Erdheim-Chester Disease: Investigating the Correlation between Targeted Treatment Therapy and Disease Outcomes.

A retrospective analysis of 20 adult patients with histopathological and clinical diagnoses of ECD was conducted at a single institution over a twenty-year period (2002-2022). Clinical responses were compared on the basis of treatments rendered, which included chemotherapy, immunotherapy, systemic corticosteroids, surgery and radiation, or targeted agents, referring to any small molecular inhibitors. Treatment response evaluation varied by the anatomic site(s) of disease, the extent of disease at diagnosis, and the imaging modality employed. In this analysis, patients were treated with a combination of targeted agents, myelosuppressive therapies, and radiation at various points in their disease courses. Of these, the most common treatment modality rendered was targeted therapy, employed in 11 of 20 patients. Partial responses or better were observed in 15 of 20 patients. Rates of stable disease trended towards being more frequent with targeted therapy versus conventional therapy but did not reach significance (p = 0.2967). Complete response rates trended towards being more common with conventional therapy than molecular (p = 0.5) but were equivocal overall. Trends of peripheral blood absolute monocytes with relation to disease activity were reviewed as recent literature implied that monocyte levels surrounding disease progression were of potential prognostic significance in histiocytic diseases. Amongst the patients who progressed at any point during their treatment course, absolute monocyte count (in K/µL) was identified at the closest available timepoint prior to or following disease progression and at the lowest value (nadir) following re-institution of therapy prior to any additional agent(s) being employed. There was no statistically significant difference in either of these monocyte values nor in disease outcomes with respect to treatments rendered within our cohort. However, our cohort consists of a heterogenous population of patients with ECD with data that highlights several trends over a longitudinal period, spanning the advent of targeted therapy. Significant differences are anticipated in ongoing analyses.

Investigating the correlation between small molecular inhibitor utilization, peripheral blood monocytes, and treatment outcomes in Rosai Dorfman disease.

Rosai Dorfman disease (RDD) is a non-Langerhans cell histiocytic neoplasm characterized by sinus histiocytosis with variable emperipolesis. There is a limited understanding of the factors that contribute to disease progression. Traditional management of RDD consists of local therapies (resection, radiation) for localized disease and myelosuppression for systemic disease; targeted medications have also recently been introduced into clinical practice as an additional therapeutic modality. The goals of this study are to compare the impact of targeted therapies to conventional management of RDD and identify trends in laboratory data that may provide insight into disease progression. A retrospective analysis was conducted at a single institution over a 20-year period in 35 adult patients with histopathologic evidence of RDD without confounding secondary malignancies. Clinical data points included laboratory evaluation, molecular diagnostics, imaging, and therapies rendered. Binary data was utilized for statistical analysis and comparison of outcomes by treatment type and utilization of targeted agents. Evaluation of treatment response varied based on anatomic disease sites and baseline imaging modality. To standardize the radiographic analysis, we included PERCIST (if PET was utilized) or RECIST assessments (in the cases of CT or MR imaging). Conventional therapies rendered included local treatment (surgery, radiation, intralesional injections), systemic corticosteroids, immunotherapy, and chemotherapy while targeted agents included only small molecule inhibitors. In this analysis, primary disease was identified in cutaneous, osseous, and CNS structures (17, 11, and 6/35 patients respectively). Management consisted of surgery (12/35 patients), steroid and myelosuppressive therapies (9/35 each), immunotherapy (5/35), and targeted molecular agents (5/35). In evaluating outcomes, the proportion of partial responses was substantially higher in recipients of molecular as compared to conventional therapy (4/5 patients compared to 6/29) while complete responses were more common in the conventional therapy cohort (12/29 compared to 1/5). Lastly, an evaluation of peripheral blood absolute monocytes in all patients who had progressed on therapy identified a significant decrease in pre-progression values as compared to values following therapy re-institution (averages of 0.70 and 0.27 K/µL, respectively; p = 0.0002, 95% CI 0.652-0.2360). Larger-scale studies are needed to further evaluate the relevance of the monocyte trends that were identified in terms of their relationship to disease status. This study is the largest analysis of Rosai Dorfman disease, that we are aware of, from a single institution. In this cohort, the utilization of small molecule inhibitors corresponded to a greater increase in partial responses than conventional therapies, although the opposite effect has been observed in complete responses. This finding can be attributed to the recent introduction of targeted agents and shorter follow-up. We anticipate higher complete response rates with the use of small molecule in ongoing analyses over a longer follow-up period. The recognition of relative monocyte elevation prior to disease progression is an intriguing and to our knowledge, novel finding in the field of Rosai Dorfman disease. Future studies aimed at elucidating the implications of this trend are in progress.

