Multiomic Profiling of Human Clonal Hematopoiesis Reveals Genotype and Cell-Specific Inflammatory Pathway Activation.

Clonal hematopoiesis (CH) is an age-associated phenomenon that increases risk for hematologic malignancy and cardiovascular disease. CH is thought to enhance disease risk through inflammation in the peripheral blood1. Here, we profile peripheral blood gene expression in 66,968 single cells from a cohort of 17 CH patients and 7 controls. Using a novel mitochondrial DNA barcoding approach, we were able to identify and separately compare mutant TET2 and DNMT3A cells to non-mutant counterparts. We discovered the vast majority of mutated cells were in the myeloid compartment. Additionally, patients harboring DNMT3A and TET2 CH mutations possessed a pro-inflammatory profile in CD14+ monocytes through previously unrecognized pathways such as galectin and macrophage Inhibitory Factor (MIF). We also found that T cells from CH patients, though mostly un-mutated, had decreased expression of GTPase of the immunity associated protein (GIMAP) genes, which are critical to T cell development, suggesting that CH impairs T cell function.

Intra-abdominal omental mass as a desmoplastic round cell tumor: A rare case report.

Key Clinical Message: Desmoplastic round cell tumor, though rare, must be taken into consideration as a differential diagnosis, thus aiding in early evaluation and changing the trajectory of the natural history of the disease condition, and improving the prognosis of patients. Abstract: Desmoplastic small round cell tumor is a rare, aggressive tumor of mesenchymal origin with an incidence of 0.74 cases per million. We present a young adult with a periumbilical mass who was diagnosed as a desmoplastic round cell tumor and later was treated with exploratory laparotomy and resection of the tumor with no recurrence during a 6-month follow-up period.

Appendicular actinomycosis: The first reported case of an uncommon finding of a common ailment from Nepal.

Key Clinical Message: Actinomycosis is a rare cause of appendicitis with an incidence of 0.3-1 incident per year per 100,000 people. A significant preoperative diagnostic challenge exists and is usually diagnosed incidentally on histopathological examination. Abstract: Appendicular actinomycosis, a rare, chronic granulomatous infection caused by actinomyces species, holds a significant preoperative diagnostic summons and is often diagnosed serendipitously during the regular histopathological examination. Herein, we present a case of a 36-year-old female who presented with features suggestive of acute appendicitis, underwent laparoscopic appendicectomy, and was diagnosed with appendicular actinomycosis from the histopathological examination.

Cholecystopathia chronica calcarea (Porcelain gall bladder): A case report from Nepal.

Introduction and importance: Porcelain gall bladder is an uncommon end-stage modification of chronic cholecystitis, with an incidence ranging from 0.06 to 0.8% along with a plausibility of malignant transformation. Case presentation: We present a 55-year-old female presenting with complaints of epigastric and right hypochondriac region pain who underwent prophylactic laparoscopic cholecystectomy after making a provisional diagnosis of calcified gall bladder on a computed tomography workup. On histopathological examination, she was later diagnosed with a porcelain gallbladder devoid of features suggestive of malignant transformation. Clinical discussion: Porcelain gallbladder is a cholecystopathological condition in which the gallbladder wall gets calcified, either completely or partially. Though the exact pathomechanism of gallbladder calcification is unknown, it is believed to be due to chronic inflammation. Recent studies have shown that gallbladder calcification is associated with a lower risk of the development of gallbladder cancer. Imaging studies, followed by post-operative histopathological examinations, are used to diagnose the porcelain gallbladder. Though the management of asymptomatic patients is debatable, prophylactic cholecystectomy is the preferred treatment for symptomatic porcelain gallbladder patients. Conclusion: Individual porcelain GB patients should be addressed based on the presenting condition, whether surgically or via clinical monitoring and follow-up, taking into consideration the advantages and limitations of both treatment modalities.

Amyand hernia; a case report on serendiptous intra-operative diagnosis.

Introduction and Importance: Amyand hernia is an accidental finding that occurs in 0.19-1.7% of patients with inguinal hernia, with children being more commonly affected than adults. However, the management depends on the guidelines given by Losanoff and Basson. Case Presentation: A 62-year-old male presented with complaints of progressive swelling in the right inguinal region without any clinical spectrum of bowel obstruction or strangulation. Examination revealed a right-sided indirect inguinal hernia with positive Ziemann technique. Open hernioplasty revealed an appendix within a hernia sac and was found to be adhered to the surrounding structure with a fibrotic band. According to the Losanoff and Basson protocol, the patient had an appendectomy and an open mesh repair with polypropylene mesh without any post-operative complications. Clinical Discussion: Amyand hernia are often predominantly present in children, with a rare presence in the elderly. Pre-operative clinical diagnosis remains a challenge, and the management depends upon the Losanoff and Basson protocol. Appendectomy of the normal appendix within the hernia sac is often recommended to prevent the sequelae (appendicitis, rupture) following manipulation during hernioplasty. Conclusion: Amyand's hernia is a rare clinical entity and difficult to diagnose due to its uncomplicated presentation. Nevertheless, the progress of appendix inflammation, the possibility of abdominal sepsis, and co-morbidities should all be taken into consideration when deciding how to manage individual patients.

