Detection of herpes viruses by multiplex and real-time polymerase chain reaction in bronchoalveolar lavage fluid of patients with acute lung injury or acute respiratory distress syndrome

Qualitative evaluation of connective tissue disease with cytomegalovirus infection: A meta-analysis of case reports

BACKGROUND

The primary therapies for connective tissue disease include glucocorticoids and immunosuppressants. However, their prolonged usage can precipitate opportunistic infections, such as cytomegalovirus infection. When managing connective tissue disease complicated by cytomegalovirus infection, judicious selection of treatment modalities is crucial. This involves assessing the necessity for antiviral therapy and contemplating the reduction or cessation of glucocorticoids and immunosuppressants.

OBJECTIVE

This investigation sought to methodically review existing literature regarding treating connective tissue disease patients with cytomegalovirus infection.

METHODS

On July 5, 2023, an exhaustive literature search was conducted. Data analysis utilized the Kruskal-Wallis test or one-way analysis of variance, supplemented by Bonferroni post hoc testing.

RESULTS

Our meta-analysis incorporated 88 studies encompassing 146 connective tissue disease patients with CMV infections. The results indicated that patients with connective tissue disease and cytomegalovirus disease benefitted more from antiviral therapy than those not receiving such treatment (P = 0.003, P < 0.005). Furthermore, the strategic reduction of glucocorticoids and/or immunosuppressants was beneficial (P = 0.037, P < 0.05). Poor clinical outcomes with glucocorticoid-immunosuppressant combination therapy compared to other treatment modalities. The findings also suggested that CMV infection patients fare better without Cyclosporine A than using it (P = 0.041, P < 0.05).

CONCLUSION

Antiviral therapy is a viable treatment option in cases of connective tissue disease co-occurring with cytomegalovirus disease. Additionally, when connective tissue disease is stable, there is potential merit in reducing glucocorticoids and/or immunosuppressants, especially avoiding the combination of these drugs. For all cytomegalovirus infection patients, Cyclosporine A may be avoided wherever possible for selecting immunosuppressive agents if its use is not deemed essential in the treatment regimen.

Cytomegalovirus detection is associated with ICU admission in non-AIDS and AIDS patients with Pneumocystis jirovecii pneumonia

OBJECTIVES

Cytomegalovirus (CMV) is frequently detected in lung and/or blood samples of patients with Pneumocystis jirovecii pneumonia (PJP), although this co-detection is not precisely understood. We aimed to determine whether PJP was more severe in case of CMV detection.

METHODS

We retrospectively included all patients with a diagnosis of PJP between 2009 and 2020 in our centre and with a measure of CMV viral load in blood and/or bronchoalveolar lavage (BAL). PJP severity was assessed by the requirement for intensive care unit (ICU) admission.

RESULTS

The median age of the 249 patients was 63 [IQR: 53-73] years. The main conditions were haematological malignancies (44.2%), solid organ transplantations (16.5%), and solid organ cancers (8.8%). Overall, 36.5% patients were admitted to ICU. CMV was detected in BAL in 57/227 patients; the 37 patients with viral load ≥3 log copies/mL were more frequently admitted to ICU (78.4% vs 28.4%, p<0.001). CMV was also detected in blood in 57/194 patients; the 48 patients with viral load ≥3 log copies/mL were more frequently admitted to ICU (68.7% vs 29.4%, p<0.001). ICU admission rate was found to increase with each log of BAL CMV viral load and each log of blood CMV viral load.

CONCLUSIONS

PJP is more severe in the case of concomitant CMV detection. This may reflect either the deleterious role of CMV itself, which may require antiviral therapy, or the fact that patients with CMV reactivation are even more immunocompromised.

Isolation of Epstein-Barr virus-deoxyribonucleic acid in the lower respiratory tract for distinguishing critically ill patients from those with influenza-associated pneumonia: A pilot study

BACKGROUND

When influenza A-related pneumonia is complicated by bacteria, aspergillus, and other infections, the disease is aggravated, while there is no research on the role of Epstein-Barr virus (EBV) on patients with influenza A-related pneumonia. This study aimed to evaluate the relationship between the isolation of EBV and influenza A-related pneumonia.

