IL-17: a key player in the P. acnes inflammatory cascade?

A review of skin immune processes in acne

Acne vulgaris is one of the most prevalent skin conditions, affecting almost all teenagers worldwide. Multiple factors, including the excessive production of sebum, dysbiosis of the skin microbiome, disruption of keratinization within hair follicles, and local inflammation, are believed to trigger or aggravate acne. Immune activity plays a crucial role in the pathogenesis of acne. Recent research has improved our understanding of the immunostimulatory functions of microorganisms, lipid mediators, and neuropeptides. Additionally, significant advances have been made in elucidating the intricate mechanisms through which cutaneous innate and adaptive immune cells perceive and transmit stimulatory signals and initiate immune responses. However, our understanding of precise temporal and spatial patterns of immune activity throughout various stages of acne development remains limited. This review provides a comprehensive overview of the current knowledge concerning the immune processes involved in the initiation and progression of acne. Furthermore, we highlight the significance of detailed spatiotemporal analyses, including analyses of temporal dynamics of immune cell populations as well as single-cell and spatial RNA sequencing, for the development of targeted therapeutic and prevention strategies.

Anti-IL-17A blockade did not significantly reduce inflammatory lesions in a placebo-controlled pilot study in adult patients with moderate to severe acne

BACKGROUND

CJM112 is a potent anti-IL-17A monoclonal antibody, whose clinical efficacy in psoriasis was recently documented. This study aimed to assess the effect of IL-17A blockade, using CJM112, in patients with moderate to severe acne.

METHODS

A randomized, placebo-controlled, double-blind, parallel-group, proof-of-concept study was conducted on patients with moderate to severe acne. Patients received CJM112 300 mg, 75 mg, or placebo subcutaneously during Treatment Period 1 (0-12 weeks). Patients receiving placebo were re-randomized to receive CJM112 300 mg or 75 mg during Treatment Period 2 (12-24 weeks). The primary endpoint was the number of inflammatory facial lesions at Week 12.

RESULTS

As the futility criterion was met during the interim analysis, only 52/75 (69.3%) patients were recruited. In total, 48/52 (92.3%) and 26/41 (63.4%) completed Treatment Periods 1 and 2, respectively. All groups exhibited a reduction in facial inflammatory lesions, with no difference observed between CJM112 and placebo (CJM112 300 mg 27.6 ± 20.7; CJM112 75 mg 30.4 ± 34.8; placebo 23.6 ± 13.6; primary endpoint). Additionally, no differences were observed between groups in other secondary and exploratory endpoints at Week 12.

CONCLUSIONS

Anti-IL-17A therapy was not significantly different compared to the placebo in reducing inflammatory lesions in patients with moderate to severe acne.

Discovery and Characterization of a Novel Bacteriocin HA2-5 that Strongly Inhibits Propionibacterium acnes

Increased drug resistance has significantly reduced the effectiveness of antibiotics used in the treatment of Propionibacterium acnes. Therefore, there has been a trend toward the development of new antimicrobial agents to circumvent drug resistance. In this study, we isolated and purified a novel bacteriocin, HA2-5, from Bacillus haynesii HA2, which effectively killed P. acnes through membrane disruption at a minimum inhibitory concentration (MIC) of 8 μg/mL. HA2-5 with 2× MIC was able to kill 99.9% of P. acnes within 24 h. HA2-5 shows excellent stability and tolerance to temperature, pH, proteases, chemical reagents, UV radiation, and metal ions, with almost no loss of inhibitory activity after treatment. In addition, the very low hemolytic activity and cytotoxicity suggest that HA2-5 is biosafe. Notably, HA2-5 exhibits preferred antibacterial activity against gram-positive pathogens with an MIC of 16-32 μg/mL. In conclusion, this study shows that bacteriocin HA2-5 has the potential to be used as an alternative to antibiotics for acne treatment.

Markers of Oxidative Stress in Patients with Acne: A Literature Review

Acne vulgaris is a chronic inflammatory skin disease of the pilosebaceous unit. Its pathogenesis is multifactorial and involves the overlap between four main processes: alteration of the keratinization, increased sebum production, colonization with Cutibacterium acnes, and inflammation. The role of oxidative stress (OS) has been intensively studied in inflammatory skin conditions such as psoriasis, vitiligo, or atopic dermatitis. However, the involvement of OS in the pathogenesis of acne is less known. The evidence accumulated over the last decade suggests that in the case of acne patients, there is an imbalance between oxidants and antioxidants. In this review, we analyzed studies that evaluated markers of OS in patients with acne, published in the last ten years, with the aim of providing new insights into the pathogenesis of acne.

