FLT3L governs the development of partially overlapping hematopoietic lineages in humans and mice.

FMS-related tyrosine kinase 3 ligand (FLT3L), encoded by FLT3LG, is a hematopoietic factor essential for the development of natural killer (NK) cells, B cells, and dendritic cells (DCs) in mice. We describe three humans homozygous for a loss-of-function FLT3LG variant with a history of various recurrent infections, including severe cutaneous warts. The patients' bone marrow (BM) was hypoplastic, with low levels of hematopoietic progenitors, particularly myeloid and B cell precursors. Counts of B cells, monocytes, and DCs were low in the patients' blood, whereas the other blood subsets, including NK cells, were affected only moderately, if at all. The patients had normal counts of Langerhans cells (LCs) and dermal macrophages in the skin but lacked dermal DCs. Thus, FLT3L is required for B cell and DC development in mice and humans. However, unlike its murine counterpart, human FLT3L is required for the development of monocytes but not NK cells.

Deep cutaneous mycoses in kidney transplant recipients: Diagnostic and therapeutic challenges.

Deep cutaneous mycoses (DCMs) are rare infections that extend throughout the dermis and subcutis, often occurring after inoculation with pathogenic fungi. Trends toward a growing incidence have been observed that may be partially related to an increasing population of solid organ transplant patients. The aim of this study is to describe the diagnostics and the outcomes of DCM among kidney transplant recipients so as to optimize their management. We performed a retrospective review of cases of DCM occurring among kidney transplant recipients in our institution over 12 years. Twenty cases were included. Lesions were only located on the limbs and presented mainly as single (10/20, 50%) nodular lesions (15/20, 75%), with a mean size of 3 cm. Direct mycological examination was positive for 17 patients (17/20, 85%) and the cultures were consistently positive. Thirteen different fungal species were observed, including phaehyphomycetes (n = 8), hyalohyphomycetes (n = 3), dermatophytes (n = 1), and mucorale (n = 1). The (1-3) beta-D-glucan antigen (BDG) was also consistently detected in the serum (20/20, 100%). Systematic imaging did not reveal any distant infectious lesions, but locoregional extension was present in 11 patients (11/14, 79%). Nineteen patients received antifungal treatment (19/20, 95%) for a median duration of 3 months, with surgery for 10 (10/20, 50%). There is a great diversity of fungal species responsible for DCMs in kidney transplant recipients. The mycological documentation is necessary to adapt the antifungal treatment according to the sensitivity of the species. Serum BDG positivity is a potentially reliable and useful tool for diagnosis and follow-up.

International Consensus on Anti-Aging Dermocosmetics and Skin Care for Clinical Practice Using the RAND/UCLA Appropriateness Method.

BACKGROUND: The objective was to provide international recommendations on anti-aging dermocosmetics for clinical practice starting with essential ingredients for protection and repair before working up to advanced products for specific concerns.  Methods: Seven international experts reviewed 8 hypothetical case scenarios covering different ages, skin issues (eg, sensitivity, acne, melasma), and exposure to exposome factors for both sexes and all Fitzpatrick skin types (FST). The RAND/UCLA appropriateness method was used to obtain consensus. Seventeen key ingredients were rated on a scale from 1 (totally inappropriate) to 9 (totally appropriate). Statistical analysis, 2 meetings, and email discussions refined the recommendations. RESULTS: High-factor broad-spectrum sunscreen (ie, protects against ultraviolet [UV] A and B rays), niacinamide, and other topical antioxidants were recommended for all scenarios. Further discussions were required for other ingredients. Tinted sunscreen/iron oxide were recommended for all FST, although compliance may be sub-optimal for darker skin phototypes (IV-VI), if not cosmetically acceptable. Combining a facial foundation with broad-spectrum sunscreen was recommended for darker phototypes to obtain visible light protection closely matching diverse color tones. Retinols were not recommended as a first-line treatment for sensitive skin, especially FST V and VI, due to the risk of irritation. After ablative laser treatment, alpha hydroxy acids should be avoided or used with caution in FST IV to VI due to the risk of post-inflammatory hyperpigmentation. CONCLUSION: We describe a simple, practical tool for use in daily dermatology consultations for providing recommendations on anti-aging dermocosmetics to cover diverse and inclusive populations of patients, addressing all skin types and international needs.  J Drugs Dermatol. 2024;23(1):1337-1343.     doi:10.36849/JDD.7798.

