LASSO-Based Machine Learning Algorithm for Prediction of PICS Associated with Sepsis.

Introduction: This study aims to establish a comprehensive, multi-level approach for tackling tropical diseases by proactively anticipating and managing Persistent Inflammation, Immunosuppression, and Catabolism Syndrome (PICS) within the initial 14 days of Intensive Care Unit (ICU) admission. The primary objective is to amalgamate a diverse array of indicators and pathogenic microbial data to pinpoint pivotal predictive variables, enabling effective intervention specifically tailored to the context of tropical diseases. Methods: A focused analysis was conducted on 1733 patients admitted to the ICU between December 2016 and July 2019. Utilizing the Least Absolute Shrinkage and Selection Operator (LASSO) regression, disease severity and laboratory indices were scrutinized. The identified variables served as the foundation for constructing a predictive model designed to forecast the occurrence of PICS. Results: Among the subjects, 13.79% met the diagnostic criteria for PICS, correlating with a mortality rate of 38.08%. Key variables, including red-cell distribution width coefficient of variation (RDW-CV), hemofiltration (HF), mechanical ventilation (MV), Norepinephrine (NE), lactic acidosis, and multiple-drug resistant bacteria (MDR) infection, were identified through LASSO regression. The resulting predictive model exhibited a robust performance with an Area Under the Curve (AUC) of 0.828, an accuracy of 0.862, and a specificity of 0.977. Subsequent validation in an independent cohort yielded an AUC of 0.848. Discussion: The acquisition of RDW-CV, HF requirement, MV requirement, NE requirement, lactic acidosis, and MDR upon ICU admission emerges as a pivotal factor for prognosticating PICS onset in the context of tropical diseases. This study highlights the potential for significant improvements in clinical outcomes through the implementation of timely and targeted interventions tailored specifically to the challenges posed by tropical diseases.

A Case Report on Primary Collapsing Glomerulopathy in a Filipino Post-partum Female and An Updated Review of Literature.

Collapsing Glomerulopathy (CG) is a rare entity presenting as nephrotic syndrome and rapidly progressive renal deterioration. It has been first identified among African-American patients and subsequently dubbed HIV-associated nephropathy after a number of patients with HIV were found to have CG. It has re-emerged recently among patients with COVID-19. To our knowledge, this is the first case of primary collapsing glomerulopathy in the country to be published. The case is a 36-year-old Filipino female admitted due to bipedal edema which started 2 weeks post-partum. She has no comorbidities and social history was negative for illicit drug use. Initial work up showed hypoalbuminemia and diffuse hepatic disease on ultrasound. She was referred to a gastroenterologist where albumin infusion and paracentesis was done but with no improvement. She developed anasarca and was admitted. Paracentesis obtained minimal ascitic fluid. Serum ascites albumin gradient was low and baseline laboratories showed high creatinine, hypoalbuminemia, and albuminuria. 24-hour urine protein was 11 grams, ANA and anti-DsDNA were negative and c3 and c4 levels were normal. Hepatitis profile was negative for infection. Abdominal CT scan revealed multiple hypoenhancing lesions. Tumor markers CA-125, CA 19-9 and CA 15-3 were high. Breast ultrasound showed simple breast cyst. Gynecology consult was called where pap smear was negative for atypical cells. Surgery service recommended monitoring for the pancreatic and breast lesions. Kidney biopsy was delayed due to new onset bacterial pneumonia. COVID-19 RT-PCR test was negative. Patient was discharged improved with no edema. On follow up, the kidney biopsy result came out to be collapsing glomerulopathy. HIV test was then done and was negative. Bipedal edema and albuminuria recurred. She was started on tacrolimus. She has been on regular follow up and currently has no edema, no proteinuria and normal creatinine level. This is an interesting case as the primary glomerular disease has been masked by the earlier laboratory findings which led us to think of liver disease then a paraneoplastic nephrotic syndrome. Ultimately, the renal biopsy revealed the diagnosis. This serves as an index case for primary collapsing glomerulopathy in a Filipino patient on remission after being treated with tacrolimus.

Myeloid­derived suppressor cells as targets of emerging therapies and nanotherapies (Review).

