Central venous catheter tip colonization and associated bloodstream infection in patients with severe burns under routine catheter changing.

BACKGROUND: Although routine changing of central venous catheters (CVCs) is commonly performed in patients with severe burns, information on pathogen colonization of the CVC tip and associated bloodstream infections (BSIs) is limited in those patients. METHODS: The medical records of 214 patients with severe burns who underwent routine CVC changing at 7-day intervals and their results of 686 pairs of CVC tips and concurrent blood cultures were retrospectively reviewed to evaluate the CVC colonization rate and associated BSI pathogens. RESULTS: Of the 686 CVCs, 137 (20.0%) were colonized by pathogens, and 81 (59.1%) of them had BSIs caused by the same pathogen. Nonflame burn (P = .002), total body surface area burn ≥30% (P = .004), femoral catheterization (P = .001), CVC changing during pre-existing BSI (P < .001), and renal replacement therapy (P = .017) were associated with catheter-related BSI in the multivariate analysis. Most BSIs were caused by Gram-negative bacteria (most commonly Acinetobacter baumannii, Klebsiella pneumoniae, and Pseudomonas aeruginosa). CONCLUSIONS: The CVC colonization rate in patients with severe burns and routine CVC changing was not high. Lengthening the CVC duration might be attempted in patients at a lower risk of catheter-related BSI although further prospective studies are necessary.

Pioneering predictions of AKI and AKIN severity in burn patients: a comprehensive CBC approach.

This study aims to evaluate the utility of complete blood count (CBC) markers, in conjunction with the acute kidney injury network (AKIN) criteria, for the early detection, severity assessment, and prediction of mortality outcomes of acute kidney injury (AKI) in burn patients. The research seeks to fill existing gaps in knowledge and validate the cost-effectiveness of using CBC as a routine diagnostic tool for better management of AKI. The study was conducted at Hangang Sacred Heart Hospital. We performed a large-scale retrospective analysis of 2758 adult patients admitted to the burn intensive care unit over a 12-year period. Among these patients, AKI occurred in 1554 patients (56.3%). Based on the AKIN stage classification, 794 patients (28.8%) were categorized as AKIN 1, 494 patients (17.9%) as AKIN 2, and 266 patients (9.6%) as AKIN 3. We defined several ratio markers, including the Neutrophil-to-lymphocyte ratio (NLR), Platelet-to-lymphocyte ratio (PLR), Monocyte-to-lymphocyte ratio (MLR), systemic immune-inflammation index (SII), and various mean platelet volume (MPV) ratios. Our statistical analyses, conducted using the R programming language, revealed significant correlations between these markers and AKI severity. The AUC values for neutrophil count and WBC count were 0.790 and 0.793, respectively, followed by immature granulocyte count with an AUC of 0.727. For red blood cell (RBC)-related parameters, the AUC values for hematocrit (Hct), hemoglobin (Hb), and RBC count were 0.725, 0.713, and 0.713, respectively. Among the platelet-related parameters, only platelet distribution width (PDW) had an AUC of 0.677. Among the ratio markers, the NLR had the highest AUC at 0.772, followed by MPVNR and SII with AUC values of 0.700 and 0.680, respectively. The findings underscore the potential of CBC as an economical, routine test for AKI, thereby paving the way for enhanced patient outcomes. Our study suggests the utility of routine CBC tests, specifically WBC count and PLR, for predicting AKI and platelet, MPV, and NLR for mortality assessment in burn patients. These findings underscore the potential of easily accessible CBC tests in enhancing AKI management. However, further multicenter studies are needed for validation.

Big data insights into the diagnostic values of CBC parameters for sepsis and septic shock in burn patients: a retrospective study.