Validation of the Canadian Institute for Health Information Diagnostic Codes for Benign Gynaecologic Surgery.

We investigated the validity of the 10th Revision Canadian modification of International Statistical Classification of Disease and Related Health Problems (ICD-10-CA) diagnostic codes for surgery for benign gynaecologic conditions in the Canadian Institute for Health Information Discharge Abstract Database (CIHI-DAD), the main source of routinely collected data in Canada. Reabstracted data from patient charts was compared to ICD-10-CA codes and measures of validity were calculated with 95% confidence intervals. A total of 1068 procedures were identified. More objective, structural diagnoses (fibroids, prolapse) had higher sensitivity and near-perfect Kappa coefficients, while more subjective, symptomatic diagnoses (abnormal uterine bleeding, pelvic pain) had lower sensitivity and moderate-substantial Kappa coefficients. Specificity, positive predictive values, and negative predictive values were generally high for all diagnoses. These findings support the use of CIHI-DAD data for gynaecologic research.

Primary Invasive Cutaneous Fusariosis in Patients with STAT3 Hyper-IgE Syndrome.

Dominant negative (DN) mutations in signal transducer and activator of transcription 3 (STAT3) are known to cause hyper-IgE syndrome, a rare primary immunodeficiency. STAT3 DN patients are prone to develop fungal infections, including chronic mucocutaneous candidiasis due to impaired IL-17-mediated immunity, and pulmonary aspergillosis. Despite having preserved phagocyte functions, STAT3 DN patients present connective tissue abnormalities and a defect in the immunological skin barrier. Fusarium species are ubiquitous molds, whose potential to infect humans depends on the host's innate and cellular immune status. Our aim was to describe four STAT3 DN patients with fusariosis confined to the skin. Medical records were reviewed and summarized. Four patients, aged 4, 11, 30, and 33 years, presented with chronic skin lesions which started in the extremities. Two patients had remote lesions, and none had systemic involvement. Skin biopsies showed mycelial threads with deep inflammatory-occasionally granulomatous-infiltrates, reaching the dermis; cultures grew Fusarium solani. Response to treatment was heterogeneous, often requiring multimodal therapies, including topical antifungal preparations. In this work, we describe primary invasive cutaneous fusariosis as a syndromic entity in four STAT3 DN patients.

Juvenile vervet monkeys rely on others when responding to danger.

Primate alarm calls are mainly hardwired but individuals need to adapt their calling behaviours according to the situation. Such learning necessitates recognising locally relevant dangers and may take place via their own experience or by observing others. To investigate monkeys alarm calling behaviour, we carried out a field experiment in which we exposed juvenile vervet monkeys to unfamiliar raptor models in the presence of audiences that differed in experience and reliability. We used audience age as a proxy for experience and relatedness as a proxy for reliability, while quantifying audience reactions to the models. We found a negative correlation between alarm call production and callers' age. Adults never alarm called, compared to juveniles. We found no overall effect of audience composition and size, with juveniles calling more when with siblings than mothers or unrelated individuals. Finally, concerning audience reactions to the models, we observed juveniles remained silent with vigilant mothers and only alarm called with ignoring mothers, whereas we observed the opposite for siblings: juveniles remained silent with ignoring siblings and called with vigilant siblings. Despite the small sample size, juvenile vervet monkeys, confronted with unfamiliar and potentially dangerous raptors, seem to rely on others to decide whether to alarm call, demonstrating that the choice of the model may play an important key role in the ontogeny of primate alarm call behaviour.

Evaluation of adapted dermocosmetic regimens for perimenopausal and menopausal women using an artificial intelligence-based algorithm and quality of life questionnaires: An open observational study.

