Integrating skin color assessments into clinical practice and research: A review of current approaches.

Skin color classification can have importance in skin health, pigmentary disorders, and oncologic condition assessments. It is also critical for evaluating disease course and response to a variety of therapeutic interventions and aids in accurate classification of participants in clinical research studies. A panel of dermatologists conducted a literature review to assess the strengths and limitations of existing classification scales, as well as to compare their preferences and utilities. We identified 17 skin classification systems utilized in dermatologic settings. These systems include a range of parameters such as UV light reactivity, race, ethnicity, and degree of pigmentation. The Fitzpatrick skin type classification is most widely used and validated. However it has numerous limitations including its conflation with race, ethnicity, and skin color. There is a lack of validation data available for the remaining scales. There are significant deficiencies in current skin classification instruments. Consensus-based initiatives to drive the development of validated and reliable tools are critically needed.

Nutritional Risk, Depression, and Physical Function in Older People Living Alone.

This study investigated depression and physical function as factors associated with nutritional risk in older adults living alone. The study included 2896 people 65 years or older who lived alone. Data were collected in South Korea between September and November 2020. Descriptive statistics, a chi-squared test, independent samples t-test, weighted multiple regression analysis, and binary logistic regression analysis were performed using IBM SPSS for Windows ver. 23.0. In this study, 44.8% of participants were in the nutritional risk group. Furthermore, 60.9% of those at risk for depression, 75.1% of those with instrumental activities of daily living (IADLs) dependency, and 59.1% of those with chewing limitations were at nutritional risk. The factors that increased nutritional risk in the weighted multiple regression analysis were depression (ß = 0.27, p < 0.001), chewing limitations (ß = 0.12, p < 0.001), IADL dependency (ß = 0.09, p < 0.001), and basic physical movement (ß = 0.04, p = 0.020). Binary logistic regression analysis showed that those with IADL dependency had a 2.59 times higher nutritional risk than those with IADL non-dependency (p < 0.001). The nutritional risk group had a higher risk of depression (2.01 times higher [p < 0.001]), chewing limitations (1.76 times higher [p < 0.001]), and basic physical movement limitations (1.35 times higher [p = 0.009]) than the good nutritional group. Therefore, nutritional screening is required of older individuals living alone. To mitigate nutritional risks, it is necessary to assess depression and physical function, including IADL dependency.

Implications for cumulative and prolonged clinical improvement induced by cross-linked hyaluronic acid: An in vivo biochemical/microscopic study in humans.

In photoaged human skin, type I collagen fragmentation impairs dermal extracellular matrix (ECM) integrity, resulting in collapsed/contracted fibroblasts with reduced type I procollagen synthesis. Injections of cross-linked hyaluronic acid (CL-HA) reverse these deleterious changes. To investigate the time course and effects of biochemical changes induced by injected CL-HA, particularly whether fibroblast activation leads to accumulation/deposition of dermal collagen, we injected CL-HA into photoaged skin of human participants over 60 years-old and performed biochemical/microscopic analyses of skin samples. Beginning 1 week post-injection and lasting 6-9 months, fibroblasts exhibited activation, including increased immunostaining and gene expression of markers of type I collagen synthesis, such as heat shock protein 47 and components of the transforming growth factor-ß pathway. At 1 week post-injection, multiphoton microscopy revealed elongation/stretching of fibroblasts, indicating enhanced dermal mechanical support. At 4 weeks, second-harmonic generation microscopy revealed thick collagen bundles densely packed around pools of injected CL-HA. At 12 months, accumulation of thick collagen bundles was observed and injected CL-HA remained present in substantial amounts. Thus, by occupying space in the dermal ECM, injected CL-HA rapidly and durably enhances mechanical support, stimulating fibroblast elongation and activation, which results in thick, densely packed type I collagen bundles accumulating as early as 4 weeks post-injection and continuing for at least a year. These observations indicate that early and prolonged clinical improvement following CL-HA injection results from space-filling and collagen deposition. As type I collagen has an estimated half-life of 15 years, our data provide the foundations for optimizing the timing/frequency of repeat CL-HA injections.

