Correlation of CD38 expression with the progression of hemorrhagic fever with renal syndrome.

To assess the relationship between the expression of CD38 and the progression of hemorrhagic fever with renal syndrome (HFRS), we determined the levels of CD38 during different phases of HFRS and evaluated the relationship between changes in CD38 expression and the progression of HFRS. The expression of CD38 in 68 patients with HFRS was analyzed by flow cytometry, and this method was also used to determine the levels of CD4+T, CD8+T, and B lymphocytes and NK cells. Furthermore, creatinine (Cr), uric acid (UA), and urea in serum at each stage of HFRS were measured using commercial kits. The basic clinical reference values for leukocytes, platelets (PLT), and red blood cells were determined by conventional methods. The colloidal gold method was used to measure HFRS antibody levels in the patients. A significant change in CD38 expression was observed from the fever phase to the recovery phase in patients with HFRS. Moreover, the expression of CD38 was proportionally correlated with the levels of Cr, UA, and urea in serum. In contrast, there was an inverse correlation between CD38 and PLT. Interestingly, an increase in CD38 expression correlated with an increase in CD8+T lymphocytes, B cells, and NK cells, but with a decrease in CD4+T lymphocytes. The expression of CD38 is associated with the progression of HFRS, suggesting that it may be a potent indicator of the stages of this disorder.

Hantavirus infection in Iranian patients suspected to viral hemorrhagic fever.

BACKGROUND: Hantaviruses are a group of emerging pathogens causing hemorrhagic fever with renal syndrome and Hantavirus cardiopulmonary syndrome in human. This study was conducted to investigate Hantavirus infection among Iranian viral hemorrhagic fever suspected patients. METHODS: From April 2014 to June 2016, 113 cases from 25 different provinces of Iran were analyzed for Hantavirus infection by IgM/IgG ELISA and pan-Hantavirus RT-PCR tests. RESULTS: Although, viral genome was detected in none of the subjects, IgM and IgG antibodies were detected in 19 and 4 cases, respectively. Differentiation of the anti-Hantavirus antibodies according to virus species by EUROLINE Anti-Hantavirus Profile Kit revealed three Puumala virus IgM positive, one Hantaan virus IgM positive, one Hantaan virus IgM borderline, and two Puumala virus IgG borderline cases. CONCLUSIONS: This study demonstrates the circulation of Hantaviruses in Iran and calls for further investigations of these life-threatening viruses in the country.

Serum fatty acids and progression from dengue fever to dengue haemorrhagic fever/dengue shock syndrome.

PUFA might modulate inflammatory responses involved in the development of severe dengue. We aimed to examine whether serum PUFA concentrations in patients diagnosed with dengue fever (DF) were related to the risk of progression to dengue haemorrhagic fever/dengue shock syndrome (DHF/DSS). A secondary aim was to assess correlations between fatty acids (FA) and inflammatory biomarkers in patients with DF. We conducted a prospective case-control study nested within a cohort of patients who were diagnosed with DF and followed during the acute episode. We compared the distribution of individual FA (% of total FA) at onset of fever between 109 cases who progressed to DHF/DSS and 235 DF non-progressing controls using unconditional logistic regression. We estimated correlations between baseline FA and cytokine concentrations and compared FA concentrations between the acute episode and >1 year post-convalescence in a subgroup. DHA was positively related to progression to DHF/DSS (multivariable adjusted OR (AOR) for DHA in quintile 5 v. 1=5·34, 95 % CI 2·03, 14·1; P trend=0·007). Dihomo-γ-linolenic acid (DGLA) was inversely associated with progression (AOR for quintile 5 v. 1=0·30, 95 % CI 0·13, 0·69; P trend=0·007). Pentadecanoic acid concentrations were inversely related to DHF/DSS. Correlations of PUFA with cytokines at baseline were low. PUFA were lower during the acute episode than in a disease-free period. In conclusion, serum DHA in patients with DF predicts higher odds of progression to DHF/DSS whereas DGLA and pentadecanoic acid predict lower odds.

Platelets and infections in the resource-limited countries with a focus on malaria and viral haemorrhagic fevers.