Recent advances in understanding inflammatory acne: Deciphering the relationship between Cutibacterium acnes and Th17 inflammatory pathway

Acne vulgaris is a common chronic inflammatory skin disease of the pilosebaceous units. Four factors contribute to acne: hyperseborrhea and dysseborrhea, follicular hyperkeratinisation, skin microbiome dysbiosis and local immuno-inflammation. Recent key studies have highlighted a better understanding of the important role of Cutibacterium acnes (C. acnes) in the development of acne. Three major findings in the last decade include: (1) the ability of C. acnes to self-organize in a biofilm associated with a more virulent activity, (2) the loss of the C. acnes phylotype diversity and (3) the central role of the Th17 pathway in acne inflammation. Indeed, there is a close link between C. acnes and the activation of the Th17 immuno-inflammatory pathway at the initiation of acne development. These mechanisms are directly linked to the loss of C. acnes phylotype diversity during acne, with a predominance of the pro-pathogenic phylotype IA1. This specifically contributes to the induction of the Th17-mediated immuno-inflammatory response involving skin cells, such as keratinocytes, monocytes and sebocytes. These advancements have led to new insights into the underlying mechanisms which can be harnessed to develop novel treatments and diagnostic biomarkers. A major disadvantage of traditional treatment with topical antibiotics is that they induce cutaneous dysbiosis and antimicrobial resistance. Thus, future treatments would no longer aim to 'kill' C. acnes, but to maintain the skin microbiota balance allowing for tissue homeostasis, specifically, the restoration of C. acnes phylotype diversity. Here, we provide an overview of some of the key processes involved in the pathogenesis of acne, with a focus on the prominent role of C. acnes and the Th17-inflammatory pathways involved.

Skin dysbiosis and Cutibacterium acnes biofilm in inflammatory acne lesions of adolescents

Acne vulgaris is a common inflammatory disorder affecting more than 80% of young adolescents. Cutibacterium acnes plays a role in the pathogenesis of acne lesions, although the mechanisms are poorly understood. The study aimed to explore the microbiome at different skin sites in adolescent acne and the role of biofilm production in promoting the growth and persistence of C. acnes isolates. Microbiota analysis showed a significantly lower alpha diversity in inflammatory lesions (LA) than in non-inflammatory (NI) lesions of acne patients and healthy subjects (HS). Differences at the species level were driven by the overabundance of C. acnes on LA than NI and HS. The phylotype IA1 was more represented in the skin of acne patients than in HS. Genes involved in lipids transport and metabolism, as well as potential virulence factors associated with host-tissue colonization, were detected in all IA1 strains independently from the site of isolation. Additionally, the IA1 isolates were more efficient in early adhesion and biomass production than other phylotypes showing a significant increase in antibiotic tolerance. Overall, our data indicate that the site-specific dysbiosis in LA and colonization by virulent and highly tolerant C. acnes phylotypes may contribute to acne development in a part of the population, despite the universal carriage of the microorganism. Moreover, new antimicrobial agents, specifically targeting biofilm-forming C. acnes, may represent potential treatments to modulate the skin microbiota in acne.

Sarcoidosis and sarcoidal foreign body reaction after permanent eye makeup application: Analysis by immunohistochemistry with commercially available antibodies specific to Cutibacterium acnes and Mycobacteria

We report two cases of eyebrow granulomas in patients who underwent a permanent eye makeup procedure. A rash was observed 16 months after the procedure in case 1 and 10 years after the procedure in case 2. Histopathologically, both patients exhibited non-caseating epithelioid cell granulomas. In case 1, most of the black-brown granules of the permanent makeup were not present in the granulomas but were localized in the upper dermis. In contrast, in case 2, some of the black-brown granules were phagocytized in the granulomas, preferentially within the giant cells. Based on systemic examinations, the patients from cases 1 and 2 were diagnosed with sarcoidosis and sarcoidal foreign body reaction, respectively. To clarify the pathogenesis of our cases, we performed immunohistochemistry using commercially available monoclonal antibodies specific to Cutibacterium acnes, previously Propionibacterium acnes (PAB), and Mycobacteria (LAM antibody). PAB antibody results were positive in granulomas only in case 1, and the LAM antibody results were negative in both cases. Immunohistochemical detection of C. acnes in granulomas could provide useful information for differentiating between cutaneous sarcoidosis and sarcoidal foreign body reactions.

