Marrow Activity Research Articles

O-05 A RARE CAUSE OF BILATERAL GIANT ADRENAL MASS: PRIMARY ADRENAL LYMPHOMA

Abstract Introduction Primary adrenal lymphoma (PAL) is an extremely rare form of non-Hodgkin lymphoma, representing less than 1% of cases. It is usually bilateral, unlike secondary adrenal lymphoma, which is often unilateral. Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of PAL, making up about 70% of cases. PAL primarily affects older patients and lacks distinct nodular lesions, making diagnosis difficult; pathological examination is essential for confirmation. Clinical Case A 62-year-old male patient with no known comorbidities presented with symptoms of night sweats, weight loss (approximately 10 kg over the past month), and general weakness persisting for the past two months. Physical examination revealed decreased breath sounds in the bilateral lower lung fields and a dullness to percussion over Traube's space on abdominal examination. No other pathological findings were noted. Vital signs were in normal range. Laboratory evaluation showed normocytic anemia, thrombocytopenia, and hypercalcemia with suppressed parathyroid hormone levels. Additionally, lactate dehydrogenase levels were elevated (see Table 1). A thoracic, abdominal, and pelvic computed tomography (CT) scan was performed to assess for malignancy. The CT scan revealed a solid mass lesion measuring approximately 11 x 18 x 10 cm with an average density of 50 HU, exhibiting non-homogeneous contrast enhancement. This lesion is located in the bilateral adrenal regions and show confluent extension anterior to the abdominal aorta (see Figure 1). Subsequently, the patient underwent hormonal analysis to assess adrenal function and an 18F-FDG PET/CT scan was planned. Hormonal analysis indicated that the adrenal mass was non-functional, with preserved adrenal gland function (see Table 2). The PET/CT scan showed intense pathological activity accumulation in the adrenal mass lesion (SUVmax: 25.9) and diffuse increased activity in the bone marrow. Following this, both bone marrow and adrenal mass biopsies were performed. The bone marrow biopsy did not reveal infiltrative pathology. However, the biopsy of the adrenal mass was reported as aggressive mature large B-cell lymphoma. Primary bilateral adrenal lymphoma was diagnosed. The patient was evaluated by hematology and subsequently initiated on R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone) chemotherapy. Following six cycles of R-CHOP, the suprarenal mass is completely resolved. However, during follow-up one year later, the disease relapsed with a cranial mass. Conclusion PAL is a rare extranodal non-Hodgkin's lymphoma, predominantly affecting males around 70 years old. It usually presents with large bilateral adrenal masses and can cause primary adrenal insufficiency (PAI) in up to 70% of cases. Diagnosis is confirmed by histology after imaging. Treatment typically involves a combination of surgery, chemotherapy, and/or radiotherapy, with PAI requiring hormone replacement therapy.Figure 1:Imaging of the Tumor Lesion Before and After Chemotherapya/b) Pre/Post-Chemotherapy PET/CT Imaging, c/d) Pre/Post-Chemotherapy CT Imaging Table 1:Patient’s laboratory parameters Table 2:Patient’s adrenal function assessment(Values marked with an asterisk (*) were measured in a 24-hour urine collection, while the other values were measured in plasma.) (DHEAS: Dehydroepiandrosterone sulfate)

Transfusional hemosiderosis in childhood cancer patients and survivors.

Children treated for cancer are at risk for adverse effects of iron due to transfusions administered during prolonged marrow suppression, which may increase exposure to toxic forms of iron, extrahepatic iron accumulation, and long-term organ damage. This study aimed to characterize the severity and organ distribution of clinically significant, multisystem iron overload (IO) in an at-risk cohort of pediatric cancer patients. This was a retrospective, cross-sectional study of childhood cancer patients who underwent a magnetic resonance imaging (MRI) due to clinical concern for IO. Data regarding cancer type and treatment, transfusion history, MRI and laboratory results, and treatment for IO were collected. Severity of IO was analyzed by non-parametric tests with respect to clinical characteristics. Of the 103 patients, 98% of whom had a Cancer Intensity Treatment Rating (ITR-3) of 3 or higher, 53% (54/102) had moderate or greater hepatic siderosis, 80% (77/96) had pancreatic siderosis, 4% (3/80) had cardiac siderosis, and 45% (13/29) had pituitary siderosis and/or volume loss. Pancreatic iron was associated with both cardiac (p=.0043) and pituitary iron (p=.0101). In the 73 off-therapy patients, ferritin levels were lower (p=.0008) with higher correlation with liver iron concentration (LIC) (p=.0016) than on-therapy patients. Fifty-eight subjects were treated for IO. In this heavily treated cohort of pediatric cancer patients, more than 80% had extrahepatic iron loading, which occurs with significant exposure to toxic forms of iron related to decreased marrow activity in setting of transfusions. Further studies should examine the effects of exposure to reactive iron on long-term outcomes and potential strategies for management.