BACKGROUND: The decline in estrogen levels from several years before (perimenopause) and during menopause has various negative effects, including skin specific issues, which often receive less attention than other menopausal symptoms despite having a significant negative effect on quality of life (QoL). The objective of this study was to evaluate the effectiveness of anti-aging dermocosmetic products designed for women during the perimenopause and menopause. MATERIALS AND METHODS: An open study of 101 perimenopausal women (no menstruation for 4-12 months or irregular menstruation for <5 years) and 101 menopausal women (no menstruation for >12 months), not taking hormone replacement therapy, was conducted. Adapted dermocosmetic regimens, specific to each group (day cream, night cream and serum), were applied for 56 days. Assessments included automatic artificial intelligence diagnostics of eight clinical facial signs, hydration and transepidermal water loss (TEWL), and a menopause skin QoL questionnaire. RESULTS: Mean age was 50 ± 3.9 years (range 41-57) and 59 ± 3.8 years (range 50-66) for the perimenopause and menopause groups, respectively. Significant improvements in wrinkles and vascular signs, increases in hydration, decreases in TEWL, and a positive impact on QoL were observed after 56 days of application of the respective dermocosmetic regimens for both the perimenopause and menopause groups. CONCLUSION: The anti-aging skin care products designed specifically for perimenopausal and menopausal women increased skin hydration and improved wrinkles with a positive impact on QoL.

Eosinophilic Pustular Folliculitis of Infancy: A Histologic Assessment of 43 Cases.

ABSTRACT: Eosinophilic pustular folliculitis of infancy is a sterile, inflammatory dermatosis that mainly affects children younger than 36 months. The underlying physiopathologic mechanism is unclear. Clinical diagnosis is challenging, and a skin biopsy may be necessary. The literature data are sometimes contradictory, and a histologic series of eosinophilic pustular folliculitis of infancy cases has not been previously published.

A Validation of Hysterectomy Procedural Codes in the Canadian Institute for Health Information Discharge Abstract Database.

OBJECTIVE: The Canadian Institute of Health Information (CIHI) Discharge Abstract Database (DAD) is the main source of routinely collected data for gynaecologic surgery in Canada and is increasingly used for research. These data are prone to error as they were originally collected for administrative purposes, and they therefore should be validated for clinical research. The objective of this study was to validate hysterectomy codes from the DAD at a single institution. METHODS: This was a retrospective observational study using an existing hospital database. We obtained a consecutive sample of all gynaecologic procedures performed at The Ottawa Hospital from April 2016 to March 2017 using the DAD. Patient data, including diagnosis, procedure type, concomitant procedure, and surgical approach, were reabstracted from records. These data were compared with the DAD Canadian Classification of Health Interventions (CCI) codes using sensitivity, specificity, positive predictive value (PPV), and κ coefficient with associated 95% confidence intervals (CIs). RESULTS: Of 1068 gynaecologic procedures, 639 hysterectomies were performed: 39.2% vaginally, 35.4% laparoscopically, and 25.4% abdominally. Median patient age was 46 years (IQR 41-54 y). The κ, sensitivity, specificity, and PPV for all hysterectomies were 0.92 (95% CI 0.90-0.95), 95.1% (95% CI 93.2-96.7), 97.9% (95% CI 96.6-99.3), and 98.5% (95% CI 97.6-99.5), respectively. The κ coefficients for vaginal, laparoscopic, and abdominal hysterectomy were 0.91 (95% CI 0.88-0.94), 0.92 (95% CI 0.89-0.95), and 0.92 (95% CI 0.89-0.95), respectively. Agreement for sub-total hysterectomy and bilateral salpingectomy with oophorectomy was excellent, with κ exceeding 0.80. The level of agreement for salpingectomy alone was poor, though specificity and PPV were high. CONCLUSIONS: Our study suggests that hysterectomy-associated CCI codes in CIHI's DAD have a high level of validity for clinical research purposes.

Diagnosis of Endometriosis at Laparoscopy: A Validation Study Comparing Surgeon Visualization with Histologic Findings.

