Cytomegalovirus pneumonia in immunocompetent host: case report and literature review

Immune surveillance of cytomegalovirus in tissues

Cytomegalovirus (CMV), a representative member of the Betaherpesvirinae subfamily of herpesviruses, is common in the human population, but immunocompetent individuals are generally asymptomatic when infected with this virus. However, in immunocompromised individuals and immunologically immature fetuses and newborns, CMV can cause a wide range of often long-lasting morbidities and even death. CMV is not only widespread throughout the population but it is also widespread in its hosts, infecting and establishing latency in nearly all tissues and organs. Thus, understanding the pathogenesis of and immune responses to this virus is a prerequisite for developing effective prevention and treatment strategies. Multiple arms of the immune system are engaged to contain the infection, and general concepts of immune control of CMV are now reasonably well understood. Nonetheless, in recent years, tissue-specific immune responses have emerged as an essential factor for resolving CMV infection. As tissues differ in biology and function, so do immune responses to CMV and pathological processes during infection. This review discusses state-of-the-art knowledge of the immune response to CMV infection in tissues, with particular emphasis on several well-studied and most commonly affected organs.

The Wide Spectrum of Presentations of Cytomegalovirus Infection in Immunocompetent Hosts: An Exhaustive Narrative Review

CMV is a ubiquitous DNA virus that establishes infection and results in 40-100% seropositivity. Viral replication occurs following an acquired primary infection (or reinfection) or by the reactivation of life-long latency. In immunocompetent patients, CMV infection is mostly asymptomatic or mild and self-limited. However, an extensive review of the literature published up to April 2024 reveals that despite immunocompetence, CMV can cause a very large variety of clinical syndromes in any part of the gastrointestinal tract (the most common pattern), the central or peripheral nervous system, and the eyes, as well as hematological, pulmonary, cardiac, and cutaneous disease. Not uncommonly, more than one system is involved, and though the disease is often self-limited, treatment with intravenous ganciclovir or oral valganciclovir may be required, and in isolated cases, fatalities may occur. Thus, a potential CMV infection should be considered in the differential of myriad syndromes in non-immunocompromised patients. Associated systemic symptoms (fever, sweats, and weight loss), lymphocytosis, and hepatitis are not uncommon and can be a useful clue. Some populations, such as critically ill patients in intensive care, pregnant women, elderly patients, and those with inflammatory bowel disease, may be more susceptible. Moreover, the potential of past, latent CMV infection (i.e., CMV seropositivity) to be associated with significant cardiovascular morbidity and all-cause mortality years later is intriguing and requires further study. All these data indicate the outstanding importance of developing a vaccine against CMV, which hopefully will become available in the foreseeable future. Meanwhile, a solid diagnosis of active CMV infection can be quickly established (or ruled out) by widely available serology tests and PCR amplification, and clinicians in all disciplines need to be more aware of the diverse guises of CMV infection and remember to consider it in any host, including an immunocompetent one.

Clinical characteristics of pediatric patients hospitalized with community-acquired pneumonia and cytomegalovirus DNA detected in bronchoalveolar lavage fluid

Background

This study aimed to investigate the clinical characteristics of pediatric patients hospitalized with community-acquired pneumonia (CAP) and concomitant cytomegalovirus (CMV) infection.

Methods

This cross-sectional study enrolled consecutive pediatric patients admitted with CAP who tested positive for CMV DNA in bronchoalveolar lavage fluid (BALF). Flexible fiberoptic bronchoscopy was performed when routine treatment for CAP proved ineffective. The study participants were further stratified into two groups based on CMV serological test results: recent CMV infection group and CMV replication group. Clinical characteristics were compared between these two groups.

Results

Among 124 patients aged 1-11 months included in this study, 80 (64.5%) patients were categorized as having recent CMV infection, and 44 (35.5%) tested positive for CMV replication. Co-infection with other pathogens was detected more frequently in the CMV replication group (n = 29, 65.9%) than in the recent CMV infection group (n = 35, 43.7%; P = 0.018). Patients with recent CMV infection were younger and exhibited higher levels of alanine transaminase (ALT) and aspartate aminotransferase compared to those with CMV replication (all P < 0.05). Multivariable regression analysis showed age was independently associated with recent CMV infection (odds ratio [OR], 0.707; 95% confidence interval [CI], 0.586-0.853; P < 0.001). Notably, receiver operating characteristic curve analysis showed that a CMV PCR level of 3,840 copies/ml in blood samples had a sensitivity of 34.7% and specificity of 90.0% for diagnosis of recent CMV infection with an area under the curve (AUC) of 0.625 (95% CI: 0.513-0.736, P = 0.048). A CMV PCR level of 6,375 copies/ml in urine samples had a sensitivity of 77.1% and specificity of 61.5% for diagnosis of recent CMV infection with an AUC of 0.695 (95% CI: 0.531-0.858, P = 0.04). Furthermore, multivariate linear regression analysis revealed that the blood CMV DNA copy number was associated with ALT (B = 0.001; P < 0.001).