Exploring Mean Platelet Volume and Platelet Count Recovery in Dengue Patients: Findings From an Observational Retrospective Clinical Study.

Introduction Mean platelet volume (MPV) measures platelet size in the blood, which is important because dengue fever often leads to low platelet counts, especially during the critical phase. However, predicting when a patient's platelet count will recover is challenging due to the lack of clinical data. MPV may offer a solution as it tends to rise when platelet counts fall, suggesting a possible link to bone marrow activity. This study aims to understand how MPV changes during the three phases of dengue fever and how it relates to platelet count recovery. Successful results could provide valuable markers for clinicians, helping improve patient care and management. Material The study was carried out in the Department of Medicine,Kalinga Institute of Medical Sciences (KIMS), Bhubaneswar, Odisha, India. The patients who were admitted with dengue fever/dengue haemorrhagic fever in the month of July 2023 were analysed. Observations A total of 130 patients were analysed. The average (avg) MPV on day one was 10.85 ± 1.56, on day three was 10 ± 1.48, and on day five was 9.80 ± 1.30. The avg. total platelet on day one was 119476.92 ± 78,107.78, on day three was 119000 ± 59962.52, and on day five was 169200 ± 100839.84. The correlation between MPV and platelet on day one was r= -0.22, p=0.011, which was statistically significant; on day three was r= -0.32, p=0.0001, which was statistically significant, and on day five was r= -0.30, p= 0.0004, which was statistically significant. Conclusion These findings suggest that as dengue fever progresses, MPV tends to increase as platelet counts decline. This information can be beneficial in clinical practice as it highlights the potential utility of MPV as a predictive marker for platelet recovery, aiding healthcare providers in the timely management of dengue patients to mitigate bleeding risks.

Extramedullary Hematopoiesis in a Patient with Beta Thalassemia: A Rare Case Report

Extramedullary hematopoiesis (EMH) is a rare disorder, defined as the appearance of hematopoietic elements outside the bone marrow or peripheral blood due to ineffective erythropoiesis or inadequate bone marrow activity in a variety of hematological diseases. EMH often manifests as hemopoietic masses in a variety of normal and abnormal bodily sites. We present a 21-year-old man with a medical history of beta thalassemia since he was nine months old. The primary clinical symptom was mild abdominal pain. In this case, we describe a rare instance of small bowel obstruction due to EMH and portal hypertension. Surgery solved the clinical problems, and the patient was discharged home.

Development of a novel methodology to assess response to lymphoma treatment in real-world data.

e19081 Background: Innovation in the use of real-world data (RWD) for regulatory purposes is an important provision of 21st Century Cures Act. Numerous initiatives to enhance RWD methodologies in oncology drug development are ongoing, including evaluation of treatment response assessment to support effectiveness research. Blinded independent central review (BICR) standardizes response assessment in clinical trials, and corresponding RWD methodologies are needed. This study assess feasibility of BICR using RWD, and evaluates a novel, standardized treatment response methodology among patients with diffuse large B-cell lymphoma (DLBCL). Methods: A retrospective multisite chart review identified adult patients with DLBCL treated with first-line chemoimmunotherapy in US (01JAN2015-31DEC2022). Clinical data, including physician-reported response, were abstracted from medical charts and positron emission tomography-computed tomography (PET-CT) reports at treatment initiation and first response assessment. Lugano 2014 criteria, such as standardized uptake value (SUV) and Deauville score, were extracted and converted to an algorithm (rwLugano). Absence of normal tissue SUV in PET-CT reports was addressed using published values for background, mediastinum, and liver to facilitate a real-world Deauville (rwDeauville) score for rwLugano classification. PET-CTs underwent deidentified digital image transfer for BICR using Lugano 2014 criteria by two lymphoma radiologists. Descriptive analyses assessed BICR feasibility and completeness of rwLugano data elements. Results: Six oncology practices, comprising 77 physicians, abstracted medical records and PET-CT reports for 185 patients. PET-CT scans were available for BICR for 174/185 (94%) patients (41% female, mean age 66 years). BICR discordance for Deauville score at baseline and initial response occurred in 7% (12/174) and 29% (50/174), respectively. For response assessment per Lugano, BICR discordance occurred in 9% (16/174), and were further adjudicated by a third party. Lugano discordance was often related to interpretation of marrow activity and/or new disease sites, highlighting variability in lymphoma treatment response assessment. Medical record review found Deauville score charted for 97 (56%) patients at baseline and 145 (83%) at first response. Tumor SUV was complete (174/174, 100%) at baseline and for all patients (63/63, 100%) not charted as CR at first response. Thus, 29 patients (17%) required calculation of rwDeauville at first response, providing data to calculate rwLugano for all patients in the final cohort (174/174, 100%). Conclusions: This study suggests BICR, though resource intensive, can be performed, and the component measures necessary to assess response per Lugano criteria can be obtained using RWD. Accordingly, rwLugano warrants further analysis for concordance with BICR- and physician-reported response.