Infections continue to cause a high incidence of mortality and morbidity in resource-poor nations. Although antimicrobial therapy has aided mostly in dealing with the pathogenic micro-organisms themselves, the collateral damage caused by the infections continue to cause many deaths. Intensive care support and manipulation of the hosts' abnormal response to the infection have helped to improve mortality in well-resourced countries. But, in those areas with limited resources, this is not yet the case and simpler methods of diagnosis and interventions are required. Thrombocytopenia is one of the most common manifestations in all these infections and may be used as an easily available prognostic indicator and marker for the severity of the infections. In this review, the relevance of platelets in infections in general, and specifically to tropical infections, malaria, and viral haemorrhagic fevers in the emerging countries is discussed. Better understanding of the pathophysiology and the role of platelets in particular in such conditions is likely to translate into better patient care and thus reduce morbidity and mortality.

Low-dose ribavirin potentiates the antiviral activity of favipiravir against hemorrhagic fever viruses.

Favipiravir is approved in Japan to treat novel or re-emerging influenza viruses, and is active against a broad spectrum of RNA viruses, including Ebola. Ribavirin is the only other licensed drug with activity against multiple RNA viruses. Recent studies show that ribavirin and favipiravir act synergistically to inhibit bunyavirus infections in cultured cells and laboratory mice, likely due to their different mechanisms of action. Convalescent immune globulin is the only approved treatment for Argentine hemorrhagic fever caused by the rodent-borne Junin arenavirus. We previously reported that favipiravir is highly effective in a number of small animal models of Argentine hemorrhagic fever. We now report that addition of low dose of ribavirin synergistically potentiates the activity of favipiravir against Junin virus infection of guinea pigs and another arenavirus, Pichinde virus infection of hamsters. This suggests that the efficacy of favipiravir against hemorrhagic fever viruses can be further enhanced through the addition of low-dose ribavirin.

Undiagnosed acute viral febrile illnesses, Sierra Leone.

Sierra Leone in West Africa is in a Lassa fever-hyperendemic region that also includes Guinea and Liberia. Each year, suspected Lassa fever cases result in submission of ≈500-700 samples to the Kenema Government Hospital Lassa Diagnostic Laboratory in eastern Sierra Leone. Generally only 30%-40% of samples tested are positive for Lassa virus (LASV) antigen and/or LASV-specific IgM; thus, 60%-70% of these patients have acute diseases of unknown origin. To investigate what other arthropod-borne and hemorrhagic fever viral diseases might cause serious illness in this region and mimic Lassa fever, we tested patient serum samples that were negative for malaria parasites and LASV. Using IgM-capture ELISAs, we evaluated samples for antibodies to arthropod-borne and other hemorrhagic fever viruses. Approximately 25% of LASV-negative patients had IgM to dengue, West Nile, yellow fever, Rift Valley fever, chikungunya, Ebola, and Marburg viruses but not to Crimean-Congo hemorrhagic fever virus.

Simultaneous detection of IgG antibodies associated with viral hemorrhagic fever by a multiplexed Luminex-based immunoassay.

Viral hemorrhagic fevers (VHFs) are worldwide diseases caused by several kinds of viruses. With the emergence of new viruses, advanced diagnostic methods are urgently needed for identification of VHFs. Based on Luminex xMAP technology, a rapid, sensitive, multi-pathogen and high-throughput method which could simultaneously detect hemorrhagic fever viruses (HFVs) specific IgG antibodies was developed. Recombinant antigens of nine HFVs including Hantaan virus (HTNV), Seoul virus (SEOV), Puumala virus (PUUV), Andes virus (ANDV), Sin Nombre virus (SNV), Crimean-Congo hemorrhagic fever virus (CCHFV), Rift Valley fever virus (RVFV), Severe fever with thrombocytopenia syndrome bunyavirus (SFTSV) and dengue virus (DENV) were produced and purified from a prokaryotic expression system and the influence of the coupling amount was investigated. Cross-reactions among antigens and their rabbit immune sera were evaluated. Serum samples collected from 51 laboratory confirmed hemorrhagic fever with renal syndrome (HFRS) patients, 43 confirmed SFTS patients and 88 healthy donors were analyzed. Results showed that recombinant nucleocapsid protein of the five viruses belonging to the genus Hantavirus, had serological cross-reactivity with their corresponding rabbit immune sera, but not apparent with immune sera of other four viruses. Evaluation of this new method with clinical serum samples showed 98.04% diagnostic sensitivity for HFRS, 90.70% for SFTS detection and the specificity was ranging from 66.67% to 100.00%. The multiplexed Luminex-based immunoassay has firstly been established in our study, which provides a potentially reliable diagnostic tool for IgG antibody detection of VHFs.