Conclusions

The CMV DNA copy numbers in blood and urine could serve as discriminatory markers between recent CMV infection and CMV replication. Measuring CMV DNA levels in blood may be an effective method for monitoring liver function impairment in pediatric patients presenting with CAP and concurrent CMV infection.

Influenza and Viral Pneumonia

Influenza and other respiratory viruses are commonly identified in patients with community-acquired pneumonia, hospital-acquired pneumonia, and in immunocompromised patients with pneumonia. Clinically, it is difficult to differentiate viral from bacterial pneumonia. Similarly, the radiological findings of viral infection are in general nonspecific. The advent of polymerase chain reaction testing has enormously facilitated the identification of respiratory viruses, which has important implications for infection control measures and treatment. Currently, treatment options for patients with viral infection are limited but there is ongoing research on the development and clinical testing of new treatment regimens and strategies.

Cytomegalovirus Pneumonia in a Patient with Down Syndrome

Down syndrome (DS) is a chromosomal disorder due to the presence of an additional chromosome 21 that causes intellectual deficit and physical anomalies and predisposes patients to develop infections throughout their lives. Pneumonias are more serious in patients with DS, requiring hospitalization, and they represent an important cause of mortality in this population. Cytomegalovirus (CMV) causes widespread and serious infections in immunocompromised individuals, affecting the respiratory tract and, when causing interstitial pneumonia, associated with a high mortality rate. However, CMV-induced pneumonia is not reported in DS patients. The prevalence and severity of CMV respiratory infections in subjects with DS is unknown. This case describes a 50-year-old female patient with DS who developed extensive bilateral pneumonia with severe respiratory failure which required hospitalization in intensive care, intubation, and mechanical ventilation after approximately 10 days of empiric antibiotic and anitimycotic therapy for fever, cough, and dyspnea. The patient was diagnosed with CMV pneumonia and recovered after treatment with ganciclovir. To the best of our knowledge, this is the first reported case of CMV pneumonia in a patient with DS. This case aims to highlight that CMV pneumonia in individuals with DS can be a life-threatening condition. It also clarifies the importance of early diagnosis of infections from opportunistic pathogens such as CMV to ensure timely and efficient treatment.

Primary Cytomegalovirus Pneumonia Successfully Treated with Corticosteroid Therapy and Valganciclovir

Cytomegalovirus infection is typically asymptomatic in immunocompetent individuals. A 26-year-old woman was admitted to our hospital with a fever and breathlessness. Chest computed tomography (CT) revealed bilateral diffuse reticulation and nodules. Laboratory investigations showed atypical lymphocytosis and increased transaminases. She was treated with corticosteroid pulse therapy because of acute lung injury, and her clinical condition improved. Based on the presence of cytomegalovirus antibodies, antigen, and polymerase chain reaction findings, she was diagnosed with primary cytomegalovirus pneumonia and treated with valganciclovir. Primary cytomegalovirus pneumonia is very rare in immunocompetent individuals. The efficacy of corticosteroid and valganciclovir against cytomegalovirus pneumonia in this patient is noteworthy.

Cytomegalovirus-Related Gastritis in an Immunocompetent Host Presenting With Infectious Gastroparesis

Cytomegalovirus (CMV) infection is usually asymptomatic or causes a mild mononucleosis-like syndrome, whereas severe symptoms are rarely reported. We report a case of a 70-year-old woman who was admitted to our center because of severe clinical presentation with anorexia, epigastric pain, nausea, postprandial vomiting, and significant weight loss. Esophagogastroduodenoscopy with biopsies showed ulcerative chronic gastritis with scattered large cells with inclusion bodies. Immunohistochemistry and polymerase chain reaction for CMV-DNA resulted positive. A gastric emptying of solid scintigraphy showed severe gastroparesis. The patient was discharged after 2 months of antiviral therapy completely asymptomatic. To the best of our knowledge, this is the first case of CMV-related gastroparesis in an immunocompetent patient, successfully treated with antiviral therapy.