METHODS

This is a clinical study based on the baseline data of a retrospective cohort. A total of 113 cases of influenza A-related pneumonia who underwent polymerase chain reaction test for isolation of EBV-DNA in lower respiratory tract specimens during six influenza seasons from 2013-2014 to 2018-2019 were enrolled. According to the results of EBV-DNA, patients were divided into EBV-positive group and EBV-negative group, and the role of EBV-DNA on patients with influenza A-related pneumonia was analyzed. Regression analysis was used to explore the potential risk factors for the development of moderate-to-severe acute respiratory distress syndrome (ARDS) in patients with influenza A-related pneumonia during hospitalization.

RESULTS

Among 113 patients with influenza A-related pneumonia, there were 53 patients with EBV-positive and 60 patients with EBV-negative. The EBV-positive group had higher intensive care unit admission rate, hospital stay, invasive mechanical ventilation rate, extracorporeal membrane oxygenation rate, Sequential Organ Failure Assessment (SOFA) score, and moderate-to-severe ARDS rate. Patients were divided into severe group and mild group. Patients in severe group had lower lymphocyte count, platelet count, and albumin level, while the levels of aspartate aminotransferase, alanine transaminase, creatine kinase, lactic dehydrogenase, and total bilirubin were higher in severe group. The levels of D-dimer, serum ferritin, C-reactive protein, and procalcitonin were higher in severe group than those in the mild group. Multivariate logistic regression analysis revealed that the isolation of EBV (odds ratio = 2.713, 95% confidence interval: 1.094-6.729, P = 0.031) and lymphocyte count (odds ratio = 3.585, 95% confidence interval: 1.157-11.101, P = 0.027) were independent risk factors for moderate-to-severe ARDS in patients with influenza A-related pneumonia.

CONCLUSION

The isolation rate of EBV in the lower respiratory tract was 46.9%. The length of hospital stays, intensive care unit admission rate, invasive mechanical ventilation rate, extracorporeal membrane oxygenation rate, SOFA score, and the proportion of moderate-to-severe ARDS in the EBV-positive group were higher than those in the EBV-negative group, while there was no effect on the death during hospitalization. The isolation of EBV in the lower respiratory tract and low lymphocyte count are independent risk factors for the development of moderate-to-severe ARDS in patients with influenza A-related pneumonia.

PANoptosis: Mechanism and Role in Pulmonary Diseases

PANoptosis is a newly defined programmed cell death (PCD) triggered by a series of stimuli, and it engages three well-learned PCD forms (pyroptosis, apoptosis, necroptosis) concomitantly. Normally, cell death is recognized as a strategy to eliminate unnecessary cells, inhibit the proliferation of invaded pathogens and maintain homeostasis; however, vigorous cell death can cause excessive inflammation and tissue damage. Acute lung injury (ALI) and chronic obstructive pulmonary syndrome (COPD) exacerbation is related to several pathogens (e.g., influenza A virus, SARS-CoV-2) known to cause PANoptosis. An understanding of the mechanism and specific regulators may help to address the pathological systems of these diseases. This review presents our understanding of the potential mechanism of PANoptosis and the role of PANoptosis in different pulmonary diseases.

Incidence and clinical features of HHV-7 detection in lower respiratory tract in patients with severe pneumonia: a multicenter, retrospective study

PURPOSE

The significance of detecting human herpesvirus 7 (HHV-7) in the lower respiratory tract of patients with severe pneumonia is unclear. This study aims to evaluate the clinical characteristics and prognosis of detecting HHV-7 in the lower respiratory tract of patients with severe pneumonia.

METHODS

Patients with severe pneumonia requiring invasive mechanical ventilation and underwent commercial metagenomic next-generation sequencing (mNGS) testing of bronchoalveolar lavage fluid from January 2019 to March 2023 were enrolled in 12 medical centers. Clinical data of patients were collected retrospectively, and propensity score matching was used for subgroup analysis and mortality assessment.

RESULTS

In a total number of 721 patients, 45 cases (6.24%) were identified with HHV-7 positive in lower respiratory tract. HHV-7 positive patients were younger (59.2 vs 64.4, p = 0.032) and had a higher rate of co-detection with Cytomegalovirus (42.2% vs 20.7%, p = 0.001) and Epstein-Barr virus (35.6% vs 18.2%, p = 0.008). After propensity score matching for gender, age, SOFA score at ICU admission, and days from ICU admission to mNGS assay, there was no statistically significant difference in the 28-day mortality rate between HHV-7 positive and negative patients (46.2% vs 36.0%, p = 0.395). Multivariate Cox regression analysis adjusting for gender, age, and SOFA score showed that HHV-7 positive was not an independent risk factor for 28-day mortality (HR 1.783, 95%CI 0.936-3.400, p = 0.079).

