Monday, November 7, 2011

Mechanisms of Allergen-Specific Immunotherapy

Akdis CA, Akdis M. Mechanisms of allergen-specific immunotherapy. Journal of Allergy and Clinical Immunology 2011; 127:18-27; quiz: 28-29. Abstract
PubMed ID (PMID): 21211639
ReprintC. Akdis 
Comments: Like the previous review published in 2007 by the same authors in this journal, this article is remarkable because it provides a clear and precise digest on the known or suspected mechanisms of allergen-specific immunotherapy (ASIT). Such mechanisms now include:
1. an early mast cell and basophil suppression-related desensitization effect (as observed in rush immunotherapy)
2. an induction of regulatory T-cells
3. an induction of peripheral T-cell tolerance to allergens 
3. a late modulation of allergen-specific IgE and IgG responses In addition to conventional immunotherapy, sublingual and peptide immunotherapy and the use of various adjuvants are discussed herein. Finally, one can find a summary box at the end of the paper, which highlights proven mechanisms of ASIT and questions that still need to be answered. This is a recommended review for everybody: residents, allergologists or for those who still believe that ASIT is just an empirical therapy....
Recommended by: Pascal Prélaud and Ana Rostaher, Clinique Advetia, Paris, France

Sunday, November 6, 2011

Filaggrin and Human Skin Diseases

Irvine AD, McLean IWH, Leung DYM. Filaggrin mutations associated with skin and allergic skin diseases. New England Journal of Medicine 2011; 365: 1315-1327. No Abstract
PubMed ID (PMID): 21991953 
ReprintD. Leung 
Comments: This is a nicely written and well illustrated review on the structure of filaggrin, its function and the implications of FLG mutations in the pathogenesis of ichthyosis vulgaris and atopic dermatitis in humans. Don't forget to view the supplementary material, which has an additional beautiful figure.
Recommended by: Thierry Olivry, NC State University, Raleigh, North Carolina, USA

Wednesday, October 26, 2011

Update on Pruritus Mechanism

Ikoma A, Cevikbas F, Kempkes C et al. Anatomy and neurophysiology of pruritus. Seminars in Cutaneous Medicine and Surgery 2011; 30: 64-70. Abstract
PubMed ID (PMID): 21767766
ReprintA. Ikoma 
Comments: This paper reviews recent advances in the deciphering of neural pathways and receptors involved in itch sensation. It will introduce some mediators and receptors with which our veterinary dermatology community is unlikely to be familiar, but this short paper paper is one of the simplest that I have recently read on this topic, so it makes for a nice reading.
Recommended by: Thierry Olivry, NC State University, Raleigh, North Carolina, USA

Lethal Junctional Epidermolysis Bullosa in Sheep

Ostmeier M, Kerkmann A, Frase R et al. Inherited junctional epidermolysis bullosa (Herlitz type) in German black-headed mutton sheep. Journal of Comparative Pathology 2011; ePub ahead of print. Abstract
PubMed ID (PMID): 22000950
Comments: This second paper from a series of three further describes the clinical, histopathological and ultrastructural characteristics of lethal junctional EB in a German ovine breed. For those interested in molecular genetics, details of the complex mutation of LAMC2, which encodes the gamma-2 chain of laminin-332 (laminin-5), can be found in the open access article in PLoS One (Click here to view)
The first paper of this series provides additional information on the origin of the trait and more in depth clinical and autopsy information (see (Click here for abstract).
Recommended by: Thierry Olivry, NC State University, Raleigh, North Carolina, USA

LeishVet Guidelines for Canine Leishmaniosis

Solano-Gallego L, Miró G, Koutinas A et al. LeishVet guidelines for the practical management of canine leishmaniosis. Parasite Vectors 2011; 20: 86. Abstract
PubMed ID (PMID): 21599936
Comments: In this paper, the LeishVet group provides practical and updated guidelines for the diagnosis, treatment, follow-up, control and prevention of canine leishmaniosis. It is also a very good review for background, epidemiology and distribution of this disease. The interpretation of diagnostic tests for different clinical presentations is made easy and is well substantiated.  The treatment recommendations are based on four clinical stages after extensive evidence-based research. These guidelines are highly recommended for specialists and residents.
Recommended by: Ana Oliveira, Lisbon, Portugal.