Sepsis and septic shock are prevalent and life-threatening complications in burn patients. Despite their severity, existing diagnostic methods are limited. This study aims to evaluate the efficacy of Complete Blood Count (CBC) and CBC ratio markers in diagnosing sepsis and septic shock, and in predicting mortality among burn patients. A cohort of 2757 burn patients was examined to ascertain the correlation between various CBC parameters, their ratios, and the incidence of sepsis and related mortality. Key markers analyzed included Red Cell Distribution Width (RDW), Mean Platelet Volume (MPV), Neutrophil-to-Lymphocyte Ratio (NLR), Platelet-to-Lymphocyte Ratio (PLR), and Mean Platelet Volume-to-Platelet Ratio (MPVPR). Our findings indicate that 65.5% of the patients developed sepsis, and 24.3% succumbed to their conditions. The CBC parameters RDW, MPV, NLR, MPVPR, and MPV-to-Lymphocyte Ratio (MPVLR) were significantly associated with sepsis and mortality. These markers showed considerable temporal variation and yielded an Area Under the Curve (AUC) of over 0.65 in an unadjusted Generalized Estimating Equations (GEE) model. This study underscores the potential of RDW, MPV, NLR, MPVPR, and MPVLR as vital prognostic tools for diagnosing sepsis, septic shock, and predicting mortality in burn patients. Although based on a single-center dataset, our results contribute to the enhancement of sepsis management by facilitating earlier, more precise diagnosis and treatment strategies. Further multi-center research is necessary to confirm these findings and broaden their applicability, establishing a solid base for future explorations in this crucial field.

Vitamin D supplementation can enhance therapeutic effects of excimer laser in patients with vitiligo.

PURPOSE: Vitiligo is a disease of acquired depigmentation characterized by the destruction of melanocytes. A theoretical association between low level of 25-hydroxyvitamin D [25(OH)D] and vitiligo has been previously suggested. The objective of this study was to determine the efficacy of intramuscular injection of cholecalciferol with excimer laser compared with the excimer laser alone for vitiligo treatment. METHODS: This study included 26 patients diagnosed with non-segmental vitiligo and low serum 25(OH)D levels (<20 ng/mL). The participants were randomly divided into two groups through randomization. The treatment using a 308-nm excimer laser was administered to both groups, and the study group additionally received cholecalciferol injection. RESULTS: The Vitiligo Area Scoring Index (VASI) scores showed an 83.6% improvement over the initial score in the study group, whereas the control group showed a 54.7% improvement after 6 months of treatment. After 6 months of treatment, the study group showed a significantly higher proportion of patients who achieved VASI50 and VASI75 compared with the control group. CONCLUSION: Intramuscular injection of cholecalciferol can be a supplemental option for the treatment of vitiligo patients with vitamin D deficiency with excimer laser therapy.

Case Report: Erythema Multiforme Induced by Lithium Contact.

Erythema multiforme (EM) is an acute, self-limited mucocutaneous disease with diverse triggering factors, and the recurrences are quite common. A 24-year old male presented with multiple erythematous, itchy papules and plaques on multiple sites. He has worked in a lithium battery factory and experienced the chemical burn 2 weeks ago. A histopathologic examination on right wrist showed a scattered lymphocytic infiltration, vacuolar degeneration, and necrotic keratinocyte. The final diagnosis was EM after occupational lithium exposure. He was treated by oral methylprednisolone and experienced recurrences after returning to the same workplace after remission. Although the precise pathogenesis is unknown, the pathogenesis of EM by lithium is related to the effect of lithium on immune system, different from other etiologies. To our knowledge, our case is the first report of EM following the chemical burn and occupational lithium exposure. We report this as an interesting case of EM.

Multiple Eruptive Epithelioid Hemangiomas on the Right Upper Extremity in an Asian Man.

Epithelioid hemangioma is a rare benign vascular neoplasm. Recently, the term "multiple eruptive epithelioid hemangioma" has been proposed for epithelioid hemangioma with distinct features. It is different from usual epithelioid hemangioma because of the multifocal distributions in various body regions with an eruptive onset. In addition, the histopathology of multiple eruptive epithelioid hemangioma shows increased cellular proliferation, mitosis, and nuclear pleomorphism and positive findings for FOS-B compared to classic epithelioid hemangioma. Herein, we report the case of a 59-year-old man with unusual manifestations suitable for multiple eruptive epithelioid hemangioma. He had multiple erythematous to purple-red dome-shaped nodules on the right hand, arm, and shoulder. The initial lesion was a solitary erythematous nodule on the right hand that abruptly extended to the right arm and shoulder. Microscopically, the tumor was a well-demarcated dermal nodule and showed capillary sized vascular structures. Vascular structures had epithelioid endothelial cells with abundant eosinophilic cytoplasm and vesicular nuclei. The tumor cells showed mild nuclear pleomorphism and a few mitosis and feature of resembling cobble stone was observed. In immunohistochemistry, CD31 and CD34 were positive in the endothelial cells. The endothelial cells showed nuclear positivity in FOS-B. Based on the clinical and histopathological findings, the final diagnosis was multiple eruptive epithelioid hemangiomas. This is the first report of multiple eruptive epithelioid hemangiomas in an Asian man after the term had been introduced.