Updated Treatment for Acne: Targeted Therapy Based on Pathogenesis

Previous approaches to acne management have focused on the four main factors implicated in acne, namely, androgen-mediated sebogenesis (considered integral to acne), hyperkeratinization, colonization with Cutibacterium acnes, and inflammation related to both innate and adaptive mechanisms. Recent advances have facilitated potential novel approaches to acne management, as the pathophysiology and the immunological aspects related to acne and wound healing have evolved. Particular targets that have been shown to be closely involved in acne pathophysiology and wound healing include interleukin (IL)-1β, IL-17, IL-23, and tumor necrosis factor alpha (TNFα). Biological antibodies targeting IL-1β, IL-17, IL-23, and TNFα could provide novel approaches for treating severe acne and related disorders. Acne is primarily a disease associated with sebogenesis. Monosaturated free acids are important components. Insulin growth factor 1 (IGF-1) promotes the proliferation and differentiation of sebocytes and IL-1β. Research into the microbiome may also provide insights into potential future therapeutic options for acne. Scars, both atrophic and hypertrophic, are common sequelae to acne. Risk factors associated with the development of acne scars include genetic, systemic, local, and lifestyle factors. Pro-inflammatory cytokines have been shown to play a crucial role in the development of acne-induced hypertrophic scars. Treatment for extensive inflammatory keloid scarring is limited. Surgery and postoperative radiotherapy are two possible options. Transforming growth factor-β (TGFβ), IL-6, matrix metalloproteinase (MMP), IGF-1, and B cells are found in keloid or hypertrophic scar tissues. Biological antibodies targeting these cytokines may be a potential strategy for the prevention and treatment of this type of scar in the future. Future treatment for acne should embrace approaches that target the main etiological factors of acne. In particular, specific emphasis on aggressive treatment in the acute inflammatory phase to reduce the likelihood of scarring and other clinical sequelae, such as pigmentary changes would be highly desirable. Treatment for established acne-induced sequelae should also be considered.

Immunohistochemical Detection of Potential Microbial Antigens in Granulomas in the Diagnosis of Sarcoidosis

Sarcoidosis may have more than a single causative agent, including infectious and non-infectious agents. Among the potential infectious causes of sarcoidosis, Mycobacterium tuberculosis and Propionibacterium acnes are the most likely microorganisms. Potential latent infection by both microorganisms complicates the findings of molecular and immunologic studies. Immune responses to potential infectious agents of sarcoidosis should be considered together with the microorganisms detected in sarcoid granulomas, because immunologic reactivities to infectious agents reflect current and past infection, including latent infection unrelated to the cause of the granuloma formation. Histopathologic data more readily support P. acnes as a cause of sarcoidosis compared with M. tuberculosis, suggesting that normally symbiotic P. acnes leads to granuloma formation in some predisposed individuals with Th1 hypersensitivity against intracellular proliferation of latent P. acnes, which may be triggered by certain host or drug-induced conditions. Detection of bacterial nucleic acids in granulomas does not necessarily indicate co-localization of the bacterial proteins in the granulomas. In the histopathologic diagnosis of sarcoidosis, M. tuberculosis-associated and P. acnes-associated sarcoidosis will possibly be differentiated in some patients by immunohistochemistry with appropriate antibodies that specifically react with mycobacterial and propionibacterial antigens, respectively, for each etiology-based diagnosis and potential antimicrobial intervention against sarcoidosis.

Intestinal ulcers induced by intravesical bacillus Calmette-Guérin therapy

Intravesical bacillus Calmette-Guérin (iBCG) therapy, one of the established treatments for bladder carcinoma, is known for its association with adverse events, including rheumatic manifestations. We describe the case of a 72-year-old man with synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome who developed inflammatory bowel disease unclassified after iBCG therapy for bladder carcinoma. The critical role of the IL-23/IL-17 axis in the pathogenesis IBD and all the domains of SAPHO syndrome has been reported previously. In the present case, the activation of the IL-23/IL-17 axis, probably due to the disease, could have been exacerbated by iBCG therapy, as observed in mice that received BCG immunotherapy. We suggest that patients with rheumatic diseases on iBCG therapy should be observed carefully since iBCG could be a contributing factor for autoimmune pathology including IBD.