Breast cancer (BC) is the leading cause of cancer-related mortality among women worldwide. Immunotherapies are a promising approach in cancer treatment, particularly for aggressive forms of BC with high mortality rates. However, the current eligibility for immunotherapy remains limited to a limited fraction of patients with BC. Myeloid-derived suppressor cells (MDSCs), originating from myeloid cells, are known for their dual role in immunosuppression and tumor promotion, significantly affecting patient outcomes by fostering the formation of premetastatic niches. Consequently, targeting MDSCs has emerged as a promising avenue for further exploration in therapeutic interventions. Leveraging nanotechnology-based drug delivery systems, which excel in accumulating drugs within tumors via passive or active targeting mechanisms, are a promising strategy for the use of MDSCs in the treatment of BC. The present review discusses the immunosuppressive functions of MDSCs, their role in BC, and the diverse strategies for targeting them in cancer therapy. Additionally, the present review discusses future advancements in BC treatments focusing on MDSCs. Furthermore, it elucidates the mechanisms underlying MDSC activation, recruitment and differentiation in BC progression, highlighting the clinical characteristics that render MDSCs suitable candidates for the therapy and targeted nanotherapy of BC.

Case report: CMV retinitis following local and systemic immunosuppression.

We report the case of a 71-year-old man who presented 2 years following renal transplantation with diffuse, unilateral cytomegalovirus retinitis five weeks after receiving an intravitreal dexamethasone implant device for the management of central retinal vein occlusion. Examination of the left eye showed diffuse retinal hemorrhages, attenuated and tortuous retinal vessels, and superior retinal whitening. The patient was successfully treated with serial intravitreal foscarnet injections and oral valganciclovir with disease regression observed by 12 weeks after presentation. The patient's visual acuity and examination remained stable at 9-months follow-up.

VISTA: A promising target for overcoming immune evasion in gynecologic cancers.

Immune checkpoint blockade (ICB) therapy has revolutionized cancer treatment but has shown limited efficacy in gynecologic cancers. VISTA (V-domain Ig suppressor of T-cell activation), a member of the B7 family, is emerging as another checkpoint that regulates the anti-tumor immune responses within the tumor microenvironment. This paper reviews the structure, expression, and mechanism of action of VISTA. Furthermore, it highlights recent advances in VISTA-blocking therapies and their potential in improving outcomes for patients with gynecologic cancers. By understanding the role of VISTA in mediating the immune evasion of gynecologic tumors, we can develop more effective combinatory treatment strategies that could overcome resistance to current ICB therapies.

Paraneoplastic neuromyelitis optica spectrum disorder associated with ovarian dysgerminoma: a case report and literature review.

Neuromyelitis optica spectrum disorder (NMOSD) is a clinical syndrome characterized by attacks of acute optic neuritis and transverse myelitis. We report a case with paraneoplastic NMOSD that improved after immunosuppressive therapy, surgical resection, and chemotherapy. A 48-year-old woman initially presented with gradual binocular visual loss over the course of one week. The patient was evaluated using magnetic resonance imaging (MRI), computed tomography (CT), visual evoked potential (VEP), pathological biopsy, immunohistochemistry, and autoimmune antibody testing. The brain MRI findings were normal. The VEP revealed prolonged P100 latencies in the right eye and an absence of significant waves in the left eye. Positive serum AQP4-IgG antibodies were found. The patient was diagnosed as NMOSD. Then the patient responded well to treatment with methylprednisolone. An ovarian tumor was found in the patient using abdominal MRI and CT. The tumor was surgically resected, and a pathological biopsy revealed that it was ovarian dysgerminoma. The patient received four rounds of chemotherapy after surgery. One month after the final chemotherapy treatment, a positron emission tomography (PET) scan revealed no tumor. The vision of the patient gradually recovered and serum AQP4 was negative. Furthermore, we summarized the characteristics of patients diagnosed with paraneoplastic NMOSD associated with ovarian neoplasms in previous studies. This is a characteristic case of overlapping NMOSD and ovarian dysgerminoma, demonstrating the importance of tumor therapy in cases of paraneoplastic NMOSD.

