CD30+ T cell enriched primary cutaneous CD4+ small/medium sized pleomorphic T cell lymphoma: A distinct variant of indolent CD4+ T cell lymphoproliferative disease.

Primary cutaneous CD4+ small/medium sized pleomorphic T-cell lymphoma (SMPTCL) is unique among the peripheral T-cell lymphomas because of its indolent nature, typically presenting as a solitary nodule or plaque in the head and neck area of middle-aged and older adults. Recent studies have suggested a follicular helper cell origin for these lesions. MATERIALS AND METHODS: A retrospective review was conducted on all cases of SMPTCL diagnosed between 2008 and 2017. The goal of our study was to better categorize the clinical, pathologic and molecular features of cases of SMPTCL showing a significant degree of CD30 neoplastic large cell infiltration. RESULTS: Fifteen patients (10 male, 5 female) were encountered (age 33-86years at presentation). All lesions were solitary and the head and neck region was the most common area of involvement (7 cases). Surgical excision alone was performed in 6 cases and was supplemented with radiation in 5 cases. Disease recurrence did not occur. Spontaneous regression following biopsy was reported and two patients had a history compatible with lymphomatoid papulosis. All cases showed pathologic features characteristic of SMPTCL. Additionally, there were many larger CD30+ T-cells occupying 15-30% of the infiltrate. Monoclonality was demonstrated in 5 of 10 cases in which clonality studies were performed. CONCLUSION: CD30 positivity amidst large neoplastic T-cells is not uncommon in SMPTCL. The extent of CD30 positivity in SMPTCL needs to be defined further along with its association with other forms of CD30+ lymphoproliferative disease including its potential categorization as a form of endogenous CD30+ lymphoproliferative disease.

Astrocyte-derived BDNF supports myelin protein synthesis after cuprizone-induced demyelination.

It is well established that BDNF may enhance oligodendrocyte differentiation following a demyelinating lesion, however, the endogenous sources of BDNF that may be harnessed to reverse deficits associated with such lesions are poorly defined. Here, we investigate roles of astrocytes in synthesizing and releasing BDNF. These cells are known to express BDNF following injury in vivo. In culture, they increase BDNF synthesis and release in response to glutamate metabotropic stimulation. Following cuprizone-elicited demyelination in mice, astrocytes contain BDNF and increase levels of metabotropic receptors. The metabotropic agonist, trans-(1S,3R)-1-amino-1,3-cyclopentanedicarboxylic acid (ACPD), was therefore injected into the demyelinating lesion. Increases in BDNF, as well as myelin proteins, were observed. Effects of ACPD were eliminated by coinjection of trkB-Fc to locally deplete BDNF and by deletion of astrocyte-derived BDNF. The data indicate that astrocyte-derived BDNF may be a source of trophic support that can be used to reverse deficits elicited following demyelination.

Mesenchymal Stem Cell Extracellular Vesicles as a New Treatment Paradigm in Solid Abdominal Organ Transplantation: A Case Series.

Solid abdominal organ transplantation is fraught with variable rates of rejection and graft versus host disease (GVHD). We sought to determine the safety and efficacy of an advanced extracellular vesicle (EV) investigational product (IP) derived from mesenchymal stem cells (MSC) in the transplant patient population. Seven separate emergency investigational new drug (eNIDs) were filed with the Food and Drug Administration (FDA) for the emergency treatment of rejection of an isolated intestinal graft (n = 2), liver allograft graft (n = 2), modified multivisceral graft (n = 3), and GVHD in isolated intestinal transplant patients (n = 2). Fifteen milliliters of IP was administered intravenously on Day 0, 2, 4, and this treatment cycle was repeated up to four times in each patient depending on the treatment protocol allowed by the FDA. Safety (adverse event reporting) and efficacy (clinical status, serologies, and histopathology) were evaluated. There were no adverse events related to IP. All patients had improvement in clinical symptoms within 24 h, improved serologic laboratory evaluation, improved pulmonary symptoms and dermatologic manifestations of GVHD, and complete histologic resolution of graft inflammation/rejection within 7 days of IP administration. Systemic use of a MSC-derived EV IP was successful in achieving histological clearance of intestinal, liver, and multivisceral graft inflammation, and skin and pulmonary manifestations of GVHD.

