T lymphocytes

CAR-NK cell therapy in AML: Current treatment, challenges, and advantage

Over the last decade, discovery of novel therapeutic method has been attention by the researchers and has changed the therapeutic perspective of hematological malignancies. Although NK cell play a pivotal role in the elimination of abnormal and cancerous cells, there are evidence that NK cell are disarm in hematological malignancy. Chimeric antigen receptor NK (CAR-NK) cell therapy, which includes the engineering of NK cells to detect tumor-specific antigens and, as a result, clear of cancerous cells, has created various clinical advantage for several human malignancies treatment. In the current review, we summarized NK cell dysfunction and CAR-NK cell based immunotherapy to treat AML patient.

Lymphocyte to C-Reactive Protein Ratio as an Early Biomarker to Distinguish Sepsis from Pneumonia in Neonates

Background

Neonatal sepsis is an acute and severe disease that seriously threatens the life and health of newborns. Neonates with pneumonia may also have unrecognized neonatal sepsis. Early diagnosis of neonatal sepsis is beneficial for early treatment. This study aimed to evaluate the clinical significance of the lymphocyte-to-C-reactive protein ratio (LCR) as an early biomarker to distinguish sepsis from pneumonia.

Methods

This retrospective study enrolled 1635 neonates with pneumonia from February 2016 to March 2022. Among them, 182 cases were diagnosed with sepsis based on the positive blood culture results. Clinical and laboratory data were extracted from the electronic medical records. LCR was calculated as the ratio of the total lymphocyte count (×109 cells/L) to the C-reactive protein level (mg/L). Binary logistic regression analysis was conducted to evaluate the clinical significance of LCR as an early biomarker in distinguishing sepsis from pneumonia. Receiver operating characteristic (ROC) analysis was performed to assess the diagnostic value of LPCR in sepsis cases. All statistical analyses were conducted using Statistical Product and Service Solutions, version 24.0.

Results

The neonates with pneumonia combined with sepsis had a lower LCR than that of the neonates with pneumonia. Further analysis showed that the prevalence of neonatal pneumonia combined with sepsis was significantly higher in the low-LCR group than in the high-LCR group (20.7% vs 5.5%, P < 001). Binary logistic regression revealed that LCR was an independent risk factor for identifying pneumonia combined with sepsis. The ROC curve analysis revealed that LCR had better power than the lymphocyte count and CRP level individually in diagnosing neonatal pneumonia combined with sepsis (0.72 vs 0.65 vs 0.66, P < 0.001), with 62% sensitivity and 72% specificity.

Conclusion

LCR can be a potential early biomarker in distinguishing neonates with sepsis from those with pneumonia.

The Peripheral Immune Traits Changed in Patients with Multiple System Atrophy

A growing body of evidence suggests immune involvement in the pathology of multiple system atrophy (MSA). Research on detailed peripheral immune indices, however, is relatively sparse, and is one of the intriguing aspects of MSA yet to be elucidated. A total of 26 MSA patients and 56 age-and sex-matched healthy controls (HC) were enrolled in the current case-control study to delineate the peripheral immune traits of MSA patients. The ratio of CD4⁺/CD8⁺ T cells, natural killer cells, CD28 expression on both CD4⁺ T cells and CD8⁺ T cells increased in MSA patients compared to HC, but CD8⁺ T cells and active marker (HLA-DR) expression on total T cells decreased (p < 0.05). This study sheds light on the dysregulation of cellular immunity in MSA, pointing to future mechanistic research.

Immunonutrition in Critical Illness: What Is the Role?

Acute illness-associated malnutrition leads to muscle wasting, delayed wound healing, failure to wean from ventilator support, and possibly higher rates of infection and longer hospital stays unless appropriate metabolic support is provided in the form of nutrition therapy. Agreement is still lacking about the value of individual immune-modulating substrates for specific patient populations. However, it has long been agreed that there are 3 primary targets for these substrates: 1) mucosal barrier function, 2) cellular defense function, and 3) local and systemic inflammation. These targets guide the multitude of interventions necessary to stabilize and treat the hypercatabolic intensive care unit patient, including specialized nutrition therapy. The paradigm shift that occurred 30 years ago created a unique role for nutrition as an agent to support host defense mechanisms and prevent infectious complications in the critically ill patient. This overview of immunonutrition will discuss the evidence for its role in critical illness today.