Critical considerations for the management of acute abdomen in transplant patients.

The number of solid organ transplantations performed annually is increasing and are increasing in the following order: Kidney, liver, heart, lung, pancreas, small bowel, and uterine transplants. However, the outcomes of transplants are improving (organ survival > 90% after the 1st year). Therefore, there is a high probability that a general surgeon will be faced with the management of a transplant patient with acute abdomen. Surgical problems in immunocompromised patients may not only include graft-related problems but also nongraft-related problems. The perioperative regulation of immunosuppression, the treatment of accompanying problems of immunosuppression, the administration of cortisol and, above all, the realization of a rapidly deteriorating situation and the accurate evaluation and interpretation of clinical manifestations are particularly important in these patients. The perioperative assessment and preparation includes evaluation of the patient's cardiovascular system and determining if the patient has hypertension or suppression of the hypothalamic-pituitary-adrenal axis, or if the patient has had any coagulation mechanism abnormalities or thromboembolic episodes. Immunosuppression in transplant patients is associated with the use of calcineurin inhibitors, corticosteroids, and antiproliferation agents. Many times, the clinical picture is atypical, resulting in delays in diagnosis and treatment and leading to increased morbidity and mortality. Multidetector computed tomography is of utmost importance for early diagnosis and management. Transplant recipients are prone to infections, especially specific infections caused by cytomegalovirus and Clostridium difficile, and they are predisposed to intraoperative or postoperative complications that require great care and vigilance. It is necessary to follow evidence-based therapeutic protocols. Thus, it is required that the clinician choose the correct therapeutic plan for the patient (conservative, emergency open surgery or minimally invasive surgery, including laparoscopic or even robotic surgery).

The timing of death in burn patients.

Aim: When treating burn patients, some patients die in the chronic phase, even if they overcome the acute phase of the burn. To elucidate the timing of death and its underlying causes among burn patients. Methods: Patients evaluated were admitted to our burn center between January 2015, and December 2019. Patient information, time, and cause of death were retrospectively collected from their medical records. Results: Among 342 admitted patients, 49 died. The time of death was as follows: within 24 h (n = 9), within 3 days (n = 7), within 1 week (n = 5), within 2 weeks (n = 4), within 3 weeks (n = 3), within 30 days (n = 6), within 60 days (n = 5), and after 60 days (n = 9). The causes of death within 3 days were hypoxic encephalopathy, extensive burns (>80%), severe heat stroke, and acute coronary syndrome. The causes of death after 3 days were sepsis, pneumonia, intestinal ischemia, pancreatitis, and worsening of chronic diseases. The mortality rate was similar for patients ≥65 years of age and those with a burn area of ≥20%, with both groups showing a particularly poor prognosis. Conclusions: The timing of death in hospitalized burn patients showed a bimodal distribution as approximately 40% of patients who survived the resuscitation period died after 30 days. Elderly patients were at particularly high risk for mortality. In burn care, treatment planning should consider not only the short-term but also the long-term prognosis.

Revisiting the role of mesenchymal stromal cells in cancer initiation, metastasis and immunosuppression.

Immune checkpoint blockade (ICB) necessitates a thorough understanding of intricate cellular interactions within the tumor microenvironment (TME). Mesenchymal stromal cells (MSCs) play a pivotal role in cancer generation, progression, and immunosuppressive tumor microenvironment. Within the TME, MSCs encompass both resident and circulating counterparts that dynamically communicate and actively participate in TME immunosurveillance and response to ICB. This review aims to reevaluate various facets of MSCs, including their potential self-transformation to function as cancer-initiating cells and contributions to the creation of a conducive environment for tumor proliferation and metastasis. Additionally, we explore the immune regulatory functions of tumor-associated MSCs (TA-MSCs) and MSC-derived extracellular vesicles (MSC-EVs) with analysis of potential connections between circulating and tissue-resident MSCs. A comprehensive understanding of the dynamics of MSC-immune cell communication and the heterogeneous cargo of tumor-educated versus naïve MSCs may unveil a new MSC-mediated immunosuppressive pathway that can be targeted to enhance cancer control by ICB.