Prediction of mortality in pneumonia patients with connective tissue disease treated with glucocorticoids or/and immunosuppressants by machine learning

Objectives

The assessment of accurate mortality risk is essential for managing pneumonia patients with connective tissue disease (CTD) treated with glucocorticoids or/and immunosuppressants. This study aimed to construct a nomogram for predicting 90-day mortality in pneumonia patients using machine learning.

Methods

Data were obtained from the DRYAD database. Pneumonia patients with CTD were screened. The samples were randomly divided into a training cohort (70%) and a validation cohort (30%). A univariate Cox regression analysis was used to screen for prognostic variables in the training cohort. Prognostic variables were entered into the least absolute shrinkage and selection operator (Lasso) and a random survival forest (RSF) analysis was used to screen important prognostic variables. The overlapping prognostic variables of the two algorithms were entered into the stepwise Cox regression analysis to screen the main prognostic variables and construct a model. Model predictive power was assessed using the C-index, the calibration curve, and the clinical subgroup analysis (age, gender, interstitial lung disease, diabetes mellitus). The clinical benefits of the model were assessed using a decision curve analysis (DCA). Similarly, the C-index was calculated and the calibration curve was plotted to verify the model stability in the validation cohort.

Results

A total of 368 pneumonia patients with CTD (training cohort: 247; validation cohort: 121) treated with glucocorticoids or/and immunosuppressants were included. The univariate Cox regression analysis obtained 19 prognostic variables. Lasso and RSF algorithms obtained eight overlapping variables. The overlapping variables were entered into a stepwise Cox regression to obtain five variables (fever, cyanosis, blood urea nitrogen, ganciclovir treatment, and anti-pseudomonas treatment), and a prognostic model was constructed based on the five variables. The C-index of the construction nomogram of the training cohort was 0.808. The calibration curve, DCA results, and clinical subgroup analysis showed that the model also had good predictive power. Similarly, the C-index of the model in the validation cohort was 0.762 and the calibration curve had good predictive value.

Conclusion

In this study, the nomogram developed performed well in predicting the 90-day risk of death in pneumonia patients with CTD treated with glucocorticoids or/and immunosuppressants.

Deciphering Microbiota of Acute Upper Respiratory Infections: A Comparative Analysis of PCR and mNGS Methods for Lower Respiratory Trafficking Potential

Although it is clinically important for acute respiratory tract (co)infections to have a rapid and accurate diagnosis, it is critical that respiratory medicine understands the advantages of current laboratory methods. In this study, we tested nasopharyngeal samples (n = 29) with a commercially available PCR assay and compared the results with those of a hybridization-capture-based mNGS workflow. Detection criteria for positive PCR samples was Ct < 35 and for mNGS samples it was >40% target coverage, median depth of 1X and RPKM > 10. A high degree of concordance (98.33% PPA and 100% NPA) was recorded. However, mNGS yielded positively 29 additional microorganisms (23 bacteria, 4 viruses, and 2 fungi) beyond PCR. We then characterized the microorganisms of each method into three phenotypic categories using the IDbyDNA Explify^® Platform (Illumina^® Inc, San Diego, CA, USA) for consideration of infectivity and trafficking potential to the lower respiratory region. The findings are significant for providing a comprehensive yet clinically relevant microbiology profile of acute upper respiratory infection, especially important in immunocompromised or immunocompetent with comorbidity respiratory cases or where traditional syndromic approaches fail to identify pathogenicity. Accordingly, this technology can be used to supplement current syndrome-based tests, and data can quickly and effectively be phenotypically characterized for trafficking potential, clinical (co)infection, and comorbid consideration-with promise to reduce morbidity and mortality.

Hemophagocytic Lymphohistiocytosis Associated With Cytomegalovirus Infection: 5 Cases and a Systematic Review of the Literature

Hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening disorder characterized by an uncontrolled, persistent, hyperimmune response. It can be triggered by an infectious, neoplastic, or autoimmune event. The involvement of cytomegalovirus (CMV) in the onset of HLH is subject to debate, and the epidemiology of CMV-associated HLH (HLH-CMV) remains poorly characterized. We identified 5 cases of HLH-CMV in our hospital, systematically searched the PubMed database for publications on HLH-CMV, and reviewed 57 publications with a total of 67 cases of HLH-CMV. Only 48 patients (71.6%) were immunodeficient, suggesting that HLH-CMV can occur in immunocompetent patients. The major cause of underlying immunodepression (51%) was inflammatory bowel disease (mainly treated with azathioprine). CMV infection was nearly always symptomatic, and lung involvement was frequent (31 cases). Fifty-five patients recovered. Nineteen patients were treated for CMV infection only and had a good outcome, suggesting that antiviral drugs might be the cornerstone of HLH-CMV treatment.