The clinical differentiation of blood culture-positive and -negative sepsis in burn patients: a retrospective cohort study.

Background: Sepsis is a potentially life-threatening condition that occurs when the body's response to infection leads to widespread inflammation and tissue damage. Negative cultures can make it difficult for clinicians to make a diagnosis and may raise questions about the validity of the definition of sepsis. In addition, the clinical distinctions between burn patients with blood culture-positive and -negative sepsis are also poorly understood. Therefore, this study aimed to examine the clinical differences between blood culture-positive and -negative sepsis in burn patients in order to improve the understanding of the pathophysiology and epidemiology of sepsis in this population. Methods: This study had a retrospective design, and the participants were adults aged ≥18 years. Patients diagnosed with sepsis were divided into two groups based on their blood culture results within 1 week of sepsis diagnosis. Results: We enrolled 1643 patients admitted to our institution's burn intensive care unit between January 2010 and December 2021. pH, platelet count, bicarbonate and haematocrit were significant in both the positive and negative groups. However, lymphocyte, red cell distribution width and blood urea nitrogen were significant only in the positive group, whereas lactate dehydrogenase was significant only in the negative group. Acinetobacter baumannii, Pseudomonas aeruginosa, and Klebsiella pneumonia are common gram-negative bacterial species, and Staphylococcus aureus and Staphylococcus epidermidis are common gram-positive bacterial species seen in burn patients with positive blood cultures. Carbapenem resistance was found to be associated with an unfavourable prognosis in gram-negative bacteria, with the exception of P. aeruginosa. Conclusions: pH, platelet count, bicarbonate and haematocrit were routine biomarkers that demonstrated statistical significance in both groups. Lactate dehydrogenase was significant in the blood-negative group, while red cell distribution width, blood urea nitrogen and lymphocyte count were significant in the positive group. Furthermore, the most common causes of sepsis are gram-negative bacteria, including A. baumannii, K. pneumoniae and P. aeruginosa. Additionally, resistance to carbapenems is associated with unfavourable outcomes.

Adipose-Derived Stem Cell Exosomes Alleviate Psoriasis Serum Exosomes-Induced Inflammation by Regulating Autophagy and Redox Status in Keratinocytes.

Introduction: Exosomes play a key role in cell communication and are involved in both pathological and physiological processes. Autophagy dysfunction and oxidative stress are linked to immune-mediated inflammatory diseases such as psoriasis. Stem cell-derived exosomes exhibit immunomodulatory and antioxidant efficacy. Methods: We aimed to investigate the impact of psoriasis serum-derived exosomes on inflammation, oxidative stress, and autophagy in keratinocytes. Additionally, we explored the therapeutic potential of adipose-derived stem cell (ADSC) exosomes against inflammation induced by psoriasis serum exosomes. To validate psoriasis patient serum-derived exosomes and ADSC exosomes, we used nanoparticle tracking analysis, Western blotting, flow cytometry, and immunofluorescence. qPCR was used to study changes in the gene expression of proinflammatory cytokines and oxidative stress markers in HaCaT cells treated with psoriasis serum-derived exosomes or ADSC exosomes. The effects of these exosomes on autophagy in HaCaT cells were evaluated by Western blotting and immunofluorescence. Result: The treatment of HaCaT cells with psoriasis serum-derived exosomes increased proinflammatory cytokine production and oxidative stress-related factor (Nox2 and Nox4) expression and decreased Nrf2 expression via P65/NF-κB and P38/MAPK activation. Compared with healthy control serum-derived exosomes, psoriasis serum-derived exosomes decreased ATG5, P62, Beclin1, and LC3 expression and autophagosome production in HaCaT cells. Conversely, ADSC exosomes suppressed proinflammatory cytokine and oxidative stress production, and restored autophagy in HaCaT cells treated with psoriasis serum-derived exosomes. Discussion: These findings suggest that ADSC exosomes exhibit a suppressive effect on psoriasis serum exosome-induced inflammation and oxidative stress by regulating autophagy in keratinocytes.