Single-Cell RNA Sequencing Reveals Dysregulated POSTN+WNT5A+ Fibroblast Subclusters in Prurigo Nodularis.

Prurigo nodularis (PN) is an intensely pruritic, inflammatory skin disease with a poorly understood pathogenesis. We performed single-cell transcriptomic profiling of 28,695 lesional and nonlesional PN cells. Lesional PN has increased dysregulated fibroblasts (FBs) and myofibroblasts. FBs in lesional PN were shifted toward a cancer-associated FB-like phenotype, with POSTN+WNT5A+ cancer-associated FBs increased in PN and similarly so in squamous cell carcinoma. A multicenter cohort study revealed an increased risk of squamous cell carcinoma and cancer-associated FB-associated malignancies (breast and colorectal) in patients with PN. Systemic fibroproliferative diseases (renal sclerosis and idiopathic pulmonary fibrosis) were upregulated in patients with PN. Ligand-receptor analyses demonstrated an FB neuronal axis with FB-derived WNT5A and periostin interactions with neuronal receptors melanoma cell adhesion molecule and ITGAV. These findings identify a pathogenic and targetable POSTN+WNT5A+ FB subpopulation that may predispose cancer-associated FB-associated malignancies in patients with PN.

Social Interaction and Life Satisfaction among Older Adults by Age Group.

This study examined the effect of social interaction on life satisfaction in older adults. A total of 8188 participants were selected according to the inclusion criteria. SPSS Windows software (version 23.0) was used for statistical analyses. Data were analyzed using the independent samples t-test, chi-squared test, and multiple regression analysis with weights based on two age groups: 65-74 and ≥75 years. The results showed that social interaction factors influenced the life satisfaction of older adults. In the 65-74 age group, factors that statistically significantly increased life satisfaction were meeting children (ß = 0.17, p < 0.001) and volunteer activities (ß = 0.04, p = 0.007). In the ≥75 age group, factors that significantly increased life satisfaction were talking with friends (ß = 0.11, p = 0.002), talking with children (ß = 0.07, p = 0.013), using senior citizen community centers (ß = 0.08, p = 0.001), and hobby club activities (ß = 0.07, p = 0.001). In order to increase the life satisfaction of older adults, different ways to support social interactions need to be explored.

A Polygenic Risk Score for Predicting Racial and Genetic Susceptibility to Prurigo Nodularis.

Prurigo nodularis (PN) is an understudied inflammatory skin disease characterized by pruritic, hyperkeratotic nodules. Identifying the genetic factors underlying PN could help to better understand its etiology and guide the development of therapies. In this study, we developed a polygenic risk score that predicts a diagnosis of PN (OR = 1.41, P = 1.6 × 10-5) in two independent and continentally distinct populations. We also performed GWASs, which uncovered genetic variants associated with PN, including one near PLCB4 (rs6039266: OR = 3.15, P = 4.8 × 10-8) and others near TXNRD1 (rs34217906: OR = 1.71, P = 6.4 × 10-7; rs7134193: OR = 1.57, P = 1.1 × 10-6). Finally, we discovered that Black patients have over a two-times greater genetic risk of developing PN (OR = 2.63, P = 7.8 × 10-4). Combining the polygenic risk score and self-reported race together was significantly predictive of PN (OR = 1.32, P = 4.7 × 10-3). Strikingly, this association was more significant with race than after adjusting for genetic ancestry. Because race is a sociocultural construct and not a genetically bound category, our findings suggest that genetics, environmental influence, and social determinants of health likely affect the development of PN and may contribute to clinically observed racial disparities.

Treatment recommendations for acne-associated hyperpigmentation: Results of the Delphi consensus process and a literature review.

