Molecular diagnostics in dermatology: An online survey to study usage, obstacles and requirements in Germany

Inflammatory Skin Diseases: The Importance of Immunological Signatures

BACKGROUND

The understanding and classification of inflammatory skin diseases is shifting from a historical-descriptive perspective to a molecular-pathophysiological one based on immune response patterns. These are derived from a few key immunological mediators, each of which induces its own characteristic clinical, histopathological, and molecular patterns in the skin.

METHODS

This discussion of the definition of the immune response patterns of inflammatory skin diseases is based on information from pertinent publications retrieved by a selective literature search. A systematic literature search was also conducted on the response of inflammatory skin diseases to treatment with specific biologic agents.

RESULTS

The described immune response patterns are: autoinflammation; type 1, cytotoxic; type 2a, eczematous; type 2b, blistering; type 3, psoriasiform; type 4a, fibrosing; and type 4b, granulomatous. Each signature can usually be treated in a targeted manner. In general, each therapeutic target structure is associated with an adequate treatment response if and only if the skin disease under treatment has the relevant signature type. Hardly any biomarkers are currently available for the determination of immune response patterns in routine clinical practice.

CONCLUSION

The classification of inflammatory skin diseases by their immune response patterns opens up the prospect of specifically targeted immunotherapy for each immune response pattern regardless of the historical-descriptive disease entity. Targeting is intended to improve response rates. Initial findings suggest that this strategy is likely to succeed.

A Narrative Review of Molecular, Immunohistochemical and In-Situ Techniques in Dermatopathology

Skin disorders pose a significant health burden globally, affecting millions of individuals across diverse demographics. Advancements in molecular techniques have revolutionised our understanding of the underlying mechanisms of skin disorders, offering insights into their pathogenesis, diagnosis, and potential targeted treatment. Furthermore, the integration of molecular diagnostics into clinical practice has enhanced the accuracy of skin disorder diagnoses. Polymerase chain reaction (PCR), next-generation sequencing (NGS), and other molecular assays have allowed for the detection of infectious agents, assessment of genetic mutations, and profile gene expression patterns with unequalled precision. These techniques have proven instrumental in distinguishing between subtypes of skin cancers, aiding treatment strategies and prognostic assessments. Moreover, molecular profiling is increasingly guiding the selection of therapeutic agents, ensuring a personalised and effective approach to managing skin disorders. The application of PCR has revolutionised the field by enabling the identification of microbial DNA (i.e., Mycobacterium tuberculosis and Epstein-Barr Virus) in skin infections and detecting specific genetic mutations associated with dermatological disorders (e.g., BRAF). DNA sequencing technologies, such as next-generation sequencing, have facilitated the elucidation of genetic variations and mutations in skin diseases (i.e., bullous disorders), paving the way for personalised treatment approaches. Gene expression profiling techniques, such as microarrays and RNA sequencing, have provided insights into dysregulated pathways and molecular signatures associated with conditions ranging from inflammatory skin disorders to cutaneous malignancies. Immunohistochemistry and fluorescence in situ hybridization have proven invaluable in determining protein expression patterns and detecting chromosomal abnormalities, respectively, aiding in the characterization of skin lesions in conjunction with the molecular data. Proteomic studies have contributed to understanding the intricate protein networks involved in dermatological conditions (i.e., psoriasis), while epigenetic analyses have shed light on the role of epigenetic modifications in gene regulation within skin cancer (i.e., Malignant Melanoma). Together, these molecular techniques have laid the groundwork for targeted therapies and precision medicine in dermatology, with implications for improved diagnostics and treatment outcomes. This review focuses on the routinely employed molecular techniques within dermatopathology, with a focus on cutaneous malignancies, autoimmune diseases, infectious diseases, and neonatal screening which can be implemented in the diagnosis and contribute to improved patient care.

