Infiltration by monocytes of the central nervous system and its role in multiple sclerosis: reflections on therapeutic strategies

Mononuclear macrophage infiltration in the central nervous system is a prominent feature of neuroinflammation. Recent studies on the pathogenesis and progression of multiple sclerosis have highlighted the multiple roles of mononuclear macrophages in the neuroinflammatory process. Monocytes play a significant role in neuroinflammation, and managing neuroinflammation by manipulating peripheral monocytes stands out as an effective strategy for the treatment of multiple sclerosis, leading to improved patient outcomes. This review outlines the steps involved in the entry of myeloid monocytes into the central nervous system that are targets for effective intervention: the activation of bone marrow hematopoiesis, migration of monocytes in the blood, and penetration of the blood–brain barrier by monocytes. Finally, we summarize the different monocyte subpopulations and their effects on the central nervous system based on phenotypic differences. As activated microglia resemble monocyte-derived macrophages, it is important to accurately identify the role of monocyte-derived macrophages in disease. Depending on the roles played by monocyte-derived macrophages at different stages of the disease, several of these processes can be interrupted to limit neuroinflammation and improve patient prognosis. Here, we discuss possible strategies to target monocytes in neurological diseases, focusing on three key aspects of monocyte infiltration into the central nervous system, to provide new ideas for the treatment of neurodegenerative diseases.

Single-cell transcriptome profiling of sepsis identifies HLA-DR^(low)S100A^(high)monocytes with immunosuppressive function

Background Sustained yet intractable immunosuppression is commonly observed in septic patients,resulting in aggravated clinical outcomes.However,due to the substantial heterogeneity within septic patients,precise indicators in deciphering clinical trajectories and immunological alterations for septic patients remain largely lacking.Methods We adopted cross-species,single-cell RNA sequencing(scRNA-seq)analysis based on two published datasets containing circulating immune cell profile of septic patients as well as immune cell atlas of murine model of sepsis.Flow cytometry,laser scanning confocal microscopy(LSCM)imaging and Western blotting were applied to identify the presence of S100A9^(+)monocytes at protein level.To interrogate the immunosuppressive function of this subset,splenic monocytes isolated from septic wild-type or S100a9^(–/–)mice were co-cultured with naive CD4^(+)T cells,followed by proliferative assay.Pharmacological inhibition of S100A9 was implemented using Paquinimod via oral gavage.Results scRNA-seq analysis of human sepsis revealed substantial heterogeneity in monocyte compartments following the onset of sepsis,for which distinct monocyte subsets were enriched in disparate subclusters of septic patients.We identified a unique monocyte subset characterized by high expression of S100A family genes and low expression of human leukocyte antigen DR(HLA-DR),which were prominently enriched in septic patients and might exert immunosuppressive function.By combining single-cell transcriptomics of murine model of sepsis with in vivo experiments,we uncovered a similar subtype of monocyte significantly associated with late sepsis and immunocompromised status of septic mice,corresponding to HLA-DR^(low)S100A^(high)monocytes in human sepsis.Moreover,we found that S100A9^(+)monocytes exhibited profound immunosuppressive function on CD4^(+)T cell immune response and blockade of S100A9 using Paquinimod could partially reverse sepsis-induced immunosuppression.Conclusions This study identifies HLA-DR^(low)S100A^(high)monocytes correlated with immunosuppressive state upon septic challenge,inhibition of which can markedly mitigate sepsis-induced immune depression,thereby providing a novel therapeutic strategy for the management of sepsis.