Gut-Skin Axis: Current Knowledge of the Interrelationship between Microbial Dysbiosis and Skin Conditions

The microbiome plays an important role in a wide variety of skin disorders. Not only is the skin microbiome altered, but also surprisingly many skin diseases are accompanied by an altered gut microbiome. The microbiome is a key regulator for the immune system, as it aims to maintain homeostasis by communicating with tissues and organs in a bidirectional manner. Hence, dysbiosis in the skin and/or gut microbiome is associated with an altered immune response, promoting the development of skin diseases, such as atopic dermatitis, psoriasis, acne vulgaris, dandruff, and even skin cancer. Here, we focus on the associations between the microbiome, diet, metabolites, and immune responses in skin pathologies. This review describes an exhaustive list of common skin conditions with associated dysbiosis in the skin microbiome as well as the current body of evidence on gut microbiome dysbiosis, dietary links, and their interplay with skin conditions. An enhanced understanding of the local skin and gut microbiome including the underlying mechanisms is necessary to shed light on the microbial involvement in human skin diseases and to develop new therapeutic approaches.

Activation of Janus kinase signaling pathway in acne lesions

The Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway has been linked to the pathogenesis of many inflammatory skin diseases; however, the role of JAKs in the pathogenesis of acne vulgaris has not been previously elucidated. We aimed to analyze the cutaneous expression of JAK1/2/3 proteins in acne vulgaris and investigate the possible role of JAK signaling in acne pathogenesis. This case-control study was carried out on 28 patients with inflammatory acne vulgaris vs 20 age- and sex-matched healthy volunteers. Acne severity was assessed using Global acne severity grading system (GAGS). Skin biopsies were collected from lesional and non-lesional skin of patients and from control group. The expression of JAK1/2/3 proteins was examined by real-time quantitative polymerase chain reaction. JAK1 and JAK3 were overexpressed in acne lesions, compared to non-lesional skin and the control group. No significant difference was found in JAK2 expression between patients and controls. JAK1 and JAK3 showed no significant relation with the patients' age, sex, family history, duration of acne, or GAGS score. Our results suggest the activation of JAK pathway in acne lesions, indicating that it may play a pivotal role in the inflammatory disease process. JAK1 and JAK3 may be possible new targets for acne therapy.

Altered Gene Expression in Acne Vulgaris Patients Treated by Oral Isotretinoin: A Preliminary Study

Background/Objective

The role of gene expression changes in acne patients treated by oral isotretinoin (ISO) and in influencing the ISO therapeutic effects is still unclear. In this study, we investigated the gene profiles of patients with severe acne who responded variously to ISO therapy.

Methods

The peripheral blood of 113 acne vulgaris patients (Pillsbury IV grade) was collected before treatment. After 8 weeks of oral ISO, nine acne patients were selected and divided into the following groups. A: effectively treated by ISO, group B: ineffectively treated by ISO, group C: ISO-induced acne flare-up, and 3 healthy subjects were included as control group D. The peripheral blood of patients pre- and post-treatment was subjected to high-throughput RNA sequencing technology and bioinformatics analysis of the separate groups (n = 3). The candidate genes were validated by qRT-PCR.

Results

Comparing pre- and post-oral ISO treatment, gene expression was changed as 39 genes in ISO-effective group, 345 genes in ISO-ineffective group, and 57 genes in ISO-induced acne flare-up group. Comparing the ISO-induced acne flare-up group with healthy control subjects revealed 34 upregulated genes and 23 downregulated genes, while comparing the ISO-induced acne flare-up group with ISO-ineffective patients identified 1835 changed genes. Expression of GATA2 (2.73 fold, P=0.024512), C4BPA (35.87 folds, P=0.038073), and CCR5 (2.48 folds, P=0.004681) increased in the ISO-induced acne flare-up patients. Meanwhile, the expression of DEFA3 (0.18 fold, P=0.041934), ELANE (0.14 fold, P=0.030767), MMP9 (0.41 fold, P=0.013383), and RPS4Y1 (0.00018 fold, P=0.000986) decreased when compared with ISO-ineffective patients.

Conclusion

Oral ISO treatment could temporarily alter gene expression in acne patients. ISO therapeutic mechanisms were involved, not only in regulating the inflammatory reaction but also in the process of DNA repair. GATA2, C4BPA, CCR5, DEFA3, ELANE, MMP9, and RPS4Y1 might be susceptible to genes that could participate in the ISO-induced aggravation of acne.