Tracking longitudinal biomarkers in burn patients with sepsis and acute kidney injury: an unsupervised clustering approach.

BACKGROUND: Sepsis is a grave medical disorder characterized by a systemic inflammatory response to infection. Furthermore, it is a leading cause of morbidity and mortality, especially in hospitalized patients. Acute kidney injury (AKI) is a common complication of sepsis and is associated with increased morbidity and mortality. Patients with burns are particularly vulnerable to developing sepsis and AKI due to the extensive tissue damage and immune suppression resulting from burn injury. In this study, unsupervised clustering algorithms were used to track longitudinal biomarkers in patients with burns and assess their impact on mortality. METHODS: This retrospective study included adult patients with burns aged ≥ 18 years, who were admitted to the burn intensive care unit of Hallym University and Hangang Sacred Heart Hospital between July 2010 and December 2021. The patients were divided into two subgroups: those with sepsis (538 patients) and those without sepsis (826 patients). The longitudinal biomarkers were grouped into three clusters using the k-means clustering algorithm. Each cluster was assigned a letter from A to C according to its mortality rate. RESULTS: The odds ratio (OR) of pH was 9.992 in the positive group and 31.745 in the negative group in cluster C. The OR for lactate dehydrogenase (LD) was 3.704 in the positive group and 6.631 in the negative group in cluster C. The OR for creatinine was 2.784 in the positive group and 8.796 in the negative group in cluster C. The OR for blood urea nitrogen (BUN) in the negative group was 0.348, indicating a negative predictor of mortality. Regarding the application of Continuous Renal Replacement Therapy (CRRT) and ventilation, ventilation was significant in both groups. In contrast, CRRT application was not significant in the sepsis-positive group. Furthermore, it was not selected as a variable in the negative group. CONCLUSIONS: The pH, LD, and creatinine were significant in both groups, while lactate and platelets were significant in the sepsis-positive group. In addition, albumin, glucose, and BUN were significant in the sepsis-negative group. Continuous renal replacement therapy was not significant in either group. However, the use of a ventilator was associated with poor prognosis.

Evaluating clinical heterogeneity and predicting mortality in severely burned patients through unsupervised clustering and latent class analysis.

Burn injuries often result in a high level of clinical heterogeneity and poor prognosis in patients with severe burns. Clustering algorithms, which are unsupervised methods that can identify groups with similar trajectories in patients with heterogeneous diseases, can provide insights into the mechanisms of the disease pathogenesis. This study aimed to analyze routinely collected biomarkers to understand their mortality prediction power, identify the clinical meanings or subtypes, and inform treatment decisions to improve the outcomes of patients with burns. This retrospective cohort study included patients aged ≥ 18 years who were admitted between January 2010 and December 2021. The patients were divided into four subgroups based on the time period of their admission: week 1, 2, 3, and 4. The study revealed that 22 biomarkers were evaluated, and the red blood cell distribution width, bicarbonate level, pH, platelets, and lymphocytes were significantly associated with the mortality risk. Latent class analysis further demonstrated that the pH, platelets, lymphocytes, lactate, and albumin demonstrated the lowest levels in the cluster with the highest risk of mortality, with the lowest levels of pH and lactate being particularly noteworthy in week 1 of the study. During the week 2, the pH and lymphocyte levels were demonstrated to be significant predictors of the mortality risk, whereas the lymphocyte and platelet counts were meaningful predictors in week 3. During week 4, pH, platelet count, and albumin level were important predictors of mortality risk. Analysis of routinely collected biomarkers using clustering algorithms and latent class analysis can provide valuable insights into the heterogeneity of burn injuries and improve the ability to predict disease progression and mortality. Our findings suggest that lactate levels are a better indicator of cellular hypoxia in the early stages of burn shock, whereas platelet and lymphocyte levels are more indicative of infections such as sepsis. Albumin levels are considered a better indicator of reduced nutritional loss with decrease in unhealed burn wounds; however, the pH levels reflect the overall condition of the patient throughout the study period. These findings can be used to inform treatment decisions and improve the outcomes of burn patients.

Three-Dimensional Artificial Skin Construct Bioprinted with a Marine-Based Biocomposite.