Severe cytomegalovirus encephalitis in an immunocompetent healthy young woman: A case report

Cytomegalovirus (CMV) causes a mild illness in immunocompetent patients. Conversely, it can be life-threatening in immunocompromised or critically ill patients. We present a 48-year-old immunocompetent woman presenting primary severe CMV encephalitis. She presented with a headache, fever, and drowsiness. She did not respond to empirical treatment. Her level of consciousness deteriorated, she was put on mechanical ventilation on day two. Bacterial culture, herpes simplex virus, and tuberculosis were negative in cerebrospinal fluid (CSF). After three weeks, the patient was transferred to our center due to financial matters. Brain magnetic resonance imaging (MRI) showed diffuse hydrocephalus, periventricular T2 hyperintensity, patchy basal ganglia, and diffuse leptomeningeal enhancement. CMV polymerase chain reaction (PCR) was positive in cerebrospinal fluid (CSF) specimen. Ganciclovir (5 mg/kg/IV q12h) was initiated. Subsequently, a brain shunt was inserted. Her level of consciousness raised, she was weaned from the ventilator. She was discharged after 52 days in a bedridden state, quadriplegic, and only able to speak words with a minor swallowing problem. She remained in the same condition for one year. She was expired one year later due to aspiration pneumonia after four weeks of hospitalization. Early diagnosis and treatment of severe CMV encephalitis are crucial to prevent neurological sequelae.

Cytomegalovirus Pulmonary Involvement in an Immunocompetent Adult

Introduction

Cytomegalovirus (CMV) is a linear double-stranded DNA virus that may cause severe and potentially fatal infection in immunocompromised hosts. In immunocompetent individuals, the infection is typically mild or asymptomatic. However, in the last years, some cases of severe cytomegalovirus infection in immunocompetent individuals have been described. Clinical Presentation. The authors present a male patient aged 42 years, without specific medical history, who presented a 15-day history of fever, headache, night sweats, odynophagia, and bilateral otalgia, without improvement after four days of therapy with amoxicillin/clavulanic acid. Blood count and biochemistry were performed with liver cytolysis pattern. Chest teleradiography showed diffuse interstitial infiltrate. Thoracic CT scan revealed areas in a ground glass with a cross-linking component in the left and right upper lung lobes compatible with an inflammatory/infectious process. Blood serology was positive for CMV IgG and IgM. The detection on blood and bronchoalveolar lavage of CMV DNA by polymerase chain reaction (PCR) was also positive. Ganciclovir was started based on the clinical features and the result of CMV serology. After 48 hours, there was a significant clinical improvement, with remission of fever, and he was discharged on the 13th day of hospitalization with oral valganciclovir, completing a 21-day antiviral course at home.

Conclusion

With this clinical case, the authors highlight the importance of considering CMV infection in evaluating patients with pneumonia, even in immunocompetent ones, particularly in those with no clinical improvement with antibiotics instituted for bacterial pneumonia, and when other causes have been ruled out.

Viral Respiratory Pathogens and Lung Injury

Several viruses target the human respiratory tract, causing different clinical manifestations spanning from mild upper airway involvement to life-threatening acute respiratory distress syndrome (ARDS). As dramatically evident in the ongoing SARS-CoV-2 pandemic, the clinical picture is not always easily predictable due to the combined effect of direct viral and indirect patient-specific immune-mediated damage. In this review, we discuss the main RNA (orthomyxoviruses, paramyxoviruses, and coronaviruses) and DNA (adenoviruses, herpesviruses, and bocaviruses) viruses with respiratory tropism and their mechanisms of direct and indirect cell damage. We analyze the thin line existing between a protective immune response, capable of limiting viral replication, and an unbalanced, dysregulated immune activation often leading to the most severe complication. Our comprehension of the molecular mechanisms involved is increasing and this should pave the way for the development and clinical use of new tailored immune-based antiviral strategies.