Serum cystatin C,monocyte/high-density lipoprotein-C ratio,and uric acid for the diagnosis of coronary heart disease and heart failure

BACKGROUND Coronary heart disease(CHD)and heart failure(HF)are the major causes of morbidity and mortality worldwide.Early and accurate diagnoses of CHD and HF are essential for optimal management and prognosis.However,conventional diagnostic methods such as electrocardiography,echocardiography,and cardiac biomarkers have certain limitations,such as low sensitivity,specificity,availability,and cost-effectiveness.Therefore,there is a need for simple,noninvasive,and reliable biomarkers to diagnose CHD and HF.AIM To investigate serum cystatin C(Cys-C),monocyte/high-density lipoprotein cholesterol ratio(MHR),and uric acid(UA)diagnostic values for CHD and HF.METHODS We enrolled 80 patients with suspected CHD or HF who were admitted to our hospital between July 2022 and July 2023.The patients were divided into CHD(n=20),HF(n=20),CHD+HF(n=20),and control groups(n=20).The serum levels of Cys-C,MHR,and UA were measured using immunonephelometry and an enzymatic method,respectively,and the diagnostic values for CHD and HF were evaluated using receiver operating characteristic(ROC)curve analysis.RESULTS Serum levels of Cys-C,MHR,and UA were significantly higher in the CHD,HF,and CHD+HF groups than those in the control group.The serum levels of Cys-C,MHR,and UA were significantly higher in the CHD+HF group than those in the CHD or HF group.The ROC curve analysis showed that serum Cys-C,MHR,and UA had good diagnostic performance for CHD and HF,with areas under the curve ranging from 0.78 to 0.93.The optimal cutoff values of serum Cys-C,MHR,and UA for diagnosing CHD,HF,and CHD+HF were 1.2 mg/L,0.9×10^(9),and 389μmol/L;1.4 mg/L,1.0×10^(9),and 449μmol/L;and 1.6 mg/L,1.1×10^(9),and 508μmol/L,respectively.CONCLUSION Serum Cys-C,MHR,and UA are useful biomarkers for diagnosing CHD and HF,and CHD+HF.These can provide information for decision-making and risk stratification in patients with CHD and HF.

Pro-resolving lipid mediator reduces amyloid-β42–induced gene expression in human monocyte–derived microglia

Specialized pro-resolving lipid mediators including maresin 1 mediate resolution but the levels of these are reduced in Alzheimer's disease brain, suggesting that they constitute a novel target for the treatment of Alzheimer's disease to prevent/stop inflammation and combat disease pathology. Therefore, it is important to clarify whether they counteract the expression of genes and proteins induced by amyloid-β. With this objective, we analyzed the relevance of human monocyte–derived microglia for in vitro modeling of neuroinflammation and its resolution in the context of Alzheimer's disease and investigated the pro-resolving bioactivity of maresin 1 on amyloid-β42–induced Alzheimer's disease–like inflammation. Analysis of RNA-sequencing data and secreted proteins in supernatants from the monocyte-derived microglia showed that the monocyte-derived microglia resembled Alzheimer's disease–like neuroinflammation in human brain microglia after incubation with amyloid-β42. Maresin 1 restored homeostasis by down-regulating inflammatory pathway related gene expression induced by amyloid-β42 in monocyte-derived microglia, protection of maresin 1 against the effects of amyloid-β42 is mediated by a re-balancing of inflammatory transcriptional networks in which modulation of gene transcription in the nuclear factor-kappa B pathway plays a major part. We pinpointed molecular targets that are associated with both neuroinflammation in Alzheimer's disease and therapeutic targets by maresin 1. In conclusion, monocyte-derived microglia represent a relevant in vitro microglial model for studies on Alzheimer's disease-like inflammation and drug response for individual patients. Maresin 1 ameliorates amyloid-β42–induced changes in several genes of importance in Alzheimer's disease, highlighting its potential as a therapeutic target for Alzheimer's disease.

Monocyte and macrophage function in respiratory viral infections

Pulmonary macrophages,such as tissue-resident alveolar and interstitial macrophages and recruited monocyte-derived macrophages,are the major macrophages present in the lungs during homeostasis and diseased conditions.While tissue-resident macrophages act as sentinels of the alveolar space and play an important role in maintaining homeostasis and immune regulation,recruited macrophages accumulate in the respiratory tract after acute viral infections.Despite sharing similar anatomical niches,these macrophages are distinct in terms of their origins,surface marker expression,and transcriptional profiles,which impart macrophages with distinguished characteristics in physi-ological and pathophysiological conditions.In this review,we summarize the current view on these macrophage populations,their shared functions,and what makes them distinct from each other in the context of homeostasis andrespiratoryviral infections.

