Severe Hemorrhagic Fever With Renal Syndrome Research Articles

Sivelestat Inhibits Vascular Endothelial Injury Induced by Inflammatory Response and Improves the Prognosis of Hemorrhagic Fever with Renal Syndrome in Children: An Ambispective Cohort Study.

In Asia, Hanta virus (HTNV) results in severe hemorrhagic fever with renal syndrome (HFRS). The efficacy of sivelestat in treating children with HTNV-induced HFRS remains unclear. An ambispective cohort study was performed on children diagnosed with HFRS and hospitalized at the Children's Hospital Affiliated to Xi'an Jiaotong University from August 2018 to 2023. Patients who received neutrophil elastin-inhibitor infusion between August 2019 and August 2023 were assigned to the sivelestat group, while patients who did not were assigned to the control group. The independent sample t test was used for inter-group analysis. The Chi-square test and Fisher's exact probability test were used for categorical variables. Spearman correlation test was used to evaluate the correlation between two sets of continuous variables. Kaplan-Meier survival curve and Log -Rank test was used to evaluate the difference in cumulative probability of survival between the two groups. No significant differences were observed between the two groups in gender, age, contact history, body mass index, HFRS severity, clinical indexes at admission. Compared to the control group, the sivelestat group exhibited a significant decrease in the interleukin-8 level at 48 h (28.5±3 vs 34.5±3.5) and 72 h (21.3±4.5 vs 31.5±5.6) (P<0.05), as well as the ICAM-1 level at 48 h (553±122 vs 784±187) and 72 h (452±130 vs 623±85) (P<0.05). The concentration of VCAM-1 in the sivelestat group exhibited a consistent downward trend. Moreover, the level of VCAM-1 was significantly lower than that in the control group at 24 h (1760±289 vs 2180±445), 48 h (1450±441 vs 1890±267), and 72 h (1149±338 vs 1500±396) (P<0.05). Kaplan-Meier curve analysis revealed a statistically significant difference in the cumulative probability of survival between two groups (P = 0.041). In the secondary outcomes, the sivelestat group demonstrated a decrease in the utilization rate of mechanical ventilation and continuous renal replacement therapy (CRRT). Sivelestat may suppress neutrophil-mediated inflammatory response to reduce endothelial and organ damage, and improve clinical outcomes in children with severe hemorrhagic fever and renal syndrome.

Levels of peripheral blood routine, biochemical and coagulation parameters in patients with hemorrhagic fever with renal syndrome and their relationship with prognosis: an observational cohort study

BackgroundHantaan virus (HTNV), Seoul virus (SEOV) and Puumala virus (PUUV) are major serotypes of the Hantavirus, which can cause hemorrhagic fever with renal syndrome (HFRS). The pathophysiology of HFRS in humans is complex and the determinants associated with mortality, especially the coagulation and fibrinolysis disorders, are still not been fully elucidated. Severe patients usually manifest multiple complications except for acute kidney injury (AKI). The aim of this study was to observe the levels of peripheral blood routine, biochemical and coagulation parameters during the early stage, so as to find independent risk factors closely related to the prognosis, which may provide theoretical basis for targeted treatment and evaluation.MethodsA total of 395 HFRS patients from December 2015 to December 2018 were retrospectively enrolled. According to prognosis, they were divided into a survival group (n = 368) and a death group (n = 27). The peripheral blood routine, biochemical and coagulation parameters were compared between the two groups on admission. The relationship between the parameters mentioned above and prognosis was analyzed, and the dynamic changes of the coagulation and fibrinolysis parameters during the first week after admission were further observed.ResultsIn addition to AKI, liver injury was also common among the enrolled patients. Patients in the death group manifested higher levels of white blood cell counts (WBC) on admission. 27.30% (107/392) of the patients enrolled presented with disseminated intravascular coagulation (DIC) on admission and DIC is more common in the death group; The death patients manifested longer prothrombin time (PT) and activated partial thromboplastin time (APTT), higher D-dimer and fibrinogen degradation product (FDP), and lower levels of platelets (PLT) and fibrinogen (Fib) compared with those of the survival patients. The proportion of D-dimer and FDP abnormalities are higher than PT, APTT and Fib. Prolonged PT, low level of Fib and elevated total bilirubin (TBIL) on admission were considered as independent risk factors for prognosis (death).ConclusionsDetection of PT, Fib and TBIL on admission is necessary, which might be benefit to early predicting prognosis. It is also important to pay attention to the dynamic coagulation disorders and hyperfibrinolysis during the early stage in the severe HFRS patients.