Pathogenic mechanisms involved in the hematological alterations of arenavirus-induced hemorrhagic fevers.

Viral hemorrhagic fevers (VHFs) caused by arenaviruses are acute diseases characterized by fever, headache, general malaise, impaired cellular immunity, eventual neurologic involvement, and hemostatic alterations that may ultimately lead to shock and death. The causes of the bleeding are still poorly understood. However, it is generally accepted that these causes are associated to some degree with impaired hemostasis, endothelial cell dysfunction and low platelet counts or function. In this article, we present the current knowledge about the hematological alterations present in VHF induced by arenaviruses, including new aspects on the underlying pathogenic mechanisms.

Simian hemorrhagic fever virus infection of rhesus macaques as a model of viral hemorrhagic fever: clinical characterization and risk factors for severe disease.

Simian Hemorrhagic Fever Virus (SHFV) has caused sporadic outbreaks of hemorrhagic fevers in macaques at primate research facilities. SHFV is a BSL-2 pathogen that has not been linked to human disease; as such, investigation of SHFV pathogenesis in non-human primates (NHPs) could serve as a model for hemorrhagic fever viruses such as Ebola, Marburg, and Lassa viruses. Here we describe the pathogenesis of SHFV in rhesus macaques inoculated with doses ranging from 50 PFU to 500,000 PFU. Disease severity was independent of dose with an overall mortality rate of 64% with signs of hemorrhagic fever and multiple organ system involvement. Analyses comparing survivors and non-survivors were performed to identify factors associated with survival revealing differences in the kinetics of viremia, immunosuppression, and regulation of hemostasis. Notable similarities between the pathogenesis of SHFV in NHPs and hemorrhagic fever viruses in humans suggest that SHFV may serve as a suitable model of BSL-4 pathogens.

[Fluorescent microbeads-based multiplex detection of IgM antibodies to pathogens caused viral hemorrhagic fever].

OBJECTIVE: To develop and evaluate a multiplex detection of IgM antibodies to pathogens caused viral hemorrhagic fever. METHODS: The nucleocapsid proteins (NP) of HTN, SEO, Puu MBV, Lassa, RFV and HPS viruses expressed in prokaryotic cells and purified were coupled to 7 different xMAP fluorescent microbeads. The assay was evaluated and optimized when screened against a panel of reference sera collected from HFRS patients, and compared to commonly used MacELISA Kits. RESULTS: For detection of anti-NP antibodies, the sensitivity and specificity of the assay were comparable to a commonly used MacELISA kit, but it could detect different antigen specific antibodies in one reaction simultaneously. CONCLUSION: A robust, rapid and multiplex assay based on NPs could be developed via Luminex xMAP platform for laboratory diagnosis of viral hemorrhagic fever and seroepidemiological investigation.

Viral haemorrhagic fever and vascular alterations.

Pathogenesis of viral haemorrhagic fever (VHF) is closely associated with alterations of the vascular system. Among the virus families causing VHF, filoviruses (Marburg and Ebola) are the most fatal, and will be focused on here. After entering the body, Ebola primarily targets monocytes/macrophages and dendritic cells. Infected dendritic cells are largely impaired in their activation potency, likely contributing to the immune suppression that occurs during filovirus infection. Monocytes/macrophages, however, immediately activate after viral contact and release reasonable amounts of cytokines that target the vascular system, particularly the endothelial cells. Some underlying molecular mechanisms such as alteration of the vascular endothelial cadherin/catenin complex, tyrosine phosphorylation, expression of cell adhesion molecules, tissue factor and the effect of soluble viral proteins released from infected cells to the blood stream will be discussed.

[A clinical study on CD178 positive T lymphocyte in hemorrhagic fever with renal syndrome].

BACKGROUND: To further probe into the role of CD178 in the pathogenesis of hemorrhagic fever with renal syndrome (HFRS). METHODS: The expression of CD178 and HLA-DR on T cell subsets in peripheral blood of patients with HFRS and their dynamic changes were detected by Flow cytometry. RESULTS: CD4+ CD178+ and CD8+ CD178+ T lymphocytes both in fever and polyuria phases were significantly higher than those in normal controls, while there was no significant difference between the both phases of HFRS (P > 0.05). CD178 expression on CD4+ HLA-DR+ and CD8+ HLA-DR+ T lymphocytes were significantly higher than those in normal controls (P < 0.05, P < 0.01, P < 0.001, P < 0.001), while there was no significant difference between CD4+ HLA-DR+ and CD8+ HLA-DR+ T lymphocytes (P > 0.05). CONCLUSION: CD178 was expressed on both CD4+ and CD8+ T cell subsets, but mainly on CD8+ T cell subsets both in early stage and in later stage in the pathogenesis of HFRS. Cytotoxic T lymphocyte (CTL) might kill target cells infected by hantavirus (HV) and eliminate HV via cell apoptosis mediated by CD178 in early stage of HFRS. In later stage of HFRS, CD178 might reduce antigen-specific T lymphocytes by activation induced cell death (AICD) and help to maintain the homeostasis of immune system.