Acne vulgaris can be associated with hyperpigmentation, particularly in individuals with skin of color. This acne-induced macular hyperpigmentation (AMH), also called postinflammatory hyperpigmentation, is often long lasting and negatively impacts quality of life. Large-scale, randomized, controlled clinical trials with regard to the treatment of acne and AMH are lacking. For this reason, evidence-based treatment recommendations cannot be made. However, AMH is a common condition, and it is important for clinicians to have guidance on management strategies. The authors, a group of 10 board-certified dermatologists, conducted a modified Delphi consensus process to reach a consensus on first-line therapy for AMH and determine whether therapeutic choices change in different patient subgroups. We reached a consensus that most patients with acne and AMH should receive early and efficacious acne treatment with a topical retinoid and benzoyl peroxide. Therapies aimed at addressing AMH-including hydroquinone, azelaic acid, chemical peel, or antioxidants-may also be considered for enhancing the effect of the treatment regimen on acne and pigmentation. Chemical peels may be used as adjunctive or second-line therapy. This article details the results of the Delphi process, reviews relevant literature for providing recommendations for AMH, and discusses appropriate treatment options.

Single-cell RNA sequencing reveals dysregulated fibroblast subclusters in prurigo nodularis.

Prurigo nodularis (PN) is an intensely pruritic, chronic inflammatory skin disease that disproportionately affects black patients. However, the pathogenesis of PN is poorly understood. We performed single-cell transcriptomic profiling, ligand receptor analysis and cell trajectory analysis of 28,695 lesional and non-lesional PN skin cells to uncover disease-identifying cell compositions and genetic characteristics. We uncovered a dysregulated role for fibroblasts (FBs) and myofibroblasts as a key pathogenic element in PN, which were significantly increased in PN lesional skin. We defined seven unique subclusters of FBs in PN skin and observed a shift of PN lesional FBs towards a cancer-associated fibroblast (CAF)-like phenotype, with WNT5A+ CAFs increased in the skin of PN patients and similarly so in squamous cell carcinoma (SCC). A multicenter PN cohort study subsequently revealed an increased risk of SCC as well as additional CAF-associated malignancies in PN patients, including breast and colorectal cancers. Systemic fibroproliferative diseases were also upregulated in PN patients, including renal sclerosis and idiopathic pulmonary fibrosis. Ligand receptor analyses demonstrated increased FB1-derived WNT5A and periostin interactions with neuronal receptors MCAM and ITGAV, suggesting a fibroblast-neuronal axis in PN. Type I IFN responses in immune cells and increased angiogenesis/permeability in endothelial cells were also observed. As compared to atopic dermatitis (AD) and psoriasis (PSO) patients, increased mesenchymal dysregulation is unique to PN with an intermediate Th2/Th17 phenotype between atopic dermatitis and psoriasis. These findings identify a pathogenic role for CAFs in PN, including a novel targetable WNT5A+ fibroblast subpopulation and CAF-associated malignancies in PN patients.

Effects of safe handling education on cognition, compliance and stress handling of antineoplastic drugs in clinical nurses.

To evaluate the effects of safe-handling education on the cognition, practice and stress handling of antineoplastic drugs in clinical nurses. This study uses a quasi-experimental, non-equivalent control group pre-test and post-test design. The experimental and control groups had 30 nurses each, who handled antineoplastic drugs from three institutions. This study examines the safe handling of antineoplastic drugs six times, for two hours each over two weeks. To verify the homogeneity of the experimental and control groups and the effectiveness of safe-handling education about antineoplastic drugs, a chi-square test and independent samples t-test were performed. The results were statistically significant in both groups (cognition [t = 6.84, p < 0.001], practice [t = 5.86, p < 0.001], and the stress of handling antineoplastic drugs [t = 5.15, p < 0.001]). Education on ways to safely handle antineoplastic drugs improves cognition, practice and stress handling of these drugs; moreover, proper education minimizes exposure.

Sex-specific differences in oxidative stress markers and collagen expression in perioral skin wrinkling.

Wrinkling is the hallmark of skin ageing. We previously reported that perioral wrinkling is more severe in females; however, the molecular basis is unknown. This study assessed sex differences in the molecular expression of key ageing regulators in perioral skin. Twelve subjects (n = 6 male/female) were enrolled in this cross-sectional study and biopsies were taken from the perioral and periocular regions. RNA expression of collagen I, collagen III, cysteine-rich angiogenic inducer 61 (CYR61) and insulin-like growth factor 1 (IGF-1) was assessed by qPCR. There was no difference between females' and males' Griffith's grades (6 and 5.67, respectively, p = 0.092) or periocular wrinkling grades (3.2 and 2.6, p = 0.421), but females had more severe perioral wrinkling grades than males (6.2 and 2.8, p = 0.020). Females not only expressed significantly more CYR61 (p = 0.018) in the perioral region than malesm but also expressed more collagen III (p = 0.016). There was no difference in collagen I (p = 0.115) or IGF-1 (p = 0.124) expression in the perioral region between sexes. In the periocular region, there were no significant differences between sexes in the expression of all four markers. The significant molecular differences in the perioral region between the sexes may contribute to the greater perioral skin wrinkling seen clinically in females.