Predictive value of CD4+CD8+ double positive T cells for the severity of hemorrhagic fever with renal syndrome

PurposesWe aimed to investigate the levels of CD4+CD8+ double positive (DP) T cells in patients with various severities of hemorrhagic fever with renal syndrome (HFRS), and the predictive capacity of DP T cells for the severity of this disorder. MethodsThe levels of DP T cells in 213 patients and 48 healthy donors were measured by flow cytometry, as were the levels of CD4+ T cells, CD8+ T cells, B lymphocytes, and natural killer (NK) cells. In each type of HFRS patient, we tested the basic clinical reference values for leukocytes, platelets, creatinine (Cr), uric acid (UA), and urea, and the values for activated partial thromboplastin time, prothrombin time, and fibrinogen, using conventional methods. The colloidal gold method was used to measure HFRS antibody levels in the patients. ResultsThe frequency of DP T cells increased with disease severity and peaked in patients with critical disease. Furthermore, the level of DP T cells proportionally correlated with the levels of Cr, UA, and urea in the serum. In contrast, there was an inverse correlation between DP T cells and platelets. Interestingly, the pattern of change in DP T cell frequency was similar to those of CD8+ T cells, B cells, and NK cells, but an inverse tendency was observed for CD4+ T cells. DP T cells demonstrated significant predictive value for the severity of HFRS. ConclusionsThe level of DP T cells is associated with HFRS severity, suggesting that it may be a potent indicator for the course of this disorder.

Increased blood CD226- inflammatory monocytes with low antigen presenting potential correlate positively with severity of hemorrhagic fever with renal syndrome

Background Hantaan virus (HTNV) infection can cause severe hemorrhagic fever with renal syndrome (HFRS). Inflammatory monocytes (iMOs) are involved in early antiviral responses. Previous studies have found that blood iMOs numbers increase in the acute phase of HFRS. Here, we further identified the phenotypic characteristics of iMOs in HFRS and explored whether phenotypic changes in iMOs were associated with HFRS severity. Materials and Methods Blood samples from 85 HFRS patients were used for phenotypic analysis of iMOs by flow cytometry. Plasma HTNV load was determined using RT-PCR. THP-1 cells overexpressing CD226 were used to investigate the effects of CD226 on HLA-DR/DP/DQ and CD80 expression. A mouse model was used to test macrophage phenotype following HTNV infection. Results The proportion of CD226- iMOs in the acute phase of HFRS was 66.83 (35.05-81.72) %, which was significantly higher than that in the convalescent phase (5.32 (1.36-13.52) %) and normal controls (7.39 (1.15-18.11) %) (p < 0.0001). In the acute phase, the proportion of CD226- iMOs increased more in patients with more severe HFRS and correlated positively with HTNV load and negatively with platelet count. Notably, CD226- iMOs expressed lower levels of HLA-DR/DP/DQ and CD80 than CD226+ iMOs, and overexpression CD226 could enhance the expression of HLA-DR/DP/DQ and CD80. In a mouse model, HTNV also induced the expansion of CD226- macrophages, with decreased expression of I-A/I-E and CD80. Conclusions CD226- iMOs increased during HTNV infection and the decrease in CD226 hampered the expression of HLA-DR/DP/DQ and CD80, which may promote the immune escape of HTNV and exacerbate clinical symptoms.

Early Warning Models for Predicting Severity in Febrile and Nonfebrile Stages of Hemorrhagic Fever with Renal Syndrome.