Mapping the complexity and diversity of tertiary lymphoid structures in primary and peritoneal metastatic gastric cancer.

BACKGROUND: Tertiary lymphoid structures (TLSs) are thought to stimulate antitumor immunity and positively impact prognosis and response to immune checkpoint blockade. In gastric cancers (GCs), however, TLSs are predominantly found in GC with poor prognosis and limited treatment response. We, therefore, hypothesize that immune cell composition and function of TLS depends on tumor location and the tumor immune environment. METHODS: Spatial transcriptomics and immunohistochemistry were used to characterize the phenotype of CD45+ immune cells inside and outside of TLS using archival resection specimens from GC primary tumors and peritoneal metastases. RESULTS: We identified significant intrapatient and interpatient diversity of the cellular composition and maturation status of TLS in GC. Tumor location (primary vs metastatic site) accounted for the majority of differences in TLS maturity, as TLS in peritoneal metastases were predominantly immature. This was associated with higher levels of tumor-infiltrating macrophages and Tregs and less plasma cells compared with tumors with mature TLS. Furthermore, mature TLSs were characterized by overexpression of antitumor immune pathways such as B cell-related pathways, MHC class II antigen presentation while immature TLS were associated with protumor pathways, including T cell exhaustion and enhancement of DNA repair pathways in the corresponding cancer. CONCLUSION: The observation that GC-derived peritoneal metastases often contain immature TLS which are associated with immune suppressive regulatory tumor-infiltrating leucocytes, is in keeping with the lack of response to immune checkpoint blockade and the poor prognostic features of peritoneal metastatic GC, which needs to be taken into account when optimizing immunomodulatory strategies for metastatic GC.

EBF1-COX4I2 signaling axis promotes a myofibroblast-like phenotype in cancer-associated fibroblasts (CAFs) and is associated with an immunosuppressive microenvironment.

Immunotherapy has limited response rates in colorectal cancer (CRC) due to an immunosuppressive tumor microenvironment (TME). Combining transcriptome sequencing, clinical specimens, and functional experiments, we identified a unique group of CAF subpopulations (COX4I2 + ) with inhibited mitochondrial respiration and enhanced glycolysis. Through bioinformatics predictions and luciferase reporter assays, we determined that EBF1 can upstreamly regulate COX4I2 transcription. COX4I2 + CAFs functionally and phenotypically resemble myofibroblasts, are important for the formation of the fibrotic TME, and are capable of activating the M2 phenotype of macrophages. In vitro experiments demonstrated that COX4I2 + CAFs promote immunosuppressive TME by blocking CD8 + T cell infiltration and inducing CD8 + T cell dysfunction. Using multiple independent cohorts, we also found a strong correlation between the immunotherapy response rate of CRC patients and COX4I2 expression in their tumors. Our results identify a CAF subpopulation characterized by activation of the EBF1-COX4I2 axis, and this group of CAFs can be targeted to improve cancer immunotherapy outcomes.

Omission of etoposide in the treatment of haemophagocytic lymphohistiocytosis secondary to primary central nervous system lymphoma with satisfactory response.

Haemophagocytic lymphohistiocytosis (HLH) is a hyperinflammatory condition that can be either familial or acquired and, if untreated, frequently results in multiorgan failure and death. Treatment of HLH typically requires a combination of glucocorticoids and cytotoxic chemotherapy. We describe the case of a woman who presented with signs and symptoms concerning for HLH who was later found to have a primary central nervous system (CNS) diffuse large B-cell lymphoma. Her HLH symptoms were successfully treated with high doses of dexamethasone, and her primary CNS lymphoma was treated with high-dose methotrexate and rituximab. This is a rare case of HLH secondary to primary CNS lymphoma where HLH was controlled with steroids alone and did not require the use of an etoposide-based regimen or cyclophosphamide, doxorubicin, vincristine and prednisone.

Hepatitis E virus infection in immunosuppressed patients and its clinical manifestations.