CONCLUSION

HHV-7 was detected in the lungs of 6.24% of patients with severe pneumonia. The presence of HHV-7 in patients with severe pneumonia requiring invasive mechanical ventilation is associated with a younger age and co-detected of Cytomegalovirus and Epstein-Barr virus. While HHV-7 positivity was not found to be an independent risk factor for mortality in this cohort, this result may have been influenced by the relatively small sample size of the study.

Updates in the management of respiratory virus infections in ICU patients: revisiting the non-SARS-CoV-2 pathogens

INTRODUCTION

Although viruses are an underestimated cause of community-acquired pneumonias (CAP) and hospital-acquired pneumonias (HAP)/ventilator-associated pneumonias (VAP) in intensive care unit (ICU) patients, they have an impact on morbidity and mortality.

AREAS COVERED

In this perspective article, we discuss the available data regarding the management of severe influenza CAP and herpesviridae HAP/VAP. We review diagnostic and therapeutic strategies in order to give clear messages and address unsolved questions.

EXPERT OPINION

Influenza CAP affects yearly thousands of people; however, robust data regarding antiviral treatment in the most critical forms are scarce. While efficacy of oseltamivir has been investigated in randomized controlled trials (RCT) in uncomplicated influenza, only observational data are available in ICU patients. Herpesviridae are an underestimated cause of HAP/VAP in ICU patients. Whilst incidence of herpesviridae identification in samples from lower respiratory tract of ICU patients is relatively high (from 20% to 50%), efforts should be made to differentiate local reactivation from true lung infection. Only few randomized controlled trials evaluated the efficacy of antiviral treatment in herpesviridae reactivation/infection in ICU patients and all were exploratory or negative. Further studies are needed to evaluate the impact of such treatment in specific populations.

Viral Ventilator-Associated Pneumonia/Hospital-Acquired Pneumonia

Among the viruses possibly responsible for hospital-acquired and ventilator-associated pneumonia, herpes simplex virus (HSV) is probably the most often involved: HSV reactivation is frequent in intensive care unit patients, and lung parenchymal infection (HSV bronchopneumonitis) has been well described, either using cytological signs of parenchymal involvement in cells obtained during bronchoalveolar lavage or using HSV virus load in the lower respiratory tract. Although treating patients with HSV bronchopneumonitis may be recommended, based on expert opinion, prophylactic or preemptive treatment of HSV reactivation should be avoided. Ventilator-associated pneumonia due to cytomegalovirus (CMV) is less frequent than HSV bronchopneumonitis, and more difficult to diagnose. No data exists on the impact of antiviral treatment on CMV pneumonia. The involvement of respiratory viruses has been described in patients with healthcare-associated pneumonia and hospital-acquired pneumonia, but their role in ventilator-associated pneumonia is not clear.

Multipathogen Detection in Patients with Respiratory Tract Infection: Identification of Non-respiratory Viruses Using Multiplex Real-time Polymerase Reaction

Background: Due to the overlapping clinical characteristics of respiratory tract infections (RTIs) and the unavailability of appropriate diagnostic techniques, the diagnosis of RTIs is controversial. Objectives: The study aimed to prompt the diagnosis of RTIs using commercial multiplex real-time PCR. Methods: The survey undertook for two years (2019 - 2020) on 144 flu-negative immunocompetent outpatients. Respiratory samples were examined by multiplex PCR assays. Results: Study population consisted of females (n = 77, 53.5%) and males (n = 67, 46.5%). The mean age was 42.8 ± 23.7 years. Thirty-one (21.5%) patients were infected with only one viral or bacterial infection. Eighty-two (57%) were infected with more than one pathogen. Ninety-five (37%) and 161 (62%) tests were positive for bacterial and viral pathogens, respectively. Community-acquired Pneumonia (CAP) and atypical CAP pathogens included 17% and 10% of respiratory specimens, respectively. The predominant pathogens consisted of Human Herpes Virus 7 (HHV-7) (n = 38, 15.5%), Epstein-Barr Virus (EBV) (n = 34, 13.8%), Mycoplasma pneumoniae (n = 24, 9.8%), and Human Herpes Virus 6 (HHV-6) (n = 21, 8.5%). There were associations between pathogen findings and special age categories. Fever, cough, dyspnea, and hemoptysis were associated with certain pathogens. There was no substantial difference between viral and bacterial Ct concerning gender, age group, and comorbidities. Conclusions: Multiplex diagnostic assays significantly increased the rate of appropriate diagnosis of respiratory pathogens. However, further investigation is needed to find non-respiratory viruses' significance in respiratory specimens of immunocompetent symptomatic patients.