Treating severe hemorrhagic fever with renal syndrome (HFRS) cases is difficult. There is currently no early warning model for patients with severe HFRS. Data from 235 patients with HFRS between January 2013 and December 2019, as well as 394 laboratory indicators, were retrospectively collected. A multivariate logistic regression model was used to construct an early warning model for severe diseases. The model's accuracy was evaluated based on the area under the receiver operating characteristic curve. The area under the curve of the early warning models for both exceeded 0.9 for the two stages. In the febrile stage, there were significant differences between the severe and mild groups (P < 0.05) in renal estimated glomerular filtration rate (eGFR), urinary leukocytes, electrolytes, urine conductivity, and urinary epithelial cell count. In the nonfebrile stage, there were significant differences between the severe and mild groups (P < 0.05) in renal eGFR, electrolytes, urine conductivity, and renal cystatin C levels. The two early warning models were well-fitted and exhibited excellent predictive performance. This can help clinicians gain time to provide appropriate preemptive treatment to avoid the further development of severe disease and reduce the mortality rate.

Exosomal miRNA-155 and miRNA-146a are promising prognostic biomarkers of the severity of hemorrhagic fever with renal syndrome.

Hemorrhagic fever with renal syndrome (HFRS), caused by Orthohantaviruses, occupies one of the leading places among natural focal human diseases, for which there are no modern accurate and highly sensitive diagnostic methods. To improve this situation, a better understanding of the Hantavirus pathogenesis of HFRS is required. Determination of the expression level of exosomal microRNAs (miRNAs) in the serum/plasma of patients makes them potential biomarkers for diagnosing and predicting HFRS. The purpose of this study was to analyze the expression level of miRNA-146a, miRNA-126, miRNA-218, miRNA-410, miRNA-503 and miRNA-155 in patients with HFRS at different stages (fever stage, polyuric stage and convalescence stage) and with different severity of the course this disease. The moderate group of patients with HFRS included 105 patients, the severe group included 99 patients, and the severe group with complications included 84 patients. Blood samples from patients with HFRS for molecular genetic analysis were collected three times: during the initial febrile period (days 1-4 of illness), the polyuric period (days 15-22 of the disease), and during convalescence. Total RNA isolation was performed using the exoRNeasy Midi Kit (Qiagen, Germany). Quantitative real-time PCR (qRT-PCR) was performed using the miRCURY LNA SYBR Green PCR Kit (Qiagen, Germany) and the LightCycler96 real-time PCR product detection system (Roche, Switzerland). When comparing the expression level of exosomal miRNAs in groups of patients with different severity of the disease, a statistically significant increase in the expression level of miRNA-146a was revealed in patients with severe HFRS with complications (Fold change 2.694; p=0.0022) compared to the group with a moderate disease form, as well as an increase in miRNA-155 expression in patients with severe and severe HFRS with complications compared to the moderate form (Fold change 1.861; p=0.0492; Fold change 1.976; p=0.001, respectively). Comparative analysis of the expression level of other miRNAs in patients with HFRS at various stages and with different severity of HFRS did not reveal any statistically significant results (P>0.05). MiRNA-155 and miRNA-146a may be promising prognostic biomarkers in HFRS. However, further investigations are needed to evaluate the changes in the expression of miRNAs and the network of genes that can be potential targets for the studied miRNAs in order to elucidate the molecular mechanisms that can influence the occurrence and development of HFRS.

Hantaan virus-induced elevation of plasma osteoprotegerin and its clinical implications in hemorrhagic fever with renal syndrome