BACKGROUND & AIMS: Hepatitis E virus (HEV) is a main cause of acute hepatitis globally. However, immunosuppressed patients regularly develop chronic courses. The aim of this study was to analyse the current status of HEV diagnostics, characterize clinical manifestations and identify risk factors for complicated HEV infections. METHODS: In this retrospective study at two large hospitals, 512 patients with borderline and positive anti-HEV-IgM and 94 patients with positive HEV-PCR between January 1999 and May 2023 were included. RESULTS: Detection by anti-HEV-IgM-ELISA led to a positive HEV-PCR in only 17.9 %. Amongst patients with positive HEV-PCR, 61 had underlying immunosuppression and 23 were patients after solid organ transplantation (SOT). All 13 patients with chronic HEV infections were immunosuppressed. Generally, immunosuppression led to higher HEV-RNA concentrations and a higher probability of receiving immediate treatment. However, all fulminant courses with liver failure happened in patients without immunosuppression. Immunocompetent patients showed symptoms more frequently and primarily had higher bilirubin levels indicating more severe liver damage. A risk factor for delayed or failed viral clearance after SOT was the administration of mTOR inhibitors. CONCLUSIONS: Fulminant HEV infections happen primarily in immunocompetent patients. Nevertheless, immunosuppressed patients bear the risk of undetected, prolonged HEV infections, reflected by the rare occurrence of symptoms.

Altered extracellular matrix correlates with an immunosuppressive tumor microenvironment and disease progression in younger adults with oral cavity squamous cell carcinoma.

Introduction: Oral cavity squamous cell carcinoma (OSCC) occurs most frequently in patients >60 years old with a history of tobacco and alcohol use. Epidemiological studies describe increased incidence of OSCC in younger adults (<45 years). Despite its poor prognosis, knowledge of OSCC tumor microenvironment (TME) characteristics in younger adults is scarce and could help inform possible resistance to emerging treatment options. Methods: Patients with OSCC were evaluated using TCGA-HNSC (n=121) and a stage and subsite-matched institutional cohort (n=8) to identify differential gene expression focusing on the extracellular matrix (ECM) and epithelial-mesenchymal transition (EMT) processes in younger (≤45 years) vs. older adults (≥60 years). NanoString nCounter analysis was performed using isolated total RNA from formalin-fixed paraffin-embedded (FFPE) tumor samples. Stained tumor slides from young and old OSCC patients were evaluated for CD8+ T-cell counts using immunohistochemistry. Results: Younger OSCC patients demonstrated significantly increased expression of ECM remodeling and EMT process genes, as well as TME immunosuppression. Gene set enrichment analyses demonstrated increased ECM pathways and concurrent decreased immune pathways in young relative to old patients. Transcripts per million of genetic markers involved in ECM remodeling including LAMB3, VCAN, S100A9, COL5A1, and ITGB2 were significantly increased in tumors of younger vs. older patients (adjusted p-value < 0.10). Young patient TMEs demonstrated a 2.5-fold reduction in CD8+ T-cells as compared to older patients (p < 0.05). Conclusion: Differential gene expression impacting ECM remodeling and TME immunosuppression may contribute to disease progression in younger adult OSCC and has implications on response to evolving treatment modalities, such as immune checkpoint inhibitor therapy.

Methylprednisolone alone or combined with cyclosporine or mycophenolate mofetil for the treatment of immune-mediated hemolytic anemia in dogs, a prospective study.

