[Alopecia areata in animal models--new insights into pathogenesis and treatment of a T cell-mediated autoimmune disorder]

MiR-199a-3p Regulates the PTPRF/β-Catenin Axis in Hair Follicle Development: Insights into the Pathogenic Mechanism of Alopecia Areata

Alopecia areata is an autoimmune disease characterized by the immune system attacking self hair follicles, mainly in the scalp. There is no complete cure, and the pathogenesis is still not fully understood. Here, sequencing of skin tissues collected from 1-month-old coarse- and fine-wool lambs identified miR-199a-3p as the only small RNA significantly overexpressed in the fine-wool group, suggesting a role in hair follicle development. MiR-199a-3p expression was concentrated in the dermal papillae cells of sheep hair follicles, along with enhanced β-catenin expression and the inhibition of PTPRF protein expression. We also successfully constructed a mouse model of alopecia areata by intracutaneous injection with an miR-199a-3p antagomir. Injection of the miR-199a-3p agomir resulted in hair growth and earlier anagen entry. Conversely, local injection with the miR-199a-3p antagomir resulted in suppressed hair growth at the injection site, upregulation of immune system-related genes, and downregulation of hair follicle development-related genes. In vivo and in vitro analyses demonstrated that miR-199a-3p regulates hair follicle development through the PTPRF/β-catenin axis. In conclusion, a mouse model of alopecia areata was successfully established by downregulation of a small RNA, suggesting the potential value of miR-199a-3p in the study of alopecia diseases. The regulatory role of miR-199a-3p in the PTPRF/β-catenin axis was confirmed, further demonstrating the link between alopecia areata and the Wnt-signaling pathway.

Sequential high- and low-dose systemic corticosteroid therapy for severe childhood alopecia areata

BACKGROUND

Given the limited number of therapeutic options, severe childhood alopecia areata (AA) poses a clinical challenge. The best and most rapid response rates can be achieved with high-dose systemic corticosteroids, however, relapse following treatment discontinuation is inevitable. Due to systemic side effects, long-term high-dose corticosteroid regimens are not feasible. Following initial pulse therapy, continuation of corticosteroid therapy at a dose below the Cushing threshold might be able to suppress disease activity without causing severe side effects.

PATIENTS AND METHODS

Thirteen children with severe AA were enrolled in our open observational study. Seven had alopecia totalis or universalis; the remaining six children had multifocal alopecia affecting more than 50 % of the scalp. The treatment regimen consisted of initial pulse therapy with prednisolone 2 mg/kg PO, which was subsequently tapered to a maintenance dose below the individual Cushing threshold within nine weeks. Children were followed-up for one to three years.

RESULTS

Sixty-two percent of individuals showed complete hair regrowth. The mean time to response was 6.6 weeks. Said response was sustained with maintenance therapy for the entire follow-up period. Noticeable side effects included weight gain (1-3 kg), which was observed in all children, and mild steroid acne in 23 % of cases.

CONCLUSIONS

Sequential high- and low-dose prednisolone therapy is an effective and safe therapeutic option for childhood AA.

Kombinierte Hoch-/Niedrig-Dosis-Therapie mit systemischen Glukokor-tikoiden bei schweren Verlaufsformen der Alopecia areata im Kindesalter

HINTERGRUND

Schwere Verlaufsformen der Alopecia areata (AA) im Kindesalter sind aufgrund limitierter Optionen therapeutisch herausfordernd. Systemische, hochdosierte Glukokortikoide weisen die schnellste Ansprechrate auf, nach dem Absetzen kommt es allerdings zu Rezidiven. Eine längerfristige Hochdosis-Anwendung ist aufgrund der zu erwartenden Nebenwirkungen nicht empfehlenswert. Eine dauerhafte Steroiderhaltungstherapie unterhalb der Cushing-Schwellen-Dosis nach Bolustherapie könnte die Krankheitsaktivität ohne Nebenwirkungen längerfristig unterdrücken.

PATIENTEN UND METHODIK

Im Rahmen einer offenen Anwendungsbeobachtung wurden 13 Kinder mit schweren Formen der AA in diese Studie eingeschlossen. Bei sieben Kindern lag eine AA totalis/universalis vor, bei sechs eine multifokale AA mit Befall von mehr als 50 % der Kopfhaut. Das Therapieregime sah eine initiale Prednisolon-Dosierung von 2 mg/kg Körpergeweicht (KG) vor und wurde innerhalb von neun Wochen auf eine Erhaltungsdosierung unter der individuellen Cushing-Schwelle reduziert. Der Nachbeobachtungszeitraum betrug ein bis drei Jahre.