Sunday, October 9, 2011

Malassezia Dermatitis in Humans

Hay RJ. Malassezia, dandruff and seborrheic dermatitis: an overview. British Journal of Dermatology 2011; 165 (Suppl. 2): 2-8. Abstract
PubMed ID (PMID): 21919896
Reprint: R. Hay 
Comments: This is a simple and well-written paper that reviews the main skin diseases associated with Malassezia colonization in humans (mainly pityriasis versicolor and seborrheic dermatitis). This article is worth reading for comparative purposes and better appreciate the homology of Malassezia dermatitis of animals with human seborrheic dermatitis. 
Recommended by: Thierry Olivry, NC State University, Raleigh, North Carolina, USA

Sunday, August 7, 2011

Oral Fatty Acids Restore Stratum Corneum Lipids in Atopic Dogs

Popa I, Pin D, Remoue N et al. Analysis of epidermal lipids in normal and atopic dogs, before and after administration of an oral omega-6/omega-3 fatty acid feed supplement. A pilot study. Veterinary Research Communications 2011: 35: 501-509. Abstract
PubMed ID (PMID): 21786009
ReprintM. Haftek
Comments: This pilot study provides evidence that supplementing the diet of atopic dogs with an omega-6/omega-3 commercial formulation for two months increased stratum corneum lipids and the coverage of deep intercellular spaces with lipid lamellae. These study is important for the demonstration that orally-administered fatty acids can have a biochemical and morphological effect on the skin barrier. Nevertheless, whether or not such an effect would be associated with any relevant clinical benefit has not yet been proven with certainty.
Recommended by: Thierry Olivry, NC State University, Raleigh, North Carolina, USA

Monday, August 1, 2011

Glucose Homeostasis After Prednisolone Anti-Allergic Therapy

Kovalik M, Thoday KL, Evans H et al. Prednisolone is associated with an increase in serum insulin but not serum fructosamine concentrations in dogs with atopic dermatitis. Veterinary Journal 2011: EPub ahead of print. Abstract
PubMed ID (PMID): 21745752
ReprintR. Mellanby
Comments: This clinical study revealed that prednisolone given at around 1 mg/kg once daily for 7 days then every other day for 5 weeks to 16 dogs had no effect on plasma glucose and serum fructosamine concentrations. In contrast, serum insulin levels were higher after treatment, but only one of 16 values was above the reference range. 
Recommended by: Thierry Olivry, NC State University, Raleigh, North Carolina, USA

Papillomavirus are Normal Dog Skin Commensals

Lange C, Zollinger S, Tobler K et al. Clinically healthy skin of dogs is a potential reservoir for canine papillomaviruses. Journal of Clinical Microbiology 2011; 49: 707-709. Abstract
PubMed ID (PMID): 21159938
ReprintC. Lange
Comments: This study established that canine papillomavirus DNA was amplified by PCR from oral cavity and interdigital skin cytobrushes of a little over 50% of dogs presented to the University of Zurich Small Animal Clinic without any skin lesions suggesting papillomatosis. In dogs, like in other species, papillomavirus are part of the commensal microbial flora. The paper is very technical, clinical information is minimal, yet, its conclusions are noteworthy.
Recommended by: Thierry Olivry, NC State University, Raleigh, North Carolina, USA

Drug Efflux Pump Polymorphisms Explain Enrofloxacin Toxicity in Cats

Ramirez CJ, Minch JD, Gay JM et al. Molecular genetic basis for fluoroquinolone-induced retinal degeneration in cats. Pharmacogenetics and Genomics 2011; 21: 66-75. Abstract
PubMed ID (PMID): 21150813
ReprintK. Mealey
Comments: this paper reports that cats have species-specific aminoacid changes in conserved regions of the ABCG2 gene that encodes a drug efflux pump present, among other locations, on the luminal surface of retinal endothelial cells. Interestingly, these aminoacid changes appear to affect the cell membrane expression of the pump, the efficiency of its drug substrate transport function and its protective effect from enrofloxacin-induced phototoxicity. This set of studies provides a pharmacogenetic explanation to enrofloxacin-associated retinal degeneration. The paper is quite heavy in laboratory methods, but it is very well written, clear to follow, and interesting on a mechanistic point of view.
Recommended by: Thierry Olivry, NC State University, Raleigh, North Carolina, USA

Sunday, July 31, 2011

Effect of Type-1 and Type-4 Antihistamines in Experimental Canine Atopic Skin Lesions

Bäumer W, Stahl J, Sander K et al. Lack of effect of systematically and topically administered histamine H(1) or H(4) receptor antagonists in a dog model of atopic dermatitis. Experimental Dermatology 2011; 20: 577-581. Abstract
PubMed ID (PMID): 21521369
ReprintT. Olivry
Comments: this study showed that hydroxyzine, cetirizine and two selective type-4 antihistamines were unable to prevent the development of Dermatophagoides farinae-induced skin lesions in mite-sensitized dogs. In contrast, and not surprisingly, topical triamcinolone spray completely prevented the development of skin lesions. 