Esc-1GN shows therapeutic potentials for acne vulgaris and inflammatory pain

The inflammatory response plays important roles in acne vulgaris and pain pathogenesis. In previous study, Esc-1GN with anti-inflammatory, antimicrobial, and lipopolysacchride (LPS) binding activity was identified from the skin of the frog Hylarana guentheri. Here, we report its therapeutic potentials for acne vulgaris and inflammatory pain. Esc-1GN destroyed the cell membrane of Propionibacteria acnes in the membrane permeability assays. In addition, bacterial agglutination test suggested that Esc-1GN triggered the agglutination of P. acnes, which was affected by LPS and Ca²⁺ . Meanwhile, in vivo anti-P. acnes and anti-inflammatory effects of Esc-1GN were confirmed by reducing the counts of P. acnes in mice ear, relieving P. acnes-induced mice ear swelling, decreasing mRNA expression and the production of pro-inflammatory cytokines, and attenuating the infiltration of inflammatory cells. Moreover, Esc-1GN also displayed antinociceptive effect in mice induced by acetic acid and formalin. Therefore, Esc-1GN is a promising candidate drug for treatment of acne vulgaris and inflammatory pain.

Acne: Transient Arrest in the Homeostatic Host-Microbiota Dialog?

We propose that acne vulgaris represents a naturally developing, transient inflammatory interaction of adolescent facial skin with its new microbial/chemical milieu (Cutibacterium acnes, sebum), replacing a state of previous childhood skin homeostasis. This concept might explain why acne is characterized by strong regional and age specificity, prevalent occurrence, and resolution.

Retinoids as an Immunity-modulator in Dermatology Disorders

The skin is the largest epithelial surface protecting the body from invading microbes. Vitamin A plays vital roles in the host defence of the skin, including promoting epithelial cell integrity, proliferation, and differentiation and even mediating immune responses. Furthermore, vitamin A derivatives, retinoid drugs, are widely used to treat skin diseases, such as acne and psoriasis. However, the immunoregulatory mechanisms of retinoids in dermatology have not been systematically described. In this paper, we discuss the immunological functions of retinoids during disease treatment, especially in skin disorders caused by exogenous infections.

Antibiotic susceptibility of Propionibacterium acnes isolated from patients with acne in a public hospital in Southwest China: prospective cross-sectional study

OBJECTIVE

Antibiotics have been routinely used for several decades against Propionibacterium acnes (P. acnes), but antibiotic resistance of P. acnes is becoming a global problem. Only one related Chinese study is available. The aim of this study was to assess the antibiotic susceptibility of P. acnes obtained from patients with acne in Southwest China.

DESIGN

This was a prospective cross-sectional study. Cutaneous samples were obtained from acne lesions on the face of 375 patients. Samples were cultured in anaerobic medium to identify the presence of P. acnes. Susceptibility tests of isolated P. acnes were performed for tetracycline, doxycycline, clindamycin, erythromycin, azithromycin and clarithromycin using the Epsilometer test.

RESULTS

P. acnes was isolated from 227 patients; 224 isolates (98.7%) were susceptible to doxycycline and 220 (96.9%) were susceptible to tetracycline, followed by clindamycin and clarithromycin in 101 (44.5%) and 102 (44.93%) isolates, respectively. Susceptibility of P. acnes was detected for erythromycin in 96 (42.3%) patients, followed by azithromycin in 94 (41.4%). Subjects who received antibiotics (topical and oral) had higher frequencies of antibiotic-resistant P. acnes as well as increased antibiotic minimum inhibitory concentrations compared with patients without antibiotic treatment.

CONCLUSIONS

P. acnes was highly sensitive to cyclines (doxycycline and tetracycline). P. acnes showed higher resistance rates to macrolides-lincosamides-streptogramins antibiotics (such as erythromycin, azithromycin, clarithromycin and clindamycin). The irrational use of antibiotics for acne treatment is probably a problem in China and elsewhere. These results suggest that dermatologists should be more prudent in prescribing antibiotics for acne.

Recent advances in understanding Propionibacterium acnes ( Cutibacterium acnes) in acne

The skin commensal Propionibacterium acnes, recently renamed Cutibacterium acnes, along with the other major pathophysiological factors of increased seborrhea, hyperkeratinization of the pilosebaceous unit, and inflammation, has long been implicated in the pathogenesis of acne. Recent advances have contributed to our understanding of the role of P. acnes in acne. Although there are no quantitative differences in P. acnes of the skin of patients with acne compared with controls, the P. acnes phylogenic groups display distinct genetic and phenotypic characteristics, P. acnes biofilms are more frequent in acne, and different phylotypes may induce distinct immune responses in acne. P. acnes plays a further important role in the homeostasis of the skin’s microbiome, interacting with other cutaneous commensal or pathogenic microorganisms such as Staphylococcus epidermidis, Streptococcus pyogenes, and Pseudomonas species. In the era of increasing antimicrobial resistance, the selection of acne treatment targeting P. acnes and the prevention of antibiotic resistance play a key role in improving outcomes in acne patients and public health.

