Differential diagnosis of bone marrow failure syndromes guided by machine learning.

The choice to postpone treatment while awaiting genetic testing can result in significant delay in definitive therapies in patients with severe pancytopenia. Conversely, the misdiagnosis of inherited bone marrow failure (BMF) can expose patients to ineffectual and expensive therapies, toxic transplant conditioning regimens, and inappropriate use of an affected family member as a stem cell donor. To predict the likelihood of patients having acquired or inherited BMF, we developed a 2-step data-driven machine-learning model using 25 clinical and laboratory variables typically recorded at the initial clinical encounter. For model development, patients were labeled as having acquired or inherited BMF depending on their genomic data. Data sets were unbiasedly clustered, and an ensemble model was trained with cases from the largest cluster of a training cohort (n = 359) and validated with an independent cohort (n = 127). Cluster A, the largest group, was mostly immune or inherited aplastic anemia, whereas cluster B comprised underrepresented BMF phenotypes and was not included in the next step of data modeling because of a small sample size. The ensemble cluster A-specific model was accurate (89%) to predict BMF etiology, correctly predicting inherited and likely immune BMF in 79% and 92% of cases, respectively. Our model represents a practical guide for BMF diagnosis and highlights the importance of clinical and laboratory variables in the initial evaluation, particularly telomere length. Our tool can be potentially used by general hematologists and health care providers not specialized in BMF, and in under-resourced centers, to prioritize patients for genetic testing or for expeditious treatment.

A case of melanoma in situ of the central forehead repair by V-Y advancement flap and Burow graft.

Large defects on the face after Mohs surgery have posed significant reconstructive challenges. A 90-year-old man presented with melanoma in situ of the central forehead, which resulted in a 4.5cmx4.3cm defect after multiple stages of Mohs surgery. Although different approaches for forehead repair with nasal root involvement are possible, we demonstrate that the V-Y advancement flap and subsequent Burrow graft for nasal root repair represents a viable closure technique for large circular defects of the central forehead.

Skin of Color Representation in Clinical Trials: An Analysis of Clinicaltrials.gov From 2008-2022.

There is a plethora of dermatologic clinical trials; however, little is known regarding the representation of skin of color (SOC) populations. We evaluated the 15 most prevalent skin conditions in SOC patients and their representation in clinical trials over 14 years (2008-2022) to address the lack of research regarding dermatologic clinical trials and SOC inclusion. There have been 1,419 clinical trials conducted over the last 14 years regarding the 15 dermatologic conditions most commonly affecting SOC. Despite the prevalence of these conditions in SOC, Black/African American participation was greater than 50% in clinical trials for two conditions, keloids (77.9%) and seborrheic dermatitis (55.3%). Due to the disparities in inclusion, clinical trial data is difficult to extrapolate the results to SOC patients, limiting therapeutic options and potentially contributing to worse outcomes for such patients. Our study confirms that there is limited data available in clinical trials with respect to race, ethnicity, and FST. Further, it highlights how essential it is for SOC to be both adequately represented and reported in research regarding dermatologic skin conditions to ensure equality and equity in dermatologic care. J Drugs Dermatol. 2023;22(3) doi:10.36849/JDD.7087.

Transcranial Doppler Screening Adherence among Children with Sickle Cell Anemia Seen in the Emergency Department.

OBJECTIVE: To evaluate adherence to annual transcranial Doppler ultrasound (TCD) screening to prevent stroke among patients with sickle cell anemia (SCA) seen in the emergency department (ED). STUDY DESIGN: This retrospective chart review included patients with SCA seen at a large pediatric ED over 64 weeks. Patients who did not need a TCD (age <2 or ≥16 years, on chronic transfusions, history of an inadequate TCD) or were not followed at the study institution were excluded. Patients who had received a TCD in the last 12 months (TCD adherent) were compared with patients who had not (TCD nonadherent). RESULTS: During the study period, 257 patients with SCA in need of an annual TCD were identified and 63 patients (25%) had not received an annual TCD, including 19 patients (7%) who had never had a TCD. All TCD adherent patients had a clinic visit in the last year compared with 75% of TCD nonadherent patients, P < .0001. The mean interval time since the last hematology clinic appointment from the ED encounter was greater for the TCD nonadherent group: 70 vs 270 days, P < .0001. Demographics including markers of socioeconomic status were not significantly different between the 2 groups. CONCLUSIONS: Patients with SCA who present to the ED and are nonadherent to TCD screening guidelines are less likely to have had a recent hematology clinic visit. Future interventions to improve screening for stroke in SCA should target this patient population seen in the ED but not clinic.