Recommended by: Thierry Olivry, NC State University, Raleigh, North Carolina, USA

Analysis of Stratum Corneum Ceramides in Atopic Dogs (2)

Yoon JS, Nishifuji K, Sasaki A et al. Alteration of stratum corneum ceramide profiles in spontaneous canine atopic dermatitis. Experimental Dermatology 2011; ePub Jun 7. Abstract
PubMed ID (PMID): 21649737
ReprintT. Iwasaki
Comments: this paper confirms the existence of a decrease in the quantity of total and some ceramide subclasses in the stratum corneum of atopic compared to that of normal dogs.
Recommended by: Thierry Olivry, NC State University, Raleigh, North Carolina, USA

Analysis of Stratum Corneum Ceramides in Atopic Dogs (1)

Popa I, Remoue N, Hoang LT et al. Atopic dermatitis in dogs is associated with a high heterogeneity in the distribution of protein-bound lipids within the stratum corneum. Archives of Dermatological Research 2011; 303: 433-440. Abstract
PubMed ID (PMID): 21240511
ReprintI. Popa
Comments: this is an important paper that reports, in the stratum corneum of atopic compared to normal dogs, a decrease in the quantities of free and protein-bound ceramides, a concurrent increase in the amounts of glycosylceramides and a variation in ceramide composition among stratum corneum layers. These results suggest a possible abnormal ceramide metabolic pathway in the stratum corneum of dogs with atopic dermatitis, and that successive waves of inflammation might transiently alter stratum corneum lipid biosynthesis.

Recommended by: Thierry Olivry, NC State University, Raleigh, North Carolina, USA

Normal Canine Stratum Corneum Ceramides

Popa I, Thuy LH, Colsch B et al. Analysis of free and protein-bound ceramides by tape stripping of stratum corneum in dogs. Archives of Dermatological Research 2010; 302: 639-644. Abstract
PubMed ID (PMID): 20361334
ReprintI. Popa
Comments: this is an important article that defines the nature and amount of normal canine stratum corneum ceramides and the similarity between canine and human stratum corneum lipids. Do note that the new nomenclature for ceramides is being used.

Recommended by: Thierry Olivry, NC State University, Raleigh, North Carolina, USA

Allergic Conjunctivitis is Common in Atopic Dogs

Lourenço-Martins AM, Delgado E, Neto I et al. Allergic conjunctivitis and conjunctival provocation test in atopic dogs. Veterinary Ophthalmology 2011; 14: 248-256. Abstract
PubMed ID (PMID): 21733066
ReprintE. Delgado
Comments: this article provides evidence of the high prevalence of concurrent allergic conjunctivitis in dogs with atopic dermatitis. This is also the first demonstration of the validity of conjunctival provocation tests for the diagnosis of atopic conjunctivitis.

Recommended by: Thierry Olivry, NC State University, Raleigh, North Carolina, USA

The Cause of Shar Pei Mucinosis and Periodic Fever Syndrome

Olsson M, Meadows JRS, Truvé K et al. A novel unstable duplication upstream of HAS2 predisposes to a breed-defining skin phenotype and a periodic fever syndrome in Chinese Shar-Pei dogs. PLoS Genetics 2011; 7(3): e1001332. Abstract
PubMed ID (PMID): 2143727
Reprint: open access (click-to-view)
Comments: this is an important article that reports the elucidation of the cause of both Shar-Pei fever and cutaneous mucinosis (now: hyaluronanosis): duplications upstream from the gene HAS2, which encodes the hyaluronic acid synthase 2, result in hyperactivation of the gene and increased hyaluronic acid secretion. The paper is heavy in genetics, but the findings are important to understand the pathogenesis of this breed-specific trait and its association with the recurrent fever syndrome previously identified in this breed.