Exploring the Molecular Landscape of Myelofibrosis, with a Focus on Ras and Mitogen-Activated Protein (MAP) Kinase Signaling.

Myelofibrosis (MF) is a clonal myeloproliferative neoplasm (MPN) characterized clinically by cytopenias, fatigue, and splenomegaly stemming from extramedullary hematopoiesis. MF commonly arises from mutations in JAK2, MPL, and CALR, which manifests as hyperactive Jak/Stat signaling. Triple-negative MF is diagnosed in the absence of JAK2, MPL, and CALR but when clinical, morphologic criteria are met and other mutation(s) is/are present, including ASXL1, EZH2, and SRSF2. While the clinical and classic molecular features of MF are well-established, emerging evidence indicates that additional mutations, specifically within the Ras/MAP Kinase signaling pathway, are present and may play important role in disease pathogenesis and treatment response. KRAS and NRAS mutations alone are reportedly present in up to 15 and 14% of patients with MF (respectively), and other mutations predicted to activate Ras signaling, such as CBL, NF1, BRAF, and PTPN11, collectively exist in as much as 21% of patients. Investigations into the prevalence of RAS and related pathway mutations in MF and the mechanisms by which they contribute to its pathogenesis are critical in better understanding this condition and ultimately in the identification of novel therapeutic targets.

New approaches to tackle cytopenic myelofibrosis.

Myelofibrosis (MF) is a clonal hematopoietic stem cell neoplasm characterized by constitutional symptoms, splenomegaly, and risks of marrow failure or leukemic transformation and is universally driven by Jak/STAT pathway activation. Despite sharing this pathogenic feature, MF disease behavior can vary widely. MF can generally be categorized into 2 distinct subgroups based on clinical phenotype: proliferative MF and cytopenic (myelodepletive) MF. Compared to proliferative phenotypes, cytopenic MF is characterized by lower blood counts (specifically anemia and thrombocytopenia), more frequent additional somatic mutations outside the Jak/STAT pathway, and a worse prognosis. Cytopenic MF presents unique therapeutic challenges. The first approved Jak inhibitors, ruxolitinib and fedratinib, can both improve constitutional symptoms and splenomegaly but carry on-target risks of worsening anemia and thrombocytopenia, limiting their use in patients with cytopenic MF. Supportive care measures that aim to improve anemia or thrombocytopenia are often ineffective. Fortunately, new treatment strategies for cytopenic MF are on the horizon. Pacritinib, selective Jak2 inhibitor, was approved in 2022 to treat patients with symptomatic MF and a platelet count lower than 50 × 109/L. Several other Jak inhibitors are in development to extend therapeutic benefits to those with either anemia or thrombocytopenia. While many other novel non-Jak inhibitor therapies are in development for MF, most carry a risk of hematologic toxicities and often exclude patients with baseline thrombocytopenia. As a result, significant unmet needs remain for cytopenic MF. Here, we discuss clinical implications of the cytopenic MF phenotype and present existing and future strategies to tackle this challenging disease.

Fat Embolism Syndrome With Cerebral Involvement: An Underrecognized Complication of Long Bone Fractures.

Fat embolism syndrome (FES) occurs when fat particles are aberrantly distributed into the microcirculation, and it often manifests as either hypoxemia, neurological deficit, or petechial rash. Although cases have been reported in the literature since the twentieth century, no formal diagnostic criteria have been universally adopted, and FES remains a diagnostic challenge. We present a unique case of FES from a long bone fracture, leading to pulmonary embolism with paradoxical arterial embolization and cerebral infarction, and provide a review of the related literature.