Heart failure promotes multimorbidity through innate immune memory.

Patients with heart failure (HF) often experience repeated acute decompensation and develop comorbidities such as chronic kidney disease and frailty syndrome. Although this suggests pathological interaction among comorbidities, the mechanisms linking them are poorly understood. Here, we identified alterations in hematopoietic stem cells (HSCs) as a critical driver of recurrent HF and associated comorbidities. Bone marrow transplantation from HF-experienced mice resulted in spontaneous cardiac dysfunction and fibrosis in recipient mice, as well as increased vulnerability to kidney and skeletal muscle insults. HF enhanced the capacity of HSCs to generate proinflammatory macrophages. In HF mice, global chromatin accessibility analysis and single-cell RNA-seq showed that transforming growth factor-β (TGF-β) signaling was suppressed in HSCs, which corresponded with repressed sympathetic nervous activity in bone marrow. Transplantation of bone marrow from mice in which TGF-β signaling was inhibited similarly exacerbated cardiac dysfunction. Collectively, these results suggest that cardiac stress modulates the epigenome of HSCs, which in turn alters their capacity to generate cardiac macrophage subpopulations. This change in HSCs may be a common driver of repeated HF events and comorbidity by serving as a key carrier of "stress memory."

Histopathological Confirmed Polycythemia Vera with Transformation to Myelofibrosis Depicted on [18F]FDG PET/CT.

We present a case of a 59-year-old male diagnosed with polycythemia vera (PV) for many years, who presented with a relatively abrupt onset of heavy constitutional symptoms, including fatigue, night sweats, and a 10% weight loss over 6 weeks. Despite the known initial diagnosis of PV, the presence of profound B-symptoms prompted further investigation. A positron emission tomography/computed tomography (PET/CT) scan with 18F-Fluorodeoxyglucose ([18F]FDG) was performed to exclude malignant diseases. The [18F]FDG PET/CT revealed intense metabolic activity in the bone marrow of the proximal extremities and trunk skeleton, as well as a massively enlarged spleen with increased metabolic activity. Histopathologically, a transformation to myelofibrosis was revealed on a bone marrow biopsy. The case intends to serve as an exemplification for [18F]FDG PET/CT in PV with transformation to myelofibrosis (post-PV myelofibrosis).

Abstract 1103: The Relationship Between PAI-1, Corticosterone, And Splenic Activity: Data From The Washington, D.C. Cardiovascular Health And Needs Assessment

Background: Chronic psychosocial stress (CS) has been associated with cardiovascular disease (CVD) which disproportionally affects African Americans (AA) at least partially via activation of the neuro-hematopoietic axis. Prior studies suggest plasminogen activator inhibitor 1 (PAI-1) is associated with hypertension, obesity, atherosclerosis, and major adverse cardiac events. Yet, little is known about the connection between CS and PAI-1 and its potential association with the neuro-hematopoietic axis in AA. Research Question: We examined associations between measures of CS and PAI-1 in a community-based cohort of AA residing in resource-limited Washington, D.C. neighborhoods, at risk for CVD. Methods: Participants were enrolled in the Washington, D.C. CV Health and Needs Assessment (DC-CHNA). CS was evaluated using the Cohen Stress Scale questionnaire. Fasting blood samples were taken to measure circulating levels of PAI-1 as well as cortisol and corticosterone, known biomarkers of stress. Participants underwent 18 FDG PET/CT to measure metabolic activity of the amygdala, bone marrow, and spleen, indicators of the neuro-hematopoietic axis. Multivariable linear regression analyses were adjusted for BMI and ASCVD 10-year risk score. Results: The DC-CHNA consisted of AA, the majority of whom were women, (N=60, mean age: 61±10.52, mean BMI: 33±7.85) at intermediate risk for CVD. Higher CS scores associated with higher PAI-1 levels (β=0.32, p=0.02). Higher PAI-1 associated with higher corticosterone (β=0.35, p=0.01) but not cortisol. Additionally, higher corticosterone associated with splenic activity (β=0.46, p=0.03) but not amygdala or bone marrow activity. Subsequently, higher PAI-1 also associated with higher splenic activity (β=0.22, p=0.01), while bone marrow activity was shown to be trending (β=0.14, p=0.06). Conclusions: We found that chronic psychosocial stress is associated with higher PAI-1 levels, which are associated with corticosterone and splenic activity, thus providing a potential link to how CS contributes to disparate CVD risk and health outcomes. Larger longitudinal studies are needed to investigate the predictive and potential therapeutic value of PAI-1 in individuals at risk for CVD.