Role of lymphocyte-to-monocyte ratio as a predictive marker for diabetic coronary artery disease: A cross-sectional study

BACKGROUND The lymphocyte to monocyte ratio(LMR)is considered a marker of systemic inflammation in cardiovascular disease and acts as predictor of mortality in coronary artery disease.AIM To investigate the predictive role of LMR in diabetic coronary artery disease patients.METHODS This cross-sectional study was conducted at tertiary care super-specialty hospital at New Delhi,India.A total of 200 angiography-proven coronary artery disease(CAD)patients were enrolled and grouped into two categories:Group I[CAD patients with type 2 diabetes mellitus(T2DM)and glycated hemoglobin(HbA1c)levels≥6.5%],and Group II(CAD patients without T2DM and HbA1c levels<6.5%).Serum lipoproteins,HbA1c,and complete blood count of enrolled patients were analyzed using fully automatic analyzers.RESULTS The logistic regression analysis showed an odds ratio of 1.48(95%CI:1.28-1.72,P<0.05)for diabetic coronary artery disease patients(Group I)in unadjusted model.After adjusting for age,gender,diet,smoking,and hypertension history,the odds ratio increased to 1.49(95%CI:1.29-1.74,P<0.01)in close association with LMR.Further adjustment for high cholesterol and triglycerides yielded the same odds ratio of 1.49(95%CI:1.27-1.75,P<0.01).Receiver operating characteristic curve analysis revealed 74%sensitivity,64%specificity,and 0.74 area under the curve(95%CI:0.67-0.80,P<0.001),suggesting moderate predictive accuracy for diabetic CAD patients.CONCLUSION LMR showed positive association with diabetic coronary artery disease,with moderate predictive accuracy.These findings have implications for improving CAD management in diabetics,necessitating further research and targeted interventions.

Analysis of the Peripheral Blood Helper T-Cell 17- Cell Level and Monocyte/Lymphocyte Ratio for Colorectal Cancer Prognosis Prediction

Objective: To investigate the value of peripheral blood helper T cell 17 cell level and monocyte/lymphocyte ratio to predict the prognosis of colorectal cancer patients. Methods: 74 colorectal cancer patients who attended Hospital 960 from January 2021 to January 2022 were retrospectively analyzed. Clinical data of the patients were collected, including gender, age, and histologic type. Immunohistochemical indexes such as Th17 cell level and monocyte/ lymphocyte ratio in the peripheral blood of patients were also collected. The prognosis of patients after treatment, as well as peripheral blood Th17 and MLR levels, were observed and analyzed. Results: After follow-up after treatment, in the final 74 patients, the prognosis was good in 32 patients, accounting for 43.24%, and the prognosis was bad in 42 patients, accounting for 56.76%. There were no significant differences between the average age and tumor diameters of the good prognosis and poor prognosis groups (P > 0.05). However, the TNM staging, intervention taken, differentiation degree, presence of distant metastasis, presence of lymph node metastasis, Th17 level, and MLR level are significantly different between the two groups (P < 0.05). Conclusion: Peripheral blood Th17 and MLR have predictive value for the prognosis of colorectal cancer patients, and high levels of peripheral blood Th17 and MLR imply poor prognosis. The detection of peripheral blood Th17 and MLR levels is simple and convenient and can be used as indicators to provide a reference for the prognostic assessment of colorectal cancer patients.