Impact of multiplexed respiratory viral panels on infection control measures and antimicrobial stewardship: a review of the literature

Multiplexed respiratory viral panels (MRVP) have recently been added to the diagnostic work-up of respiratory infections. This review provides a summary of the main literature of MRVP for patients with regard to 3 different topics. Can the results of MRVP reduce the inappropriate use of antibiotics, can they guide the use of appropriate antiviral therapy and do they have an added value with respect to infection control measures? Literature was searched for based on a defined search string using both the PubMed and Embase database. Twenty-five articles report on the impact of MRVP on antibiotic therapy. In all the articles where active antimicrobial stewardship was performed (e.g., education/advice on interpreting results of MRVP) (N = 9), a reduction in antibiotic therapy was shown (with exception of 2 studies). Three studies evaluating the effect of MRVP on antimicrobial use in a population that is not suspected of having bacterial pneumonia (e.g., absence of radiology suggestive for bacterial infection or low PCT) found a positive impact on antibiotic therapy. Eight studies with a short TAT (< 7 h) had a positive impact on use of antibiotic therapy. Eleven studies focused on the impact of MRVP on antiviral use. In contrast to antibiotic reduction, all studies systematically objectified improved antiviral use as a consequence of MRVP results. With regard to the impact of MRVP on infection control, eleven articles were withheld. All these studies led to a more accurate use of infection control measures by detecting unidentified pathogens or stopping isolation precautions in case of a negative MRVP result. MRVP don’t reduce antibiotic therapy in all populations. Reduction seems more likely if the following factors are present: active antimicrobial stewardship, low likelihood of a bacterial infection, and a short turnaround time to result. With respect to antiviral therapy, all studies have an impact but the targeted use of antivirals is so far not that evidence based for all viral respiratory pathogens. Regarding infection control measures, the potential impact of MRVP is high because of the need of additional isolation precautions for many respiratory viruses, although logistical problems can occur.

[Reactivation of Epstein-Barr virus (Herpesviridae: Lymphocryptovirus, HHV-4) infection during COVID-19: epidemiological features]

INTRODUCTION

Immunodeficiency underlying the development of severe forms of new coronavirus infection may be the result of mixed infection with SARS-CoV-2 and other pathogens, including Epstein-Barr virus (EBV).The aim is to study the prevalence and epidemiological features of co-infection with SARS-CoV-2 and EBV.

MATERIAL AND METHODS

A cross-sectional randomized study was conducted in Moscow region from March to May 2020. Two groups were examined for EBV-markers: hospital patients (n = 95) treated for SARS-CoV-2 infection and blood donors (n = 92).

RESULTS

With equal EBV prevalence the detection of active infection markers in donors (10.9%) was noticeably lower than in SARS-CoV-2 patients (80%). Significant differences in this indicator were also found when patients from subgroups with interstitial pneumonia with the presence (96.6%) and absence (97.2%) of SARS-CoV-2 in the nasopharyngeal smear were compared with the subgroup of patients with mild COVID-19 (43.3%). The average IgG VCA and IgG EBNA positivity coefficients in donor group were higher than in patient group (p &lt; 0.05). Patients with active EBV infection markers were significantly more likely to have pneumonia, exceeding the reference values of ALT and the relative number of monocytes (odds ratio - 23.6; 3.5; 9.7, respectively).

DISCUSSION

The present study examined the incidence and analyzed epidemiological features of active EBV infection in patients with COVID-19.