Chronic Exposure to Carbon Tetrachloride (CCl4) Disrupted the Functional Integrity of the Bone Marrow of Splenectomized Wistar Rats

Splenectomy is a surgical intervention recommended for a variety of diseases and neoplastic conditions. Understanding the vulnerabilities of splenectomized individuals to various forms of toxicities will inform the lifestyle changes and management of such individuals. In this study, bone marrow integrity following chronic carbon tetrachloride (CCl4) toxicity in splenectomized female Wistar rats was investigated. Fifteen (15) female Wistar rats, with a mean body weight of 172.36 ± 2.48g and randomly allocated into three groups of five rats each were used. Group I were untreated and served as the control. Group II were unsplenectomized (intact) and CCl4 treated. Group III were splenectomized and CCl4 treated. For the treatment, CCl4 was diluted in paraffin oil to a concentration of 10% CCl4 and administered at the dose of 3 ml/kg each, intraperitoneally. Bone marrow activities for all groups were evaluated using haematopoietic indices relating to proliferation and maturation of myeloid, erythroid and lymphoid cell lines. The result showed that while chronic CCl4 toxicity in rats moderately depressed the maturation of myeloid and erythroid cell lines without severely affecting the overall haematopoietic capabilities of the marrow, these changes were exacerbated in the bone marrow of splenectomized rats.

Pattern of Bone Marrow Hypometabolism on 18 F-FDG PET CT in Systemic Lupus Erythematous-Associated Aplastic Anemia.

We present the case of a 23-year-old woman with juvenile onset systemic lupus erythematous on a background of thrombotic thrombocytopenic purpura, who was referred for 18 F-FDG PET CT scan due to pyrexia of unknown origin with raised inflammatory markers, severe thrombocytopenia, and anemia. An interesting pattern of predominantly photopenic hypometabolic bone marrow activity was demonstrated on 18 F-FDG PET CT.

A metabolic perspective of the neutrophil life cycle: new avenues in immunometabolism.

Neutrophils are the most abundant innate immune cells. Multiple mechanisms allow them to engage a wide range of metabolic pathways for biosynthesis and bioenergetics for mediating biological processes such as development in the bone marrow and antimicrobial activity such as ROS production and NET formation, inflammation and tissue repair. We first discuss recent work on neutrophil development and functions and the metabolic processes to regulate granulopoiesis, neutrophil migration and trafficking as well as effector functions. We then discuss metabolic syndromes with impaired neutrophil functions that are influenced by genetic and environmental factors of nutrient availability and usage. Here, we particularly focus on the role of specific macronutrients, such as glucose, fatty acids, and protein, as well as micronutrients such as vitamin B3, in regulating neutrophil biology and how this regulation impacts host health. A special section of this review primarily discusses that the ways nutrient deficiencies could impact neutrophil biology and increase infection susceptibility. We emphasize biochemical approaches to explore neutrophil metabolism in relation to development and functions. Lastly, we discuss opportunities and challenges to neutrophil-centered therapeutic approaches in immune-driven diseases and highlight unanswered questions to guide future discoveries.

Incidence of Thrombocytopenia in NICU and Its Association with Immature Platelet Fraction and Absolute Immature Platelet Count: A Cross-sectional Study

Introduction: Neonatal Thrombocytopenia (TCP) is frequently encountered in the Neonatal Intensive Care Unit (NICU), occurring either due to decreased production or increased destruction of platelets. This condition often leads to increased platelet transfusions in a NICU setting. Immature Platelet Fraction (IPF) and Absolute Immature Platelet Count (AIPC) are hypothesised to be surrogate markers of bone marrow activity and can help in differentiating between TCP caused by decreased production or increased destruction. Aim: To estimate the incidence of neonatal TCP in newborns admitted to a tertiary care NICU and to investigate the association of IPF percentage and AIPC values with the cause of TCP. Materials and Methods: This cross-sectional study was conducted in the Department of Paediatrics and Neonatology at Dr. D.Y. Patil Medical College, Navi Mumbai, Maharashtra, India, from April 2021 to May 2022. All 46 newborns admitted to the NICU with TCP were enrolled in the study. The total number of NICU admissions during the study period was used to calculate the incidence. The Complete Blood Count (CBC) with reticulocyte count and peripheral smear was examined using the impedance technique. The IPF and AIPC values were determined using an automated CBC counter based on flow cytometry principles. Statistical analysis was performed using the Chi-square test. Results: The study included a total of 46 neonates with TCP, with an incidence rate of 6.14%. Among the patients with TCP, 18 (39.13%) had mild, 17 (36.95%) had moderate, and 11 (23.91%) had severe TCP. The majority of neonates (21.7%) had a significant maternal history of Pregnancy Induced Hypertension (PIH). Of the neonates with TCP, 42 (91.3%) had high IPF and 4 (8.6%) had normal IPF. Regarding AIPC, 29 (63.04%) had normal values, 11 (23.91%) had high values, and 6 (13%) had low values. No significant association was found between IPF and AIPC values and the diagnosis of TCP in this study. Conclusion: The present study concludes that IPF and AIPC investigations cannot be recommended as markers to confirm the cause of TCP.