Combining surgery and immunotherapy: turning an immunosuppressive effect into a therapeutic opportunity

Background

Cancer surgery is necessary and life-saving. However, the majority of patients develop postoperative recurrence and metastasis, which are the main causes of cancer-related deaths. The postoperative stress response encompasses a broad set of physiological changes that have evolved to safeguard the host following major tissue trauma. These stress responses, however, intersect with cellular mediators and signaling pathways that contribute to cancer proliferation.

Main

Previous descriptive and emerging mechanistic studies suggest that the surgery-induced prometastatic effect is linked to impairment of both innate and adaptive immunity. Existing studies that combine surgery and immunotherapies have revealed that this combination strategy is not straightforward and patients have experienced both therapeutic benefit and drawbacks. This review will specifically assess the immunological pathways that are disrupted by oncologic surgical stress and provide suggestions for rationally combining cancer surgery with immunotherapies to improve immune and treatment outcomes.

Short conclusion

Given the prevalence of surgery as frontline therapy for solid cancers, the emerging data on postoperative immunosuppression and the rapid development of immunotherapy for oncologic treatment, we believe that future targeted studies of perioperative immunotherapy are warranted.

Nutritional aspects of enhanced recovery after esophagectomy with gastric conduit reconstruction

Enhanced Recovery After Surgery (ERAS) aims to accelerate recovery by a set of multimodality management strategies. For esophagectomy, several nutritional elements of ERAS can be safely introduced and are advised in routine practice, including preadmission counseling to screen and treat for potential malnutrition, shortened preoperative fasting, and carbohydrate loading. However, the timing of oral intake and the use of routine nasogastric decompression remain matter of debate after esophagectomy. Furthermore, more research is needed on future developments such as perioperative immunonutrition.

Acquired Amino Acid Deficiencies: A Focus on Arginine and Glutamine

Nonessential amino acids are synthesized de novo and therefore not diet dependent. In contrast, essential amino acids must be obtained through nutrition since they cannot be synthesized internally. Several nonessential amino acids may become essential under conditions of stress and catabolic states when the capacity of endogenous amino acid synthesis is exceeded. Arginine and glutamine are 2 such conditionally essential amino acids and are the focus of this review. Low arginine bioavailability plays a pivotal role in the pathogenesis of a growing number of varied diseases, including sickle cell disease, thalassemia, malaria, acute asthma, cystic fibrosis, pulmonary hypertension, cardiovascular disease, certain cancers, and trauma, among others. Catabolism of arginine by arginase enzymes is the most common cause of an acquired arginine deficiency syndrome, frequently contributing to endothelial dysfunction and/or T-cell dysfunction, depending on the clinical scenario and disease state. Glutamine, an arginine precursor, is one of the most abundant amino acids in the body and, like arginine, becomes deficient in several conditions of stress, including critical illness, trauma, infection, cancer, and gastrointestinal disorders. At-risk populations are discussed together with therapeutic options that target these specific acquired amino acid deficiencies.

Preoperative Immunonutrition and Elective Colorectal Resection Outcomes

BACKGROUND

Randomized controlled trials demonstrate the efficacy of arginine-enriched nutritional supplements (immunonutrition) in reducing complications after surgery. The effectiveness of preoperative immunonutrition has not been evaluated in a community setting.

OBJECTIVE

This study aims to determine whether immunonutrition before elective colorectal surgery improves outcomes in the community at large.

DESIGN

This is a prospective cohort study with a propensity score-matched comparative effectiveness evaluation.

SETTINGS

This study was conducted in Washington State hospitals in the Surgical Care Outcomes Assessment Program from 2012 to 2015.

PATIENTS

Adults undergoing elective colorectal surgery were selected.

INTERVENTIONS

Surgeons used a preoperative checklist that recommended that patients take oral immunonutrition (237 mL, 3 times daily) for 5 days before elective colorectal resection.

MAIN OUTCOME MEASURES

Serious adverse events (infection, anastomotic leak, reoperation, and death) and prolonged length of stay were the primary outcomes measured.