ObjectivesThe bleeding tendency is a hallmark of hemorrhagic fever with renal syndrome (HFRS) after Hantaan virus (HTNV) infection. Growing reports indicate the importance of osteoprotegerin (OPG) in vascular homeostasis, implying OPG might be involved in the pathogenesis of coagulopathy in patients with HFRS. MethodsAcute and convalescence plasmas of 32 patients with HFRS were collected. Enzyme-linked immunosorbent assays (ELISA) were used to detect plasma OPG levels and other parameters. The human umbilical vein endothelial cells were stimulated with HTNV and/or tumor necrosis factor-α (TNF-α) to explore the source of OPG. ResultsPlasma OPG levels of patients with HFRS were elevated and correlated positively with the severity of HFRS and negatively with platelet counts. Abundant OPG was released from endothelial cells in response to TNF-α stimuli, along with HTNV infection, which was in accordance with the findings of positive correlations between plasma OPG and TNF-α or c-reactive protein. Importantly, plasma OPG levels correlated positively with activated partial thromboplastin time and the content of d-dimer. ConclusionThese findings suggested that increased plasma OPG levels induced by HTNV might be an important factor for the severity of HFRS, and was likely involved in endothelium dysfunction and hemorrhagic disorder of HFRS, which might contribute to the pathogenesis of hemorrhage in HFRS.

Evaluation of Serum Ferritin, Procalcitonin, and C-Reactive Protein for the Prediction of Severity and Mortality in Hemorrhagic Fever With Renal Syndrome

This study aimed to analyze the clinical significance of serum ferritin, procalcitonin (PCT), and C-reactive protein (CRP) in patients with hemorrhagic fever with renal syndrome (HFRS). The demographical, clinical, and laboratory data of 373 patients with HFRS in northeastern China were retrospectively analyzed. The levels of serum ferritin and PCT in severe patients (n = 108) were significantly higher than those in mild patients (n = 265, p < 0.001) and associated with HFRS severity. The area under the receiver operating characteristic curve (AUC) values of serum ferritin and PCT for predicting the severity of HFRS were 0.732 (95% CI 0.678–0.786, p < 0.001) and 0.824 (95% CI 0.773–0.875, p < 0.001), respectively, showing sensitivity and specificity of 0.75 and 0.88 for serum ferritin, and 0.76 and 0.60 for PCT. The CRP level in HFRS with bacterial co-infection (n = 115) was higher than that without bacterial co-infection (n = 258, p < 0.001). The AUC value of CRP for predicting bacterial co-infection was 0.588 (95% CI 0.525–0.652, p < 0.001), showing sensitivity and specificity of 0.43 and 0.76, respectively. The serum ferritin level in non-survivors (n = 14) was significantly higher than in survivors (n = 359, p < 0.001). The AUC value of serum ferritin for predicting mortality was 0.853 (95% CI 0.774–0.933, p < 0.001), showing sensitivity and specificity of 0.933 and 0.739. Serum ferritin and PCT have a robust association with HFRS severity and mortality, which may be promising predictors, and CRP is an effective biomarker to assess bacterial co-infection in HFRS.

LncRNA NEAT1 Potentiates SREBP2 Activity to Promote Inflammatory Macrophage Activation and Limit Hantaan Virus Propagation.

As the global prototypical zoonotic hantavirus, Hantaan virus (HTNV) is prevalent in Asia and is the leading causative agent of severe hemorrhagic fever with renal syndrome (HFRS), which has profound morbidity and mortality. Macrophages are crucial components of the host innate immune system and serve as the first line of defense against HTNV infection. Previous studies indicated that the viral replication efficiency in macrophages determines hantavirus pathogenicity, but it remains unknown which factor manipulates the macrophage activation pattern and the virus-host interaction process. Here, we performed the transcriptomic analysis of HTNV-infected mouse bone marrow-derived macrophages and identified the long noncoding RNA (lncRNA) nuclear enriched abundant transcript 1 (NEAT1), especially the isoform NEAT1-2, as one of the lncRNAs that is differentially expressed at the early phase. Based on coculture experiments, we revealed that silencing NEAT1-2 hinders inflammatory macrophage activation and facilitates HTNV propagation, while enhancing NEAT1-2 transcription effectively restrains viral replication. Furthermore, sterol response element binding factor-2 (SREBP2), which controls the cholesterol metabolism process, was found to stimulate macrophages by promoting the production of multiple inflammatory cytokines upon HTNV infection. NEAT1-2 could potentiate SREBP2 activity by upregulating Srebf1 expression and interacting with SREBP2, thus stimulating inflammatory macrophages and limiting HTNV propagation. More importantly, we demonstrated that the NEAT1-2 expression level in patient monocytes was negatively correlated with viral load and HFRS disease progression. Our results identified a function and mechanism of action for the lncRNA NEAT1 in heightening SREBP2-mediated macrophage activation to restrain hantaviral propagation and revealed the association of NEAT1 with HFRS severity.