Potential Indicators of Bone Marrow Suppression in Patients with Schizophrenia Receiving Clozapine: Platelet-Large Cell Ratio and Immature Granulocytes

Aim/background: The use of clozapine is restricted due to its serious side effects, particularly bone marrow suppression, which occurs at an average rate of 1%. These side effects are markedly related to blood concentrations of clozapine and its metabolite nor-clozapine. Therefore, therapeutic drug monitoring is recommended for clozapine. Currently, laboratory monitoring of bone marrow suppression includes neutrophil count follow-up. However, using early-changing biomarkers may be more effective in detecting and preventing this side effect before neutropenia develops. Therefore, we aimed to evaluate serum clozapine and nor-clozapine levels and their relationship with early parameters reflecting bone marrow activity in complete blood count (CBC), immature granulocyte (IG) for neutrophils, mean platelet volume (MPV) and platelet-to-large cell ratio (P-LCR) for platelets in patients with schizophrenia receiving clozapine. Methods: Fifty-one patients with schizophrenia receiving clozapine were included in the study. Of these, 49% (n=25) were on a low dose (<300 mg/day), 49% (n=25) on a middle dose (300-600 mg/day), and one patient was on a high dose (>600 mg/day) clozapine. CBC parameters—especially IG, MPV and P-LCR—and serum clozapine/nor-clozapine levels along with clozapine doses were recorded on the same day. The relationship between serum drug concentrations and CBC parameters was evaluated separately for the total patients and dose groups. Results: There was no correlation between clozapine dose and serum clozapine or nor-clozapine concentrations. None of the patients had neutropenia or agranulocytosis. Serum clozapine and nor-clozapine levels negatively correlated with P-LCR (r=-0.402, p=0.006 and r=-0.465, p=0.001, respectively) and MPV (r=-0.294, p=0.036 and r=-0.397, p=0.004, respectively); positively correlated with neutrophil (r=0.381, p=0.011 and r=0.387, p=0.009, respectively) and IG counts (r=0.346, p=0.018 and r=0.335, p=0.023, respectively); but not with other CBC sub-parameters. Although the clozapine dosing differed between the two groups, the serum levels of clozapine and nor-clozapine were not significantly different (p=0.078 and p=0.058, respectively). Furthermore, in the middle dose group, serum clozapine and nor-clozapine levels were negatively correlated with P-LCR (rho=-0.547, p=0.007 and rho=-0.636, p=0.001, respectively), consistent with the total group. Conclusion: Monitoring early biomarkers reflecting bone marrow activity, such as P-LCR for platelets and IG for neutrophils, alongside serum clozapine and nor-clozapine levels, is promising for predicting and preventing bone marrow suppression in patients receiving clozapine, thereby protecting against this serious side effect. However, our findings need to be supported by further research.

Cimetidine Does Not Inhibit 5-Aminolevulinic Acid Synthase or Heme Oxygenase Activity: Implications for Treatment of Acute Intermittent Porphyria and Erythropoietic Protoporphyria.

Acute intermittent porphyria (AIP) is characterized by acute neurovisceral attacks that are precipitated by the induction of hepatic 5-aminolevulinic acid synthase 1 (ALAS1). In erythropoietic protoporphyria (EPP), sun exposure leads to skin photosensitivity due to the overproduction of photoreactive porphyrins in bone marrow erythroid cells, where heme synthesis is primarily driven by the ALAS2 isozyme. Cimetidine has been suggested to be effective for the treatment of both AIP and EPP based on limited case reports. It has been proposed that cimetidine acts by inhibiting ALAS activity in liver and bone marrow for AIP and EPP, respectively, while it may also inhibit the hepatic activity of the heme catabolism enzyme, heme oxygenase (HO). Here, we show that cimetidine did not significantly modulate the activity or expression of endogenous ALAS or HO in wildtype mouse livers or bone marrow. Further, cimetidine did not effectively decrease hepatic ALAS activity or expression or plasma concentrations of the putative neurotoxic porphyrin precursors 5-aminolevulinic acid (ALA) and porphobilinogen (PBG), which were all markedly elevated during an induced acute attack in an AIP mouse model. These results show that cimetidine is not an efficacious treatment for acute attacks and suggest that its potential clinical benefit for EPP is not via ALAS inhibition.