Serum albumin level correlates with disease severity in patients with Hemorrhagic Fever with Renal Syndrome.

Hypoalbuminemia frequently occurs in Hemorrhagic Fever with Renal Syndrome (HFRS), but clinical significance of hypoalbuminemia is not well known. This study was designed to evaluate hypoalbuminemia as a marker of severity of disease in patients with HFRS. We evaluated the relationship between the level of serum albumin and clinical parameters representing the severity of disease in 144 patients with HFRS. The patients were divided into three groups based on the level of serum albumin; Group I (normal serum albumin), Group II (serum albumin <3.5 g/dL and >/=3.0 g/dL), and Group III (serum albumin <3.0 g/dL). Of the total of 144 patients, 42 patients (29.2%) were categorized as Group I, 39 patients (27.1%) as Group II, and 63 patients (43.8%) as Group III. Group III had a higher rate of incidence in episode of hypotension, pulmonary edema than did Group I and Group II. The lowest level of serum albumin was positively correlated with platelet count (r=0.505, p<0.001) and was negatively correlated with leukocyte count (r=-0.329, p<0.001), BUN (r=-0.484, p<0.001), serum creatinine (r=-0.394, p<0.001), and AST (r=-0.251, p=0.002). Our data suggest that hypoalbuminemia frequently occurs in the acute stage of HFRS, and level of serum albumin is associated with the disease severity of HFRS.

Serum Albumin Level Correlates with Disease Severity in Patients with Hemorrhagic Fever with Renal Syndrome

Hypoalbuminemia frequently occurs in Hemorrhagic Fever with Renal Syndrome (HFRS), but clinical significance of hypoalbuminemia is not well known. This study was designed to evaluate hypoalbuminemia as a marker of severity of disease in patients with HFRS. We evaluated the relationship between the level of serum albumin and clinical parameters representing the severity of disease in 144 patients with HFRS. The patients were divided into three groups based on the level of serum albumin; Group I (normal serum albumin), Group II (serum albumin or =3.0 g/dL), and Group III (serum albumin <3.0 g/dL). Of the total of 144 patients, 42 patients (29.2%) were categorized as Group I, 39 patients (27.1%) as Group II, and 63 patients (43.8%) as Group III. Group III had a higher rate of incidence in episode of hypotension, pulmonary edema than did Group I and Group II. The lowest level of serum albumin was positively correlated with platelet count (r=0.505, p<0.001) and was negatively correlated with leukocyte count (r=-0.329, p<0.001), BUN (r=-0.484, p<0.001), serum creatinine (r=-0.394, p<0.001), and AST (r=-0.251, p=0.002). Our data suggest that hypoalbuminemia frequently occurs in the acute stage of HFRS, and level of serum albumin is associated with the disease severity of HFRS.

Effects of viral hemorrhagic fever inactivation methods on the performance of rapid diagnostic tests for Plasmodium falciparum.

Blood samples from patients with viral hemorrhagic fever (VHF) pose a serious risk to laboratory workers. Current contingency plans for VHF samples recommend the use of heat, gamma-irradiation, or Triton X-100 to inactivate samples before handling. Malaria is the most important alternative diagnosis to be excluded in cases of suspected VHF. Interpretation of malaria smears using samples inactivated with these methods is problematic because morphology is altered. The objective of this study was to assess the impact of different inactivation methods on the performance of rapid diagnostic tests for Plasmodium falciparum. Triton X-100 and gamma-irradiation of samples preserved detection. The impact of Triton X-100 inactivation was also "blindly" evaluated using 100 blood samples from febrile travelers. Triton X-100 inactivation of samples did not significantly affect the performance of these tests. This may represent a useful strategy for excluding the diagnosis of falciparum malaria in cases of suspected VHF.