A variety of artificial skin scaffolds, including 3D-bioprinted constructs, have been widely studied for regenerating injured skin tissue. Here, we devised a new composite biomaterial ink using fish-skin-based decellularized extracellular matrices (dECM) from tilapia and cod fish. The composition of the biocomposite mixture was carefully selected to obtain a mechanically stable and highly bioactive artificial cell construct. In addition, the decellularized extracellular matrices were methacrylated, followed by exposure to UV light to initiate photo-cross-linking. Porcine-skin-based dECMMa (pdECMMa) and tilapia-skin-based dECMMa (tdECMMa) biomaterials were used as controls. Assessment of various biophysical parameters and in vitro cellular activities, including cytotoxicity, wound healing ability, and angiogenesis, showed that the biocomposite exhibited much higher cellular activities compared to the controls owing to the synergistic effect of the favorable biophysical properties of tdECMMa and bioactive components (collagen, glycosaminoglycans (GAGs), elastin, and free fatty acids) from the decellularized cod skin. Furthermore, the skin constructs bioprinted using the bioinks exhibited more than 90% cell viability, performed with 3 days of submerged culture and then 28 days of air-liquid culture. For all cell constructs, the expression of cytokeratin 10 (CK10) was observed on the top surface of the epidermal layer, and cytokeratin 14 (CK14) was detected in the lower section of the keratinocyte layer. However, more developed CK10 and CK14 antibodies were observed in the cell-laden biocomposite construct [tilapia-skin-based dECMMa with cod-skin-based dECM] than in the controls [porcine-skin-based dECMMa (pdECMMa) and tilapia-skin-based dECMMa (tdECMMa)]. Based on these results, we believe that the fish-skin-based biocomposite construct is a potential biomaterial ink for skin regeneration.

Clinical application of functional near-infrared spectroscopy for burn assessment.

Significance: Early assessment of local tissue oxygen saturation is essential for clinicians to determine the burn wound severity. Background: We assessed the burn extent and depth in the skin of the extremities using a custom-built 36-channel functional near-infrared spectroscopy system in patients with burns. Methods: A total of nine patients with burns were analyzed in this study. All second-degree burns were categorized as superficial, intermediate, and deep burns; non-burned skin on the burned side; and healthy skin on the contralateral non-burned side. Hemodynamic tissue signals from functional near-infrared spectroscopy attached to the burn site were measured during fNIRS using a blood pressure cuff. A nerve conduction study was conducted to check for nerve damage. Results: All second-degree burns were categorized into superficial, intermediate, and deep burns; non-burned skin on the burned side and healthy skin on the contralateral non-burned side showed a significant difference distinguishable using functional near-infrared spectroscopy. Hemodynamic measurements using functional near-infrared spectroscopy were more consistent with the diagnosis of burns 1 week later than that of the degree of burns diagnosed visually at the time of admission. Conclusion: Functional near-infrared spectroscopy may help with the early judgment of burn extent and depth by reflecting differences in the oxygen saturation levels in the skin.

Erratum: Assessment of Disease Severity and Quality of Life in Patients with Atopic Dermatitis from South Korea.

This corrects the article on p. 419 in vol. 34, PMID: 36478424.

Longitudinal profile of routine biomarkers for mortality prediction using unsupervised clustering algorithm in severely burned patients: a retrospective cohort study with prospectively collected data.

Purpose: Burn injury has high clinical heterogeneity and worse prognosis in severely burned patients. Clustering algorithms using unsupervised methods to identify groups with similar trajectories in heterogeneous disease patients can provide insight into mechanisms of disease pathogenesis. This study analyzed routinely collected biomarkers to evaluate mortality prediction, find clinical meanings for these or their subtypes, and evaluate patterns. Methods: This retrospective cohort study included patients aged >18 years, between July 2012 and June 2021. All eligible patients received fluid resuscitation and survived for at least 7 days. Characteristics of clinical interest to the physician at 4 clinically important time points were evaluated. Results: Eligible patients were divided into 4 subgroups according to these time points: from 1st week to 4th week. Total of 1,249 patients admitted within 2 days after burns and receiving fluid resuscitation were included. Mean Harrell's C-index of pH was the highest (0.816), followed by platelets (0.807), creatinine (0.796), red cell distribution width (RDW, 0.778), and lactate (0.759). Longitudinal profiles among biomarkers were different. Conclusion: The main predictors were pH, platelets, creatinine, RDW, and lactate. Creatinine and RDW showed consistent patterns. The other markers varied according to patient condition. Thus, these markers could provide clues into underlying mechanisms and predict mortality.