The First Case of Ignatzschineria ureiclastica/larvae in the United States Presenting as a Myiatic Wound Infection.

Ignatzschineria is a recently identified genus of bacteria that has been isolated from the digestive tract of multiple flies associated with decomposing tissue. Species within this genus are rarely implicated in human disease, and less than 10 cases worldwide have been documented in the literature. Although there have been several documented cases of Ignatzschineria indica bacteremia in the United States (with one previous case in Louisville, KY), this case represents the first documented case of Ignatzschineria ureiclastica/larvae bacteremia in the United States. The natural insect host of this bacteria, parasitic flies that are commonly found among sheep and other livestock, may pose a public health hazard in the city and implicate geographic spread of this bacteria species and its host.

The Clinical Characteristics of Multiple Myeloma in the Acute Care Setting: Case Presentation and Clinical Recommendations.

The acute complications of multiple myeloma can be varied and devastating, including electrolyte derangements, renal failure, and infections amongst others. The varying pathological mechanisms behind these complications make the management of patients presenting with multiple myeloma a complicated and sometimes tenuous process. The patient compliance can further exacerbate these difficulties. The patient discussed in this case initially presented with newly developed altered mental status, fatigue, epistaxis, and an ecchymotic rash. Laboratory testing and imaging would conclude a diagnosis of multiple myeloma, but unfortunately treatment was cut short. Admission at a later date would show rapidly deteriorating condition with new lung consolidations and worsening laboratory findings. Herein the authors discuss the clinical findings of patients with acute manifestations of multiple myeloma, their prognostic value, and the implications of patient compliance and early intervention in the setting of multiple myeloma.

Management of thrombocytopenia in a patient with a mechanical mitral valve undergoing autologous hematopoietic stem cell transplantation: case report and review of literature.

Mechanical mitral valves require life-long anticoagulation with Vitamin K Antagonists (VKA), targeted to an international normalized ratio (INR) of 2.5-3.5. While complications, including valve thrombosis and bleeding, are well known, there is a paucity of data on the management of mechanical mitral valves in patients with thrombocytopenia. Due to an increased bleeding risk, the presence of a mechanical mitral valve is considered by some providers as an exclusion criterion for autologous hematopoietic stem-cell transplantation (HSCT). Presented here is a case of a patient with multiple myeloma who successfully underwent autologous HSCT with simultaneous alterations in VKA therapy for continued anticoagulation in the setting of an underlying mechanical mitral valve.

Bilateral Vocal Fold Paralysis After Epidural Anesthesia.

Cranial neuropathies are known potential complications of spinal anesthesia, with most reports describing upper cranial nerve involvement. Intrathecal hypotension resulting in traction injury of the cranial nerves is the likely mechanism of injury. Unilateral vagal neuropathy was first described recently. The patient discussed in this case presented with hoarseness and dysphagia after receiving epidural anesthesia for childbirth. Following videostroboscopy and laryngeal electromyogram, she was diagnosed with bilateral vocal fold paralysis. The patient was managed conservatively with expectant management. She exhibited complete spontaneous recovery, as has been the natural history previously described for similar injuries. The proposed mechanism for this patient, and in others described in the literature, is puncture of the dura with subsequent egress of cerebrospinal fluid, leading to intracranial hypotension and traction on cranial nerves. Unilateral vocal fold paralysis following spinal anesthesia has been reported in one case series consisting of three patients, but this represents the first case of bilateral paralysis. Spontaneous resolution has been observed in all patients. Patients presenting with idiopathic vocal fold paralysis, in summary, should be questioned about recent history of epidural or spinal anesthesia, as a positive history may point to transient intrathecal hypotension as a potential etiology of the paralysis.

Debilitating Metastatic Spindle Cell Carcinoma of the Breast.