A novel murine model of pyoderma gangrenosum reveals that inflammatory skin-gut crosstalk is mediated by IL-1ß-primed neutrophils.

Pyoderma gangrenosum (PG) is a debilitating skin condition often accompanied by inflammatory bowel disease (IBD). Strikingly, ~40% of patients that present with PG have underlying IBD, suggesting shared but unknown mechanisms of pathogenesis. Impeding the development of effective treatments for PG is the absence of an animal model that exhibits features of both skin and gut manifestations. This study describes the development of the first experimental drug-induced mouse model of PG with concomitant intestinal inflammation. Topical application of pyrimidine synthesis inhibitors on wounded mouse skin generates skin ulcers enriched in neutrophil extracellular traps (NETs) as well as pro-inflammatory cellular and soluble mediators mimicking human PG. The mice also develop spontaneous intestinal inflammation demonstrated by histologic damage. Further investigations revealed increased circulating low density IL-1ß primed neutrophils that undergo enhanced NETosis at inflamed tissue sites supported by an increase in circulatory citrullinated histone 3, a marker of aberrant NET formation. Granulocyte depletion dampens the intestinal inflammation in this model, further supporting the notion that granulocytes contribute to the skin-gut crosstalk in PG mice. We anticipate that this novel murine PG model will enable researchers to probe common disease mechanisms and identify more effective targets for treatment for PG patients with IBD.

Epstein-Barr virus-associated smooth muscle tumors in immunocompromised patients: Six case reports.

BACKGROUND: Epstein-Barr virus associated smooth muscle tumor (EBV-SMT) is a rare oncological entity. However, there is an increasing incidence of EBV-SMTs, as the frequency of organ transplantation and immunosuppression grows. EBV-SMT diagnosis relies on histopathology and immunochemical staining to distinguish it from post-transplant lymphoproliferative disorder (PTLD). There is no clear consensus on the treatment of EBV-SMTs. However, surgical resection, chemotherapy, radiation therapy, and immunosuppression reduction have been explored with varying degrees of success. CASE SUMMARY: Our case series includes six cases of EBV-SMTs across different age groups, with different treatment modalities, adding to the limited existing literature on this rare tumor. The median latency time between immunosuppression and disease diagnosis is four years. EBV-SMTs present with variable degrees of aggressiveness and seem to have worse clinical outcomes in patients with tumor multiplicity and worse immunocompetency. CONCLUSION: It is imperative to continue building on this knowledge and keeping EBV-SMTs on the differential in immunocompromised individuals.

Human hepatocyte PNPLA3-148M exacerbates rapid non-alcoholic fatty liver disease development in chimeric mice.

Advanced non-alcoholic fatty liver disease (NAFLD) is a rapidly emerging global health problem associated with pre-disposing genetic polymorphisms, most strikingly an isoleucine to methionine substitution in patatin-like phospholipase domain-containing protein 3 (PNPLA3-I148M). Here, we study how human hepatocytes with PNPLA3 148I and 148M variants engrafted in the livers of broadly immunodeficient chimeric mice respond to hypercaloric diets. As early as four weeks, mice developed dyslipidemia, impaired glucose tolerance, and steatosis with ballooning degeneration selectively in the human graft, followed by pericellular fibrosis after eight weeks of hypercaloric feeding. Hepatocytes with the PNPLA3-148M variant, either from a homozygous 148M donor or overexpressed in a 148I donor background, developed microvesicular and severe steatosis with frequent ballooning degeneration, resulting in more active steatohepatitis than 148I hepatocytes. We conclude that PNPLA3-148M in human hepatocytes exacerbates NAFLD. These models will facilitate mechanistic studies into human genetic variant contributions to advanced fatty liver diseases.

Crohn Disease Infrequently Affects the Appendix and Rarely Causes Granulomatous Appendicitis.