Update in the management of acne in adolescence

PURPOSE OF REVIEW

This review will update the pediatric provider on recent data on the pathogenesis and treatment of acne in adolescent patients. A special focus was made to summarize recent guidelines and fill in several identified practice gaps.

RECENT FINDINGS

Our understanding of the pathogenesis of acne is greatly expanding and data is emerging to tie diet, particularly the role of IGF-1 with inflammation in acne. Additionally, stronger recommendations to limit antibiotic usage in acne are being made worldwide. Although retinoids are considered the base of most effective acne treatment strategies, data suggests that all providers need to emphasize their importance in maintenance of acne.

SUMMARY

An effective acne management strategy targets multiple pathogenic factors in acne, using a retinoid as the foundation. Systemic antibiotics for moderate-to-severe acne should be used for acute management, then discontinued at 3-4 months, while maintaining on topical treatments. If therapy is ineffective, alternate treatments, such as combined oral contraceptives in females or isotretinoin, should be promptly employed to prevent prolonged psychological impact and cutaneous scarring.

Verantwortlicher Umgang mit Antibiotika: Notwendigkeit der Antibiotikareduktion in der Aknetherapie

Der übermäßige oder unkritische weltweite Einsatz von Antibiotika in der Medizin hat die Ausbreitung von Antibiotikaresistenzen beschleunigt. In einigen Bereichen sind viele Antibiotika bei bakteriellen Infektionen, die zuvor noch gut auf antibakterielle Wirkstoffe reagierten, mittlerweile wirkungslos geworden. Dermatologen/Venerologen setzten orale und topische Antibiotika bei der Behandlung von Acne vulgaris routinemäßig ein, obwohl Akne weder eine infektiöse Erkrankung ist noch alleine durch das Propionibacterium getriggert wird. Vielmehr ist sie eine komplexe, chronische entzündliche Hauterkrankung, die durch verschiedene pathogenetische Faktoren wie follikuläre Hyperkeratose, erhöhter Sebumproduktion, bakterielle Proliferation und Entzündung zustande kommt. Folglich sollte eine erfolgreiche Therapie auf die Bekämpfung verschiedener pathogenetischer Faktoren und nicht nur auf die von Propionibacterium acnes abzielen. Daher wurden topische Retinoide und Benzoylperoxid als Mittel der ersten Wahl definiert. Monotherapien mit lokalen Antibiotika sollten insgesamt vermieden werden. Systemische Antibiotika der Tetrazyklin-Gruppe haben bei bestimmen Krankheitsstadien ihren Sinn, ihre Wirkung könnte aber eher auf der antientzündlichen als auf der antibiotischen Reaktion beruhen. Gesundheitsbehörden ermahnen alle Gesundheitsdienstleister, den Einsatz von Antibiotika einzuschränken. Das Nutzen-Risiko-Verhältnis muss bei der Entscheidung für oder gegen eine antibiotische Therapie bei einem einzelnen Patienten immer auch in Bezug auf das öffentliche Interesse am Erhalt der Wirksamkeit von Antibiotika abgewogen werden. Im Folgenden werden das aktuelle Krankheitskonzept zu Acne vulgaris und die sich daraus ableitenden Konsequenzen für den Einsatz von Antibiotika vorgestellt.

Adult-onset acne: prevalence, impact, and management challenges

Acne is a multifactorial and inflammatory disease of pilosebaceous follicles, which affects most adolescents. Recent epidemiological data revealed a difference in adults affected by this disease. Women have a high prevalence and incidence when compared with men, especially after 25 years of age. In contrast to what was initially thought, most of these patients do not present endocrinopathy capable of leading to the development of the lesions. When present, polycystic ovarian syndrome is the main cause. However, in these cases, acne is rarely the only dermatological manifestation; hirsutism and acanthosis nigricans are often present. The majority of the normoandrogenic acne patients present a history since adolescence, but in many cases the lesion distribution and intensity change with time. There is often a typical localization of the lesions in the lower third of the face and lateral region of the neck. Another interesting feature is related to the impact on quality of life (QoL), which is always intense. Often there are signs of depression, even when the lesions are mild. As most adult patients are women, in addition to the conventional options, there is also hormone treatment. Combined oral contraceptives and spironolactone are good options. Knowing more about the particularities in etiopathogenesis, impact on QoL, and specific treatment options is important to all dermatologists who face the challenge of treating acne in adults.