Thrombocytopenia associated with apoptotic megakaryocytes in a viral haemorrhagic syndrome induced by a moderately virulent strain of African swine fever virus.

A viral haemorrhagic syndrome was induced in 14 pigs by inoculation with an African swine fever (ASF) virus strain of moderate virulence, to determine changes in megakaryocyte (MK) numbers and morphology and thus to assess the role of these cells in the thrombocytopenia characteristic of subacute ASF. The strain tested induced changes in the proportion of different types of MK (typical nucleated MKs, apoptotic MKs and immature MKs); it also caused subcellular lesions over the first 7 days post-inoculation (dpi). At 7 dpi, severe thrombocytopenia was observed. There was a statistically significant increase in apoptotic MK numbers. The MKs showed three stages in the course of the disease: a compensatory stage, represented by cytoplasmic projections, a hypermaturity stage, represented by apoptotic MKs, and a regenerative stage, represented by clusters of immature MKs. These changes, especially the presence of numerous apoptotic MKs, may explain the early and transitory thrombocytopenia detected in subacute ASF. The large number of apoptotic MKs observed may be associated with the accelerated maturation of these cells, resulting from the action of cytokines, or peripheral platelet consumption, or both.

Lethal experimental infections of rhesus monkeys by aerosolized Ebola virus.

The potential of aerogenic infection by Ebola virus was established by using a head-only exposure aerosol system. Virus-containing droplets of 0.8-1.2 microns were generated and administered into the respiratory tract of rhesus monkeys via inhalation. Inhalation of viral doses as low as 400 plaque-forming units of virus caused a rapidly fatal disease in 4-5 days. The illness was clinically identical to that reported for parenteral virus inoculation, except for the occurrence of subcutaneous and venipuncture site bleeding and serosanguineous nasal discharge. Immunocytochemistry revealed cell-associated Ebola virus antigens present in airway epithelium, alveolar pneumocytes, and macrophages in the lung and pulmonary lymph nodes; extracellular antigen was present on mucosal surfaces of the nose, oropharynx and airways. Aggregates of characteristic filamentous virus were present within type I pneumocytes, macrophages, and air spaces of the lung by electron microscopy. Demonstration of fatal aerosol transmission of this virus in monkeys reinforces the importance of taking appropriate precautions to prevent its potential aerosol transmission to humans.

Viruses and hemostasis.

The great majority of viral infections are not associated with significant alterations in hemostasis. Occasionally, common viral pathogens lead to illnesses in which hemostatic impairment is an important feature. In these instances, two clinical syndromes usually are present: thrombocytopenic purpura and disseminated intravascular coagulation. Immune mechanisms are implicated in the first, while the second is associated with severe disease. Hepatitis viruses produce hemorrhage by a third mechanism. In cases of fulminant hepatitis, hepatocellular injury leads to decreased production of multiple coagulation factors and impairment of other hepatic functions that modulate hemostasis. A small number of viruses stand apart by virtue of the frequency with which they cause hemorrhage. These are the hemorrhagic fever viruses. Much more needs to be learned about how these viruses cause disease and induce hemorrhage. The first line of therapy in viral infections complicated by hemorrhage is early treatment with an antiviral agent. Unfortunately, effective antiviral therapy is usually not available. There is little useful information and no controlled studies on the efficacy of therapy aimed directly at correcting hemostatic impairment.

Firsthand clinical observations of hemorrhagic manifestations in Ebola hemorrhagic fever in Zaire.

About 5 weeks after the beginning of the outbreak of Ebola virus fever in Yambuku, Zaire, several acute cases of the disease were observed. All of those affected had the following common signs and symptoms: sudden onset of high fever, with chills, headache, myalgia, anorexia, nausea, abdominal pain, sore throat, expressionless face, and profound prostration. In some cases, on around the fifth day of the acute phase, the appearance of an exanthematous rash on the trunk announced the hemorrhagic manifestations: hemorrhagic conjunctivitis, bleeding ulcerations in the mouth and on the lips, gingival bleeding, hematemesis, and melena; epistaxis, ear bleeding, hematuria, and postpartum hemorrhages were also reported. All these hemorrhagic cases had a fatal outcome within about a week. The hemorrhagic manifestations were less severe in the cases that occurred by the end of the outbreak than in the first reported cases. Hemorrhagic manifestations were less frequent and less severe, or even absent, in the nonfatal cases (convalescents, serologically confirmed). No biologic investigation of the hemostatic impairment could be performed under the emergency conditions of this field study.