobic ceramide and hydrophilic sugar chains. GSLs cluster to form membrane microdomains (lipid rafts) on plasma membranes, along with several kinds of transducer molecules, including Src family kinases and small G proteins. However, GSL-mediated biological functions remain unclear. Lactosylceramide (LacCer, CDw17) is highly expressed on the plasma membranes of human phagocytes and mediates several immunological and inflammatory reactions, including phagocytosis, chemotaxis, and superoxide generation. LacCer forms membrane microdomains with the Src family tyrosine kinase Lyn and the Gαi subunit of heterotrimeric G proteins. The very long fatty acids C24:0 and C24:1 are the main ceramide components of LacCer in neutrophil plasma membranes and are directly connected with the fatty acids of Lyn and Gαi. These observations suggest that the very long fatty acid chains of ceramide are critical for GSL-mediated outside-in signaling. Sphingosine is another component of ceramide, with the hydrolysis of ceramide by ceramidase producing sphingosine and fatty acids. Sphingosine is phosphorylated by sphingosine kinase to sphingosine-1-phosphate, which is involved in a wide range of cellular functions, including growth, differentiation, survival, chemotaxis, angiogenesis, and embryogenesis, in various types of cells. This review describes the role of ceramide moiety of GSLs and its metabolites in immunological and inflammatory reactions in human.

Nail psoriasis: the journey so far

Nail involvement is an extremely common feature of psoriasis and affects approximately 10-78% of psoriasis patients with 5-10% of patients having isolated nail psoriasis. However, it is often an overlooked feature in the management of nail psoriasis, despite the significant burden it places on the patients as a result of functional impairment of manual dexterity, pain, and psychological stress. Affected nail plates often thicken and crumble, and because they are very visible, patients tend to avoid normal day-to-day activities and social interactions. Importantly, 70-80% of patients with psoriatic arthritis have nail psoriasis. In this overview, we review the clinical manifestations of psoriasis affecting the nails, the common differential diagnosis of nail psoriasis, Nail Psoriasis Severity Index and the various diagnostic aids for diagnosing nail psoriasis especially, the cases with isolated nail involvement. We have also discussed the available treatment options, including the topical, physical, systemic, and biological modalities, in great detail in order to equip the present day dermatologist in dealing with a big clinical challenge, that is, management of nail psoriasis.

Pseudomonas-derived ceramidase induces production of inflammatory mediators from human keratinocytes via sphingosine-1-phosphate

Ceramide is important for water retention and permeability barrier functions in the stratum corneum, and plays a key role in the pathogenesis of atopic dermatitis (AD). A Pseudomonas aeruginosa-derived neutral ceramidase (PaCDase) isolated from a patient with AD was shown to effectively degrade ceramide in the presence of Staphylococcus aureus-derived lipids or neutral detergents. However, the effect of ceramide metabolites on the functions of differentiating keratinocytes is poorly understood. We found that the ceramide metabolite sphingosine-1-phosphate (S1P) stimulated the production of inflammatory mediators such as TNF-α and IL-8 from three-dimensionally cultured human primary keratinocytes (termed "3D keratinocytes"), which form a stratum corneum. PaCDase alone did not affect TNF-α gene expression in 3D keratinocytes. In the presence of the detergent Triton X-100, which damages stratum corneum structure, PaCDase, but not heat-inactivated PaCDase or PaCDase-inactive mutant, induced the production of TNF-α, endothelin-1, and IL-8, indicating that this production was dependent on ceramidase activity. Among various ceramide metabolites, sphingosine and S1P enhanced the gene expression of TNF-α, endothelin-1, and IL-8. The PaCDase-enhanced expression of these genes was inhibited by a sphingosine kinase inhibitor and by an S1P receptor antagonist VPC 23019. The TNF-α-binding antibody infliximab suppressed the PaCDase-induced upregulation of IL-8, but not TNF-α, mRNA. PaCDase induced NF-κB p65 phosphorylation. The NF-κB inhibitor curcumin significantly inhibited PaCDase-induced expression of IL-8 and endothelin-1. VPC 23019 and infliximab inhibited PaCDase-induced NF-κB p65 phosphorylation and reduction in the protein level of the NF-κB inhibitor IκBα. Collectively, these findings suggest that (i) 3D keratinocytes produce S1P from sphingosine, which is produced through the hydrolysis of ceramide by PaCDase, (ii) S1P induces the production of TNF-α via S1P receptors, and (iii) released TNF-α stimulates the production of inflammatory mediators such as IL-8.

The use of biologic agents in pediatric inflammatory bowel disease

PURPOSE OF REVIEW

Therapeutic options and approaches in inflammatory bowel disease (IBD) continue to evolve. This review will summarize the recent studies of treatment strategies, efficacy, safety and outcome of biological agents in the treatment of children with Crohn's disease and ulcerative colitis.