ERGEBNISSE

Wir beobachteten in 62 % aller Fälle ein komplettes Nachwachsen der Haare. Die mittlere Dauer bis zum Ansprechen lag bei 6,6 Wochen und konnte mit der Erhaltungstherapie über den gesamten Beobachtungszeitraum aufrechterhalten werden. An Nebenwirkungen wurden ausschließlich eine Gewichtszunahme (1-3 kg) bei allen Behandelten sowie eine milde Steroidakne in 23 % der Fälle beobachtet.

SCHLUSSFOLGERUNGEN

Die kombinierte Hoch-/Niedrig-Dosis-Therapie mit systemischen Glukokortikoiden mittels Prednisolon zeigte eine hohe, dauerhafte Ansprechrate ohne signifikante Nebenwirkungen.

Comparative Study of Efficacy and Safety of Topical Squaric Acid Dibutylester and Diphenylcyclopropenone for the Treatment of Alopecia Areata

BACKGROUND

Topical squaric acid dibutylester and diphenylcyclopropenone are still the most effective therapy for alopecia areata among widely available treatment options. Hence, it is important to know which one is more effective and safer between the two.

AIMS

The aim of this study was to compare topical squaric acid dibutylester and diphenylcyclopropenone for the treatment of alopecia areata in terms of their efficacy and side effects.

SUBJECTS AND METHODS

In the time period of January-March 2015, a total of 40 patients were selected for this study from the outpatient department of Rajendra Institute of Medical Sciences, Ranchi. After dropout of 16 patients, the remaining 24 patients were randomly divided into two groups; that is, group A for squaric acid dibutylester and group B for diphenylcyclopropenone. Each group received treatment for 6 months between March-November 2015. Their efficacy and side effects were compared.

STATISTICAL TEST

Unpaired student t-test was performed. P < 0.05 was considered to be significant and 95% confidence interval was also used to evaluate the efficacy.

RESULTS

The mean values of percentage change in baseline severity of alopecia tool score for squaric acid dibutylester and diphenylcyclopropenone were 52.25 and 34.45, respectively. At 6 months, 95% confidence interval was 43.5-61% for group A and 25-44% for group B. In 58.33% of group A patients, A3 (50-74%) grade of improvement was observed, whereas in group B patients, it was 33.33%. A4 grade of improvement (75-99%) was also seen in 1 patient of group A. Minor side effects were seen in 2 patients of group A and 10 patients of group B. None of the group A patients showed major side effects, however, 2 patients suffered major side effects in group B.

CONCLUSIONS

Between squaric acid dibutylester and diphenylcyclopropenone, squaric acid dibutylester is more efficacious. Further, frequencies of major and minor side effects are also lower than diphenylcyclopropenone.

Profiling of Alopecia Areata Autoantigens Based on Protein Microarray Technology

Protein biochips have a great potential in future parallel processing of complex samples as a research tool and in diagnostics. For the generation of protein biochips, highly automated technologies have been developed for cDNA expression library production, high throughput protein expression, large scale analysis of proteins, and protein microarray generation. Using this technology, we present here a strategy to identify potential autoantigens involved in the pathogenesis of alopecia areata, an often chronic disease leading to the rapid loss of scalp hair. Only little is known about the putative autoantigen(s) involved in this process. By combining protein microarray technology with the use of large cDNA expression libraries, we profiled the autoantibody repertoire of sera from alopecia areata patients against a human protein array consisting of 37,200 redundant, recombinant human proteins. The data sets obtained from incubations with patient sera were compared with control sera from clinically healthy persons and to background incubations with anti-human IgG antibodies. From these results, a smaller protein subset was generated and subjected to qualitative and quantitative validation on highly sensitive protein microarrays to identify novel alopecia areata-associated autoantigens. Eight autoantigens were identified by protein chip technology and were successfully confirmed by Western blot analysis. These autoantigens were arrayed on protein microarrays to generate a disease-associated protein chip. To confirm the specificity of the results obtained, sera from patients with psoriasis or hand and foot eczema as well as skin allergy were additionally examined on the disease-associated protein chip. By using alopecia areata as a model for an autoimmune disease, our investigations show that the protein microarray technology has potential for the identification and evaluation of autoantigens as well as in diagnosis such as to differentiate alopecia areata from other skin diseases.

Differential diagnosis of hair loss in children. Differentialdiagnose des Haarausfalls bei Kindern

Hair loss in childhood covers a broad differential diagnosis and often presents the involved dermatologist and pediatrician with a diagnostic and therapeutic challenge. Correct classification of the hair disease, especially in the case of underlying genetic syndromes, metabolic defects or endocrine disorders, is often an important prerequisite for continued normal physical and mental development of the young patients. Dealing with hair loss in childhood, one should differentiate between congenital and acquired diseases. The clinical manifestation profile, the age of the patient when the initial manifestation occurred, and the presence of associated symptoms are important for the classification of the hair disease. In the present paper, a classification of hair loss in childhood based on clinical appearance, age of onset and associated symptoms is proposed as a guide for the evaluation of hair loss and alopecia in childhood.