Severity Biomarkers in Puumala Hantavirus Infection.

Annually, over 10,000 cases of hemorrhagic fever with renal syndrome (HFRS) are diagnosed in Europe. Puumala hantavirus (PUUV) causes most of the European HFRS cases. PUUV causes usually a relatively mild disease, which is rarely fatal. However, the severity of the infection varies greatly, and factors affecting the severity are mostly unrevealed. Host genes are known to have an effect. The typical clinical features in PUUV infection include acute kidney injury, thrombocytopenia, and increased vascular permeability. The primary target of hantavirus is the endothelium of the vessels of different organs. Although PUUV does not cause direct cytopathology of the endothelial cells, remarkable changes in both the barrier function of the endothelium and the function of the infected endothelial cells occur. Host immune or inflammatory mechanisms are probably important in the development of the capillary leakage. Several immunoinflammatory biomarkers have been studied in the context of assessing the severity of HFRS caused by PUUV. Most of them are not used in clinical practice, but the increasing knowledge about the biomarkers has elucidated the pathogenesis of PUUV infection.

Epidemic process and influencing factors of hemorrhagic fever with renal syndrome: a review

Hemorrhagic fever with renal syndrome (HFRS) is a category B infectious disease caused by hantaviruses that cause acute kidney injury and has a high mortality rate, and HFRS control has been given a high priority in China. It has been found that hantavirus types are closely associated with selective host transformation and regional adaption, and continue to evolve in the form of gene recombination. The severity of HFRS varies in hantavirus types. In addition, global environmental changes and alteration of host animal behaviors accelerate Hantavirus genome variations, and large-scale land reclamation and infrastructure building increases the likelihood of human contacts with hosts and disease-transmitting vectors, thereby increasing the risk of HFRS development. This review summarizes the main characteristics and influencing factors pertaining to the epidemic process of HFRS, so as to provide insights into effective prevention and control of this infectious disease.

Heart Condition in Convalescents of Hemorrhagic Fever with Renal Syndrome According to Echocardiography Data

Aim. To study the morpho-functional parameters of the heart in convalescents of hemorrhagic fever with renal syndrome (HFRS) using echocardiography.Material and methods. The study included 27 patients without any chronic diseases who had severe or moderate HFRS (the main group) within 3 weeks after their discharge from the infection diseases hospital. The reference group consisted of 19 patients comparable by age and gender, without any chronic diseases. Transthoracic echocardiography was the basic method of heart and hemodynamics investigation. The test was performed using tissue Doppler and non-Doppler assessment of left ventricle systolic deformation method (speckle-tracking method).Results. Violation of longitudinal systolic deformation of the left ventricle was observed in 15 (55.6%) patients, which was combined with diastolic left ventricle filling by the type of relaxation violation in 8 (29.6%) cases. Mitral valve insufficiency of 1 degree was identified in 11 (40.7%) HFRS patients, insufficiency of the tricuspid valve of 1 degree was identified in 4 (14.8%) patients. Pericardial effusion was detected in 2 (7.4%) patients. In 7 (25.9%) patients in the first 3 weeks after discharge from the hospital, additional floating echoes were detected on the leaves and fibrous ring of the aortic valve, which were considered as a manifestation of thromboendocarditis.Conclusion. Further investigation is necessary to assess the prognostic value (including the risk of thromboembolic complication developing) of the changes revealed in HFRS convalescents and to support the inclusion of echocardiography in the examination program during dispensary observation of HFRS-convalescents.