BACKGROUND: Benefit of adding a second-line immunosuppressive drug to glucocorticoids for the treatment of non-associative immune-mediated hemolytic anemia (naIMHA) in dogs has not been defined prospectively. HYPOTHESIS/OBJECTIVES: Evaluate the effectiveness of different immunosuppressive protocols in naIMHA dogs. ANIMALS: Forty-three client-owned dogs. METHODS: Open label, randomized, clinical trial. Dogs were treated with methylprednisolone (M-group), methylprednisolone plus cyclosporine (MC-group) or methylprednisolone plus mycophenolate mofetil (MM-group). Dogs were defined as responders by disappearance of signs of immune-mediated destruction and hematocrit stabilization. Frequency of responders was compared between M-group and combined protocols (MC and MM-group evaluated together), and among the 3 different therapeutic groups at 14 (T14), 30 (T30), 60 (T60) days after admission. Frequency of complications, length of hospitalization and relapse were also compared. Death rate was evaluated at discharge, T60 and 365 (T365) days. RESULTS: Proportion of responders was not significantly different between M-group and combined protocols (MC and MM-groups), nor among the 3 therapeutic groups at T14, T30, and T60 (P > .17). Frequency of relapse, complications, and length of hospitalization were not significantly different between M-group and dogs treated with combined protocols, nor among the 3 treatment groups (P > .22). Death was significantly more common only for MM-group compared with MC-group at T60 (+42.8%; 95% CI: 11.5-67.4; P = .009), and at T365 (+50%; 95% CI: 17.5-73.2; P = .003). CONCLUSIONS AND CLINICAL IMPORTANCE: Combined immunosuppressive therapy did not improve hematological response in naIMHA.

Inhibitory immune checkpoints suppress the surveillance of senescent cells promoting their accumulation with aging and in age-related diseases.

The accumulation of pro-inflammatory senescent cells within tissues is a common hallmark of the aging process and many age-related diseases. This modification has been called the senescence-associated secretory phenotype (SASP) and observed in cultured cells and in cells isolated from aged tissues. Currently, there is a debate whether the accumulation of senescent cells within tissues should be attributed to increased generation of senescent cells or to a defect in their elimination from aging tissues. Emerging studies have revealed that senescent cells display an increased expression of several inhibitory immune checkpoint ligands, especially those of the programmed cell death protein-1 (PD-1) ligand-1 (PD-L1) proteins. It is known that the PD-L1 ligands, especially those of cancer cells, target the PD-1 receptor of cytotoxic CD8+ T and natural killer (NK) cells disturbing their functions, e.g., evoking a decline in their cytotoxic activity and promoting their exhaustion and even apoptosis. An increase in the level of the PD-L1 protein in senescent cells was able to suppress their immune surveillance and inhibit their elimination by cytotoxic CD8+ T and NK cells. Senescent cells are known to express ligands for several inhibitory immune checkpoint receptors, i.e., PD-1, LILRB4, NKG2A, TIM-3, and SIRPα receptors. Here, I will briefly describe those pathways and examine whether these inhibitory checkpoints could be involved in the immune evasion of senescent cells with aging and age-related diseases. It seems plausible that an enhanced inhibitory checkpoint signaling can prevent the elimination of senescent cells from tissues and thus promote the aging process.

The canonical Hippo pathway components modulate the differentiation of lamina propria regulatory T cells and T helper 17-like regulatory T cells in mouse colitis.

Regulatory T cells (Tregs) ameliorate inflammatory bowel diseases. However, their plasticity is not completely understood. In this study using a mouse colitis model, Tregs and T helper 17 (Th17)-like Tregs were detected and sorted using flow cytometry, followed by transcriptome sequencing, real-time RT-PCR, and flow cytometry to analyze the mRNA profiles of these cells. Treg plasticity was evaluated by in vitro differentiation assays. The immunosuppressive activities of Tregs and Th17-like Tregs were assessed in an adoptive transfer assay. We found Tregs-derived Th17-like Tregs in inflamed colonic lamina propria (LP). LP Th17-like Tregs expressed higher Th17-related cytokines and lower immunosuppressive cytokines compared with LP Tregs. Notably, Tregs expressed higher Yes-associated protein 1 (YAP1) but lower transcriptional coactivator with PDZ­binding motif (TAZ) than Th17-like Tregs. Verteporfin-mediated inhibition of YAP1 activity enhanced Th17-like Treg generation, whereas IBS008739-induced TAZ activation did not affect Th17-like Treg generation. Besides, verteporfin enhanced while IBS008739 suppressed the differentiation of Th17-like Tregs into Th17 cells. Furthermore, YAP1 activated STAT5 signaling in Tregs, whereas YAP1 and TAZ activated STAT3 and STAT5 signaling in Th17-like Tregs. Compared with Tregs, Th17-like Tregs were less efficacious in ameliorating colitis. Therefore, YAP1 suppressed Treg differentiation into Th17-like Tregs. Both YAP1 and TAZ inhibited the differentiation of Th17-like Tregs into Th17 cells. Therefore, YAP1 and TAZ probably maintain the immunosuppressive activities of Tregs and Th17-like Tregs in colitis.