RESULTS

Three thousand three hundred seventy-five patients (mean age 59.9 ± 15.2 years, 56% female) underwent elective colorectal surgery. Patients receiving immunonutrition more commonly were in a higher ASA class (III-V, 44% vs 38%; p = 0.01) or required an ostomy (18% vs 14%; p = 0.02). The rate of serious adverse events was 6.8% vs 8.3% (p = 0.25) and the rate of prolonged length of stay was 13.8% vs 17.3% (p = 0.04) in those who did and did not receive immunonutrition. After propensity score matching, covariates were similar among 960 patients. Although differences in serious adverse events were nonsignificant (relative risk, 0.76; 95% CI, 0.49-1.16), prolonged length of stay (relative risk, 0.77; 95% CI, 0.58-1.01 p = 0.05) was lower in those receiving immunonutrition.

LIMITATIONS

Patient compliance with the intervention was not measured. Residual confounding, including surgeon-level heterogeneity, may influence estimates of the effect of immunonutrition.

CONCLUSIONS

Reductions in prolonged length of stay, likely related to fewer complications, support the use of immunonutrition in quality improvement initiatives related to elective colorectal surgery. This population-based study supports previous trials of immunonutrition, but shows a lower magnitude of benefit, perhaps related to compliance or a lower rate of adverse events, highlighting the value of community-based assessments of comparative effectiveness.

Role of circulating lymphocytes in patients with sepsis

Sepsis is a systemic inflammatory response syndrome due to infection. The incidence rate is estimated to be up to 19 million cases worldwide per year and the number of cases is rising. Infection triggers a complex and prolonged host response, in which both the innate and adaptive immune response are involved. The disturbance of immune system cells plays a key role in the induction of abnormal levels of immunoregulatory molecules. Furthermore, the involvement of effector immune system cells also impairs the host response to the infective agents and tissue damage. Recently, postmortem studies of patients who died of sepsis have provided important insights into why septic patients die and showed an extensive depletion of CD4 and CD8 lymphocytes and they found that circulating blood cells showed similar findings. Thus, the knowledge of the characterization of circulating lymphocyte abnormalities is relevant for the understanding of the sepsis pathophysiology. In addition, monitoring the immune response in sepsis, including circulating lymphocyte subsets count, appears to be potential biomarker for predicting the clinical outcome of the patient. This paper analyzes the lymphocyte involvement and dysfunction found in patients with sepsis and new opportunities to prevent sepsis and guide therapeutic intervention have been revealed.

The central role of arginine catabolism in T-cell dysfunction and increased susceptibility to infection after physical injury

OBJECTIVE

To explore the hypothesis that decreased arginine availability by myeloid-derived suppressor cells (MDSCs) is a cause of T-cell dysfunction after physical injury (PI).

BACKGROUND

Arginine is an essential amino acid for normal T-cell function whose availability becomes limited after PI. MDSCs expressing arginase 1 are induced by PI. T-cell dysfunction after PI seems to increase the risk of infection but the mechanisms that cause it are unclear.

METHODS

PI was created using a standard laparotomy model. Phenotypical and functional alterations in T cells were evaluated in vivo. MDSCs expressing arginase 1 were measured by flow cytometry. Infection after PI was created by intraperitoneal injection of Listeria monocytogenes. N-Hydroxy-Nor-L-arginine (Nor-NOHA) was used as an arginase inhibitor. The effect of arginine depletion on T-cell function and susceptibility to infection was assessed through adoptive transfer of MDSC or injection of arginase into noninjured mice.

RESULTS

PI caused a decrease in intracellular arginine in T cells, loss of the T-cell receptor (TCR) CD3-ζ chain, inhibition of in vivo T-cell proliferation, memory, and cytotoxicity. PI exponentially increased bacterial growth and mortality to L. monocytogenes. T-cell dysfunction and increased infection were reversed by arginase inhibitor Nor-NOHA but were reproduced by adoptively transferring MDSC or injecting arginase 1 to noninjured mice.

CONCLUSIONS

Arginine availability is decreased after PI coinciding with an induction of MDSC expressing arginase 1. Decreased arginine may inhibit T-cell function and increase susceptibility to infection after injury.