Unplanned ICU Admission Is Associated With Worse Clinical Outcomes in Geriatric Trauma Patients.

BACKGROUND: Geriatric trauma patients who require an unplanned ICU admission (UIA) may experience worse outcomes. As such, the American College of Surgeons initiated the Trauma Quality Improvement Program which tracks UIA as a quality benchmark. We sought to determine the overall rate and impact of UIA in our geriatric trauma population and to identify predictive risk factors. METHODS: All geriatric trauma patients (≥65) admitted to an urban, level I trauma center from January 2012 to June 2018 were identified. A retrospectively collected administrative database was queried for demographics, comorbidities, injury characteristics, and outcomes. UIA were identified and medical records were queried. Univariate analysis followed by binary logistic regression analysis were performed (P < 0.05 = significant). RESULTS: Of the 2923 geriatric patients identified, 95 (3.3%) patients experienced UIA, most commonly secondary to respiratory (34.7%) and cardiac (22.1%) events. Patients with UIA were older (81 versus 78, P = 0.04), and had higher injury severity score (10 versus 9, P < 0.01) and Charlson comorbidity indices (5 versus 4, P = 0.02). On logistic regression, age (OR 1.027, P = 0.04) and injury severity score (OR 1.032, P < 0.01) were predictive of unplanned ICU admission. Of the UIA, 69.4% were readmissions, or "bounce backs". Patients initially admitted to the ICU had 2.5 increased odds of requiring UIA. Patients with UIA experienced longer hospital stays (15 versus 5, P < 0.01), more days in the ICU (6 versus 1, P < 0.01), and higher rates of mortality (11.6% versus 5.0%, P = 0.02). CONCLUSIONS: Despite relatively low injury severity, geriatric trauma patients requiring UIA have a significant increase in morbidity and mortality. Those initially admitted to the ICU are at especially high risk for UIA, suggesting the benefit of strategies to provide an extra layer of care post-ICU.

A novel homozygous RTEL1 variant in a consanguineous Lebanese family: phenotypic heterogeneity and disease anticipation.

Phenotypic heterogeneity is often observed in patients with telomeropathies caused by pathogenic variants in telomere biology genes. However, the roles of recessive variants in these different phenotypes are not fully characterized. Our goal is to describe the biological roles of a novel homozygous RTEL1 variant identified in a consanguineous Lebanese family with unusual presentation of telomeropathies. A proband was screened for germline variants in telomere biology genes by whole exome sequencing. Leukocytes' telomere length was measured in the proband and eight relatives. We identified a novel homozygous p.E665K RTEL1 variant in the proband, his mother, and seven siblings that associated with telomere shortening and a broad spectrum of clinical manifestations, ranging from mild unspecific findings to severe phenotypes. Consanguinity in at least three family generations led to increased frequency of the homozygous p.E665K variant in the youngest generation and progressive telomere shortening. The increased frequency of the homozygous RTEL1 variant due to consanguinity in this Lebanese family allowed us to infer novel behaviors of recessive RTEL1 variants, as the expressivity and penetrance of this gene are very heterogenous between inter- and intra-generations. Progressive telomere shortening was associated with disease anticipation, first reported in recessive autosomal telomeropathies. Both genetic testing and telomere length measurement were critical for the clinical diagnosis of this family with telomere diseases marked by phenotypic heterogeneity.

Catheter-Related Venous Thrombosis in Hospitalized Pediatric Patients with Inflammatory Bowel Disease: Incidence, Characteristics, and Role of Anticoagulant Thromboprophylaxis with Enoxaparin.