Differentiation of Adipose-Derived Stem Cells into Smooth Muscle Cells in an Internal Anal Sphincter-Targeting Anal Incontinence Rat Model.

OBJECTIVE: Studies on development of an anal incontinence (AI) model targeting smooth muscle cells (SMCs) of the internal anal sphincter (IAS) have not been reported. The differentiation of implanted human adipose-derived stem cells (hADScs) into SMCs in an IAS-targeting AI model has also not been demonstrated. We aimed to develop an IAS-targeting AI animal model and to determine the differentiation of hADScs into SMCs in an established model. MATERIALS AND METHODS: The IAS-targeting AI model was developed by inducing cryoinjury at the inner side of the muscular layer via posterior intersphincteric dissection in Sprague-Dawley rats. Dil-stained hADScs were implanted at the IAS injury site. Multiple markers for SMCs were used to confirm molecular changes before and after cell implantation. Analyses were performed using H&E, immunofluorescence, Masson's trichrome staining, and quantitative RT-PCR. RESULTS: Impaired smooth muscle layers accompanying other intact layers were identified in the cryoinjury group. Specific SMC markers, including SM22α, calponin, caldesmon, SMMHC, smoothelin, and SDF-1 were significantly decreased in the cryoinjured group compared with levels in the control group. However, CoL1A1 was increased significantly in the cryoinjured group. In the hADSc-treated group, higher levels of SMMHC, smoothelin, SM22α, and α-SMA were observed at two weeks after implantation than at one week after implantation. Cell tracking revealed that Dil-stained cells were located at the site of augmented SMCs. CONCLUSIONS: This study first demonstrated that implanted hADSc restored impaired SMCs at the injury site, showing stem cell fate corresponding to the established IAS-specific AI model.

Validation of Sepsis-3 using survival analysis and clinical evaluation of quick SOFA, SIRS, and burn-specific SIRS for sepsis in burn patients with suspected infection.

PURPOSE: Sepsis-3 is a life-threatening organ dysfunction caused by dysregulated host responses to infection; and defined using the Sepsis-3 criteria, introduced in 2016, however, the criteria need to be validated in specific clinical fields. We investigated mortality prediction and compared the diagnostic performance of quick Sequential Organ Failure Assessment (qSOFA), systemic inflammatory response syndrome (SIRS), and burn-specific SIRS (bSIRS) in burn patients. METHODS: This single-center retrospective cohort study examined burn patients in Seoul, Korea during January 2010-December 2020. Overall, 1,391 patients with suspected infection were divided into four sepsis groups using SOFA, qSOFA, SIRS, and burn-specific SIRS. RESULTS: Hazard ratios (HRs) of all unadjusted models were statistically significant; however, the HR (0.726, p = 0.0080.001) in the SIRS ≥2 group is below 1. In the adjusted model, HRs of the SOFA ≥2 (2.426, <0.001), qSOFA ≥2 (7.198, p<0.001), and SIRS ≥2 (0.575, p<0.001) groups were significant. The diagnostic performance of dichotomized qSOFA, SIRS, and bSIRS for sepsis was defined by the Sepsis-3 criteria. The mean onset day was 4.13±2.97 according to Sepsis-3. The sensitivity of SIRS (0.989, 95% confidence interval [CI]: 0.982-0.994) was higher than that of qSOFA (0.841, 95% CI: 0.819-0.861) and bSIRS (0.803, 95% CI: 0.779-0.825). Specificities of qSOFA (0.929, 95% CI: 0.876-0.964) and bSIRS (0.922, 95% CI: 0.868-0.959) were higher than those of SIRS (0.461, 95% CI: 0.381-0.543). CONCLUSION: Sepsis-3 is a good alternative diagnostic tool because it reflects sepsis severity without delaying diagnosis. SIRS showed higher sensitivity than qSOFA and bSIRS and may therefore more adequately diagnose sepsis.

Pathogenesis and Treatment of Pruritus Associated with Chronic Kidney Disease and Cholestasis.