Arsenic trioxide inhibites transgenic tumor necrosis factor-α promoter activity in vascular smooth muscle cells and THP-1 monocytes in vitro

Aim This study was to evaluate the effect of arsenic trioxide （As2O3） on the transgenic TNF-α promoter activity in cultured vascular smooth muscle cells （VSMCs） and THP-1 monocytes. Methods Human TNF-α promoter was constructed by reporter gene system and was transiently transfected into VSMCs and THP-1 in vitro. The promoter activity was tested by luciferase activity with or without LPS and Ang Ⅱ stimulation, before and after different dosage of As2O3 treatment. Results 1. TNF-α promoter effectively expressed in VSMCs and THP-1 compared with CMV promoter （58.3% and 80.9%, respectively）. Both LPS and Ang Ⅱ significantly up-regulated TNF-α promoter activity （P〈0.05）. 2. As2O3 significantly inhibited, both intact and LPS/Ang Ⅱ stimulated promoter activity, in a dose dependent manner （P〈0.05）, and in both cell type. Conclusion These results manifested that, the inhibition effect of As2O3 on the activity of human TNF-α promoter indicated its potential inhibition on pro-inflammatory cytokine genes expression at transcriptional level and its potential anti-inflammatory property in the cardiovascular system.

Effect of HSV-2 Infected Monocytes on the Production of TNF-a and IL-6

Objective: In order to detect the role of monocytes inHSV-2 infection, we studied the effect of herpes sim-plex Virus-2 infection on the production of tumor ne-crosis factor (TNF-σ), interleukin-6 (IL-6) secretedby monocytes. Methods: Monocytes were infected by HSV-2 (333Strain). Culture supernatants were collected at 1, 3,5, 7 days post-infection. The levels of TNF-α, IL-6were measured by enzyme-linked immunosorbent as-say (ELISA). Results: The levels of TNF-α secretion by mono-cytes significantly decreased on first day post-infection. The levels of IL-6 significantly decreasedon first and third days post-infection, and then gradu-ally increased to the control on seventh day post-infection. Conclusions: TNF-α and IL-6 production by mono-cytes was inhibited during HSV-2 infection. The pro-duction of cytokines may play an important role inherpes simplex viurs-2 pathogenicity and immunity.

Effect of Herpes Simplex Virus-2 Infection in Vitro on the Expression of HLA Class II Antigen of Monocytes

Objectives: In order to investigate the role of mono-cytes and human leukocyte antigen (HLA) class II an-tigen in herpes simplex virus-2 (HSV-2) infection, westudied the effect of HSV-2 infection in vitro on theexpression of HLA class II antigen on monocytes.Methods: Monocytes were infected with HSV-2(Strain 333). Culture cells were collected 1, 3, 5 and 7days after infection. The levels of expression of HLAclass II antigen were measured by using alkaline phos-phatase antialkaline phosphatase method (APAAP).Results: The levels of the expression of HLA class IIantigen on monocytes significantly decreased on thefirst day of post-infection, and then gradually returnedto levels found in the controls by the 7th day post-infection.Conclusion: HLA class II antigen expression onmonocytes was inhibited with HSV-2 infection, whichmight be one means of virus escape at an early phase.The expression of HLA class II antigen may play animportant role in herpes simplex viurs-2 pathogenic-ity and immunity.

Essential role of monocytes and macrophages in the progression of acute pancreatitis

Acute pancreatitis(AP) is an inflammatory condition of the pancreas caused by an imbalance in factors involved in maintaining cellular homeostasis.Earliest events in AP occur within acinar cells accompanied by other principal contributors to the inflammatory response i.e.the endothelial cells,immunocytes(granulocytes,monocytes/macrophages,lymphocytes) and neutrophils.Monocytes/macrophages are important inflammatory mediators,involved in the pathophysiology of AP,known to reside in the peritoneal cavity(in the vicinity of the pancreas) and in peripancreatic tissue.Recent studies suggested that impaired clearance of injured acini by macrophages is associated with an altered cytokine reaction which may constitute a basis for progression of AP.This review focuses on the role of monocytes/macrophages in progression of AP and discusses f indings on the inflammatory process involved.