OBJECTIVE: To describe the incidence and characteristics of central venous catheter (CVC)-related thrombosis in hospitalized pediatric patients with active inflammatory bowel disease (IBD) and report the potential usefulness of anticoagulant thromboprophylaxis (AT). STUDY DESIGN: We conducted a retrospective study of patients who were admitted to our children's hospital in the last 2 years with active IBD and required a CVC and identified all patients with an objectively confirmed symptomatic CVC-related thrombosis. To assess the usefulness of a recently implemented institutional AT protocol, we compared the frequency of CVC-related thrombosis, nadir hemoglobin, and red blood cell transfusion requirements in patients who received AT with those who did not during the study period. RESULTS: A total of 40 patients with IBD who required 47 consecutive hospitalizations were included. AT was administered during 24 of 47 hospitalizations (51%). Patients who received AT were similar to those who did not receive AT with regard to demographics, IBD phenotypes, extent of colonic involvement, and thrombotic risk factors. CVC-related thrombosis occurred in 5 of 23 hospitalizations (22%) in which AT was withheld compared with 0 of 24 hospitalizations (0%) in which patients received AT (P = .02). The red blood cell transfusion requirements and nadir hemoglobin were not significantly different between the 2 groups. CONCLUSIONS: We observed a high incidence of CVC-related thrombosis in hospitalized children with IBD. Administration of AT in our population was associated with significant reduction in CVC-related thrombosis without evidence of increased bleeding.

Specific potassium ion interactions facilitate homocysteine binding to betaine-homocysteine S-methyltransferase.

Betaine-homocysteine S-methyltransferase (BHMT) is a zinc-dependent methyltransferase that uses betaine as the methyl donor for the remethylation of homocysteine to form methionine. This reaction supports S-adenosylmethionine biosynthesis, which is required for hundreds of methylation reactions in humans. Herein we report that BHMT is activated by potassium ions with an apparent K(M) for K⁺ of about 100 µM. The presence of potassium ions lowers the apparent K(M) of the enzyme for homocysteine, but it does not affect the apparent K(M) for betaine or the apparent k(cat) for either substrate. We employed molecular dynamics (MD) simulations to theoretically predict and protein crystallography to experimentally localize the binding site(s) for potassium ion(s). Simulations predicted that K⁺ ion would interact with residues Asp26 and/or Glu159. Our crystal structure of BHMT bound to homocysteine confirms these sites of interaction and reveals further contacts between K⁺ ion and BHMT residues Gly27, Gln72, Gln247, and Gly298. The potassium binding residues in BHMT partially overlap with the previously identified DGG (Asp26-Gly27-Gly28) fingerprint in the Pfam 02574 group of methyltransferases. Subsequent biochemical characterization of several site-specific BHMT mutants confirmed the results obtained by the MD simulations and crystallographic data. Together, the data herein indicate that the role of potassium ions in BHMT is structural and that potassium ion facilitates the specific binding of homocysteine to the active site of the enzyme.

Representation of Fitzpatrick skin phototype in dermatology surgical textbooks.

Given the importance of skin of color (SoC) representation in dermatologic education and training, this study quantified representation of Fitzpatrick skin phototypes (FST) in core dermatology surgery textbooks. Images within Surgery of the Skin: Procedural Dermatology, Dermatologic Surgery, and Facial Reconstruction after Mohs Surgery were categorized according to the Fitzpatrick skin phototype (FST) depicted and the dermatologic surgery topic addressed. 1501 images were analyzed, with only 5.6% of the images categorized as FST IV-VI representing SoC. Several topics (11/29, 37.9%) identified did not include images with SoC. Increasing access to high-quality images of SoC can enhance appreciation of various skin conditions, especially those predominant in SoC, by dermatologic trainees and clinicians.

Single-cell RNA sequencing coupled to TCR profiling of large granular lymphocyte leukemia T cells.

