Non-psoriatic dermatologic uses of monoclonal antibody therapy

Pyoderma gangrenosum after cesarean section treated with skin graft: A case report

RATIONALE

Pyoderma gangrenosum (PG) is a rare skin disease. Pregnancy is a unique physiological condition. Here we report a rare case of PG after cesarean section.

PATIENT CONCERNS

A 32-year-old female presented with wound breakdown 1 day after cesarean section, with progression to a skin ulcer and no response to antibiotic therapy.

DIAGNOSES

We experienced a case of PG after cesarean section. This was initially misdiagnosed as a wound infection, with fever and wound redness as clinical manifestations.

INTERVENTIONS

The patient was initially treated with antibiotics, followed by glucocorticoid and human immunoglobulin therapy. Wound debridement, vacuum sealing negative pressure drainage, skin grafting, and hyperbaric oxygen therapy were also performed.

OUTCOMES

The wound healed without adverse reactions.

LESSONS

When a surgical incision infection does not respond to antibiotic treatment and the culture is negative, PG should be considered.

A clinical audit of high-cost and off-label drug use in dermatology

BACKGROUND/OBJECTIVES

The use of high-cost, off-label, unsubsidised drugs has become valuable in the management of dermatology patients with challenging conditions unresponsive to conventional therapy. Currently, there is no dedicated funding and a paucity of evidence for such drugs. The aim of this audit was to review outcomes and costs.

METHODS

A retrospective clinical audit of high-cost off-label dermatology drug applications to the High Cost Drug's Subcommittee was undertaken at a tertiary public hospital in Brisbane, Queensland, between 2002 and 2013.

RESULTS

Of 28 applications, 25 were approved. The medications included thalidomide, mycophenolate mofetil, cyclosporin, infliximab, rituximab and adalimumab. Over 70% of patients responded to treatment. Individual annual costs for these medications ranged from $2068 to $36 984. Adverse effects resulted in drug withdrawal in five cases.

CONCLUSIONS

Despite the absence of dedicated funding for high-cost drugs and a rigorous committee approval process, most applications were approved, of which >70% benefited from treatment. This audit provides useful clinical experience with off-label use of high-cost drugs in difficult dermatological conditions.

Genome wide transcriptome analysis of dendritic cells identifies genes with altered expression in psoriasis

Activation of dendritic cells by different pathogens induces the secretion of proinflammatory mediators resulting in local inflammation. Importantly, innate immunity must be properly controlled, as its continuous activation leads to the development of chronic inflammatory diseases such as psoriasis. Lipopolysaccharide (LPS) or peptidoglycan (PGN) induced tolerance, a phenomenon of transient unresponsiveness of cells to repeated or prolonged stimulation, proved valuable model for the study of chronic inflammation. Thus, the aim of this study was the identification of the transcriptional diversity of primary human immature dendritic cells (iDCs) upon PGN induced tolerance. Using SAGE-Seq approach, a tag-based transcriptome sequencing method, we investigated gene expression changes of primary human iDCs upon stimulation or restimulation with Staphylococcus aureus derived PGN, a widely used TLR2 ligand. Based on the expression pattern of the altered genes, we identified non-tolerizeable and tolerizeable genes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (Kegg) analysis showed marked enrichment of immune-, cell cycle- and apoptosis related genes. In parallel to the marked induction of proinflammatory mediators, negative feedback regulators of innate immunity, such as TNFAIP3, TNFAIP8, Tyro3 and Mer are markedly downregulated in tolerant cells. We also demonstrate, that the expression pattern of TNFAIP3 and TNFAIP8 is altered in both lesional, and non-lesional skin of psoriatic patients. Finally, we show that pretreatment of immature dendritic cells with anti-TNF-α inhibits the expression of IL-6 and CCL1 in tolerant iDCs and partially releases the suppression of TNFAIP8. Our findings suggest that after PGN stimulation/restimulation the host cell utilizes different mechanisms in order to maintain critical balance between inflammation and tolerance. Importantly, the transcriptome sequencing of stimulated/restimulated iDCs identified numerous genes with altered expression to date not associated with role in chronic inflammation, underlying the relevance of our in vitro model for further characterization of IFN-primed iDCs.

Genome wide transcriptome analysis of dendritic cells identifies genes with altered expression in psoriasis

