Study On The Expression And Clinical Significance Of Certain Innate Immune Molecules In Monocytes Of HFRS Patients

Objective:Hemorrhagic fever with renal syndrome(HFRS)is a kind of natural focus disease caused by Hantavirus infection and characterized by fever,hemorrhage and acute kidney injury(AKI).China has a high incidence of HFRS,and the Guanzhong area in Shaanxi Province is an important epidemic area.The pathogenesis of HFRS is not fully understood yet.Monocytes,as the first line of defense of the immune system,play an important role in the pathogenesis of HFRS.Recent studies have shown that the occurrence and development of infectious diseases and immune diseases are closely related to the proportion and abnormal function of monocyte subsets.The present study investigated alterations in the expression of certain innate immune molecules,including CCR2,CCR7,CD62L,CD40,CD86,and HLA-DR,on the surface of classical,intermediate,and nonclassical monocytes in HFRS patients in different stages and clinical groups.Additionally,we analyzed the correlation between these molecules and disease severity and some clinical indicators,to provide information for exploring the innate immune mechanism of anti-hantavirus response,and to provide clues for seeking new biomarkers of HFRS.Methods:In this study,we enrolled a total of 30 patients diagnosed with HFRS and admitted in the Second Affiliated Hospital of the Air Force Medical University between June 2021 and January 2023.In addition,20 healthy individuals were recruited as controls.Based on the medical records,we inputted the essential information of HFRS patients,and documented the results of routine laboratory examinations conducted on the day of sample collection.In accordance with the disease severity,the HFRS patients were categorized into mild and severe groups.The acute phase of HFRS including febrile,hypotensive shock,and oliguric phases,while the polyuric and convalescent phases were collectively referred to as the convalescent phase.Flow cytometry analysis was employed to determine the proportions of monocyte subsets and assess the expression of CCR2,CCR7,CD62L,CD40,CD86,and HLA-DR.Further analysis was conducted to explore correlations between the expression levels of these immune molecules and clinical indicators.Results:1.This study enrolled 30 patients diagnosed with HFRS,including 19 cases in the mild group and 11 cases in the severe group,with age ranging from 18 to 70 years.Notably,there was no significant difference in terms of age and gender between the two groups.2.WBC,monocyte counts and AST were higher,APTT was longer,PLT,Fib and ALB levels were lower in the acute phase than convalescent phase of both groups of patients with significant difference.In the severe group,ALT level in the acute phase was significantly higher than in the convalescent phase.In the mild group,Cr concentration in the acute phase was significantly higher than in the convalescent phase.In the acute phase,APTT in the severe group was significantly longer than in the mild group.3.Our findings reveal that the proportion of intermediate monocytes in total monocytes was significantly higher in the acute phase of HFRS patients compared to both the convalescent phase and healthy controls.Conversely,the proportions of classical and nonclassical monocytes were significantly lower in the acute phase compared to the convalescent phase and healthy controls.4.In the mild disease group of patients,no significant differences were observed in the expression of the aforementioned molecules(measured using mean fluorescence intensity,same throughout)in classical monocytes between the acute and convalescent phases.However,in intermediate monocytes,the expression of CCR2 was found to be significantly higher in the acute phase compared to the convalescent phase,while the expression of HLA-DR was significantly lower in the acute phase.In nonclassical monocytes,the expression of CD62L was significantly higher in the acute phase than in the convalescent phase,while the expression of CD40 was significantly lower in the acute phase.5.In the severe disease group of patients,significant differences were observed between the acute and convalescent phases in classical monocytes.Specifically,the expression of CCR2,CD86,and HLA-DR was found to be significantly lower in the acute phase than in the convalescent phase,while the expression of CD62L was significantly higher.In intermediate monocytes,the expression of CD86 and HLA-DR was significantly lower in the acute phase than in the convalescent phase.No significant differences were observed in the expression of these molecules in nonclassical monocytes.6.For data in the acute phase:In classical monocytes,the expression of CCR2 was found to be significantly lower in the severe group compared to the mild group.The expression of CCR2 and CD62L was found to be significantly lower in the severe group compared to healthy controls.Furthermore,in the mild group,only the expression of CD62L was found to be significantly lower compared to healthy controls.In intermediate monocytes,the expression of CCR2 and CD40 was found to be significantly higher in both the severe and mild disease groups compared with healthy controls,while the expression of HLA-DR was significantly lower in the severe disease group compared with healthy controls.In nonclassical monocytes,the expression of CD40 was significantly lower in both the severe and mild disease groups compared with healthy controls.7.We analyzed the correlation between the tested immune molecules and some laboratory indicators related to disease severity and prognosis reported in previous studies.We found that the expression of CD62L in classical monocytes in the acute phase was negatively correlated with the platelet count(r_s=-0.538,P=0.002).Additionally,the expression of CCR2 in intermediate monocytes in the acute phase was negatively correlated with blood creatinine levels(r_s=-0.500,P=0.005).Furthermore,we revealed that the area under curve(AUC)for predicting disease severity in HFRS patients evaluated by the ROC curve of CCR2 expression in intermediate monocytes during the acute phase,was 0.811(95%CI:0.653～0.969,P=0.01),with a sensitivity of 90.9%.Conclusion:The function of monocyte was affected during the course of HFRS,which was manifested by changes in the proportion of monocyte subsets,as well as differences in the expression of immune molecules such as CCR2,CD62L,CD40,CD86,and HLA-DR.Notably,CCR2 expression on intermediate monocytes in acute phase exhibits diagnostic potential for disease severity and may play a role in disease progression.