T-cell large granular lymphocyte leukemia (T-LGLL) is a lymphoproliferative disease and bone marrow failure syndrome which responds to immunosuppressive therapies. We show single-cell TCR coupled with RNA sequencing of CD3+ T cells from 13 patients, sampled before and after alemtuzumab treatments. Effector memory T cells and loss of T cell receptor (TCR) repertoire diversity are prevalent in T-LGLL. Shared TCRA and TCRB clonotypes are absent. Deregulation of cell survival and apoptosis gene programs, and marked downregulation of apoptosis genes in CD8+ clones, are prominent features of T-LGLL cells. Apoptosis genes are upregulated after alemtuzumab treatment, especially in responders than non-responders; baseline expression levels of apoptosis genes are predictive of hematologic response. Alemtuzumab does not attenuate TCR clonality, and TCR diversity is further skewed after treatment. Inferences made from analysis of single cell data inform understanding of the pathophysiologic mechanisms of clonal expansion and persistence in T-LGLL.

Single-cell profiling of T lymphocytes in deficiency of adenosine deaminase 2.

Deficiency of adenosine deaminase 2 (DADA2) is a monogenic vasculitis syndrome caused by autosomal-recessive loss-of-function mutations in the ADA2 gene (previously known as CECR1). Vasculitis, vasculopathy, and inflammation are dominant clinical features of this disease; the spectrum of manifestations includes immunodeficiency and lymphoproliferation as well as hematologic manifestations. ADA2 is primarily secreted by stimulated monocytes and macrophages. Aberrant monocyte differentiation to macrophages and neutrophils are important in the pathogenesis of DADA2, but little is known about T lymphocytes in this disease. We performed combined single-cell RNA sequencing and single-cell TCR sequencing in order to profile T cell repertoires in 10 patients with DADA2. Although there were no significant alterations of T cell subsets, we observed activation of both CD8+ and CD4+ T cells. There was no clonal expansion of T cells: most TCRs were expressed at basal levels in patients and healthy donors. TCR usage was private to individual patients and not disease specific, indicating as unlikely a common pathogenic background or predisposition to a common pathogen. We recognized activation of IFN pathways as a signature of T cells and STAT1 as a hub gene in the gene network of T cell activation and cytotoxicity. Overall, T cells in DADA2 patients showed distinct cell-cell interactions with monocytes, as compared with healthy donors, and many of these ligand-receptor interactions likely drove up-regulation of STAT1 in both T cells and other immune cells in patients. Our analysis reveals previously undercharacterized cell characteristics in DADA2.

Analysis of deficiency of adenosine deaminase 2 pathogenesis based on single-cell RNA sequencing of monocytes.

Deficiency of adenosine deaminase 2 (DADA2) is a rare autosomal recessive disease caused by loss-of-function variants in the ADA2 gene. DADA2 typically presents in childhood and is characterized by vasculopathy, stroke, inflammation, immunodeficiency, as well as hematologic manifestations. ADA2 protein is predominantly present in stimulated monocytes, dendritic cells, and macrophages. To elucidate molecular mechanisms in DADA2, CD14+ monocytes from 14 patients and 6 healthy donors were analyzed using single-cell RNA sequencing (scRNA-seq). Monocytes were purified by positive selection based on CD14 expression. Subpopulations were imputed from their transcriptomes. Based on scRNA-seq, monocytes could be classified as classical, intermediate, and nonclassical. Further, we used gene pathway analytics to interpret patterns of up- and down-regulated gene transcription. In DADA2, the frequency of nonclassical monocytes was higher compared with that of healthy donors, and M1 macrophage markers were up-regulated in patients. By comparing gene expression of each monocyte subtype between patients and healthy donors, we identified upregulated immune response pathways, including IFNα/ß and IFNγ signaling, in all monocyte subtypes. Distinctively, the TNFR2 noncanonical NF-κB pathway was up-regulated only in nonclassical monocytes. Patients' plasma showed increased IFNγ and TNFα levels. Our results suggest that elevated IFNγ activates cell signaling, leading to differentiation into M1 macrophages from monocytes and release of TNFα. Immune responses and more general response to stimuli pathways were up-regulated in DADA2 monocytes, and protein synthesis pathways were down-regulated, perhaps as stress responses. Our identification of novel aberrant immune pathways has implications for therapeutic approaches in DADA2 (registered at clinicaltrials.gov NCT00071045).