CONCLUSION

A significantly higher rate of detection of active EBV infection markers in hospital patients indicates a combined participation SARS-CoV-2 and EBV in the development of interstitial pneumonia. Low levels of specific IgG EBV serve as predictors of EBV reactivation. Exceeding the reference values of ALT and the relative number of monocytes in patients should serve as a reason for examination for active EBV infection markers.

Bronchoalveolar lavage as a diagnostic procedure: a review of known cellular and molecular findings in various lung diseases

Bronchoalveolar lavage (BAL) is a commonly used procedure in the evaluation of lung disease as it allows for sampling of the lower respiratory tract. In many circumstances, BAL differential cell counts have been reported to be typical of specific lung disorders. In addition, more specific diagnostic tests including molecular assays such as polymerase chain reaction (PCR) or enzyme-linked immunosorbent assay, special cytopathologic stains, or particular microscopic findings have been described as part of BAL fluid analysis. This review focuses on common cellular and molecular findings of BAL in a wide range of lung diseases. Since the performance of the first lung irrigation in 1927, BAL has become a common and important diagnostic tool. While some pulmonary disorders have a highly characteristic signature of BAL findings, BAL results alone often lack specificity and require interpretation along with other clinical and radiographic details. Development of new diagnostic assays is certain to reinforce the utility of BAL in the future. Our review of the BAL literature is intended to serve as a resource to assist clinicians in the care of patients with lung disorders.

Influenza Infections and Emergent Viral Infections in Intensive Care Unit

Critically ill patients are admitted to an intensive care unit (ICU) for multiple reasons. In this study, we aim to analyze the current evidence and findings associated with influenza and other emergent viral infections, namely, herpes simplex virus type 1 (HSV-1), Epstein-Barr virus (EBV), and cytomegalovirus (CMV).

Among medical conditions, community-acquired respiratory infections are the most frequent reason for ventilatory support in ICUs. Community-acquired pneumonia in a severe form including the need of invasive mechanical ventilation and/or vasopressors is associated with high mortality rates. However, after the pandemic that occurred in 2009 by H1N1 influenza, the number of cases being admitted to ICUs with viral infections is on the rise. Patients in whom an etiology would not have been identified in the past are currently being tested with more sensitive viral molecular diagnostic tools, and patients being admitted to ICUs have more preexisting medical conditions that can predispose to viral infections. Viral infections can trigger the dysregulation of the immune system by inducing a massive cytokine response. This cytokine storm can cause endothelial damage and dysfunction, deregulation of coagulation, and, consequently, alteration of microvascular permeability, tissue edema, and shock. In severe influenza, this vascular hyperpermeability can lead to acute lung injury, multiorgan failure, and encephalopathy. In immunocompetent patients, the most common viral infections are respiratory, and influenza should be considered in patients with severe respiratory failure being admitted to ICU. Seasonality and coinfection are two important features when considering influenza as a pathogen in critically ill patients.

Herpesviridae (HSV, CMV, and EBV) may reactivate in ICU patients, and their reactivation is associated with morbidity/mortality. However, whether a specific treatment may impact on outcome remains to be determined.

Cytomegalovirus-associated acute respiratory failure in lupus patients: case reports in relation to cytomegalovirus biology

With the wide use of immunosuppressive agents, life-threatening cytomegalovirus-associated acute respiratory failure occurs frequently. However, this condition is yet to be fully recognized and the therapeutic approach to it can only be based on comprehensive protocols rather than the biological characteristics of cytomegalovirus. We describe three acute respiratory failure events that were related to the pathogenicity of cytomegalovirus, the primary cytopathic effect and secondary antiviral immunity-mediated damage. All cytomegalovirus infection occurred after immunosuppressive usage while the acute respiratory failure events took place in different clinical settings. The first acute respiratory failure event originated from the immunoinflammatory response after cytomegalovirus infection was circumscribed, while the second resulted from cytomegalovirus reactivation and the third was caused by the combined effect of acute cytomegalovirus infection and the subsequent immunoinflammatory response. According to the clinical setting, corresponding therapeutic approaches (sequential or combined strategy) were carried out. All the patients here presented were responsive to the above therapeutic strategies. Consequently, cytomegalovirus-associated acute respiratory failure in systemic lupus erythematosus patients should be carefully differentiated and a sequential or combined strategy should be carried out according to the clinical setting. Overall, we find that there are three patterns of cytomegalovirus-associated acute respiratory failure in systemic lupus erythematosus patients and propose a novel therapeutic strategy in relation to cytomegalovirus biology.