Role of monocytes and macrophages in experimental and human acute liver failure

Acute liver failure (ALF) is a devastating clinical syndrome characterised by progressive encephalopathy, coagulopathy, and circulatory dysfunction, which commonly leads to multiorgan failure and death. Central to the pathogenesis of ALF is activation of the immune system with mobilisation of cellular effectors and massive production of cytokines. As key components of the innate immune system, monocytes and macrophages are postulated to play a central role in the initiation, progression and resolution of ALF. ALF in humans follows a rapidly progressive clinical course that poses inherent difficulties in delineating the role of these pivotal immune cells. Therefore, a number of experimental models have been used to study the pathogenesis of ALF. Here we consider the evidence from experimental and human studies of ALF on the role of monocytes and macrophages in acute hepatic injury and the ensuing extrahepatic manifestations, including functional monocyte deactivation and multiple organ failure.

Specific function and modulation of teleost monocytes/macrophages: polarization and phagocytosis

Macrophages exist in most tissues and play a variety of functions in vertebrates.Teleost fish species are found in most aquatic environments throughout the world and are quite diverse for a group of vertebrate animals.Due to whole genome duplication and en vironme ntal adaptati on,teleost monocytes/macrophages possess a variety of different functions and modulations compared with those of mammals.A deeper understanding of teleost monocytes/macrophages in the immune system will not only help develop teleost-specific methods of disease prevention but will also help improve our understanding of the various immune mechanisms in mammals.In this review,we summarize the differences in polarizati on and phagocytosis of teleost and mammalian macrophages to improve our understanding of the various immune mechanisms in vertebrates.

HCV-specific cytokine induction in monocytes of patients with different outcomes of hepatitis C

AIM:Cytokine release by macrophages critically determines the type of immune response to an antigen.Therefore,we studied hepatitis C virus(HCV)-specific induction of interleukins-1β,-10,-12(IL-1β,IL-10,IL-12),and tumor necrosis factor-α(TNF-α)in monocytes. METHODS:Intracallular cytokine expression was studied by flow cytometry in 23 patients with chronic hepatitis C,14 anti-HCV seropositives without viremia and 11 controls after stimulation of peripheral blood mononuclear calls with recombinant core,NS3,NS4,NSSa and NSSb proteins. RESULTS:Patients with HCV viremia revealed greater spontaneous expression of IL-1β,TNF-α,and IL-10. Furthermore,greater than twofold higher IL-10 expression was induced by the HCV antigens in chronic hepatitis C than in the other two groups(P<0.05).In contrast,neither IL- 12 nor TNF-α was induced preferentially. CONCLUSION:In chronic hepatitis C antigen-specific cytokine induction in monocytes is apparently shifted towards predominant IL-10 induction-not counterbalanced by antiviral type 1 cytokines.This may contribute to persistent viral replication.

Monocytes in systematic inflammatory response syndrome:Differences between sepsis and acute pancreatitis

AIM: To unravel the differences between systematic in- flammatory response syndrome (SIRS) of acute pancre- atitis compared to the same syndrome in sepsis. METHODS: Twenty-five patients were enrolled, 12 with sepsis and 13 acute pancreatitis. After diagnosis 20 ml blood was sampled. Half were assayed for isolation of monocytes and 10 ml was centrifuged for serum test of tumor necrosis factor alpha (TNFα) and interleukin-6 (IL-6). Half of monocytes were incubated in the presence of patients’ serum and supernatants were collected. The other half was treated for estimation of optical photom- etry under caspase-3 inhibition. TNFα and IL-6 were es- timated by an enzyme immunoassay. RESULTS: median ± SE of serum IL-6 in septic patients and acute pancreatitis patients was 192.30 ± 35.40 ng/L and 21.00 ± 16.05 ng/L, respectively (P < 0.01). Re- spective values of caspase-3 were 0.94 ± 0.17 pmol/min 104 cells and 0.34 ± 0.09 pmol/min 104 cells (P < 0.05). IL-6 of monocyte supernatants of patients with sepsis was significantly increased after addition of patients’ serum, while that of patients with acute pancreatitis did not show significant difference. CONCLUSION: The data have shown that monocyte activity is different between acute pancreatitis and sepsis. This phenomenon might be explained as a different pathway to the pro-inflammatory cytokines release or could be a novel anti-inflammatory response in acute pancreatitis.

