Kyle T. Amber

The Merkel Cell Polyomavirus and Its Involvement in Merkel Cell Carcinoma

BACKGROUND The discovery of the Merkel cell polyomavirus (MCV) in a large number of Merkel cell carcinomas (MCCs) has led to many investigations into its potential role as an oncovirus. Many studies have recently explored the differences between MCCs infected and not infected with MCV. OBJECTIVE To review the role of MCV in MCC and its potential to influence diagnosis, prognosis, and treatment. METHODS AND MATERIALS An extensive literature search was performed on MCV and its relationship with other polyomaviruses and MCC. The immune systems role in MCC was also investigated. RESULTS We included 60 articles regarding MCC and MCV and seven pertinent to general processes involved with MCC and MCV. CONCLUSION Merkel cell polyomavirus appears to affect many aspects of MCC. An understanding of this virus may aid in future therapy options and current pathology protocols in diagnosing MCC. The hosts immune function appears to affect MCVs ability to cause cellular transformation leading to MCC.

Autoreactive T cells in the immune pathogenesis of pemphigus vulgaris

Pemphigus vulgaris is a life‐threatening autoimmune blistering disease caused by anti‐desmoglein IgG autoantibodies that finally lead to acantholysis presenting clinically as progressive blistering. Whilst the production of pathogenic antibodies is key to the development of pemphigus vulgaris, many immunological steps are required prior to autoantibody induction. We review advances in the understanding of these immunologic processes with a focus on human leucocyte antigen polymorphisms and antigen recognition, epitope spreading, central and peripheral tolerance, T helper differentiation, induction of pro‐ and anti‐inflammatory cytokines and T‐cell regulation of B cells. Targeting autoaggressive T cells as regulators and stimulators of B‐cell antibody production should allow for more specific therapeutic immune interventions, avoiding the global immunosuppression seen with many commonly used immunosuppressants in pemphigus vulgaris.

Immune response in pemphigus and beyond: progresses and emerging concepts

Pemphigus vulgaris (PV) and pemphigus foliaceus (PF) are two severe autoimmune bullous diseases of the mucosae and/or skin associated with autoantibodies directed against desmoglein (Dsg) 3 and/or Dsg1. These two desmosomal cadherins, typifying stratified epithelia, are components of cell adhesion complexes called desmosomes and represent extra-desmosomal adhesion receptors. We herein review the advances in our understanding of the immune response underlying pemphigus, including human leucocyte antigen (HLA) class II-associated genetic susceptibility, characteristics of pathogenic anti-Dsg antibodies, antigenic mapping studies as well as findings about Dsg-specific B and T cells. The pathogenicity of anti-Dsg autoantibodies has been convincingly demonstrated. Disease activity and clinical phenotype correlate with anti-Dsg antibody titers and profile while passive transfer of anti-Dsg IgG from pemphigus patients’ results in pemphigus-like lesions in neonatal and adult mice. Finally, adoptive transfer of splenocytes from Dsg3-knockout mice immunized with murine Dsg3 into immunodeficient mice phenotypically recapitulates PV. Although the exact pathogenic mechanisms leading to blister formation have not been fully elucidated, intracellular signaling following antibody binding has been found to be necessary for inducing cell-cell dissociation, at least for PV. These new insights not only highlight the key role of Dsgs in maintenance of tissue homeostasis but are expected to progressively change pemphigus management, paving the way for novel targeted immunologic and pharmacologic therapies.

Google Search Trends and Skin Cancer: Evaluating the US Population’s Interest in Skin Cancer and Its Association With Melanoma Outcomes

ues decreased, MI values increased monotonically. We then analyzed how these measurements correlated after raw values were categorized. Although ITA and MI values place individuals into 1 of 6 skin types, these classification systems are currently unrelated, with no consensus about which MI values belong to which FST group.4,5 We found that by placing participants with MI values of 750.0 or greater in FST VI, we observed a very strong correlation between these unrelated classification systems (Spearman ρ = 0.95; P < .001) (Figure, B).

Autoimmune Subepidermal Bullous Diseases of the Skin and Mucosae: Clinical Features, Diagnosis, and Management.

