Human cytomegalovirus, human herpesvirus-6 and human herpesvirus-7 in neutropenic patients with fever of unknown origin

Altered serum human cytomegalovirus microRNA levels are common and closely associated with the inflammatory status in patients with fever

Background

Fever has a complicated etiology, and diagnosing its causative factor is clinically challenging. Human cytomegalovirus (HCMV) infection causes various diseases. However, the clinical relevance, prevalence, and significance of HCMV microRNAs (miRNA) in association with fever remain unclear. In the present study, we analyzed the HCMV miRNA expression pattern in the serum of patients with fever and evaluate its clinical associations with occult HCMV infection status in immune disorders.

Methods

We included serum samples from 138 patients with fever and 151 age-gender-matched controls in this study. First, the serum levels of 24 HCMV miRNAs were determined using a hydrolysis probe-based stem-loop quantitative reverse transcription polymerase chain reaction (RT-qPCR) assay in the training set. The markedly altered miRNAs were verified in the validation and testing sets. The serum HCMV IgG/IgM and DNA titers in the testing cohort were also assessed using enzyme-linked immunosorbent assay (ELISA) and RT-qPCR, respectively.

Results

The majority of HCMV miRNAs were markedly upregulated in the serum of fever patients. We selected the five most significantly altered HCMV miRNAs: hcmv-miR-US4-3p, hcmv-miR-US29-3p, hcmv-miR-US5-2-3p, hcmv-miR-UL112-3p, and hcmv-miR-US33-3p for validation. These miRNAs were also significantly elevated in the serum of fever patients in the validation and testing sets compared with the controls. Logistic regression analysis revealed that the five miRNAs were novel potential risk factors for fever. Notably, the serum levels of four of the five confirmed HCMV miRNAs were significantly associated with blood C-reaction protein concentrations. Moreover, the five HCMV miRNA levels were closely correlated with the HCMV DNA titers in the testing cohort.

Conclusion

HCMV infection and activation are common in fever patients and could be novel risk factors for fever. These differentially expressed HCMV miRNAs could enable HCMV activation status monitoring in immune disorders.

Update in Viral Infections in the Intensive Care Unit

The advent of highly sensitive molecular diagnostic techniques has improved our ability to detect viral pathogens leading to severe and often fatal infections that require admission to the Intensive Care Unit (ICU). Viral infections in the ICU have pleomorphic clinical presentations including pneumonia, acute respiratory distress syndrome, respiratory failure, central or peripheral nervous system manifestations, and viral-induced shock. Besides de novo infections, certain viruses fall into latency and can be reactivated in both immunosuppressed and immunocompetent critically ill patients. Depending on the viral strain, transmission occurs either directly through contact with infectious materials and large droplets, or indirectly through suspended air particles (airborne transmission of droplet nuclei). Many viruses can efficiently spread within hospital environment leading to in-hospital outbreaks, sometimes with high rates of mortality and morbidity, thus infection control measures are of paramount importance. Despite the advances in detecting viral pathogens, limited progress has been made in antiviral treatments, contributing to unexpectedly high rates of unfavorable outcomes. Herein, we review the most updated data on epidemiology, common clinical features, diagnosis, pathogenesis, treatment and prevention of severe community- and hospital-acquired viral infections in the ICU settings.

Fever and Fever of Unknown Origin: Review, Recent Advances, and Lingering Dogma

Fever has preoccupied physicians since the earliest days of clinical medicine. It has been the subject of scrutiny in recent decades. Historical convention has mostly determined that 37.0°C (98.6°F) should be regarded as normal body temperature, and more modern evidence suggests that fever is a complex physiological response involving the innate immune system and should not be characterized merely as a temperature above this threshold. Fever of unknown origin (FUO) was first defined in 1961 by Petersdorf and Beeson and continues to be a clinical challenge for physicians. Although clinicians may have some understanding of the history of clinical thermometry, how average body temperatures were established, thermoregulation, and pathophysiology of fever, new concepts are emerging. While FUO subgroups and etiologic classifications have remained unchanged since 1991 revisions, the spectrum of diseases, clinical approach to diagnosis, and management are changing. This review considers how newer data should influence both definitions and lingering dogmatic principles. Despite recent advances and newer imaging techniques such as 18-fluorodeoxyglucose-positron emission tomography, clinical judgment remains an essential component of care.

Co-infections of human herpesviruses (CMV, HHV-6, HHV-7 and EBV) in non-transplant acute leukemia patients undergoing chemotherapy

Background

Human herpesviruses (HHVs) remain latent after primary infection and can be reactivated in response to immunosuppression and chemotherapy. Little is known about their incidence, potential relationships, risk factors and clinical impact in non-transplant leukemia patients.

This study investigated prospectively incidence, risk factors, clinical impact and possible association of HHVs-(1–7) infections in patients with newly diagnosed acute leukemia.