Immunosupression and infection after major surgery: a nutritional deficiency

T cell dysfunction significantly increases susceptibility to infections and organ failure after trauma or surgery (physical injury). This coincides with a persistent drop in arginine availability, a necessary amino acid for normal T cell function. Recent data led to the identification of a novel mechanism of T cell suppression caused by the depletion of arginine through the induction of arginase 1 (ARG1) in a specialized group of immature myeloid cells, now named myeloid-derived suppressor cells (MDSC). In addition to T cell dysfunction, arginine depletion leads to the decrease in nitric oxide (NO) production. Dietary therapy containing arginine at supraphysiologic concentrations along with other components such as omega-3 fat acids, antioxidants, nucleotides, and vitamin A is associated with improvement in T cell function, NO production, and a significant decrease in infection rates. The authors propose that a pathologic decrease in arginine availability is an identifiable nutrition deficiency syndrome that worsens outcomes if left untreated.

Innate immune responses to danger signals in systemic inflammatory response syndrome and sepsis

The systemic immune response induced by non-infectious agents is called systemic inflammatory response syndrome (SIRS) and infection-induced systemic immune response is called sepsis. The host inflammatory response in SIRS and sepsis is similar and may lead to multiple organ dysfunction syndrome (MODS) and ultimately death. The mortality and morbidity in SIRS and sepsis (i.e. critical illness) remain high despite advances in diagnostic and organ supporting possibilities in intensive care units. In critical illness, the acute immune response is organized and executed by innate immunity influenced by the neuroendocrine system. This response starts with sensing of danger by pattern-recognition receptors on the immune competent cells and endothelium. The sensed danger signals, through specific signalling pathways, activate nuclear transcription factor kappaB and other transcription factors and gene regulatory systems which up-regulate the expression of pro-inflammatory mediators. The plasma cascades are also activated which together with the produced pro-inflammatory mediators stimulate further the production of inflammatory biomarkers. The acute inflammatory response underlies the pathophysiological mechanisms involved in the development of MODS. The inflammatory mediators directly affect organ function and cause a decline in remote organ function by mediating the production of nitric oxide leading to mitochondrial anergy and cytopathic hypoxia, a condition of cellular inability to use oxygen. Understanding the mechanisms of acute immune responses in critical illness is necessary for the development of urgently needed therapeutics. The aim of this review is to provide a description of the key components and mechanisms involved in the immune response in SIRS and sepsis.

Clinical relevance of the severe abnormalities of the T cell compartment in septic shock patients

INTRODUCTION

Given the pivotal role of T lymphocytes in the immune system, patients with septic shock may show T cell abnormalities. We have characterised the T cell compartment in septic shock and assess its clinical implications.

METHODS

T lymphocytes from the peripheral blood of 52 patients with septic shock and 36 healthy control subjects were analysed on admission to the intensive care unit, baseline, and 3, 7, 14 and 28 days later. T cell phenotypes (CD3+CD4+/CD3+CD8+, CD45RA+/CD45RO+, CD62L+/CD28+) were assessed by quantitative flow cytometry.

RESULTS

CD3+, CD3+CD4+ and CD3+CD8+ lymphocyte counts were significantly lower in patients with septic shock than control subjects. In surviving patients, CD3+CD4+ lymphocytes had normalised after 14 days, yet CD3+CD8+ numbers were still low. Non effector CD45RA+CD45RO- subsets of CD3+CD4+ and CD3+CD8+ were persistently low during patient follow up. CD3+CD8+CD28+ and CD3+CD8+CD62L+ were reduced in patients versus controls and survivors versus nonsurvivors in the first three days. A prediction receptor operative curve revealed that for the CD3+CD8+CD28+ subset, a cutoff of 136 cells/ml showed 70% sensitivity and 100% specificity for predicting death and the area under the curve was 0.84 at admission. Corresponding values for CD3+CD8+CD62L+ were 141 cells/ml, 60% sensitivity, 100% specificity and an area under the curve of 0.75.

CONCLUSIONS

A severe redistribution of T lymphocyte subsets is found in septic shock patients. A different kinetic pattern of T cell subset involvement is observed in surviving and nonsurviving patients, with lower numbers of circulating CD3+CD8+CD28+ and CD3+CD8+CD62L+ associated with a better disease outcome.