MAIT cell activation is associated with disease severity markers in acute hantavirus infection

SummaryHantaviruses are zoonotic RNA viruses that cause severe acute disease in humans. Infected individuals have strong inflammatory responses that likely cause immunopathology. Here, we studied the response of mucosal-associated invariant T (MAIT) cells in peripheral blood of individuals with hemorrhagic fever with renal syndrome (HFRS) caused by Puumala orthohantavirus, a hantavirus endemic in Europe. We show that MAIT cell levels decrease in the blood during HFRS and that residual MAIT cells are highly activated. This activation correlates with HFRS severity markers. In vitro activation of MAIT cells by hantavirus-exposed antigen-presenting cells is dependent on type I interferons (IFNs) and independent of interleukin-18 (IL-18). These findings highlight the role of type I IFNs in virus-driven MAIT cell activation and suggest a potential role of MAIT cells in the disease pathogenesis of viral infections.

Dynamics of the level of interleukins in the blood of children undergoing hemorrhagic fever with renal syndrome

Background: Hemorrhagic fever with renal syndrome (HFRS) is caused by hantavirus, which does not have a direct cytopathic effect on endotheliocytes, but serves only as an initiator of immune inflammation. Cytokines play a leading role in the pathogenesis of many infectious diseases, including HFRS. In the literature available to us, we have not seen a single publication devoted to the dynamics of cytokines in children with HFRS. Methods and materials: The study included 147 children with HFRS hospitalized in an infectious diseases hospital in Ufa. Patients were conditionally divided into 2 groups. The first group consisted of 73 patients who were treated with a diagnosis of HFRS of moderate severity. The second group included 74 patients with a diagnosis of severe HFRS. The age in the two groups was 5–17 years. The average age is 11.1 ± 1.6 y. Results: In children with HFRS, there is an increase in the concentration of pro-inflammatory cytokines IL-1β and TNFa, starting from the febrile period. The peak increase in these cytokines is observed in the oliguric period. During the period of polyuria, the level of pro-inflammatory cytokines decreases. Moreover, during the recovery period, their difference from the control group is not statistically significant. The level of inf and inf-γ in children with HFRS decreases since the febrile period, the greatest decrease is observed in the oliguric period with severe HFRS. In the polyuric period, the level of inf and inf-γ rises, but with a severe form of the disease, their level is statistically significantly higher than in the control group even during the recovery period. The concentration of the anti-inflammatory cytokine IL-10 in the febrile period tends to increase, a statistically significant increase is noted in the oliguric period and continues to increase in the polyhuric period. In the convalescence phase, the level of IL-10 is not statistically different from the control group, while in adult patients, the level of IL-10 in the convalescence period is significantly higher than in the control group. Conclusion: Thus, the content of cytokines in children with HFRS depends on the period and severity of the disease.

Features of the course of hemorrhagic fever with renal syndrome in HIV-infected patients

Human immunodeficiency virus (HIV) is a significant medical and social problem for many developed countries. HIV infection is featured with developing chronic kidney pathology as well as acute renal damage. In some regions, hemorrhagic fever with renal syndrome (HFRS) can contribute somehow to developing renal pathology in HIVinfected subjects. The aim of the study was to identify clinical and laboratory features of HFRS course during HIV infection. A retrospective study was conducted by forming two groups: group 1 consisted of 9 patients suffered from HFRS together with verified HIV infection, group 2 — 53 patients with HFRS but lacking any clinical and epidemiological indications supporting HIV infection. Subjects in both groups were age- and sex-matched. The average age of the patients in group 1 and group 2 was 34 and 31 years, respectively. For statistical analysis, the licensed SPSS 22.0 software was used. A significance level p for statistical criteria was set equal to 0.05. In general, HFRS course in all patients was accompanied by characteristic signs: intoxication syndrome, impaired vision, hemorrhagic rash, pain in the lumbar region, decreased diuresis, thrombocytopenia, proteinuria, polymorphic urinary syndrome and azotemia. HFRS patients with concomitant HIV infection often complain of dry mouth, bloating, visible shortness of breath. Laboratory changes describe more severe kidney damage. A direct strong correlation was shown between leukocyte count and level of blood urea in patients with concomitant HIV infection (r = 0.798; p = 0.01). The combination of HFRS and HIV was accompanied by a milder HFRS course — rate of mild disease was almost 6-fold higher among patients of this group. In this case, no cases of severe hemorrhagic fever with renal syndrome combined with HIV were noted. Our study allowed to obtain unambiguous data. Predisposition of HIV-infected patients to renal pathology may be a determining factor in kidney damage upon emerging HFRS: more prominent rise in creatinine and urea level. Moreover, according to rating scale for assessing HFRS severity, it formally turned out that during concomitant HIV infection patients more often fit to a mild disease severity, even in the presence of more pronounced renal manifestations. The occurrence of acute renal pathology in HIV-infected patients is a life-threatening condition, a factor of deterioration of chronic renal pathology and a predictor of death. Consequently, this patient population requires thorough monitoring both at inpatient and outpatient stages.