Spindle cell carcinoma of the breast is a rare malignancy. If diagnosed and treated in a timely manner, it is generally associated with a good prognosis. Herein, we have presented an interesting case of metastatic spindle cell carcinoma of breast origin, with extensive metastasis and an unusually aggressive disease course. We also discussed refractory hypoglycemia as a fatal complication of highly metabolically active malignancy. Lastly, we briefly explored the importance of seeking medical attention for early detection and treatment and the need to address psychosocial barriers that influence breast cancer screening.

Rapamycin-resistant poly (ADP-ribose) polymerase-1 overexpression is a potential therapeutic target in lymphangioleiomyomatosis.

Lymphangioleiomyomatosis (LAM) is a female-predominant cystic lung disease that can lead to respiratory failure. LAM cells typically have inactivating tuberous sclerosis complex 2 (TSC2) mutations and mammalian target of rapamycin (mTOR) complex (mTORC) 1 activation. Clinical response to the mTORC1 inhibitors has been limited, prompting a search for additional therapy for LAM. In this study, we investigated the impact of TSC2 on the expression of poly (ADP-ribose) polymerase (PARP)-1 that initiates the DNA repair pathway, and tested the efficacy of PARP1 inhibitors in the survival of TSC2-deficient (TSC2(-)) cells. We analyzed publicly available expression arrays of TSC2(-) cells and validated the findings using real-time RT-PCR, immunoblotting, and immunohistochemistry. We examined the impact of rapamycin and Torin 1 on PARP1 expression. We also tested the effect of PARP1 inhibitors, 8-hydroxy-2-methylquinazoline-4-one and 3,4-dihydro-5[4-(1-piperindinyl)butoxy]-1(2H)-isoquinoline, on the survival of TSC2(-) cells. We identified the up-regulation of PARP1 in TSC2(-) cells relative to cells in which wild-type TSC2 has been reintroduced (TSC2-addback [TSC2(+)] cells). The transcript levels of PARP1 in TSC2(-) cells were not affected by rapamycin. PARP1 levels were increased in TSC2(-) cells, xenograft tumors of rat-derived TSC2(-) cells, renal cystadenomas from Tsc2(+/-) mice, and human LAM nodules. RNA interference of mTOR failed to reduce PARP1 levels. Proliferation and survival of TSC2(-) cells was reduced in response to PARP1 inhibitor treatment, more so than TSC2(+) cells. TSC2(-) cells exhibit higher levels of PARP1 relative to TSC2(+) cells in an mTOR-insensitive manner. PARP1 inhibitors selectively suppress the growth and induce apoptosis of TSC2(-) cells from patients with LAM. Targeting PARP1 may be beneficial in the treatment of LAM and other neoplasm with mTORC1 activation.

mTORC1-S6K activation by endotoxin contributes to cytokine up-regulation and early lethality in animals.

BACKGROUND: mTORC1 (mammalian target of rapamycin complex 1) activation has been demonstrated in response to endotoxin challenge, but the mechanism and significance are unclear. We investigated the effect of mTORC1 suppression in an animal model of endotoxemia and in a cellular model of endotoxin signaling. METHODOLOGY/PRINCIPAL FINDINGS: Mice were treated with the mTORC1 inhibitor rapamycin or vehicle prior to lethal endotoxin challenge. Mortality and cytokine levels were assessed. Cultured macrophage-like cells were challenged with endotoxin with or without inhibitors of various pathways known to be upstream of mTORC1. Activated pathways, including downstream S6K pathway, were assessed by immunoblots. We found that mTORC1-S6K suppression by rapamycin delayed mortality of mice challenged with lethal endotoxin, and was associated with dampened circulating levels of VEGF, IL-1ß, IFN-γ and IL-5. Furthermore, in vitro cellular studies demonstrated that LPS (lipopolysaccharide) activation of mTORC1-S6K still occurs in the presence of PI3K-Akt inhibition alone, but can be suppressed by concurrent inhibition of PI3K-Akt and MEK-ERK pathways. CONCLUSIONS/SIGNIFICANCE: We conclude that cellular activation of mTORC1-S6K contributes to cytokine up-regulation and mortality in response to endotoxin, and may occur via multiple pathways.