Monitoring immune dysfunctions in the septic patient: a new skin for the old ceremony

Septic syndromes represent a major although largely underrecognized healthcare problem worldwide, accounting for thousands of deaths every year. It is now agreed that sepsis deeply perturbs immune homeostasis by inducing an initial tremendous systemic inflammatory response which is accompanied by an antiinflammatory process, acting as negative feedback. This compensatory inhibitory response secondly becomes deleterious as nearly all immune functions are compromised. These alterations might be directly responsible for worsening outcome, as they may play a major role in the decreased resistance to nosocomial infections in patients who survived initial resuscitation. Consequently, immunostimulatory therapies may now be assessed for the treatment of sepsis. This review focuses on immune dysfunctions described in septic patients and on their potential use as markers on a routine standardized basis for prediction of adverse outcome or of occurrence of secondary nosocomial infections. This constitutes a prerequisite to a staging system for individualized treatment for these hitherto deadly syndromes.

Arginine and immunity

For many years, dietary arginine supplementation, often combined with other substances, has been used as a mechanism to boost the immune system. Considerable controversy, however, exists as to the benefits and indications of dietary arginine due in part to a poor understanding of the role played by this amino acid in maintaining immune function. Emerging knowledge promises to clear this controversy and allow for arginine's safe use. In myeloid cells, arginine is mainly metabolized either by inducible nitric oxide (NO) synthases (iNOS) or by arginase 1, enzymes that are stimulated by T helper 1 or 2 cytokines, respectively. Thus, activation of iNOS or arginase (or both) reflects the type of inflammatory response in a specific disease process. Myeloid suppressor cells (MSC) expressing arginase have been described in trauma (in both mice and humans), intra-abdominal sepsis, certain infections, and prominently, cancer. Myeloid cells expressing arginase have been shown to accumulate in patients with cancer. Arginase 1 expression is also detected in mononuclear cells after trauma or surgery. MSC efficiently deplete arginine and generate ornithine. Through arginine depletion, MSC may control NO production and regulate other arginine-dependent biological processes. Low circulating arginine has been documented in trauma and cancer, suggesting that MSC may exert a systemic effect and cause a state of arginine deficiency. Simultaneously, T lymphocytes depend on arginine for proliferation, zeta-chain peptide and T-cell receptor complex expression, and the development of memory. T-cells cocultured with MSC exhibit the molecular and functional effects associated with arginine deficiency. Not surprisingly, T-cell abnormalities, including decreased proliferation and loss of the zeta-chain, are observed in cancer and after trauma.

Immunohistochemical investigation of canine episcleritis

OBJECTIVES

To identify macrophages, B cells and T cells in archived canine episcleral biopsies and to correlate these findings with the clinical presentation and therapeutic outcome.

PROCEDURES

Archived formalin-fixed biopsies were immunohistochemically labeled for CD18, CD79a, and CD3 to identify macrophages, B cells and T cells, respectively. Slides were digitally photographed and positive cells were manually counted. Signalment, duration of illness, affected eye(s), treatment, and therapeutic outcome were reviewed for each dog. Dogs were divided into groups based on clinical presentation (unilateral episcleritis, bilateral episcleritis or nodular granulomatous episclerokeratitis (NGE).

RESULTS

Twenty-four cases were evaluated. There were 19 episcleritis (13 unilateral, six bilateral) and five NGE cases. The mean age for clinical manifestations of unilateral episcleritis was 6.8 years, bilateral episcleritis was 8.7 years, and NGE was 3.8 years. The Cocker Spaniel was over-represented in the episcleritis groups. All NGE cases were Collies. Approximately 50% of the unilateral episcleritis cases resolved and did not require long-term therapy. Almost all cases of bilateral episcleritis and NGE required continuous medical therapy to maintain remission. There was a significantly higher percentage of B lymphocytes in biopsies from lesions that required ongoing medical therapy to maintain lesion remission than in the lesions that resolved, and for which medications were discontinued (P = 0.0471).

CONCLUSIONS

The prognosis for resolution of NGE and bilateral episcleritis without long-term medical therapy is poor. There is a significant difference in the inflammatory cell population in episcleritis that resolved with medical therapy vs. episcleritis that required ongoing medical therapy.