N6-methyladenosine RNA Methylation Correlates with Immune Microenvironment and Immunotherapy Response of Melanoma.

RNA methylation normally inhibits the self-recognition and immunogenicity of RNA. As such, it is likely an important inhibitor of cancer immune recognition in the tumor microenvironment, but how N6-methyladenosine (m6A) affects prognosis and treatment response remains unknown. In eight independent melanoma cohorts (1,564 patients), the modification patterns of 21 m6A gene signatures were systematically correlated with the immune cell infiltration of melanoma tumor microenvironment. m6A modification patterns for each patient were quantified using the principal component analysis method, yielding an m6Ascore that reflects the abundance of m6A RNA modifications. Two different m6A modification patterns were observed in patients with melanoma, separated into high and low m6Ascores that correlated with survival and treatment response. Low m6Ascores were characterized by an immune-inflamed phenotype, with 61.1% 5-year survival. High m6Ascores were characterized by an immune-excluded phenotype, with 52.2% 5-year survival. Importantly, lower m6Ascores correlated with more sensitive anti-PD-1 and anti-CTLA4 treatment responses, with 90% of patients with low m6Ascore responding, whereas 10% of those with high m6Ascore nonresponding (in cohort GSE63557). At single-cell and spatial transcriptome resolution, m6Ascore reflects melanoma malignant progression, immune exhaustion, and resistance to immune checkpoint blockade therapy. Hence, the m6Ascore correlates to an important facet of tumor immune escape as a tool for personalized medicine to guide immunotherapy in patients with melanoma.

Clinical and molecular change induced by repeated low-dose visible light exposure in both light-skinned and dark-skinned individuals.

BACKGROUND: Visible light (VL) is known to induce pigmentation in dark-skinned individuals and immediate erythema in light-skinned individuals. However, the effects of accumulated low-dose VL exposure across skin types are not well established. METHODS: Thirty-one healthy subjects with light (Fitzpatrick skin types [FST] I-II, n = 13) and dark (FST V-VI, n = 18) skin types were enrolled. Subjects' buttocks were exposed daily to VL, wavelength 400-700 nm, with a dose of 120 J/cm2 at 50 mW/cm2 , for four consecutive days. Microarray using Affymetrix GeneChip (49,395 genes) was performed followed by qRT-PCR on skin samples. RESULTS: Repeated low-dose VL irradiation induced immediate pigment darkening and delayed tanning in dark-skinned individuals while no discernable pigmentation and erythema were observed in light-skinned individuals. Top ten upregulated genes by repeated VL exposure in microarray included melanogenic genes such as tyrosinase (TYR), tyrosinase-related protein-1 (TYRP1), dopachrome tautomerase (DCT), premelanosome protein (PMEL), melan-A (MLANA), and solute carrier family 24, member 5 (SLC24A5) and genes involved in inflammation/matrix remodeling/cell signaling including chemokine (C-C motif) ligand 18 (CCL18), BCL2-related protein A1 (BCL2A1), and cartilage oligomeric matrix protein (COMP). In qRT-PCR CCL18 was upregulated in light skin with a greater extent (mean fold change ± SD; 4.03 ± 3.28, p = .04) than in dark-skinned individuals (1.91 ± 1.32, p = .07) while TYR was not significantly upregulated in both skin types. CONCLUSION: This study highlights the genes upregulated by cumulative VL exposure involved in pigmentation, immune response, oxidation/reduction, and matrix remodeling across skin types providing relevant information on daily solar exposure.

Association of Early Clinical Response to Laser Rejuvenation of Photoaged Skin with Increased Lipid Metabolism and Restoration of Skin Barrier Function.