Use of an innovative and non-invasive device for virologic sampling of cough aerosols in patients with community and hospital acquired pneumonia: a pilot study

BACKGROUND

The aetiology of lower respiratory tract infections is challenging to investigate. Despite the wide array of diagnostic tools, invasive techniques, such as bronchoalveolar lavage (BAL), are often required to obtain adequate specimens. PneumoniaCheckTM is a new device that collects aerosol particles from cough, allowing microbiological analyses. Up to now it has been tested only for bacteria detection, but no study has investigated its usefulness for virus identification.

METHODS

In this pilot study we included 12 consecutive patients with pneumonia. After testing cough adequacy via a peak flow meter, a sampling with PneumoniaCheckTM was collected and a BAL was performed in each patient. Microbiological analyses for virus identification were performed on each sample and concordance between the two techniques was tested (sensitivity, specificity and positive/negative predictive values), taking BAL results as reference.

RESULTS

BAL was considered adequate in 10 patients. Among them, a viral pathogen was identified by PneumoniaCheckTM 6 times, each on different samples, whereas BAL allowed to detect the presence of a virus on 7 patients (14 positivities). Overall, the specificity for PneumoniaCheckTM to detect a virus was 100%, whereas the sensitivity was 66%. When considering only herpes viruses, PneumoniaCheckTM showed a lower sensitivity, detecting a virus in 1/4 of infected patients (25%).

CONCLUSIONS

In this pilot study PneumoniaCheckTM showed a good correlation with BAL for non-herpes virologic identification in pneumonia patients, providing excellent specificity. Further studies on larger population are needed to confirm these results and define its place in the panorama of rapid diagnostic tests for lower respiratory tract infections.

Pleural effusions induced by human herpesviruses in the immunocompetent host

METHODS

A computer-based search of the English literature for articles relative to Human Herpesviruses (HHVs) infection and pleural effusions (PEs) in the immunocompetent host was performed in PubMed and Scopus. The reference lists of the retrieved articles were also reviewed for relevant articles.

RESULTS

A total of 20 articles satisfied the selection criteria and were included in the study. In the majority of the articles, PEs were reported as clinical complications of systemic HHV-induced infection. The frequency of HHVs within the reported cases was five for HHV-1/2, one for HHV-3, six for HHV-4, six for HHV-5 and one for HHV-6. One case involved HHV-4 and HHV-5 co-infection. No case of HHV-7 or HHV-8 related PE in the immunocompetent host was retrieved.

CONCLUSIONS

Pleural effusions in the immunocompetent host occur in severe viral infections and can be due to comorbidities (or septic complications) or due to the direct HHV pathogenicity although research relative to the susceptibility of pleural mesothelial cells to HHV infection is lacking. HHV pathogenicity needs to be studied further as it could explain undiagnosed PEs.

Human herpesvirus 6 encephalitis in patients administered mycophenolate mofetil as prophylaxis for graft-versus-host disease after allogeneic hematopoietic stem cell transplantation

BACKGROUND

Human herpesvirus 6 (HHV-6) encephalitis is a known life-threatening complication following allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, few studies have focused on the occurrence of HHV-6 encephalitis in patients receiving mycophenolate mofetil (MMF) combined with a calcineurin inhibitor as prophylaxis for graft-versus-host disease (GVHD). This study aimed to investigate the impact of MMF administered for GVHD prophylaxis in the occurrence of HHV-6 encephalitis after allo-HSCT and the characteristics of this condition.

METHODS AND RESULTS

We retrospectively analyzed 73 patients who underwent allo-HSCT (83 transplants) at our hospital between April 2010 and December 2015. MMF (2-3 g/d) was administered along with a calcineurin inhibitor. Seven patients (8.0%) developed encephalitis due to HHV-6. The median period from allo-HSCT to the onset of HHV-6 encephalitis was 23 days (range, 17-98 days). The cumulative incidence of HHV-6 encephalitis on day 100 after treatment was 12% and 6% in patients who underwent cord blood transplantation (CBT) and non-CBT (ie, bone marrow transplantation and peripheral blood stem cell transplantation), respectively (P = 0.344). Neurological symptoms of encephalitis were more severe in non-CBT cases than those in CBT cases. All patients diagnosed with HHV-6 encephalitis were treated with ganciclovir or foscarnet. None of the enrolled patients died from HHV-6 encephalitis.