Integrated clustering of multiple immune marker trajectories reveals different immunotypes in severely injured patients.

BACKGROUND: The immune response of critically ill patients, such as those with sepsis, severe trauma, or major surgery, is heterogeneous and dynamic, but its characterization and impact on outcomes are poorly understood. Until now, the primary challenge in advancing our understanding of the disease has been to concurrently address both multiparametric and temporal aspects. METHODS: We used a clustering method to identify distinct groups of patients, based on various immune marker trajectories during the first week after admission to ICU. In 339 severely injured patients, we initially longitudinally clustered common biomarkers (both soluble and cellular parameters), whose variations are well-established during the immunosuppressive phase of sepsis. We then applied this multi-trajectory clustering using markers composed of whole blood immune-related mRNA. RESULTS: We found that both sets of markers revealed two immunotypes, one of which was associated with worse outcomes, such as increased risk of hospital-acquired infection and mortality, and prolonged hospital stays. This immunotype showed signs of both hyperinflammation and immunosuppression, which persisted over time. CONCLUSION: Our study suggest that the immune system of critically ill patients can be characterized by two distinct longitudinal immunotypes, one of which included patients with a persistently dysregulated and impaired immune response. This work confirms the relevance of such methodology to stratify patients and pave the way for further studies using markers indicative of potential immunomodulatory drug targets.

Comparative immune profiling of pancreatic ductal adenocarcinoma progression among South African patients.

BACKGROUND: Pancreatic Ductal Adenocarcinoma (PDAC) is an aggressive cancer characterized by an immunosuppressive microenvironment. Patients from specific ethnicities and population groups have poorer prognoses than others. Therefore, a better understanding of the immune landscape in such groups is necessary for disease elucidation, predicting patient outcomes and therapeutic targeting. This study investigated the expression of circulating key immune cell markers in South African PDAC patients of African ancestry. METHODS: Blood samples were obtained from a total of 6 healthy volunteers (HC), 6 Chronic Pancreatitis (CP) and 34 PDAC patients consisting of 22 resectable (RPC), 8 locally advanced (LAPC) and 4 metastatic (MPC). Real-time Quantitative Polymerase Chain reactions (RT-qPCR), Metabolomics, Enzyme-Linked Immunosorbent Assay (ELISA), Reactive Oxygen Species (ROS), and Immunophenotyping assays were conducted. Statistical analysis was conducted in R (v 4.3.2). Additional analysis of single-cell RNA data from 20 patients (16 PDAC and 4 controls) was conducted to interrogate the distribution of T-cell and Natural Killer cell populations. RESULTS: Granulocyte and neutrophil levels were significantly elevated while lymphocytes decreased with PDAC severity. The total percentages of CD3 T-cell subpopulations (helper and double negative T-cells) decreased when compared to HC. Although both NK (p = 0.014) and NKT (p < 0.001) cell levels increased as the disease progressed, their subsets: NK CD56dimCD16- (p = 0.024) and NKTs CD56+ (p = 0.008) cell levels reduced significantly. Of note is the negative association of NK CD56dimCD16- (p < 0.001) cell levels with survival time. The gene expression analyses showed no statistically significant correlation when comparing the PDAC groups with the controls. The inflammatory status of PDAC was assessed by ROS levels of serum which were elevated in CP (p = 0.025), (RPC (p = 0.003) and LAPC (p = 0.008)) while no significant change was observed in MPC, compared to the HC group. ROS was shown to be positively correlated with GlycA (R = 0.45, p = 0.0096). Single-cell analyses showed a significant difference in the ratio of NKT cells per total cell counts in LAPC (p < 0.001) and MPC (p < 0.001) groups compared with HC, confirming observations in our sample group. CONCLUSION: The expression of these immune cell markers observed in this pilot study provides insight into their potential roles in tumour progression in the patient group and suggests their potential utility in the development of immunotherapeutic strategies.