Autoimmune subepidermal blistering diseases of the skin and mucosae constitute a large group of sometimes devastating diseases, encompassing bullous pemphigoid, gestational pemphigoid, mucous membrane pemphigoid, epidermolysis bullosa acquisita, and anti-p200 pemphigoid. Their clinical presentation is polymorphic. These autoimmune blistering diseases are associated with autoantibodies that target distinct components of the basement membrane zone of stratified epithelia. These autoantigens represent structural proteins important for maintenance of dermo-epidermal integrity. Bullous pemphigoid (BP) is the most common subepidermal autoimmune blistering disease of the skin and mucosae. Although the disease typically presents with a generalized blistering eruption associated with itch, atypical variants with either localized bullous lesions or “non-bullous” presentations are observed in approximately 20% of patients. A peculiar form of BP typically associated with pregnancy is pemphigoid gestationis. In anti-p200 pemphigoid, patients present with tense blisters on erythematosus or normal skin resembling BP, with a predilection for acral surfaces. These patients have antibodies targeting the 200-kDa basement membrane protein. Epidermolysis bullosa is a rare autoimmune blistering disease associated with autoantibodies against type VII collagen that can have several phenotypes including a classical form mimicking dystrophic epidermolysis bullosa, an inflammatory presentation mimicking BP, or mucous membrane pemphigoid-like lesions. Mucous membrane pemphigoid (MMP) is the term agreed upon by international consensus for an autoimmune blistering disorder, which affects one or more mucous membrane and may involve the skin. The condition involves a number of different autoantigens in the basement membrane zone. It may result in severe complications from scarring, such as blindness and strictures. Diagnosis of these diseases relies on direct immunofluorescence microscopy studies and immunoserological assays. Management of affected patients is often challenging. We will here review the clinical and immunopathological features as well as the pathophysiology of this group of organ-specific autoimmune diseases. Finally, we will discuss the diagnostic approach and the principles of management in clinical practice.

TNF-α: a treatment target or cause of sarcoidosis?

Sarcoidosis is a systemic granulomatous disease that affects numerous organs, commonly manifesting at the lungs and skin. While corticosteroids remain the first line of treatment, tumour necrosis factor alpha (TNF‐α) inhibitors have been investigated as one potential steroid sparing treatment for sarcoidosis. TNF‐α is one of many components involved in the formation of granulomas in sarcoidosis. While there have been larger scale studies of biologic TNF‐α inhibition in systemic sarcoidosis, studies in cutaneous disease are limited. Paradoxically, in some patients treated with biologic TNF‐α inhibitors for other diseases, treatment can induce the development of sarcoidosis. In the light of this complexity, we discuss the role of TNF‐α in granuloma formation, the therapeutic role of TNF‐α inhibition and immunologic abnormalities following treatment with these TNF‐α inhibitors including drug‐specific alterations involving interferon‐γ, lymphotoxin‐α, TNF receptor 2 (TNFR2) and T‐regulatory cells.

Comparing the accuracy of ultrasound versus fluoroscopy in glenohumeral injections: a systematic review and meta-analysis.

We performed a systematic review with meta‐analysis to compare the accuracy of fluoroscopic‐guided glenohumeral injections with that of ultrasound‐guided glenohumeral injections as reported in prior studies.

The Use of Antioxidants in Radiotherapy-Induced Skin Toxicity

Radiation-induced skin damage is one of the most common complications of radiotherapy. In order to combat these side effects, patients often turn to alternative therapies, which often include antioxidants. Antioxidants such as those in the polyphenol chemical class, xanthine derivatives, tocepherol, sucralfate, and ascorbate have been studied for their use in either preventing or treating radiotherapy-induced skin damage. Apart from their known role as free radical scavengers, some of these antioxidants appear to alter cytokine release affecting cutaneous and systemic changes. We review the role of antioxidants in treating and preventing radiation-induced skin damage as well as the possible complications of using such therapy.

A systematic review with pooled analysis of clinical presentation and immunodiagnostic testing in mucous membrane pemphigoid: association of anti-laminin-332 IgG with oropharyngeal involvement and the usefulness of ELISA

Mucous membrane pemphigoid (MMP) is characterized by subepithelial blistering due to IgG autoantibodies targeting various components of the dermal–epidermal basement membrane zone. Immunodiagnostics play an important role in making a precise diagnosis. Measures of test sensitivity and specificity, however, typically come from studies in diseases such as bullous pemphigoid, where the exact antigenic site may not be the same. Additionally, the association of clinical phenotype and autoantibody profiles has been an area of debate.

Prophylactic valacyclovir in a patient with recurrent vestibular disturbances secondary to vestibular neuritis.

A 57-year-old woman with herpes labialis and previously diagnosed with vestibular neuritis experienced recurrences of vertigo and disequilibrium. Initially preceded by oral herpes outbreaks or upper respiratory infections, these recurrences became spontaneous and more frequent. Vestibular function demonstrated a 25% decrease in energy function in the right and the patient had left beating nystagmus on positional maneuver. Her reoccurrences of vestibular disturbances were followed up. Concurrently, she was prescribed daily valacyclovir (500 mg, 1 per day) given for the prevention of herpes labialis outbreaks by her primary care physician. Recurrences of disequilibrium stopped completely as well as oral herpes outbreaks.