Laser resurfacing treatments for photoaged skin have improved dramatically over the past decades, but few studies have examined the molecular mechanisms underlying differences in clinical response. Seventeen white female participants with moderate-to-severe photoaging received nonablative fractional laser treatment on the face and forearm once monthly for 6 months. Biopsies for microarray analysis were performed at baseline and 7 days after facial treatment and at baseline and 1, 7, 14, and 29 days after forearm treatment in each participant, resulting in 119 total samples. Participants were stratified into fast (n = 11) and slow (n = 6) responders on the basis of the presence of clinical improvement after the first treatment. Microarray analysis revealed the upregulation of genes associated with matrix metalloproteinases, collagen and extracellular components, TGF-ß signaling, double-stranded RNA signaling, and retinoic acid synthesis after treatment that did not differ significantly between fast and slow responders. Cluster and enrichment analyses suggested significantly greater activation of lipid metabolism and keratinocyte differentiation in fast responders, who showed greater upregulation of acyltransferases, fatty acid elongases, fatty acid 2-hydroxylase, fatty acid desaturases, and specific keratins that may contribute to epidermal barrier function. These results create, to our knowledge, a previously unreported atlas of molecular changes that correlate with improvements in photoaging after laser therapy.

Skin type specific photobiological response to visible light is mediated by constitutional melanin.

BACKGROUND: Visible light (VL) induces varying photobiological responses between skin types, likely influenced by inherent melanization. Individual typology angle (ITA) objectively measures skin types. We hypothesize that epidermal melanin content and distribution determine VL response. OBJECTIVES: This study describes clinical and histologic responses to VL and examines the potential role of melanin in the underlying mechanistic pathways. METHODS: We grouped enrolled participants by ITA (Light = 5, Intermediate = 4, Dark = 7) per colorimetry (CR-400, Konica Minolta). Photoprotected sites were exposed daily to 480 J/cm2 of VL (Fiber-Lite High Intensity Illuminator, Series 180, Dolan Jenner Industries Inc.) for 4 days (total = 1920 J/cm2 ), as tolerated. Treated and control sites were biopsied 96 h after first exposure. We used hematoxylin and eosin and Fontana-Mason to assess histological changes and melanin deposition, respectively. p53 and Ki67 immunohistochemical stains were done to assess DNA damage and proliferation. Matrix metalloproteinase (MMP)-1 expression was detected by immunohistochemical staining and immunofluorescence microscopy. RESULTS: Darker skin did not tolerate the full VL regimen with blistering occurring in most subjects at doses of 220-880 J/cm2 . Intermediate and Dark skin showed tanning. Light skin developed erythema. p53 counts were highest in Intermediate, followed by Light skin, although this was not statistically significant. VL treatment led to MMP-1 expression and nuclear localization in keratinocytes in Dark and Intermediate but not in Light skin, however differences between groups were not statistically significant. CONCLUSIONS: Skin types demonstrate unique biological responses to VL. The role of melanin in photoprotection is well-defined. However, given the pro-apoptotic function of nuclear MMPs, we suggest a potential mechanism by which melanin may mediate VL-induced phototoxicity.

Racial/Ethnic Variations in Acne: A Practical Algorithm for Treatment and Maintenance, Including Skincare Recommendations for Skin of Color Patients With Acne.

BACKGROUND: Racial/ethnic differences in the clinical presentation, sequelae, and desired treatment outcomes for acne have been reported. Post-inflammatory hyperpigmentation (PIH) frequently occurs in patients with richly pigmented skin complexions and can frequently be the most bothersome aspect of acne in this population. METHODS: The project used a modified Delphi hybrid process comprising face-to-face discussions followed by an online follow-up. A structured literature search was conducted to identify publications on racial/ethnic differences in the clinical presentation, sequelae, and desired treatment outcomes for skin of color (SOC) patients with acne . The advisors subsequently convened to review the results and draft an algorithm for the treatment and maintenance, including skincare recommendations, for SOC patients with acne. Online, the panel reviewed and adopted the algorithm using published evidence coupled with the panel's expert opinion and clinical experience. RESULTS: Studies suggest that strategies for improving outcomes in patients with acne who have SOC include: the early initiation and maintenance of treatment regimens; careful consideration of the tolerability of active ingredients, vehicle formulations, and dosing; and the use of skin care (eg, pH balanced, non-irritating cleansers, and non-comedogenic moisturizers) to minimize irritation or dryness. CONCLUSION: Acne treatment in patients with SOC involves unique therapeutic considerations, including management of PIH through efficacious longitudinal acne treatment, prevention of irritation, and potential active treatment of PIH. Skincare products are recommended as an adjunct to prescription therapy to maximize tolerability and may also play a role in maintenance therapy. J Drugs Dermatol. 2022;21:11(Suppl 2):s3-14.