OBJECTIVE: This study aimed to evaluate the validity of laparoscopic visualization for the diagnosis of endometriosis compared with histopathology. METHODS: We conducted a retrospective chart review at a tertiary care hospital in Canada for the period of April 1, 2016 to March 31, 2017. Of 1069 women, 96 were selected for having undergone laparoscopic visualization and concurrent histopathological biopsy for suspected endometriosis. Standard measures of validity for diagnostic tests (sensitivity, specificity, positive predictive and negative predictive values, accuracy) were used. RESULTS: Mean age of the 96 women included was 40 ± 7.2 years, and median gravidity and parity were 1 (IQR 0-3) and 0 (IQR 0-2), respectively. Common symptoms were abdominal and pelvic pain (41.7%), menstrual bleeding concerns (34.4%), dysmenorrhea (29.2%), and infertility (8.3%). Approximately one-third of women had endometriomas (31.3%), while more than half had deep infiltrating endometriosis (59.4%). The diagnosis of endometriosis was made by surgeons at laparoscopic visualization in 82.3% of women and by histopathology in 74.0%. Using histopathology as the gold standard, sensitivity for laparoscopic visualization was 90.1% (95% CI 81.0-95.1), while specificity was 40.0% (95% CI 23.4-59.3). Positive and negative predictive values were 81.0% (95% CI 71.0-88.1) and 58.8% (95% CI 36.0-78.4), respectively; and the accuracy was 77.1% (95% CI 67.7-84.4). CONCLUSION: Although laparoscopic visualization had relatively high sensitivity and positive predictive value, its specificity and negative predictive value were relatively low. These findings support the use of laparoscopic visualization with histopathological analysis for accurate diagnosis of endometriosis.

Neutralization of HSF1 in cells from PIK3CA-related overgrowth spectrum patients blocks abnormal proliferation.

PIK3CA-related overgrowth spectrum is caused by mosaicism mutations in the PIK3CA gene. These mutations, which are also observed in various types of cancer, lead to a constitutive activation of the PI3K/AKT/mTOR pathway, increasing cell proliferation. Heat shock transcription factor 1 (HSF1) is the major stress-responsive transcription factor. Recent findings indicate that AKT phosphorylates and activates HSF1 independently of heat-shock in breast cancer cells. Here, we aimed to investigate the role of HSF1 in PIK3CA-related overgrowth spectrum. We observed a higher rate of proliferation and increased phosphorylation of AKT and p70S6K in mutant fibroblasts than in control cells. We also found elevated phosphorylation and activation of HSF1, which is directly correlated to AKT activation. Specific AKT inhibitors inhibit HSF1 phosphorylation as well as HSF1-dependent gene transcription. Finally, we demonstrated that targeting HSF1 with specific inhibitors reduced the proliferation of mutant cells. As there is currently no curative treatment for PIK3CA-related overgrowth spectrum, our results identify HSF1 as a new potential therapeutic target.

Pityriasis Lichenoides: A Large Histopathological Case Series With a Focus on Adnexotropism.

INTRODUCTION: Pityriasis lichenoides (PL) is an infrequent skin disorder. The clinical manifestations are usually specific enough for a reliable diagnosis, although the histopathological assessment of a biopsy is sometimes needed to differentiate between PL and a range of other diseases. The objectives of this study were to review cases of PL managed in our hospital, confirm the classical histopathological features of PL, and identify signs that may be of value in the diagnosis of PL. MATERIALS AND METHODS: All cases of PL assessed in our pathology department between January 2007 and December 2017 were retrieved, and all slides were reviewed. Cases were selected only if a diagnosis of PL was initially suggested by a dermatologist and then confirmed by the histopathological assessment. RESULTS: Seventy-one cases met the study criteria. The following features were almost always present: vacuolar changes or necrotic keratinocytes (100%), both superficial and deep lymphocytic infiltrates (99%), and the infiltration of lymphocytes into the adnexal epithelium (97%). The inflammatory cells were always small- to medium-sized lymphocytes. There were no eosinophilic infiltrates. Superficial perivascular and/or intraepidermal red blood cells were observed in 83% of cases. DISCUSSION: We highlighted the presence of a deep dermal lymphocytic infiltrate, with a "T-shaped" periadnexal arrangement along the full length of the follicular and sudoral epithelia. This might be a feature that enables the differentiation of PL from other diseases. Our findings also prompted a number of physiopathological hypotheses for PL. CONCLUSIONS: Our present results confirmed the classical histological aspects of PL and provided some useful new diagnostic features.