RECENT FINDINGS

Although there has been little recent change in the number of biologicals easily available for the treatment of children, usage has broadened in pediatric IBD and new treatment strategies have emerged. The use of biologicals in refractory pediatric ulcerative colitis is now accepted, with evidence supporting their potential for maintenance therapy. In pediatric Crohn's disease, scheduled treatment regimens have shown superiority to episodic treatment. Although the 'top-down' approach with early use of biologicals produces superior remission rates in adults, there is still little evidence in children. Concomitant immunosuppression appears to reduce immunogenicity and improve therapeutic control, but there are added risks for infection and malignancy.

SUMMARY

Biologicals now form an integral part of the treatment algorithm in childhood IBD and their use is likely to increase. Treatment regimens, particularly those involving concomitant immunosuppressants, need to take account of the perceptions of risk.

[Association of pityriasis rubra pilaris and myasthenia]

Le pityriasis rubra pilaire est un trouble de kératinisation rare dont l’étiopathogénie reste inconnue mais dont l'association avec autres pathologies a été déjà rapportée. Nous rapportons l'observation d'une jeune patiente qui présente un pityriasis rubra pilaire associé à une myasthénie. Traitée par Néostigmine et thymectomie avec bonne évolution sur le plan neurologique. Vu son désir de grossesse un traitement systémique de son pityriasis rubra pilaire n'a pas pu être instauré et l’évolution sous dermocorticoïdes n’était pas très favorable.

Human mast cell degranulation and preformed TNF secretion require mitochondrial translocation to exocytosis sites: relevance to atopic dermatitis

BACKGROUND

Mast cells derive from hematopoietic cell precursors and participate in tissue allergic, immune, and inflammatory processes. They secrete many mediators, including preformed TNF, in response to allergic, neuropeptide, and environmental triggers. However, regulation of mast cell degranulation is not well understood.

OBJECTIVE

We investigated the role of mitochondrial dynamics in degranulation of human cultured mast cells.

METHODS

Human umbilical cord blood-derived mast cells (hCBMCs) and Laboratory of Allergic Diseases 2 (LAD2) mast cells were examined by confocal and differential interference contrast microscopy during activation by IgE/antigen and substance P (SP). Mast cells in control and atopic dermatitis (AD) skin were evaluated by transmission electron microscopy. LAD2 cells were pretreated with mitochondrial division inhibitor, a dynamin-related protein 1 (Drp1) inhibitor, and small interfering RNA for Drp1, which is necessary for mitochondrial fission and translocation. Calcineurin and Drp1 gene expression was analyzed in stimulated LAD2 cells and AD skin biopsies.

RESULTS

Stimulation of hCBMCs with IgE/antigen or LAD2 cells with SP leads to rapid (30 minutes) secretion of preformed TNF. Degranulation is accompanied by mitochondrial translocation from a perinuclear location to exocytosis sites. Extracellular calcium depletion prevents these effects, indicating calcium requirement. The calcium-dependent calcineurin and Drp1 are activated 30 minutes after SP stimulation. Reduction of Drp1 activity by mitochondrial division inhibitor and decrease of Drp1 expression using small interfering RNA inhibit mitochondrial translocation, degranulation, and TNF secretion. Mitochondrial translocation is also evident by transmission electron microscopy in skin mast cells from AD biopsies, in which gene expression of calcineurin, Drp1, and SP is higher than in normal skin.

CONCLUSION

Human mast cell degranulation requires mitochondrial dynamics, also implicated in AD.

Pityriasis rubra pilaris presenting with an abnormal autoimmune profile: two case reports

INTRODUCTION

Pityriasis rubra pilaris is an uncommon inflammatory and hyperproliferative dermatosis of juvenile or adult onset. The etiology of the disease is still unknown.

CASE PRESENTATION

We present the cases of two Caucasian men aged 53 and 48 who presented with pityriasis rubra pillaris type 1; both patients also exhibited an abnormal immunological profile.

CONCLUSION

Pityriasis rubra pillaris is currently classified as a keratinization disorder. The abnormal immunological profile reported in our patients along with the comorbidity of pityriasis rubra pilaris with autoimmune disorders reported in the literature poses the question of a possible pathogenetic role for the immune response in this disorder.

A3 adenosine receptor: pharmacology and role in disease

The study of the A(3) adenosine receptor (A(3)AR) represents a rapidly growing and intense area of research in the adenosine field. The present chapter will provide an overview of the expression patterns, molecular pharmacology and functional role of this A(3)AR subtype under pathophysiological conditions. Through studies utilizing selective A(3)AR agonists and antagonists, or A(3)AR knockout mice, it is now clear that this receptor plays a critical role in the modulation of ischemic diseases as well as in inflammatory and autoimmune pathologies. Therefore, the potential therapeutic use of agonists and antagonists will also be described. The discussion will principally address the use of such compounds in the treatment of brain and heart ischemia, asthma, sepsis and glaucoma. The final part concentrates on the molecular basis of A(3)ARs in autoimmune diseases such as rheumatoid arthritis, and includes a description of clinical trials with the selective agonist CF101. Based on this chapter, it is evident that continued research to discover agonists and antagonists for the A(3)AR subtype is warranted.