Comparison of Lymphocyte Populations in Patients With Dobrava or Puumala orthohantavirus Infection.

Hemorrhagic fever with renal syndrome (HFRS), caused by Dobrava (DOBV) and Puumala (PUUV) orthohantaviruses, is an endemic disease in Slovenia. DOBV is mainly responsible for a more severe disease, whereas PUUV usually causes a milder form. Therefore, the aim of our study was to determine whether any differences in lymphocyte population in patients infected with these two viruses exist. Mononuclear cells from peripheral blood (PBMCs) were isolated from DOBV or PUUV infected patients and different lymphocyte subpopulations were analyzed with flow cytometry. Decreased concentrations of lymphocyte subpopulation were observed in DOBV and in PUUV infected patients compared with a healthy control, which was especially evident in DOBV infected patients. The lower values of T cells are likely due to the extravasation of the activated cells from the circulation to the infected tissue. Higher percentage of NK cells were detected in DOBV infected patients in comparison to PUUV infected patients, which could be associated with a more severe HFRS caused by DOBV. PUUV infected patients had a significantly higher concentration of activated T cell subsets, expressing markers CD25, CD69, and HLA-DR in comparison to DOBV infected patients. Higher activation of T cell subsets in PUUV infected patients could be a contributor to a milder HFRS. Further studies are necessary to elucidate the relation between the protective and the harmful role of activated lymphocytes subsets in HFRS pathogenesis.

Δccr5 Genotype Is Associated with Mild Form of Nephropathia Epidemica.

Nephropathia Epidemica (NE), a mild form of hemorrhagic fever with renal syndrome (HFRS) and linked to hantavirus infection, is endemic in the Republic of Tatarstan. Several genetic markers of HFRS severity have been identified previously, including human leukocyte antigen (HLA) complexes and nucleotide polymorphism in the tumor necrosis factor alpha (TNFα) gene. Still, our understanding of the genetic markers of NE severity remains incomplete. The frequency of the C–C chemokine receptor type 5 (CCR5) gene wild type and gene with 32-base-pair deletion (Δ32CCR5) genotypes in 98 NE samples and 592 controls was analyzed using PCR. Along with the serum levels of 94 analytes, a lack of differences in the CCR5 genotype distribution between NE cases and the general population suggests that the CCR5 genotype does not affect susceptibility to hantavirus infection. However, in NE cases, significant variation in the serum levels of the host matrix metalloproteases between functional CCR5 homozygous and Δ32CCR5 heterozygous patients was detected. Also, the oliguric phase was longer, while thrombocyte counts were lower in functional CCR5 homozygous as compared to heterozygous NE cases. Our data, for the first time, presents the potential role of the CCR5 receptor genotype in NE pathogenesis. Our data suggests that NE pathogenesis in functional CCR5 homozygous and heterozygous NE patients differs, where homozygous cases may have more disintegration of the extracellular matrix and potentially more severe disease.