Modulation of Toll Like Receptor-2 on sebaceous gland by the treatment of adult female acne

Adult female acne is a chronic inflammatory, immune-mediated disease that affects the pilosebaceous unit in women in their 20s to 40s, and is considered different from acne vulgaris. Propionibacterium acnes is recognized by TLR-2, resulting in activation of this receptor and an inflammatory response through the NFκ B pathway. This therapeutic, interventional, open, randomized, evaluator-blinded and comparative trial included 38 adult women with moderate facial acne and 10 age-matched controls, all aged between 26 and 44 years. Two treatments were performed over six months: 15% azelaic acid gel (AA) bid (n = 18) and oral contraceptive (COC) drospirenone 3 mg/ethinylestradiol .02 mg (n = 20). Biopsies were taken at baseline (control, lesion, perilesional) and at the conclusion (lesion and perilesional) of the study to evaluate TLR-2 expression by immunohistochemistry. Lesion count and blind photographic evaluation were used for efficacy. The groups were homogeneous: 70% of lesions were located in the submandibular area, 95% of participants had inflammatory lesions; of these, 50% had persistent and 50% had late-onset acne. The mean ages were 33.7 ± 5.5 and 33.1 ± 5.3 years (COC and AA group, respectively). A moderate clinical improvement was observed in both groups. No difference in TLR-2 expression in the lesion or perilesional areas was observed; however, reduced TLR-2 expression was seen in the control group. A significant reduction in expression was observed after both treatments, with no difference between the groups. This finding suggests an anti-inflammatory effect of COCs and AA in adult female acne, via modulation of the TLR-2 receptor.

Phenotype and Antimicrobial Activity of Th17 Cells Induced by Propionibacterium acnes Strains Associated with Healthy and Acne Skin

Studies of the human skin microbiome suggest that Propionibacterium acnes strains may contribute differently to skin health and disease. However, the immune phenotype and functions of T helper type 17 (Th17) cells induced by healthy (P_H) versus acne (P_A) skin-associated P. acnes strains are currently unknown. We stimulated peripheral blood mononuclear cells from healthy donors and observed that P_A strains induce higher IL-17 levels than P_H strains. We next generated P_H and P_A strain-specific Th17 clones and show that P. acnes strains induce Th17 cells of varied phenotype and function that are stable in the presence of IL-2 and IL-23. Although P_H- and P_A-specific clones expressed similar levels of LL-37 and DEFB4, only P_H-specific clones secreted molecules sufficient to kill P. acnes. Furthermore, electron microscopic studies showed that supernatants derived from activated P_H and not P_A-specific clones exhibited robust bactericidal activity against P. acnes, and complete breaches in the bacterial cell envelope were observed. This antimicrobial activity was independent of IL-26, because both natural IL-26 released by Th17 clones and rhIL-26 lacked antimicrobial potency against P. acnes. Overall, our data suggest that P. acnes strains may differentially modulate the CD4⁺ T-cell responses, leading to the generation of Th17 cells that may contribute to either homeostasis or acne pathogenesis.

The imbalance of Th17/Treg cells is involved in the progression of nonalcoholic fatty liver disease in mice

Background

Non-alcoholic fatty liver disease (NAFLD) is a common, chronic liver disease worldwide. Recent studies have shown that T helper (Th) 17 and regulatory T (Treg) cells play critical roles in various disorders of liver inflammation. Here, we explored the value of polyene phosphatidylcholine capsules (PPC) for regulating the imbalance of Th17/Treg cells in the pathogenesis of mice with NAFLD.

Methods

C57BL/6 mice were randomly divided into three groups as follows:normal diet (ND), high-fat diet (HF),and HF plus PPC(HF + PPC). The frequencies of splenic Th17 and Treg cells were measured by flow cytometry, and their related cytokines were analyzed by CBA and real-time PCR.

Results

At the end of 24 weeks, mice in the HF group had a higher frequency of intrahepatic Th17 cells,and a lower proportion of Treg cells compared with the ND group. The levels of Th17 cell-related cytokines (IL-6, IL-17 and IL-23) in serum and in liver tisse were increased,and the hepatic mRNA levels of RORγt, STAT3 and IL-6 were also increased. By contrast,the FoxP3 mRNA level was decreased in the HF group. Moreover, significant pathological and biochemical changes in the liver, as well as serum biochemical changes, were found in mice with NAFLD. Interestingly, following treatment with PPC, the levels of liver inflammation,frequencies of Th17/Treg cells and associated cytokines,and biochemical data were significantly altered.

Conclusion

These findings demonstrate a critical role for PPC in partially attenuating liver inflammatory responses in mice with NAFLD that involves the imbalance of Treg/Th17 cells and associated cytokines.