Factors Related to Life Satisfaction of Older Adults at Home: A Focus on Residential Conditions.

This study examined which residential conditions increase older adults' life satisfaction at home. We used data from 8903 participants over 65 years old who did not need help in their daily lives from a 2020 survey of older adults conducted by the Korea Institute for Health and Social Affairs. Data analysis was conducted using descriptive statistics, independent sample t-test, Pearson correlation analysis, and hierarchical multiple regression with weights. The final model explained 34.2% of life satisfaction in old age. Residential conditions that increased life satisfaction the most in old age were the community environment (ß = 0.16, p < 0.001) and satisfaction with the house (ß = 0.15, p < 0.001). Other conditions that significantly affected life satisfaction were safety (ß = 0.08, p < 0.001), interaction with neighbors (ß = 0.08, p < 0.001), distance from children or relatives (ß = 0.08, p < 0.001), frequency and route of public transportation (ß = 0.05, p < 0.001), and abundance and distance of green spaces (ß = 0.02, p = 0.031). Housing welfare policies should consider these results to increase life satisfaction for an increasingly aging population. Moreover, these data can be used to design age-friendly community environments.

Update: Mechanisms of Topical Retinoids in Acne.

Topical retinoids are the cornerstone of current acne management due to their actions on multiple facets of acne pathophysiology. Retinoids are a family of compounds that structurally and functionally resemble vitamin A, an essential nutrient with a key role in cellular growth and differentiation. In the skin, retinoids exert their effects by binding retinoic acid receptors (RARs) in the cell nucleus with subsequent regulation of gene transcription. There are three subtypes of RARs, and the topical retinoids currently approved for acne have differing receptor binding profiles which may translate to clinical differences, since the specific RAR subtypes activated dictate the biological response of target cells. The activity of a retinoid depends on cellular transport, receptor-binding pattern and affinity, and the genes activated. This review discusses physiologic pathways in skin that are affected by topical retinoids during acne therapy, with a focus on new data from trifarotene, a retinoid which is highly selective for the RAR-γ receptor. Recently, bioinformatic data comparing gene expression in acne lesions treated with trifarotene versus spontaneously resolving acne lesions showed that trifarotene significantly modulates 67 genes that do not appear in the spontaneously resolving lesion. These genes are involved in cellular migration, activation of adaptive immunity, inflammation, and matrix reorganization. Expression of these trifarotene-regulated genes after treatment and in an active lesion occurred in opposite directions, providing clues to the molecular and genetic response to trifarotene in resolving acne. J Drugs Dermatol. 2022;21(7):734-740. doi:10.36849/JDD.6890.

Isotretinoin Laboratory Monitoring in Acne Treatment: A Delphi Consensus Study.