Genetic Factors in Individual Predisposition toward Hemorrhagic Fever with Renal Syndrome

Hemorrhagic fever with renal syndrome (HFRS) is a zoonotic infection disease caused by Orthohantavirus which belongs to Hantaviridae family. This article is a brief review of recent data about genetic factors which play a role in individual predisposition toward HFRS. There are reports discovered associations of polymorphic sites with HFRS severity and risk complications. Polymorphic sites in genes which code proteins of immune (МНС, TNF, IL1) and endothelial (VE-cadherin) systems, blood coagulation (SERPINE1, ITGA2B, NOS) and detoxification (CYP1A1, GSTP1) systems and their links with disease are described in this article. HLA haplotypes B*08-DRB1*03 and B*46-DRB1*09, B*51-DRB1*09 are associated with severe forms of HFRS-PUUV and HFRS-HTNV respectively. TNF A-allele and AA-genotype in -308G&gt;A SNP (rs1800629), CDH5 ТТ-genotype in 1550T&gt;C SNP, SERPINE1 G-allele in -844A&gt;G SNP (rs2227631), alleles HPA3 b, NOS2A*11 and NOS2A*11/NOS2A*12-genotype, CYP1A1 1А2С-genotype in SNP (rs1048943) and GSTP AG-genotype in SNP (rs1695) demonstrated associations with severe HFRS. Differences in the expression levels of GATA3, T-BET, CD3, IFNβ, NFkB, STAT1 and MxA genes in cell cultures stimulated by hantavirus. Expression of GATA3 was significantly higher in cell cultures of patients with severe HFRS than with a mild form. In contrast, MxA gene expression was up-regulated in cell cultures of patients with mild HFRS-PUUV. Considering individual genetic factors of HFRS patients would allow defining the best tactic of therapy and prophylaxis in this way. And as a result of applying this treatment in the clinical practice decrease of unfavorable disease outcome would occur.

Environmental Determinants of Hemorrhagic Fever with Renal Syndrome in High-Risk Counties in China: A Time Series Analysis (2002-2012).

The transmission pattern of hemorrhagic fever with renal syndrome (HFRS) is associated with environmental conditions, including meteorological factors and land-cover. In the present study, the association between HFRS and environmental factors (including maximum temperature, relative humidity, rainfall, and normalized difference vegetation index) were explored in two typical counties in Northeast and two counties in Northwest China with severe HFRS outbreaks by using seasonal autoregressive integrated moving average model with exogenous variables (SARIMAX). The results showed that rainfall with 3- to 4-month lag was closely associated with HFRS in the two counties in Northeast China, whereas relative humidity with 1- or 5-month lag significantly impacts HFRS transmission in the two counties in Northwest China. Moreover, the SARIMAX models exhibit accurate forecasting ability of HFRS cases. Our findings provide scientific support for local HFRS monitoring and control, and the development of a HFRS early warning system.

Neutrophil Activation in Acute Hemorrhagic Fever With Renal Syndrome Is Mediated by Hantavirus-Infected Microvascular Endothelial Cells.

Hantaviruses cause hemorrhagic fever with renal syndrome (HFRS) and hantavirus cardiopulmonary syndrome (HCPS) in humans. Both diseases are considered to be immunologically mediated but the exact pathological mechanisms are still poorly understood. Neutrophils are considered the first line of defense against invading microbes but little is still known of their role in virus infections. We wanted to study the role of neutrophils in HFRS using blood and tissue samples obtained from Puumala hantavirus (PUUV)-infected patients. We found that neutrophil activation products myeloperoxidase and neutrophil elastase, together with interleukin-8 (the major neutrophil chemotactic factor in humans), are strongly elevated in blood of acute PUUV-HFRS and positively correlate with kidney dysfunction, the hallmark clinical finding of HFRS. These markers localized mainly in the tubulointerstitial space in the kidneys of PUUV-HFRS patients suggesting neutrophil activation to be a likely component of the general immune response toward hantaviruses. We also observed increased levels of circulating extracellular histones at the acute stage of the disease supporting previous findings of neutrophil extracellular trap formation in PUUV-HFRS. Mechanistically, we did not find evidence for direct PUUV-mediated activation of neutrophils but instead primary blood microvascular endothelial cells acquired a pro-inflammatory phenotype and promoted neutrophil degranulation in response to PUUV infection in vitro. These results suggest that neutrophils are activated by hantavirus-infected endothelial cells and may contribute to the kidney pathology which determines the severity of HFRS.