The systemic impact of different COVID-19 vaccines in 2-[18F] FDG-PET/CT

Austria started its COVID-19-vaccination program in December 2020 with three different vaccines. As the vaccination program continues, we encountered increased 2-[18F] FDG-activity not only in axillary lymph nodes ipsilateral to the injection site but also in other organs. The aim of this retrospective study is to present results of the metabolic activity of ipsilateral axillary lymph nodes, liver, blood pool, spleen, and bone marrow after three different vaccines. To our knowledge, this is the first study to examine systemic response changes in relation to time after COVID-19 vaccination using three different vaccines. The collected data of 220 eligible vaccinated patients (127 with BioNTech/Pfizer BNT162b2, 61 with Moderna, and 32 with AstraZeneca) examined with 2-[18F] FDG-PET/CT were enrolled. The PET/CT examinations were evaluated from day 1 to day 135 (SD: 23.2, median: 26) after different vaccinations. Seventy-one out of these 220 patients underwent a pre-vaccination 2-[18F] FDG -PET/CT. SUVmax of axillary node(s), and blood pool, liver, spleen, and bone marrow as reference organs were calculated. The ratio of SUVmax activity of axillary lymph node to reference organs was also compared in all patients. The tracer activity dynamics were investigated in three different vaccines. After BioNTech/Pfizer vaccination 2-[18F] FDG activity in axillary lymph nodes shows a steady decrease in all patients. Ten days after vaccination the 2-[18F] FDG uptake was at its highest activity. Seventy days after vaccination, tracer activity is not different from the background activity of 2-[18F] FDG in the axillary region. This result also applies to other two vaccines; however, in the 4th week after Moderna vaccination SUVmax in lymph nodes showed the highest peak of tracer activity. With AstraZeneca the highest activity was at the earlier days. There was no significant statistical difference of SUVmax of lymph nodes or its ratios to other reference organs between three groups of vaccines. SUVmax in lymph nodes was statistically significant lower than SUVmax in the liver, spleen, and bone marrow with p-values of < 0.001, 0.044, and 0.001, respectively. In the group of 71 patients with a pre-vaccination PET/CT examination, the median SUVmax of lymph nodes increased significantly after vaccination from 0.82 (IQR 0.59–1.38) to 1.80 (IQR 1.07–3.89)(p < 0.001). In contrast median tracer activity in the liver decreased from 3.37 (IQR 2.83–3.91) to 3.11 (2.56–3.70) (p = 0.032). There was no significant change of tracer activity after vaccination in other reference regions (mediastinum, spleen, and bone marrow). In this group of 71 patients, there was also no significant difference in tracer activity in different types of vaccines. Local site and ipsilateral axillary lymph node activity in 2-[18F] FDG PET/CT after COVID19-vaccination is suggested in many studies. The main challenge is recognizing the changes in lymph nodes during time after vaccination to minimize false interpretation, foremost in patients with oncological diagnoses. Moreover, different vaccines cause different system metabolic changes. The knowledge of vaccine type, the time interval between vaccination and PET/CT scan is essential, especially in therapy evaluation.

HLH Secondary to Influenza

Introduction Hemophagocytic lymphohistiocytosis (HLH) is a pathological condition characterized by excessive inflammation and tissue damage resulting from an aberrant immune system response. HLH can be classified into two distinct categories: primary HLH and secondary HLH. Secondary hemophagocytic lymphohistiocytosis (HLH) is an acquired condition that can be precipitated by various infections, malignancies, or rheumatological disorders. Herein, we present a rare case of HLH secondary to influenza B infection. Case Presentation A 37-year-old who routinely vapes and smokes cannabis presented to the emergency department with subjective fevers, body pains, fatigue, productive cough, shortness of breath, nausea, non-bloody, non-bilious vomiting, and watery diarrhea for one week. He was tachypneic, tachycardic, and febrile (101.1 F). He had loud bibasilar crackles on auscultation. Hb 14.8, total WBC 2.2, platelets 170, AKI with serum creatinine 1.9, and transaminitis with AST/ALT/ALP 130/56/122 U/L were the patient's initial lab results. Rapid influenza, strep, and COVID-19 antigen tests were negative. He exhibits hypoxemia with pH 7.46, pCO2 32.5, pO2 52.1, HCO3 22.9, and FIO2 40%. Urinalysis showed nonsignificant. CRP was 8.3 mg/dL. Negative procalcitonin. chest x-ray and ct showed bilateral diffuse patchy airspace infiltration, suggesting infectious process with mild pleaural effusion. In the critical care unit, he received Antibiotics and inhaled therapy for acute hypoxic respiratory failure with severe ARDS. After deteriorating, he was intubated. The respiratory pathogen panel detected Influenza B. Blood cultures and remaining pneumonia workup were negative. The lab results suggested HLH (table 1). Autoimmune tests were negative. Oseltamivir was given for 5 days. Repeat chest x-rays showed stable pulmonary infiltrates in the right middle and lower lobes, but the patient decompensated clinically with increasing ventilator requirements and dyssynchrony despite heavy sedation, paralytics, and proning and was transferred to a different hospital for ECMO evaluation on day 12. Discussion Primary and secondary HLH: Secondary HLH is caused by infections, malignancies, or rheumatological illnesses, while primary HLH is hereditary. The mortality outcome of HLH is extremely dependent on early detection and treatment 1. Due to the rarity of this disease entity, difficult diagnostic criteria, and concern for alternate diagnoses, internists may be less aware of it. Further complicating the diagnosis is the fact that the first bone marrow biopsy may not always show hemophagocytosis 2. This is why it is important to be cognizant of this diagnosis and it's diagnostic criteria. Our patient was suspected of HLH based on HScore for reactive hemophagocytic syndrome and the newest updated HLH diagnostic criteria (5 of 8 criteria should be met) 6. EBV is the most common viral infection which can cause HLH. CMV, Parvo, HSV, and H1N1 are other infections. HLH-Influenza B connection is poorly documented 7 Only one case of HLH induced by influenza B in a healthy patient was found in literature. To our knowledge, Our 38-year-old patient is the second known case of secondary HLH secondary to Influenza B in a healthy patient. Influenza B seldom causes HLH. This connection in adulthood is poorly researched. Patients with influenza virus infections have significant intestinal apoptosis and reactive hemophagocytic activity in bone marrow, lungs, and liver3. Influenza variants reduce CD8+ T cell cytotoxicity and perforin expression, likely causing HLH syndrome 4. A study suggests that virus-associated hemophagocytic syndrome (VAHS) is a common consequence of severe 2009 influenza A (H1N1) infection and contributes to multiorgan failure and mortality. 9 (36%) of 25 severely ill patients with confirmed 2009 influenza A (H1N1) infection developed VAHS, and 8 (89%) died 5. Conclusion: We present this case to raise awareness among physicians regarding the potential occurrence of hemophagocytic lymphohistiocytosis (HLH) as a complication in adult patients who present with influenza B virus infection accompanied by fever and pancytopenia. The aim is to emphasize the importance of considering HLH as a differential diagnosis in order to facilitate timely identification and initiation of appropriate treatment for this condition.