Onset of Coronary Heart Disease is Associated with HCMV Infection and Increased CD14^+CD16^+Monocytes in a Population of Weifang,China

Objective To investigate the relationship between human cytomegalovirus(HCMV)infection and peripheral blood CD14+CD16+monocytes in the pathogenesis of coronary heart disease(CHD),and to elucidate the mechanism of pathogenesis in CHD by analyzing the correlation between infection,inflammation,and CHD,to provide a basis for the prevention,evaluation,and treatment of the disease.Methods In total,192 patients with CHD were divided into three groups:latent CHD,angina pectoris,and myocardial infarction.HCMV-IgM and-IgG antibodies were assessed using ELISA;CD14+CD16+monocytes were counted using a five-type automated hematology analyzer;mononuclear cells were assessed using fluorescence-activated cell sorting;and an automatic biochemical analyzer was used to measure the levels of triglyceride,cholesterol,high-and low-density lipoprotein cholesterols,lipoprotein,hs-CRp and Hcy.Results The positive rates of HCMV-IgM and-IgG were significantly higher in the CHD groups than in the control group.HCMV infection affects lipid metabolism to promote immune and inflammatory responses.Conclusion HCMV infection has a specific correlation with the occurrence and development of CHD.The expression of CD14+CD16+mononuclear cells in the CHD group was increased accordingly and correlated with acute HCMV infection.Thus,HCMV antibody as well as peripheral blood CD14+CD16+mononuclear cells can be used to monitor the occurrence and development of CHD.

Effect of Menopause on Gene Expression Profiles of Circu-lating Monocytes: A Pilot in vivo Microarray Study

Menopause is one of the key physiological events in the female life and can increase the risk for a number of complex autoimmune, neurodegenerative, metabolic, and cardiovascular disorders. Circulating monocytes can differentiate into various cell types and play an important role in tissue morphogenesis and immune response. We studied gene expression profiles of peripheral blood monocytes in healthy pre- and postmenopausal women using Affymetrix Human U133A GeneChip array that contains probes for -14,500 genes. Comparative analyses between the samples showed that 20 genes were up- and 20 were down-regulated. Of these genes, 28 were classified into six major GO categories relevant to such biological processes as the cell proliferation, immune response, cellular metabolism, and the others. The remaining 12 genes have yet unidentified biological functions. Our results support the hypothesis that functional state of circulating monocytes is indeed affected by menopause, and resulting changes may be determined through the genomewide gene expression profiling. Several differentially expressed genes identified in this study may be candidates for further studies of menopause-associated systemic autoimmune, neurodegenerative, and cardiovascular disorders. Our study is only the first attempt in this direction, but it lays a basis for further research.

Distinct toll-like receptor expression in monocytes and T cells in chronic HCV infection

AIM： Hepatitis C virus often establishes chronic infections. Recent studies suggest that viral and bacterial infections are more common in HCV-infected patients compared to controls. Pathogens are recognized by Toll-like receptors （TLRs） to shape adaptive and innate immune responses. METHODS： In this study, to infected host to recognize assess the ability of HCV-infected host to recognize invading pathogens, we investigated Toll-like receptor expression in innate （monocytes） and adaptive （T cells） immune cells by realtime PCR. RESULTS： We determined that RNA levels for TLRs 2, 6. 7, 8, 9 and 10 mRNA levels were upregulated in both monocytes and T cells in HCV-infected patients compared to controls. TLR4 was only upregulated in T lymphocytes, while TLR5 was selectively increased in monocytes of HCV-infected patients. MD-2, a TLR4 coreceptor, was increased in patients＇ monocytes and T cells while CD14 and MyD88 were increased only in monocytes. CONCLUSION： Our data reveal novel details on TLR expression that likely relates to innate recognition of pathogens and immune defense in HCV-infected individuals.