Sinistroposition: A case report on incidental finding of left sided gall bladder on laparoscopic cholecystectomy.

Introduction and importance: Left-sided gall bladder, a rare biliary abnormality with an incidence of 0.04-0.3%, is characterized by the presence of the gall bladder to the left of the ligamentum teres. However, they are often missed during pre-operative imaging and often encountered intraoperatively, thus challenging the surgical intervention for the surgeons. Case presentation: We herein present a 40-year-old male presented with colicky right hypochondriac pain and epigastric discomfort, diagnosed incidentally during laparoscopic cholecystectomy as a left-sided sided gall bladder without situs inversus, which was missed during pre-operative ultrasonography and was treated without any complications with conventional four-port technique without changes in the trocar placement. Clinical discussion: Gall bladder is normally found in the gall bladder fossa to the right of the ligamentum teres in the plane of the von Rex-Cantlie line; however, left-sided gall bladder is found to the left of the ligamentum teres and is frequently associated with inversus of the abdominal structures and associated vessels. They are frequently overlooked during preoperative diagnostic imaging, ultrasound for colicky discomfort, and encountered during intraoperative operations, confounding the treating surgeon's anatomic expertise. Intra-operative cholangiography is sometimes used as an adjunct, and operations can be accomplished with or without modifications in trocar position. Conclusion: Despite preoperative imaging, biliary abnormalities can be discovered accidently during laparoscopic cholecystectomy. Thus, diligent recognition of structures and related anomalies by the treating surgeon has a high value in the best possible outcome for the patient, and left-sided gall bladder can be done with minimum difficulty even without interposition of trocar placement.

CD4+ T-Cell Epitope Prediction by Combined Analysis of Antigen Conformational Flexibility and Peptide-MHCII Binding Affinity.

Antigen processing in the class II MHC pathway depends on conventional proteolytic enzymes, potentially acting on antigens in native-like conformational states. CD4+ epitope dominance arises from a competition among antigen folding, proteolysis, and MHCII binding. Protease-sensitive sites, linear antibody epitopes, and CD4+ T-cell epitopes were mapped in plague vaccine candidate F1-V to evaluate the various contributions to CD4+ epitope dominance. Using X-ray crystal structures, antigen processing likelihood (APL) predicts CD4+ epitopes with significant accuracy for F1-V without considering peptide-MHCII binding affinity. We also show that APL achieves excellent performance over two benchmark antigen sets. The profiles of conformational flexibility derived from the X-ray crystal structures of the F1-V proteins, Caf1 and LcrV, were similar to the biochemical profiles of linear antibody epitope reactivity and protease sensitivity, suggesting that the role of structure in proteolysis was captured by the analysis of the crystal structures. The patterns of CD4+ T-cell epitope dominance in C57BL/6, CBA, and BALB/c mice were compared to epitope predictions based on APL, MHCII binding, or both. For a sample of 13 diverse antigens, the accuracy of epitope prediction by the combination of APL and I-Ab-MHCII-peptide affinity reached 36%. When MHCII allele specificity was also diverse, such as in human immunity, prediction of dominant epitopes by APL alone reached 42% when using a stringent scoring threshold. Because dominant CD4+ epitopes tend to occur in conformationally stable antigen domains, crystal structures typically are available for analysis by APL, and thus, the requirement for a crystal structure is not a severe limitation.

Distinct Patterns of Clonal Evolution Drive Myelodysplastic Syndrome Progression to Secondary Acute Myeloid Leukemia.

Clonal evolution in myelodysplastic syndrome (MDS) can result in clinical progression and secondary acute myeloid leukemia (sAML). To dissect changes in clonal architecture associated with this progression, we performed single-cell genotyping of paired MDS and sAML samples from 18 patients. Analysis of single-cell genotypes revealed patient-specific clonal evolution and enabled the assessment of single-cell mutational cooccurrence. We discovered that changes in clonal architecture proceed via distinct patterns, classified as static or dynamic, with dynamic clonal architectures having a more proliferative phenotype by blast count fold change. Proteogenomic analysis of a subset of patients confirmed that pathogenic mutations were primarily confined to primitive and mature myeloid cells, though we also identify rare but present mutations in lymphocyte subsets. Single-cell transcriptomic analysis of paired sample sets further identified gene sets and signaling pathways involved in two cases of progression. Together, these data define serial changes in the MDS clonal landscape with clinical and therapeutic implications. SIGNIFICANCE: Precise clonal trajectories in MDS progression are made possible by single-cell genomic sequencing. Here we use this technology to uncover the patterns of clonal architecture and clonal evolution that drive the transformation to secondary AML. We further define the phenotypic and transcriptional changes of disease progression at the single-cell level. See related article by Menssen et al., p. 330 (31). See related commentary by Romine and van Galen, p. 270. This article is highlighted in the In This Issue feature, p. 265.

A rare presentation of gallbladder carcinoma metastasis.

Gallbladder carcinoma is the 5th most common gastrointestinal cancer. Gallbladder cancer preferentially metastasizes to regional lymph nodes and liver parenchyma. Bone metastases from gallbladder carcinoma are rare presentation. We report a case of gallbladder carcinoma with solitary metastasis to femur bone with surrounding soft tissue involvement, mimicking as soft tissue tumour involving bone.