Itching is an unpleasant sensation that provokes the desire to scratch. In general, itching is caused by dermatologic diseases, but it can also be caused by systemic diseases. Since itching hampers patients' quality of life, it is important to understand the appropriate treatment and pathophysiology of pruritus caused by systemic diseases to improve the quality of life. Mechanisms are being studied through animal or human studies, and various treatments are being tested through clinical trials. We report current trends of two major systemic diseases: chronic kidney disease and cholestatic liver disease. This review summarizes the causes and pathophysiology of systemic diseases with pruritus and appropriate treatments. This article will contribute to patients' quality of life. Further research will help understand the mechanisms and develop new strategies in the future.

Particulate matter 2.5 induces the skin barrier dysfunction and cutaneous inflammation via AhR- and T helper 17 cell-related genes in human skin tissue as identified via transcriptome analysis.

Particulate matter (PM2.5) is an environmental pollutant causing skin inflammatory diseases via epidermal barrier damage. However, the mechanism and related gene expression induced by PM2.5 remains unclear. Our aim was to determine the effect of PM2.5 on human skin tissue ex vivo, and elucidate the mechanism of T helper 17 cell-related inflammatory cytokine and skin barrier function. We verified the expression levels of gene in PM2.5-treated human skin tissue using Quantseq (3' mRNA-Seq), and Gene Ontology (GO) terms and protein-protein interaction (PPI) networks were performed. The PM2.5 treatment significantly enhanced the expression of Th 1, 2, 17 and 22 cell-related genes (cut-off value: │1.2 │ > fold change and p < 0.05). Most of all, Th17 cell-related genes are upregulated and those genes are associated with skin epidermal barrier function and Aryl hydrocarbon receptor (AhR), a xenobiotic receptor, pathway. In human keratinocyte cell lines, AhR-regulated genes (e.g. AhRR, CYP1A1, IL6 and IL36G), Th17 cell-related genes (e.g. IL17C) and epidermal barrier-related genes (e.g. SPRR2A and KRT71) are significantly increased after PM2.5. In the protein level, the secretion of IL-6 and IL-36G was increased in human skin tissue following PM2.5 treatment, and the expression of SPRR2A and KRT71 was significantly increased. PM2.5 exposure could ruin the skin epidermal barrier function via AhR- and Th17 cell-related inflammatory pathway.

Exosomes released by environmental pollutant-stimulated Keratinocytes/PBMCs can trigger psoriatic inflammation in recipient cells via the AhR signaling pathway.

Introduction: Exosomes, pivotal in intercellular communication during skin disease pathogenesis, have garnered substantial attention. However, the impact of environmental pollutants, such as benzo[a]pyrene (BaP) and 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD), on exosome release amid inflammatory skin diseases remains unexplored. This study addresses this gap by examining the influence of BaP and TCDD on exosome function, specifically focusing on immune-related pathway alterations in normal recipient keratinocytes and peripheral blood mononuclear cells (PBMCs). Methods: HaCaT cells were treated with exosomes from BaP- or TCDD-treated keratinocytes. Proinflammatory cytokines and chemokines, including TNF-α, IL-1ß, IL-6, IL-8, CXCL1, and CXCL5, were assessed. The involvement of the p65NF-κB/p38MAPK/ERK signaling pathway in recipient keratinocytes was investigated. Aryl hydrocarbon receptor (AhR) silencing was employed to elucidate its role in mediating the proinflammatory response induced by exosomes from BaP- or TCDD-treated keratinocytes. Results and discussion: Treatment with exosomes from BaP- or TCDD-treated keratinocytes induced a significant increase in proinflammatory cytokines and chemokines in HaCaT cells. The upregulation implicated the p65NF-κB/p38MAPK/ERK signaling pathway. AhR silencing attenuated this response, suggesting a role for AhR in mediating this response. In PBMCs from healthy controls, exosomes from BaP-stimulated PBMCs of psoriatic patients led to increased expression of proinflammatory cytokines and modulation of Th1/Th17 cell distribution via AhR activation. These findings unveil a novel dimension in the interplay between environmental xenobiotic agents (BaP and TCDD) and exosomal functions. The study establishes their influence on psoriatic inflammatory responses, shedding light on the underlying mechanisms mediated through the AhR signaling pathway in recipient keratinocytes and PBMCs.