Sting Activation in Bone Marrow Macrophages Targets AML Blasts for Phagocytosis in an ICAM-1 Dependent Mechanism

The initiation and proliferation of acute myeloid leukaemia (AML) is in part regulated by the bone marrow microenvironment. Previous work by our group has shown that the stimulator of interferon genes (STING) pathway is activated in macrophages in the AML bone marrow microenvironment (Moore et al., 2022) . We found that AML-derived mitochondrial damage-associated molecular patterns were processed by bone marrow macrophages (BMMs) via LC3-associated phagocytosis (LAP). Furthermore, activation of STING resulted in a suppression of AML growth through an LAP dependent mechanism. Here we have investigated how the activation of STING in bone marrow macrophages increases macrophage phagocytic activity and in turn supresses the growth of AML. To understand the role of STING activation in bone marrow derived macrophages (BMDMs) in AML we used various STING agonists including DMXAA, 2'3'-cGAMP, and CpG oligonucleotides. We showed STING activation was induced through these agonists by measuring the upregulation of STING related genes ( Gbp2, Irf7 and Ifit3). We demonstrated that STING activation caused increased phagocytic clearance of live MN1 cells (mouse AML cell line) in an in vitro phagocytosis assay. In order to investigate how STING activation increases the phagocytic clearance of AML cells by BMDMs, we used three complementary methods. First, we performed a receptor tyrosine kinase array to measure the phosphorylation of mouse kinases following STING activation. Second, we investigated the transcriptomic changes resulting from STING activation with mRNA-sequencing. Third, after combining these results we identified an upregulation of key phagocytic pathways that specifically led us to focus on the adhesion molecules, in particular ICAM-1. Further investigation using an anti-ICAM-1 blocking antibody showed a reduction in the phagocytic potential of the BMDMs demonstrating the role of ICAM-1 in the phagocytic clearance of AML. Next, we activated human macrophages (derived from peripheral blood monocytes collected from healthy donors with approval of the East of England - Cambridgeshire and Hertfordshire Research Ethics Committee and the UK Health Research Authority, IRAS Project ID 33753) through STING which depleted AML in vitro confirming the results obtained using the mouse system. To investigate the in vivo significance of these findings, we treated C57Bl/6 animals with DMXAA and observed a significantly decreased tumour burden and increased survival following engraftment with MN1 cells. Cytotoxic T cell activity and number in the bone marrow was unchanged by STING activation in this model. In summary, we have shown that the activation of STING in bone marrow macrophages directly supresses the growth and proliferation of AML by stimulating the phagocytic activity of the macrophages, and the clearance of the leukaemic cells.