Methods

Study design involved longitudinal sampling before chemotherapy and in different phases of chemotherapy: post-induction, post-remission, and post-salvage during 2016–2018. A total of 734 plasma samples from 95 patients were analyzed by a qualitative, multiplex PCR for HHVs detection and a quantitative real-time PCR was used for cytomegalovirus (CMV) quantification. HHVs-(1–6) IgG and IgM antibodies were tested using immunoassays. Risk factors were analyzed by binary logistic regression and relationships between viruses were analyzed using the Chi-square or Fisher’s exact test as appropriate.

Results

The overall seroprevalences of HHV-(1–6) IgG were high (> 80%). At least one herpes viral agent was detected in 60 patients (63.3%). CMV was the most commonly detected virus in the different phases of chemotherapy (19.4%), followed by HHV-6 (9.7%), HHV-7 (5.2%) and EBV (2.7%). HSV-1/2 and VZV DNA were not detected. Twenty-seven patients (28.4%) had more than one virus detected in the follow-up, with 23 who were co-infected. CMV/HHV-6 was the most frequent co-infection (69.5%, 16/23). HHV-6 infection (p = 0.008) was identified as a risk factor for CMV infection while salvage treatment (p = 0.04) and CMV infection (p = 0.007) were found to be independent risk factors for HHV-6 infection. CMV co-infection was associated with severe lymphopenia with an absolute lymphocyte count (ALC) (< 500/μL) (p = 0.009), rash (p = 0.011), pneumonia (p = 0.016) and opportunistic infections [bacteremia, p < 0.001 and invasive fungal infection, (p = 0.024)] more frequently than CMV mono-viral infections.

Conclusions

Our data suggest that co-infection with HHVs, especially CMV and HHV-6, may contribute to the development of serious clinical manifestations with profound lymphopenia, pneumonia rash and increased risk for bacterial and fungal co-infections. These findings may suggest the synergistic effect of HHVs associated infection.

Human herpes viruses are associated with classic fever of unknown origin (FUO) in Beijing patients

BACKGROUND

Few reports have examined the viral aetiology of fever of unknown origin (FUO).

OBJECTIVE

This study determined the prevalence of human herpes virus (HHV) DNA in blood of Chinese patients with classic FUO using the polymerase chain reaction (PCR) and explored the possible role of HHV.

STUDY DESIGN

Blood samples were collected from 186 patients (151 children, 35 adults) with classic FUO and 143 normal individuals in Beijing during the years 2009-2012. The HHV DNA, including Herpes simplex virus (HSV)-1/2, Varicella zoster virus (VZV), Cytomegalovirus (CMV), Epstein-Barr virus (EBV), and Human herpes virus (HHV)-6 and -7, was detected by multiplex PCR. The epidemiological and clinical features were also analysed.

RESULTS

HHV DNA was detected in 63 (33.9%) of the FUO patients, and the prevalence of EBV and HHV-6 was significantly higher than in the normal cohort. HHV co-infection was also frequent (10.2%) in the patients with FUO. The majority of patients with HHV infection present with a fever only. Our data also revealed that EBV infection was associated with hepatitis and abnormal blood indices, HHV-6 was associated with a cough, and HHV-7 was associated with hepatitis.

CONCLUSIONS

HHVs are associated with Chinese patients (especially for children) with classic FUO. Our study adds perspective to the aetiological and clinical characteristics of classic FUO in beijing patients.

Management of sepsis in neutropenic patients: 2014 updated guidelines from the Infectious Diseases Working Party of the German Society of Hematology and Medical Oncology (AGIHO)

Sepsis is a major cause of mortality during the neutropenic phase after intensive cytotoxic therapies for malignancies. Improved management of sepsis during neutropenia may reduce the mortality of cancer therapies. Clinical guidelines on sepsis treatment have been published by others. However, optimal management may differ between neutropenic and non-neutropenic patients. Our aim is to give evidence-based recommendations for haematologist, oncologists and intensive care physicians on how to manage adult patients with neutropenia and sepsis.

Viral findings in adult hematological patients with neutropenia

Background

Until recently, viral infections in patients with hematological malignancies were concerns primarily in allogeneic hematopoietic stem cell transplant (HSCT) recipients. During the last years, changed treatment regimens for non-transplanted patients with hematological malignancies have had potential to increase the incidence of viral infections in this group. In this study, we have prospectively investigated the prevalence of a broad range of respiratory viruses in nasopharyngeal aspirate (NPA) as well as viruses that commonly reactivate after allogeneic HSCT.

Methodology/Principal Findings

Patients with hematological malignancies and therapy induced neutropenia (n = 159) were screened regarding a broad range of common respiratory viruses in the nasopharynx and for viruses commonly detected in severely immunosuppressed patients in peripheral blood. Quantitative PCR was used for detection of viruses. A viral pathogen was detected in 35% of the patients. The detection rate was rather similar in blood (22%) and NPA (18%) with polyoma BK virus and rhinovirus as dominating pathogens in blood and NPA, respectively. Patients with chronic lymphocytic leukemia (CLL) (p<0.01) and patients with fever (p<0.001) were overrepresented in the virus-positive group. Furthermore, viral findings in NPA were associated with upper respiratory symptoms (URTS) (p<0.0001).