Activation of dendritic cells by different pathogens induces the secretion of proinflammatory mediators resulting in local inflammation. Importantly, innate immunity must be properly controlled, as its continuous activation leads to the development of chronic inflammatory diseases such as psoriasis. Lipopolysaccharide (LPS) or peptidoglycan (PGN) induced tolerance, a phenomenon of transient unresponsiveness of cells to repeated or prolonged stimulation, proved valuable model for the study of chronic inflammation. Thus, the aim of this study was the identification of the transcriptional diversity of primary human immature dendritic cells (iDCs) upon PGN induced tolerance. Using SAGE-Seq approach, a tag-based transcriptome sequencing method, we investigated gene expression changes of primary human iDCs upon stimulation or restimulation with Staphylococcus aureus derived PGN, a widely used TLR2 ligand. Based on the expression pattern of the altered genes, we identified non-tolerizeable and tolerizeable genes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (Kegg) analysis showed marked enrichment of immune-, cell cycle- and apoptosis related genes. In parallel to the marked induction of proinflammatory mediators, negative feedback regulators of innate immunity, such as TNFAIP3, TNFAIP8, Tyro3 and Mer are markedly downregulated in tolerant cells. We also demonstrate, that the expression pattern of TNFAIP3 and TNFAIP8 is altered in both lesional, and non-lesional skin of psoriatic patients. Finally, we show that pretreatment of immature dendritic cells with anti-TNF-α inhibits the expression of IL-6 and CCL1 in tolerant iDCs and partially releases the suppression of TNFAIP8. Our findings suggest that after PGN stimulation/restimulation the host cell utilizes different mechanisms in order to maintain critical balance between inflammation and tolerance. Importantly, the transcriptome sequencing of stimulated/restimulated iDCs identified numerous genes with altered expression to date not associated with role in chronic inflammation, underlying the relevance of our in vitro model for further characterization of IFN-primed iDCs.

[Surgical management of Pyoderma gangrenosum]

Pyoderma gangrenosum is a rare affection of unknown etiology, which is often associated with systemic diseases such as chronic inflammatory bowel disease, hematologic disorders, carcinomas and arthritis. Treatment may include topical corticosteroids or calcineurin inhibitors in combination with systemic corticosteroids, cyclosporine A, azathioprine, cyclophosphamide, mycophenolate mofetil, intravenous immunoglobulins or monoclonal antibodies against TNFα but all these approaches are off-label. Surgical therapy is difficult because of pathergy. Nevertheless, after having stopped the inflammation, the ulcers can be treated by split thickness skin grafts and simultaneous immunosuppression. We present three cases with successful surgical treatment.

Erbium:YAG fractional laser ablation for the percutaneous delivery of intact functional therapeutic antibodies

The physicochemical properties and stability requirements of therapeutic proteins necessitate their parenteral administration even for local therapy; however, unnecessary systemic exposure increases the risk of avoidable side-effects. The objective of this study was to use fractional laser ablation to enable the delivery of intact, functional therapeutic antibodies into the skin in vitro and in vivo. The laser-assisted delivery of Antithymocyte globulin (ATG) and Basiliximab - FDA-approved therapeutics for the induction of immunosuppression - was investigated. In vitro delivery experiments were performed using dermatomed porcine ear and human abdominal skins; an in vitro/in vivo correlation was shown using C57 BL/10 SCSnJ mice. Antibody transport was quantified by using ELISA methods developed in-house. Results showed that increasing the pore number from 300 to 450 and 900, increased total antibody delivery (sum of amounts permeated and deposited); e.g., for ATG, from 1.18±0.10 to 3.98±0.64 and 4.97±0.83 μg/cm(2), respectively - corresponding to 19.7-, 66.3- and 82.8-fold increases over the control (untreated skin). Increasing laser fluence from 22.65 to 45.3 and 135.9J/cm(2) increased total ATG delivery from 1.70±0.65 to 4.97±0.83 and 8.70±1.55 μg/cm(2), respectively. The Basiliximab results confirmed the findings with ATG. Western blot demonstrated antibody identity and integrity post-delivery; human lymphocyte cytotoxicity assays showed that ATG retained biological activity post-delivery. Immunohistochemical staining was used to visualize ATG distribution in the epidermis. Total ATG delivery across porcine ear and human abdominal skin was statistically equivalent and an excellent in vitro/in vivo correlation was observed in the murine model. Based on published data, the ATG concentrations achieved in the laser-porated human skins were in the therapeutic range for providing local immunosuppression. These results challenge the perceived limitations of transdermal delivery with respect to biopharmaceuticals and suggest that controlled laser microporation provides a less invasive, more patient-friendly "needle-less" alternative to parenteral administration for the local delivery of therapeutic antibodies.

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.

A case of atypical pyoderma gangrenosum

BACKGROUND

Pyoderma gangrenosum is a rare inflammatory disease of unknown etiology and unspecific histopathology. There are no clear-cut criteria for the diagnosis of this disease. The diagnosis is usually made based on clinical appereance, course of disease and possible, commonly coexisting disorders. In atypical cases the diagnosis is based on exclusion of other causes of similar appearing cutaneous ulcerations.

MAIN OBSERVATIONS

The 67-year-old male patient, presented with a 15-year history of painful ulcers and vegetative lesions covered with sero-hemorrhagic and purulent secretions, localized on the dorsal surface of both hands leading to self-amputation of distal phalanges. We report a step-by-step The patient refers to have these complaints for more than 15 years. An extensive diagnostic procedure led to the diagnosis of pyoderma gangrenosum as a diagnosis of exclusion.

CONCLUSION

This report shows an atypical variant of an ulcerative disease. Pyoderma gangrenosum, a diagnosis of exclusion, was sustained based on an extensive diagnostic procedure. In this article we describe the step-by-step approach which let to this diagnosis.