A global perspective on the epidemiology of acne

Acne is estimated to affect 9.4% of the global population, making it the eighth most prevalent disease worldwide. Epidemiological studies have demonstrated that acne is most common in postpubescent teens, with boys most frequently affected, particularly with more severe forms of the disease. This paper aims to provide an update on the epidemiology of acne worldwide. Recent general and institutional studies from around the world have shown that the prevalence of acne is broadly consistent globally (with the exception of specific populations, which are discussed). However, this review highlights that there is a wide range of disparate outcome measures being applied in epidemiology studies, and we emphasize the need to develop a widely accepted, credible, standard assessment scale to address this in the future. In addition we discuss special populations, such as those devoid of acne, as well as the impact of potential determinants of acne on disease epidemiology.

What's new in the physiopathology of acne?

There are four central factors that contribute to acne physiopathology: the inflammatory response, colonization with Propionibacterium acnes, increased sebum production and hypercornification of the pilosebaceous duct. In addition, research in the areas of diet and nutrition, genetics and oxidative stress is also yielding some interesting insights into the development of acne. In this paper we review some of the most recent research and novel concepts revealed in this work, which has been published by researchers from diverse academic disciplines including dermatology, immunology, microbiology and endocrinology. We discuss the implications of their findings (particularly in terms of opportunities to develop new therapies), highlight interrelationships between these novel factors that could contribute to the pathology of acne, and indicate where gaps in our understanding still exist.

Serum 25-hydroxy vitamin D levels in patients with acne vulgaris and its association with disease severity

BACKGROUND

Since vitamin D is a recent known immunoregulatory factor in some diseases which are addressed in immune system disorders such as SLE, [psoriasis] and others.

OBJECTIVE

To determine the serum levels of 25-hydroxy vitamin D3 [25(OH)D] in patients with acne vulgaris and its association with clinical features.

METHODS

This cross-sectional study was conducted over months. This study included 39 patients with acne vulgaris and 40 healthy controls. Subjects who did not use alcohol, vitamin D supplements, oral steroids or PUVA and/or NBUVB for more than three months were included. Serum 25(OH)D levels were measured. Baseline demographics, family history and comorbidities like PCO were recorded. Statistical analyses were performed using SPSS 16.0.0.

RESULTS

The median concentration of 25(OH)D was 8.4 ng/mL (range: 1.4-99) in patients and 10.4 ng/mL (range: 3.1-56.7) in controls, with no statistical significant difference. PCOS was a significant predictor of the occurrence of acne vulgaris (OR=6.25; 95% CI: 1.52-25.66; p=0.01). There were no significant associations between severity of disease and serum 25(OH)D levels (rs=-0.12, p=0.45), age (rs=-0.28, p=0.09), BMI (rs=-0.12, p=0.46), age at onset of disease (rs=-0.08, p=0.63) and duration of disease (rs=-0.10, p=0.54).

CONCLUSION

Based on the previous studies this is highly suspected that vitamin D would be a prominent factor in acne patients and more performances with bigger sample size could be useful to get positive results.

IL-17/Th17 pathway is activated in acne lesions

The mechanisms of inflammation in acne are currently subject of intense investigation. This study focused on the activation of adaptive and innate immunity in clinically early visible inflamed acne lesions and was performed in two independent patient populations. Biopsies were collected from lesional and non-lesional skin of acne patients. Using Affymetrix Genechips, we observed significant elevation of the signature cytokines of the Th17 lineage in acne lesions compared to non-lesional skin. The increased expression of IL-17 was confirmed at the RNA and also protein level with real-time PCR (RT-PCR) and Luminex technology. Cytokines involved in Th17 lineage differentiation (IL-1β, IL-6, TGF-β, IL23p19) were remarkably induced at the RNA level. In addition, proinflammatory cytokines and chemokines (TNF-α, IL-8, CSF2 and CCL20), Th1 markers (IL12p40, CXCR3, T-bet, IFN-γ), T regulatory cell markers (Foxp3, IL-10, TGF-β) and IL-17 related antimicrobial peptides (S100A7, S100A9, lipocalin, hBD2, hBD3, hCAP18) were induced. Importantly, immunohistochemistry revealed significantly increased numbers of IL-17A positive T cells and CD83 dendritic cells in the acne lesions. In summary our results demonstrate the presence of IL-17A positive T cells and the activation of Th17-related cytokines in acne lesions, indicating that the Th17 pathway is activated and may play a pivotal role in the disease process, possibly offering new targets of therapy.