CONCLUSIONS

Mycophenolate mofetil may have the potential to increase the frequency of severe HHV-6 encephalitis in patients undergoing CBT and non-CBT. Thus, MMF should be administered with caution, and patients should be monitored closely for HHV-6 encephalitis even those who did not undergo CBT.

Screening for 15 pathogenic viruses in human cell lines registered at the JCRB Cell Bank: characterization of in vitro human cells by viral infection

Human cell lines have been used in a variety of research fields as an in vitro model. These cells are all derived from human tissue samples, thus there is a possibility of virus infection. Virus tests are routinely performed in clinical practice, but are limited in cell lines. In this study, we investigated 15 kinds of viruses in 844 human cell lines registered at the Japanese Collection of Research Bioresources (JCRB) Cell Bank. Our real-time PCR analysis revealed that six viruses, EBV, HTLV-1, HBV, B19V, HHV-6 and HHV-7, were detected in 43 cell lines. Of them, 20 cell lines were transformed by intentional infection in vitro with EBV or HTLV-1. Viruses in the other 23 cell lines and one EBV transformed cell line are derived from an in vivo infection, including five de novo identifications of EBV, B19V or HHV-7 carriers. Among them, 17 cell lines were established from patients diagnosed with virus-associated diseases. However, the other seven cell lines originated from in vivo cells unrelated to disease or cellular tropism. Our approach to screen for a set of 15 viruses in each cell line has worked efficiently to identify these rare cases. Virus tests in cell lines contribute not only to safety assessments but also to investigation of in vivo viral infection which can be a characteristic feature of cell lines.

High-sensitivity virus and mycoplasma screening test reveals high prevalence of parvovirus B19 infection in human synovial tissues and bone marrow

Background

Latent microorganism infection is a safety concern for the clinical application of mesenchymal stem cells (MSCs). The aim of this study is to investigate the frequencies and sensitivities of the latent virus and mycoplasma infections in synovium, bone marrow, peripheral blood cells, and blood plasma and cultured synovial MSCs.

Methods

Total DNA and RNA of the synovium (n = 124), bone marrow (n = 123), peripheral blood cells (n = 121), plasma (n = 121), and 14-day cultured synovial MSCs (n = 63) were collected from patients who underwent total knee arthroplasty or anterior ligament reconstruction after written informed consents were obtained. The multiplex polymerase chain reaction (PCR) primers were designed to quantitatively measure the representative genomes of 13 DNA viruses, 6 RNA viruses, and 9 mycoplasmas. Multi-spliced mRNA detection and virus spike test were also performed to demonstrate the sensitivity of synovial MSCs to the candidate pathogens.

Results

In synovium and bone marrow, the positive rates of parvovirus B19 genome were significantly higher than in peripheral blood cells (18.7% and 22% vs. 0.8%, respectively). Multi-alignment analysis of amplified and sequenced viral target genes showed the proximity of the parvovirus B19 gene from different tissue in the same patients. Synovial MSCs cultured for 14 days were positive for virus infection only in two patients (2/62 = 3%). Parvovirus B19 multi-spliced mRNAs were not detected in these two samples. Virus spike test demonstrated the sensitivity of synovial MSCs to herpes simplex virus (HSV)1 and cytomegalovirus (CMV), but not to parvovirus B19.

Conclusion

This study revealed a relatively high incidence of latent parvovirus B19 in synovium and bone marrow tissue.

Electronic supplementary material

The online version of this article (10.1186/s13287-018-0811-7) contains supplementary material, which is available to authorized users.

Cause of acute encephalitis/encephalopathy in Japanese children diagnosed by a rapid and comprehensive virological detection system and differences in their clinical presentations

BACKGROUND

Acute encephalitis/encephalopathy (AE/E) is a rare and severe complication of common childhood infections; however, a treatment strategy based on clinical and pathological evidence has not been established.

METHODS

The clinical data and aetiological results using a rapid and comprehensive virological detection system of 62 Japanese children diagnosed with AE/E from 2010 to 2014 were collected. We assessed clinical differences between causes and effectiveness of our multiplex PCR system to establish a pathogen-based treatment strategy for AE/E.