Importance: Although isotretinoin may rarely be associated with laboratory abnormalities such as hypertriglyceridemia, the optimal approach to laboratory monitoring is uncertain, and there is wide variation in clinical practice. Objective: To establish a consensus for isotretinoin laboratory monitoring among a diverse, international cohort of clinical and research experts in acne. Design, Setting, and Participants: Using a modified electronic Delphi process, 4 rounds of anonymous electronic surveys were administered from 2021 to 2022. For laboratory tests reaching consensus (≥70% agreement) for inclusion, questions regarding more time-specific monitoring throughout isotretinoin therapy were asked in subsequent rounds. The participants were international board-certified dermatologist acne experts who were selected on a voluntary basis based on involvement in acne-related professional organizations and research. Main Outcomes and Measures: The primary outcome measured was whether participants could reach consensus on key isotretinoin laboratory monitoring parameters. Results: The 22 participants from 5 continents had a mean (SD) time in practice of 23.7 (11.6) years and represented a variety of practice settings. Throughout the 4-round study, participation rates ranged from 90% to 100%. Consensus was achieved for the following: check alanine aminotransferase within a month prior to initiation (89.5%) and at peak dose (89.5%) but not monthly (76.2%) or after treatment completion (73.7%); check triglycerides within a month prior to initiation (89.5%) and at peak dose (78.9%) but not monthly (84.2%) or after treatment completion (73.7%); do not check complete blood cell count or basic metabolic panel parameters at any point during isotretinoin treatment (all >70%); do not check gamma-glutamyl transferase (78.9%), bilirubin (81.0%), albumin (72.7%), total protein (72.7%), low-density lipoprotein (73.7%), high-density lipoprotein (73.7%), or C-reactive protein (77.3%). Conclusions and Relevance: This Delphi study identified a core set of laboratory tests that should be evaluated prior to and during treatment with isotretinoin. These results provide valuable data to guide clinical practice and clinical guideline development to optimize laboratory monitoring in patients treated with isotretinoin.

Biomarkers of Tretinoin Precursors and Tretinoin Efficacy in Patients With Moderate to Severe Facial Photodamage: A Randomized Clinical Trial.

Importance: Topical formulations of tretinoin precursors (retinol and its ester derivatives) are widely available over the counter and may offer similar clinical benefits to those of tretinoin for treatment of photoaging. However, which of the many purported molecular effects of retinoids most strongly drives clinical improvements in tretinoin-treated skin remains unclear. Objectives: To evaluate the clinical efficacy of topical tretinoin precursors (TTP) vs tretinoin (RA) in treating moderate to severe facial photodamage and to identify potential biomarkers that correlate with clinical efficacy. Design, Setting, and Participants: This randomized, double-blind, single-center, parallel-arm study of 24 patients with moderate to severe facial photodamage was conducted at an academic referral center from November 2010 to December 2011, with data analysis performed from January 2012 to December 2021. Interventions: Daily topical application of 0.02% RA or 1.1% TTP formulation containing retinol, retinyl acetate, and retinyl palmitate for 24 weeks. Main Outcomes and Measures: Photoaging and tolerability were assessed by dermatologist evaluations and patient-reported outcomes. Target gene expression was assessed by real-time quantitative polymerase chain reaction of biopsied tissue from treated areas. Results: A total of 20 White women were ultimately analyzed (9 randomized to TTP, 11 randomized to RA). At week 24, there was no significant difference in Griffiths photoaging scores among patients receiving TTP vs RA (median, 4 vs 5) (TTP - RA difference: -1; 95% CI, -2 to 1; P = .27). Treatment with TTP was associated with erythema 6 times less frequently than RA (11% vs 64%) (TTP - RA difference: -0.53; 95% CI, -0.88 to -0.17; P = .01). Target gene analysis showed significant CRABP2 messenger RNA (mRNA) induction (confirming retinoic acid receptor signaling) but no significant changes in procollagen I or MMP1/3/9 mRNA in TTP-treated samples. Instead, MMP2 mRNA, which encodes a type IV collagenase, was significantly reduced in TTP-treated samples (week 24 - baseline mRNA difference: -5; 96% CI, -33 to 1.6; P = .02), and changes in MMP2 were strongly correlated with changes in fine wrinkles (r = 0.54; 95% CI, 0.12 to 0.80; P = .01). Interestingly, patients with severe baseline wrinkles exhibited greater improvements (r = -0.74; 95% CI, -0.89 to -0.43; P < .001). This trend was mirrored in MMP2 mRNA, with initial expression strongly predicting subsequent changes (r = -0.78; 95% CI, -0.89 to -0.43; P < .001). Conclusions and Relevance: In this randomized clinical trial, there was no significant difference in efficacy between this particular formulation of TTP and tretinoin 0.02%. However, the results of these mechanistic studies highlight MMP2 as a possible mediator of retinoid efficacy in photoaging. Trial Registration: ClinicalTrials.gov Identifier: NCT01283464.