Genetical, clinical, and functional analysis of a large international cohort of patients with autosomal recessive congenital ichthyosis due to mutations in NIPAL4.

Autosomal recessive congenital ichthyosis (ARCI) belongs to a heterogeneous group of disorders of keratinization. To date, 10 genes have been identified to be causative for ARCI. NIPAL4 (Nipa-Like Domain-Containing 4) is the second most commonly mutated gene in ARCI. In this study, we present a large cohort of 101 families affected with ARCI carrying mutations in NIPAL4. We identified 16 novel mutations and increase the total number of pathogenic mutations in NIPAL4 to 34. Ultrastructural analysis of biopsies from six patients showed morphological abnormalities consistent with an ARCI EM type III. One patient with a homozygous splice site mutation, which leads to a loss of NIPAL4 mRNA, showed additional ultrastructural aberrations together with a more severe clinical phenotype. Our study gives insights into the frequency of mutations, a potential hot spot for mutations, and genotype-phenotype correlations.

Langerhans Cell Histiocytoma: A Benign Histiocytic Neoplasm of Diverse Lines of Terminal Differentiation.

Langerhans cell (LC) histiocytoma is a neonatal tumor that often consists of a single, ulcerated nodule. Systemic involvement is rare, and LC histiocytoma is considered to be a variant of congenital, self-healing LC histiocytosis (also referred to as Hashimoto-Pritzker disease). In view of its low prevalence, LC histiocytoma is not always diagnosed in a clinical examination and requires histological confirmation. Furthermore, the histological and molecular features of LC histiocytoma have not been well characterized. Here, we report on 6 cases of this rare disease and review the corresponding literature. LC histiocytoma differs from classical self-healing LC histiocytosis with regard to the pathological features; we found that LC histiocytoma was associated with massive infiltration by histiocytes of various sizes and shapes (although often large) throughout the dermis and the superficial subcutis. Epidermotropism was rare, mitotic figures were not inconspicuous, and necrotic or calcified areas were often present. Immunohistochemical assessment revealed a mixture of different types of histiocytes (with CD1a CD207, CD1a CD207, and CD1a CD207 CD163 cells). Genetic testing was performed in 5 cases; it revealed a BRAF mutation (p.V600E and p.485_490delinsF) in 2 cases, a HRAS mutation (p.T58I) in 1 case, a combination of 2 PTEN mutations in another case (p.I224M and p. R234W), and no mutations in the fifth case. All the lesions regressed spontaneously, and none recurred during follow-up.

APN/CD13 is over-expressed by Psoriatic fibroblasts and is modulated by CGRP and IL-4 but not by retinoic acid treatment.

Psoriasis vulgaris is a common skin inflammatory disease characterized by recurrent flare episodes associated with scaly well-demarcated skin plaques. Skin biopsies from psoriatic patients with high PASI score (22.67 ± 8.67) and from HD were used to study APN/CD13. APN/CD13 is over-expressed in LP and nLP compare to HD skins and fibroblasts. This over-expression is positively correlated with specific enzymatic activity enhancement. However, discrepancies between APN/CD13 expression in LP and nLP prompt us to focus our study on APN/CD13 modulation. Calcitonin Gene Related Peptide (CGRP), a neuropeptide, positively modulated expression and activity of APN/CD13. CGRP consistently induced IL4 secretion, which is also involved in the increase of APN/CD13 expression and activity, which is significantly reversed using IL-4 blocking antibody. Surprisingly, retinoic acid altered the APN/CD13 enzymatic activity only in nLP fibroblasts without modification of APN/CD13 expression. APN/CD13 is over-expressed on psoriatic fibroblasts and exerted high level of activity compare to HD fibroblasts. Taken together, several factors such as CGRP and IL-4 acted on positive regulation of APN/CD13 expression and activity. This study highlighted the interest of APN/CD13 as a new potential target, which should be investigated in psoriasis.