Data from previous studies suggest Crohn disease of the appendix accounts for ∼25% of granulomatous appendicitis cases. However, we have found that granulomatous inflammation in appendectomy specimens rarely heralds Crohn disease. We suspect that appendiceal involvement by Crohn disease is uncommon, even when patients have severe ileocolonic inflammation. We performed this study to determine the prevalence and nature of appendiceal inflammation among patients with Crohn disease. We reviewed 100 ileocolic specimens with strictures and fistulizing Crohn disease for the nature and distribution of inflammatory changes in the appendix and compared them with 100 appendices on colectomy specimens from age-matched and sex-matched patients with ulcerative colitis. We also evaluated 27 additional cases of granulomatous appendicitis in appendectomy specimens to determine the frequency with which this finding represented Crohn disease. The appendix was usually normal (26%) or showed fibrous obliteration (50%) in ileocolic resection specimens from patients with Crohn disease. Mucosal inflammation was much less common in appendices from patients with Crohn disease than ulcerative colitis (6% vs. 28%, P<0.0001); only 4 cases contained epithelioid granulomata, 3 showed mural fibrosis and lymphoid aggregates, and 10 displayed only periappendiceal inflammation. None of the patients with granulomatous appendicitis in appendectomy specimens had, or developed, evidence of Crohn disease. We conclude that Crohn disease infrequently affects the appendix. Interval appendectomy and infection are more important considerations when appendectomy specimens feature granulomatous inflammation and/or mural lymphoid aggregates, especially if there is no history of idiopathic inflammatory bowel disease.

A Spore-Forming Probiotic Supplement Improves the Intestinal Immune Response and Protects the Intestinal Health During Recurrent Clostridioides difficile Colonization in Mice.

BACKGROUND: Around 15%-30% of patients develop recurrent Clostridioides difficile infection (CDI) as conventional therapies disrupt protective gut microbiota. We tested if supplementation with a spore-forming probiotic would protect intestinal health in a mouse model of recurrent CD colonization. METHODS: Methods: Female CF-1 mice were exposed to CD spores (4-log10 colony-forming units/10 µL) and then randomly assigned to receive either saline (CD-S) or probiotic (CD-PRO). Control mice received only saline (control). Following confirmation of initial CD colonization, mice were treated with vancomycin (10 days). After 5 days, mice recolonized with CD were treated again with vancomycin (10 days) and euthanized 5 days later. Fecal samples were collected at select time points for bacterial analysis. Following euthanasia, blood samples, cecum contents, and the intestine were collected for analysis. RESULTS: Probiotic supplementation mitigated the antibiotic-induced changes in cecum weight (P < .001). Probiotic-supplemented mice had increased messenger RNA expression of several immune parameters, accompanied by lower serum iron levels compared with CD-S mice (P < .05). Lower expressions of TNF α and calprotectin (P ≤ .05) were observed in CD-PRO mice compared with CD-S. The probiotics also supported the expression of intestinal tight junction proteins, which were diminished in the proximal colon of CD-S mice (P < .05). CONCLUSION: Mice supplemented with targeted spore-forming probiotics exhibited improved immune responses and nutrition immunity properties, which were linked with less inflammation and enhanced intestinal barrier proteins during recurrent CD colonization.

Next-generation sequencing of residual cytologic fixative preserved DNA from pancreatic lesions: A pilot study.