Food allergy - New risks through vegan diet? Overview of new allergen sources and current data on the potential risk of anaphylaxis

A vegan diet is increasingly en vogue, i.e., a diet based on plants, in which animal products are completely avoided, often for health and environmental reasons. The menu is supplemented with pulses (e.g., soy, lentils, peas), nuts (e.g., cashew, macadamia, almond, pecan, para, walnut) and seeds (e.g., chia, flaxseed) or pseudo-grains (quinoa, buckwheat). Indeed, the product range is expanding to include vegan foods such as milk alternatives (e.g., oat, almond, soy drinks) and cheese or meat substitutes (e.g., soy-based). Food allergies are also on the rise, with an increasing prevalence worldwide. It is worthy of note that the main allergens of anaphylactic reactions to food in adults are predominantly of plant origin, mainly pulses and nuts - the very foods that form the main source of protein in the vegan diet. In this context, allergies to storage proteins (e.g., Gly m 5 and Gly m 6 from soya beans) can lead to severe anaphylactic reactions, while highly processed substitute products containing plant protein isolates (e.g., pea flour) in concentrated form continue to be of particular concern and may therefore be allergologically problematic. In this article, we aim to provide an overview of allergens and emerging allergen sources in vegan foods and highlight the anaphylaxis risk of the vegan diet.

Nahrungsmittelallergie - Neue Risiken durch vegane Ernährung? Überblick zu neuen Allergenquellen und aktuelle Daten zum Anaphylaxierisiko: Food allergy - New risks through vegan diet? Overview of new allergen sources and current data on the potential risk of anaphylaxis

Zunehmend mehr Menschen ernähren sich aus gesundheitlichen und Umweltaspekten ausschließlich von pflanzlichen Nahrungsmitteln (vegan). Dabei werden vielfach Hülsenfrüchte (wie Soja, Linsen, Erbsen), Schalenfrüchte (Cashew, Macadamia, Mandel, Pekan‐, Para‐ und Walnuss), Samen und Saaten (wie Chia, Leinsamen) oder (Pseudo‐)Getreide (wie Quinoa, Buchweizen) verzehrt. Vegane Milchalternativen sind Hafer‐, Mandel‐ und Sojadrinks, auch Käse‐ sowie Fleischersatzprodukte basieren oft auf einer Sojagrundlage. Gleichzeitig nimmt die Prävalenz von Nahrungsmittelallergien weltweit zu. Pflanzenallergene aus Hülsen‐ und Schalenfrüchten, die in der veganen Ernährung die Hauptproteinquelle ausmachen, zählen zu den häufigsten Auslösern von Nahrungsmittelallergien bei Erwachsenen. Dabei kommt es bei Allergien auf Speicherproteine (wie Gly m 5 und Gly m 6 aus der Sojabohne) zu teils schweren anaphylaktischen Reaktionen. Besonderes Augenmerk liegt weiter auf hochverarbeiteten Ersatzprodukten, die Pflanzenproteinisolate (zum Beispiel Erbsenmehl) in konzentrierter Form enthalten und damit allergologisch problematisch werden können. In diesem Artikel geben wir einen Überblick über wichtige Allergene und neue Allergenquellen in ausgesuchten veganen Nahrungsmitteln und betrachten die vegane Ernährung unter allergologischen Aspekten.

Status quo and future perspectives of molecular diagnostics in dermatology

Molecular diagnostics (MDx) has become an indispensable pillar of diagnostics in dermatology. Modern sequencing technologies allow for identification of rare genodermatoses, analysis of somatic mutations in melanoma are prerequisite for targeted therapies, and cutaneous infectious pathogens are quickly detected by PCR and other amplification methods. However, to push innovation in molecular diagnostics and tackle so far unmet clinical needs, research activities need to be bundled and the pipeline from idea to MDx product clearly rolled out. Only then, the requirements for technical validity and clinical utility of novel biomarkers can be fulfilled and the long-term vision of personalized medicine will be realized.