Multiplex epithelium dysfunction due to CLDN10 mutation: the HELIX syndrome.

PurposeWe aimed to identify the genetic cause to a clinical syndrome encompassing hypohidrosis, electrolyte imbalance, lacrimal gland dysfunction, ichthyosis, and xerostomia (HELIX syndrome), and to comprehensively delineate the phenotype.MethodsWe performed homozygosity mapping, whole-genome sequencing, gene sequencing, expression studies, functional tests, protein bioinformatics, and histological characterization in two unrelated families with HELIX syndrome.ResultsWe identified biallelic missense mutations (c.386C>T, p.S131L and c.2T>C, p.M1T) in CLDN10B in six patients from two unrelated families. CLDN10B encodes Claudin-10b, an integral tight junction (TJ) membrane-spanning protein expressed in the kidney, skin, and salivary glands. All patients had hypohidrosis, renal loss of NaCl with secondary hyperaldosteronism and hypokalemia, as well as hypolacrymia, ichthyosis, xerostomia, and severe enamel wear. Functional testing revealed that patients had a decreased NaCl absorption in the thick ascending limb of the loop of Henle and a severely decreased secretion of saliva. Both mutations resulted in reduced or absent Claudin-10 at the plasma membrane of epithelial cells.ConclusionCLDN10 mutations cause a dysfunction in TJs in several tissues and, subsequently, abnormalities in renal ion transport, ectodermal gland homeostasis, and epidermal integrity.

Cutaneous and Visceral Chronic Granulomatous Disease Triggered by a Rubella Virus Vaccine Strain in Children With Primary Immunodeficiencies.

Persistence of rubella live vaccine has been associated with chronic skin granuloma in 3 children with primary immunodeficiency. We describe 6 additional children with these findings, including 1 with visceral extension to the spleen.

Hepatitis E virus-induced primary cutaneous CD30(+) T cell lymphoproliferative disorder.

BACKGROUND & AIM: Several types of unexplained extra-hepatic manifestations, including haematological disorders, have been reported in the context of hepatitis E virus (HEV) infection. However, the underlying mechanism(s) of these manifestations are unknown. We provide evidence that HEV has an extra-hepatic endothelial tropism that can engage cutaneous T cells towards clonality. METHODS: A patient with a CD30(+) cutaneous T cell lymphoproliferative disorder (T-LPD) and biopsy-proven chronic HEV infection received three rounds of oral ribavirin treatment, administered either without or with interferon, and eventually achieved a sustained virologic response (SVR). Pathologic, virologic and immunologic investigations were carried out on biopsied skin lesion, and peripheral blood mononuclear cells between the 2nd and 3rd round of antiviral treatment and biopsied liver. RESULTS: Remission of T-LPD was observed upon antiviral treatment, and the patient remained in complete remission after achieving SVR. The T cell analysis showed large CD30(+) lymphocytes surrounding the blood vessels within the CD8(+) T cell infiltrate. HEV was detected within dermal microvascular endothelial cells using immunofluorescence staining, in situ hybridisation and electron microscopy. Infiltrating T cells mostly comprised memory CD8(+) T cells with a tissue-resident memory T cell phenotype. Overall, 98% of extracted T cells were CD8(+) T cells with aVß signature skewed towards Vß4 and with an oligoclonal profile. T cell clones from T-LPD were more like T cells in the liver than T cells in the blood [odds ratio=4.55, (3.70-5.60), p<0.0001]. No somatic mutations were found in the T-LPD exomes. CONCLUSION: HEV has an extra-hepatic tissue tropism in humans, including dermal endothelium, and can induce CD30(+) T-LPD that is sensitive to antivirals. LAY SUMMARY: Hepatitis E virus (HEV) has an extra-hepatic tissue tropism and should be added to the list of viruses associated with lymphoproliferative disorders. As such, HEV should be part of the laboratory workup of any lymphoproliferation, particularly those of the T cell phenotype that involve the skin. In the context of HEV-associated cutaneous T cell lymphoproliferative disorders, antiviral treatment could be considered a first-line treatment instead of chemotherapy.