Conclusions/Significance

Both respiratory viral infections and low titers of viruses in blood from patients with neutropenia were common. Patients with CLL and patients with fever were independently associated to these infections, and viral findings in NPA were associated to URTS indicating active infection. These findings motivate further studies on viruses' impact on this patient category and their potential role as causative agents of fever during neutropenia.

Lymphocyte and monocyte flow cytometry immunophenotyping as a diagnostic tool in uncharacteristic inflammatory disorders

BACKGROUND

Patients with uncharacteristic inflammatory symptoms such as long-standing fatigue or pain, or a prolonged fever, constitute a diagnostic and therapeutic challenge. The aim of the present study was to determine if an extended immunophenotyping of lymphocytes and monocytes including activation markers can define disease-specific patterns, and thus provide valuable diagnostic information for these patients.

METHODS

Whole blood from patients with gram-negative bacteraemia, neuroborreliosis, tuberculosis, acute mononucleosis, influenza or a mixed connective tissue disorders, as diagnosed by routine culture and serology techniques was analysed for lymphocyte and monocyte cell surface markers using a no-wash, no-lyse protocol for multi-colour flow cytometry method. The immunophenotyping included the activation markers HLA-DR and CD40. Plasma levels of soluble TNF alpha receptors were analysed by ELISA.

RESULTS

An informative pattern was obtained by combining two of the analysed parameters: (i), the fractions of HLA-DR-expressing CD4+ T cells and CD8+ T cells, respectively, and (ii), the level of CD40 on CD14+ CD16- monocytes. Patients infected with gram-negative bacteria or EBV showed a marked increase in monocyte CD40, while this effect was less pronounced for tuberculosis, borrelia and influenza. The bacterial agents could be distinguished from the viral agents by the T cell result; CD4+ T cells reacting in bacterial infection, and the CD8+ T cells dominating for the viruses. Patients with mixed connective tissue disorders also showed increased activation, but with similar engagement of CD4+ and CD8+ T cells. Analysis of soluble TNF alpha receptors was less informative due to a large inter-individual variation.

CONCLUSION

Immunophenotyping including the combination of the fractions of HLA-DR expressing T cell subpopulations with the level of CD40 on monocytes produces an informative pattern, differentiating between infections of bacterial and viral origin. Furthermore, a quantitative analysis of these parameters revealed the novel finding of characteristic patterns indicating a subacute bacterial infection, such as borreliosis or tuberculosis, or a mixed connective tissue disorder. The employed flow cytometric method is suitable for clinical diagnostic laboratories, and may help in the assessment of patients with uncharacteristic inflammatory symptoms.

Detection of β-herpesviruses in allogenic stem cell recipients by quantitative real-time PCR

The aim of this study was to investigate the clinical impact of reactivation of human herpes virus-6 (HHV-6) and HHV-7 infections in stem cell transplantation recipients, and to examine a possible increase in virulence of the two roseoloviruses when a reactivation of CMV (HHV-5) simultaneously occurs. For this purpose, quantitative real-time PCR systems were developed to assess the viral load of CMV, HHV-6, or HHV-7 in the plasma of haematopoetic stem cell recipients. One hundred and ninety-eight plasma samples from 37 patients who underwent allogeneic stem cell transplantation were tested for CMV, HHV-6, and HHV-7 by a 5'-exonuclease (TaqMan) quantitative real-time PCR. The CMV load obtained by the real-time PCR assay was compared retrospectively with results generated previously with a commercially available test (COBAS AMPLICOR CMV MONITOR Test, Roche). The results suggest that CMV and HHV-6 may be associated with post-transplantation end-organ disease, while HHV-7 reactivation had no impact on the patients included in this study. No evidence for a potential interaction of the roseoloviruses and CMV infections was found.

Real-time PCR in clinical microbiology: applications for routine laboratory testing

Real-time PCR has revolutionized the way clinical microbiology laboratories diagnose many human microbial infections. This testing method combines PCR chemistry with fluorescent probe detection of amplified product in the same reaction vessel. In general, both PCR and amplified product detection are completed in an hour or less, which is considerably faster than conventional PCR detection methods. Real-time PCR assays provide sensitivity and specificity equivalent to that of conventional PCR combined with Southern blot analysis, and since amplification and detection steps are performed in the same closed vessel, the risk of releasing amplified nucleic acids into the environment is negligible. The combination of excellent sensitivity and specificity, low contamination risk, and speed has made real-time PCR technology an appealing alternative to culture- or immunoassay-based testing methods for diagnosing many infectious diseases. This review focuses on the application of real-time PCR in the clinical microbiology laboratory.