Mudskipper interleukin-34 modulates the functions of monocytes/macrophages via the colony-stimulating factor-1 receptor 1

Interleukin-34(IL-34)is a novel cytokine that plays an important role in innate immunity and inflammatory processes by binding to the colonystimulating factor-1 receptor(CSF-1R).However,information on the function of IL-34 in fish remains limited.In the present study,we identified an IL-34 homolog from mudskippers(Boleophthalmus pectinirostris).In silico analysis showed that the mudskipper IL-34(BpIL-34)was similar to other known IL-34 variants in sequence and structure and was most closely related to an orange-spotted grouper(Epinephelus coioides)homolog.BpIL-34 transcripts were constitutively expressed in various tissues,with the highest level of expression found in the brain.Edwardsiella tarda infection significantly up-regulated the mRNA expression of BpIL-34 in the mudskipper tissues.The recombinant mature BpIL-34 peptide(rBpIL-34)was purified and used to produce anti-rBpIL-34 IgG.Western blot analysis combined with PNGase F digestion revealed that native BpIL-34 in monocytes/macrophages(MOs/MФs)was N-glycosylated.In vitro,rBpIL-34 treatment enhanced the phagocytotic and bactericidal activity of mudskipper MOs/MФs,as well as the mRNA expression of pro-inflammatory cytokines like tumor necrosis factorα(BpTNF-α)and BpIL-1βin these cells.Furthermore,the knockdown of mudskipper CSF-1R1(BpCSF-1R1),but not mudskipper BpCSF-1R2,significantly inhibited the rBpIL-34-mediated enhanced effect on MO/MФfunction.In conclusion,our results indicate that mudskipper BpIL-34 modulates the functions of MOs/MФs via BpCSF-1R1.

Systemic immune inflammation index, ratio of lymphocytes to monocytes, lactate dehydrogenase and prognosis of diffuse large Bcell lymphoma patients

BACKGROUND In malignant tumors,inflammation plays a vital role in the development,invasion,and metastasis of cancer cells.Diffuse large B-cell lymphoma(DLBCL),the most common malignant proliferative disease of the lymphatic system,is commonly associated with inflammation.The international prognostic index(IPI),which includes age,lactate dehydrogenase(LDH),number of extranodal lesions,Ann Arbor score,and Eastern Cooperative Oncology Group(ECOG)score,can evaluate the prognosis of DLBCL.However,its use in accurately identifying highrisk patients and guiding treatment is poor.Therefore,it is important to find novel immune markers in predicting the prognosis of DLBCL patients.AIM To determine the association between the systemic immune inflammation index(SII),ratio of lymphocytes to monocytes(LMR),ratio of LMR to LDH(LMR/LDH),and prognosis of patients with DLBCL.METHODS A total of 68 patients diagnosed with DLBCL,treated in our hospital between January 2016 and January 2020,were included.χ2 test,Pearson’s R correlation,Kaplan Meier curves,and Cox proportional risk regression analysis were used.The differences in the SII,LMR,and LMR/LDH among patients with different clinicopathological features were analyzed.The differences in progression-free survival time among patients with different SII,LMR,and LMR/LDH expressions and influencing factors affecting the prognosis of DLBCL patients,were also analyzed.RESULTS The LMR and LMR/LDH in patients with Ann Arbor stage III–IV,ECOG score≥2,and SII,IPI score 2–5 were significantly higher than those of patients with Ann Arbor stage I-II and ECOG score<2(P<0.05).Patients with high SII,LMR,and LMR/LDH had progression-free survival times of 34 mo(95%CI:32.52–38.50),35 mo(95%CI:33.42–36.58)and 35 mo(95%CI:33.49–36.51),respectively,which were significantly lower than those with low SII,LMR,and LMR/LDH(P<0.05);the SII,LMR,and LMR/LDH were positively correlated(P<0.05).Cox proportional risk regression analysis showed that the SII,LMR,and LMR/LDH were influencing factors for the prognosis of DLBCL patients(hazard ratio=1.143,1.665,and 1.704,respectively;P<0.05).CONCLUSION The SII,LMR,and LMR/LDH are related to the clinicopathological features of DLCBL,and they also influence the prognosis of patients with the disease.