Bidirectional Feto-Maternal Traffic of Donor Mesenchymal Stem Cells Following Transamniotic Stem Cell Therapy (TRASCET)

PurposeTransamniotic stem cell therapy (TRASCET) with mesenchymal stem cells (MSCs) has emerged experimentally as a potential treatment for different congenital diseases and maternal diseases of pregnancy. The broad applicability of TRASCET is predicated on hematogenous routing of donor MSCs via the placenta. We investigated whether donor MSC kinetics includes bidirectional traffic between the fetus and mother. MethodsEight time-dated dams had their fetuses (n = 96) divided in 4 groups on gestational day 17 (E17, term = E21). Groups populating one uterine horn received intra-amniotic injections (50 μL) of either donor amniotic fluid-derived MSCs (2×106 cells/mL) labelled with a firefly luciferase reporter gene (MSC-injected, n = 32), or of acellular luciferase (luciferase-injected, n = 26). Contra-lateral (CL) horn fetuses received no injection (MSC-CL, n = 20 and luciferase-CL, n = 18). At term, samples from 11 fetal anatomical sites from CL fetuses, along with placentas from all fetuses and maternal blood were screened for luciferase activity via microplate luminometry. ResultsOverall survival was 95 % (91/96). When controlled by the acellular injection, positive luciferase activity was observed in the placentas of all MSC-injected fetuses, confirming viability of the donor cells at term. When controlled by the acellular injection group, MSC-CL fetuses showed positive luciferase activity in the bone marrow, peripheral blood, brain and skin (p = <0.001–0.048). No luciferase activity was detected in any maternal blood sample. ConclusionAmniotic fluid-derived MSCs can traffic between the fetus and mother in both directions after simple intra-amniotic injection, in a healthy rat model. This phenomenon must be considered in TRASCET performed in twin/multiple pregnancies. Level of evidenceN/A (animal and laboratory study).

Amygdalar activity measured using FDG-PET/CT at head and neck cancer staging independently predicts survival.

The mechanisms underlying the association between chronic stress and higher mortality among individuals with cancer remain incompletely understood. To test the hypotheses that among individuals with active head and neck cancer, that higher stress-associated neural activity (ie. metabolic amygdalar activity [AmygA]) at cancer staging associates with survival. Retrospective cohort study. Academic Medical Center (Massachusetts General Hospital, Boston). 240 patients with head and neck cancer (HNCA) who underwent 18F-FDG-PET/CT imaging as part of initial cancer staging. 18F-FDG uptake in the amygdala was determined by placing circular regions of interest in the right and left amygdalae and measuring the mean tracer accumulation (i.e., standardized uptake value [SUV]) in each region of interest. Amygdalar uptake was corrected for background cerebral activity (mean temporal lobe SUV). Among individuals with HNCA (age 59±13 years; 30% female), 67 died over a median follow-up period of 3 years (IQR: 1.7-5.1). AmygA associated with heightened bone marrow activity, leukocytosis, and C-reactive protein (P<0.05 each). In adjusted and unadjusted analyses, AmygA associated with subsequent mortality (HR [95% CI]: 1.35, [1.07-1.70], P = 0.009); the association persisted in stratified subset analyses restricted to patients with advanced cancer stage (P<0.001). Individuals within the highest tertile of AmygA experienced a 2-fold higher mortality rate compared to others (P = 0.01). The median progression-free survival was 25 months in patients with higher AmygA (upper tertile) as compared with 36.5 months in other individuals (HR for progression or death [95%CI], 1.83 [1.24-2.68], P = 0.001). AmygA, quantified on routine 18F-FDG-PET/CT images obtained at cancer staging, independently and robustly predicts mortality and cancer progression among patients with HNCA. Future studies should test whether strategies that attenuate AmygA (or its downstream biological consequences) may improve cancer survival.

Macrophages Provide Essential Support for Erythropoiesis, and Extracellular ATP Contributes to a Erythropoiesis-Supportive Microenvironment during Repeated Psychological Stress.

Psychological stress is a significant contributor to various chronic diseases and affects multiple physiological processes including erythropoiesis. This study aimed to examine the tissue-specific contributions of macrophages and extracellular ATP, as a signal of disturbed tissue homeostasis, to erythropoiesis under conditions of repeated psychological stress. Adult male BALB/c mice were subjected to 2 h daily restraint stress for seven consecutive days. Clodronate-liposomes were used to deplete resident macrophages from the bone marrow and spleen two days prior to the first restraint procedure, as well as newly recruited macrophages, every third day for the duration of the experiment. Repeated stress induced a considerable increase in the number of erythroid progenitor cells as well as in the percentage of CD71+/Ter119+ and CD71-/Ter119+ cells in the bone marrow and spleen. Macrophage depletion completely abolished the stimulative effect of repeated stress on immature erythroid cells, and prevented stress-induced increases in ATP levels, P2X7 receptor (P2X7R) expression, and ectonucleotidase CD39 activity and expression in the bone marrow and spleen. The obtained results demonstrate the stimulative effects of repeated stress on erythroid cells, extracellular ATP levels, P2X7R expression, CD39 activity and expression within the bone marrow and spleen, as well as the essential role of macrophages in stress-induced changes.