BACKGROUND: Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is a sensitive and specific tool in the risk stratification of pancreatic lesions, including cysts. The sensitivity and specificity of EUS-FNA has been shown to improve when cytology is combined with next-generation sequencing (NGS). Ideally, fresh cyst fluid is used for NGS. In this pilot study, we explore the possibility of sequencing DNA derived from residual alcohol-fixed pancreatic aspirates. METHODS: Residual cytologic fixatives (n = 42) from 39 patients who underwent EUS-FNA for pancreatic lesions were collected along with demographics, imaging, and laboratory studies. Samples were designated as nonneoplastic/nonmucinous benign (NB), mucinous cyst (MC), pancreatic ductal adenocarcinoma (PDAC), or well-differentiated neuroendocrine tumor (NET) on the basis of cytopathologic evaluation and sequenced on the Oncomine platform (ThermoFisher Scientific, Waltham, Massachusetts). RESULTS: Ten of 14 (71.4%) MCs exhibited clinically significant variants, including KRAS, GNAS, and TP53. Ten of 15 (66.7%) PDACs had KRAS alterations, and 9 of 15 (60%) showed variants in TP53. No variants were detected in any NETs. Only 1 of 9 (11.1%) NB aspirates showed variants in KRAS and MAP2K. Sequencing of formalin-fixed, paraffin-embedded tissue revealed variants identical to those detected in fixative-derived DNA in 4 of 5 cases (80%). CONCLUSION: Residual DNA from alcohol-fixed aspirates are an underutilized source for NGS. Sequencing residual fixative-derived DNA has the potential to be integrated into the workup of pancreatic aspirates, possibly impacting management.

Insulin-like growth factor-I-stimulated Akt phosphorylation and oligodendrocyte progenitor cell survival require cholesterol-enriched membranes.

Previously we showed that insulin-like growth factor-I (IGF-I) promotes sustained phosphorylation of Akt in oligodendrocyte progenitor cells (OPCs) and that Akt phosphorylation is required for survival of these cells. The direct mechanisms, however, by which IGF-I promotes Akt phosphorylation are currently undefined. Recently, cholesterol-enriched membranes (CEMs) have been implicated in regulation of growth factor-mediated activation of the PI3K/Akt pathway and survival of mature oligodendrocytes; however, less is know about their role in OPC survival. In the present study, we investigate the role of CEMs in IGF-I-mediated Akt phosphorylation and OPC survival. We report that acute disruption of membrane cholesterol with methyl-beta-cyclodextrin results in altered OPC morphology and inhibition of IGF-I-mediated Akt phosphorylation. We also report that long-term inhibition of cholesterol biosynthesis with 25-hydroxycholesterol blocks IGF-I stimulated Akt phosphorylation and cell survival. Moreover, we show that the PI3K regulatory subunit, p85, Akt, and the IGF-IR are sequestered within cholesterol-enriched fractions in steady-state stimulation of the IGF-IR and that phosphorylated Akt and IGF-IR are present in cholesterol-enriched fractions with IGF-I stimulation. Together, the results of these studies support a role for CEMs or "lipid rafts" in IGF-I-mediated Akt phosphorylation and provide a better understanding of the mechanisms by which IGF-I promotes OPC survival.

Culturing oligodendrocyte lineage cells from neonatal rats.

The use of enriched oligodendrocyte lineage cell cultures has yielded insight into functions of these cells and regulatory mechanisms. This chapter details methods that result in such cultures.

Insulin-like growth factor type-I receptor internalization and recycling mediate the sustained phosphorylation of Akt.

Previously we demonstrated that insulin-like growth factor-I mediates the sustained phosphorylation of Akt, which is essential for long term survival and protection of glial progenitors from glutamate toxicity. These prosurvival effects correlated with prolonged activation and stability of the insulin-like growth factor type-I receptor. In the present study, we investigated the mechanisms whereby insulin-like growth factor-I signaling, through the insulin-like growth factor type-I receptor, mediates the sustained phosphorylation of Akt. We showed that insulin-like growth factor-I stimulation induced loss of receptors from the cell surface but that surface receptors recovered over time. Blocking receptor internalization inhibited Akt phosphorylation, whereas inhibition of receptor trafficking blocked receptor recovery at the cell surface and the sustained phosphorylation of Akt. Moreover the insulin-like growth factor type-I receptor localized with the transferrin receptor and Rab11-positive endosomes in a ligand-dependent manner, further supporting the conclusion that this receptor follows a recycling pathway. Our results provide evidence that ligand stimulation leads to internalization of the insulin-like growth factor type-I receptor, which mediates Akt phosphorylation, and that receptor recycling sustains Akt phosphorylation in glial progenitors. Mathematical modeling of receptor trafficking further supports these results and predicts an additional kinetic state of the receptor consistent with sustained Akt phosphorylation.