Nanomaterial Nitric Oxide Delivery in Traumatic Orthopedic Regenerative Medicine.

Achieving bone fracture union after trauma represents a major challenge for the orthopedic surgeon. Fracture non-healing has a multifactorial etiology and there are many risk factors for non-fusion. Environmental factors such as wound contamination, infection, and open fractures can contribute to non-healing, as can patient specific factors such as poor vascular status and improper immunologic response to fracture. Nitric oxide (NO) is a small, neutral, hydrophobic, highly reactive free radical that can diffuse across local cell membranes and exert paracrine functions in the vascular wall. This molecule plays a role in many biologic pathways, and participates in wound healing through decontamination, mediating inflammation, angiogenesis, and tissue remodeling. Additionally, NO is thought to play a role in fighting wound infection by mitigating growth of both Gram negative and Gram positive pathogens. Herein, we discuss recent developments in NO delivery mechanisms and potential implications for patients with bone fractures. NO donors are functional groups that store and release NO, independent of the enzymatic actions of NOS. Donor molecules include organic nitrates/nitrites, metal-NO complexes, and low molecular weight NO donors such as NONOates. Numerous advancements have also been made in developing mechanisms for localized nanomaterial delivery of nitric oxide to bone. NO-releasing aerogels, sol- gel derived nanomaterials, dendrimers, NO-releasing micelles, and core cross linked star (CCS) polymers are all discussed as potential avenues of NO delivery to bone. As a further target for improved fracture healing, 3d bone scaffolds have been developed to include potential for nanoparticulated NO release. These advancements are discussed in detail, and their potential therapeutic advantages are explored. This review aims to provide valuable insight for translational researchers who wish to improve the armamentarium of the feature trauma surgeon through use of NO mediated augmentation of bone healing.

Sequencing of RNA in single cells reveals a distinct transcriptome signature of hematopoiesis in GATA2 deficiency.

Constitutional GATA2 deficiency caused by heterozygous germline GATA2 mutations has a broad spectrum of clinical phenotypes, including systemic infections, lymphedema, cytopenias, and myeloid neoplasms. Genotype-phenotype correlation is not well understood mechanistically in GATA2 deficiency. We performed whole transcriptome sequencing of single hematopoietic stem and progenitor cells from 8 patients, who had pathogenic GATA2 mutations and myelodysplasia. Mapping patients' cells onto normal hematopoiesis, we observed deficiency in lymphoid/myeloid progenitors, also evident from highly constrained gene correlations. HSPCs of patients exhibited distinct patterns of gene expression and coexpression compared with counterparts from healthy donors. Distinct lineages showed differently altered transcriptional profiles. Stem cells in patients had dysregulated gene expression related to apoptosis, cell cycle, and quiescence; increased expression of erythroid/megakaryocytic priming genes; and decreased lymphoid priming genes. The prominent deficiency in lympho-myeloid lineages in GATA2 deficiency appeared at least partly due to the expression of aberrant gene programs in stem cells prior to lineage commitment. We computationally imputed cells with chromosomal abnormalities and determined their gene expression; DNA repair genes were downregulated in trisomy 8 cells, potentially rendering these cells vulnerable to second-hit somatic mutations and additional chromosomal abnormalities. Cells with complex cytogenetic abnormalities showed defects in genes related to multilineage differentiation and cell cycle. Single-cell RNA sequencing is powerful in resolving transcriptomes of cell subpopulations despite a paucity of cells in marrow failure. Our study discloses previously uncharacterized transcriptome signatures of stem cells and progenitors in GATA2 deficiency, providing a broad perspective of potential mechanisms by which germline mutations modulate early hematopoiesis in a human disease. This trial was registered at www.clinicaltrials.gov as NCT01905826, NCT01861106, and NCT00001620.