RESULTS

Suspected causes were detected in 84% of patients, and our multiplex PCR system contributed to diagnosing 38% of the patients. Furthermore, a negative virus PCR might be important for inferring underlying disease. Most cases were triggered by human herpes virus (HHV) 6/7 (32%) and influenza virus (24%). The causes of AE/E depended on age (p=0.00089) but not on sex (p=0.94). The median age of HHV6/7-associated AE/E was 2.3years, which is lower than the median ages of AE/E associated with other viruses. Major initial treatments were pulse steroid therapy (83.9%) and acyclovir (71%). Most of the patients in this study had good prognoses: 77% recovered without neurological sequalae.

CONCLUSIONS

Our virological detection system was useful for detecting the cause of AE/E, and may also contribute to construction of pathogen-based treatment strategies for AE/E. Our data indicated the possibility that early intervention with pulse steroid therapy could be effective for treating AE/E. Further investigation for selection of antiepileptic drugs and additional therapies might be required to prevent progression of AE/E.

Human herpesviruses respiratory infections in patients with acute respiratory distress (ARDS)

Acute respiratory distress syndrome (ARDS) is today a leading cause of hospitalization in intensive care unit (ICU). ARDS and pneumonia are closely related to critically ill patients; however, the etiologic agent is not always identified. The presence of human herpes simplex virus 1, human cytomegalovirus and Epstein–Barr virus in respiratory samples of critically ill patients is increasingly reported even without canonical immunosuppression. The main aim of this study was to better understand the significance of herpesviruses finding in lower respiratory tract of ARDS patients hospitalized in ICU. The presence of this group of herpesviruses, in addition to the research of influenza viruses and other common respiratory viruses, was investigated in respiratory samples from 54 patients hospitalized in ICU, without a known microbiological causative agent. Moreover, the immunophenotype of each patient was analyzed. Herpesviruses DNA presence in the lower respiratory tract seemed not attributable to an impaired immunophenotype, whereas a significant correlation was observed between herpesviruses positivity and influenza virus infection. A higher ICU mortality was significantly related to the presence of herpesvirus infection in the lower respiratory tract as well as to impaired immunophenotype, as patients with poor outcome showed severe lymphopenia, affecting in particular T (CD3+) cells, since the first days of ICU hospitalization. In conclusion, these results indicate that herpesviruses lower respiratory tract infection, which occurs more frequently following influenza virus infection, can be a negative prognostic marker. An independent risk factor for ICU patients with ARDS is an impaired immunophenotype.

Which patients with ARDS benefit from lung biopsy?

A central tenet of caring for patients with ARDS is to treat the underlying cause, be it sepsis, pneumonia, or removal of an offending toxin. Identifying the risk factor for ARDS has even been proposed as essential to diagnosing ARDS. Not infrequently, however, the precipitant for acute hypoxemic respiratory failure is unclear, and this raises the question of whether a histologic lung diagnosis would benefit the patient. In this review, we consider the historic role of pathology in establishing a diagnosis of ARDS and the published experience of surgical and transbronchial lung biopsy in patients with ARDS. We reflect on which pathologic diagnoses influence treatment and suggest a patient-centric approach to weigh the risks and benefits of a lung biopsy for critically ill patients who may have ARDS.

Herpes simplex virus 2 infection: molecular association with HIV and novel microbicides to prevent disease

Infection with herpes simplex viruses is one of the most ancient diseases described to affect humans. Infection with these viruses produces vexing effects to the host, which frequently recur. Infection with herpes simplex viruses is lifelong, and currently there is no vaccine or drug to prevent or cure infection. Prevalence of herpes simplex virus 2 (HSV-2) infection varies significantly depending on the geographical region and nears 20% worldwide. Importantly, HSV-2 is the first cause of genital ulcers in the planet. HSV-2 affects approximately 500 million people around the globe and significantly increases the likelihood of acquiring the human immunodeficiency virus (HIV), as well as its shedding. Thus, controlling HSV-2 infection and spread is of public health concern. Here, we review the diseases produced by herpes simplex viruses, the factors that modulate HSV-2 infection, the relationship between HSV-2 and HIV and novel therapeutic and prophylactic microbicides/antivirals under development to prevent infection and pathological outcomes produced by this virus. We also review mutations associated with HSV-2 resistance to common antivirals.