Cytomegalovirus pneumonia in an immunocompetent host with primary ciliary dyskinesia: A case report

Primary ciliary dyskinesia (PCD) is an autosomal-recessive inherited disease caused by mutations in genes involved in ciliary structure and function leading to impaired mucociliary clearance and repeated or chronic, usually bacterial, infections of the upper and lower airways and decreased lung function and bronchiectasis. Cytomegalovirus (CMV) is a DNA virus that usually causes subclinical infection and in 10% of the patients causes a mononucleosis-like syndrome. CMV is a causative agent of serious illness in vulnerable immunocompromised groups such as transplant recipients, patients with immunodeficiency or malignancy and neonates. Life-threatening infection due to CMV, including CMV pneumonia, is not common in immunocompetent patients. In this report we describe a case of an otherwise immunocompetent woman, suffering from PCD, who developed severe CMV pneumonia.

Endoscopic features and clinical outcomes of cytomegalovirus gastroenterocolitis in immunocompetent patients

We aimed to investigate the endoscopic features and clinical course of CMV gastroenterocolitis in immunocompetent patients. We reviewed the medical records and endoscopic images of 86 immunocompetent patients with CMV gastroenterocolitis. Immunocompetent patients were defined as those without congenital or acquired immunodeficiency syndrome, use of anti-cancer chemotherapeutic and immunosuppressive agents, and inflammatory bowel diseases. The mean age was 65.5 ± 11.8 years and 53 (61.6%) were male. Sixty-eight (79.1%) patients had comorbidities. Upper gastrointestinal-dominant, small bowel-dominant, and colon-dominant types were observed in 19, 7, and 60 patients, respectively. Endoscopic features could be classified into discrete ulcerative type with/without exudate and diffuse erythematous type with/without exudate. Antiviral treatment with ganciclovir was initiated in 51 patients (59.3%), 40 of whom improved and 1 improved after changing ganciclovir to foscarnet. Thirty-three patients (38.4%) improved without antiviral treatment. Surgery was necessary in two patients because of colon perforation before antiviral treatment. Another two patients underwent surgery because of sigmoid stricture and cecal perforation during antiviral treatment. Endoscopic type was not associated with clinical outcomes, such as surgery and death. CMV gastroenterocolitis in immunocompetent patients mostly occur in older patients with comorbidities, and the endoscopic features vary with no association with clinical outcomes.

'Lipo-tourism' gone wrong: blood transfusion-transmitted cytomegalovirus disease

Medical tourism is the pursuit of more affordable surgeries; however, this comes at the risk of suboptimal standards and potential for life-threatening complications. In this case, we describe the diagnostic challenge of cytomegalovirus (CMV) pneumonia in a 40-year-old woman who experienced wound dehiscence and subsequent blood transfusion-transmitted CMV as complications of liposuction in the Dominican Republic. We explore the role of histopathology in the diagnosis of disseminated CMV, discuss the underlying aetiology of CMV pneumonia in this patient and weigh the risks and benefits of initiating antiviral therapy in an immunocompetent patient with CMV disease.

Cytomegalovirus pneumonitis-induced secondary hemophagocytic lymphohistiocytosis and SIADH in an immunocompetent elderly male literature review

Hemophagocytic lymphohistiocytosis (HLH) is also known as hemophagocytic syndrome. It is a lethal hematologic condition due to a dysregulated immune response which results in inappropriately activated macrophages damaging host tissues. Based on the etiology, HLH can be primary (genetic) or secondary (acquired). The most common cause of a secondary HLH is an infection. Viral infections are the most common cause of secondary HLH. Among the viral causes of secondary HLH, Epstein–Barr virus is the most common etiologic agent. Cytomegalovirus (CMV) is a common causative pathogen in the immunocompromised host but is rare in an immunocompetent adult. In infection- associated secondary HLH, treatment includes antimicrobial therapy. HLH carries a high mortality and morbidity rate as it is an underdiagnosed clinical condition. Successful early diagnosis allows for adequate time for curative therapy. Treatment for HLH includes chemotherapy, immunomodulators, and a hematopoietic stem-cell transplant. The 2004 diagnostic criteria set by the Histiocyte Society serves as a guide to make an earlier clinical diagnosis. A review of PubMed literature revealed only five reported cases of CMV-induced HLH. We describe the sixth case of CMV pneumonitis-induced HLH and syndrome of inappropriate antidiuretic hormone secretion in a 72-year-old White male. He was treated successfully with oral valganciclovir and corticosteroids.

Human inborn errors of immunity to herpes viruses

Infections with any of the nine human herpes viruses (HHV) can be asymptomatic or life-threatening. The study of patients with severe diseases caused by HHVs, in the absence of overt acquired immunodeficiency, has led to the discovery or diagnosis of various inborn errors of immunity. The related inborn errors of adaptive immunity disrupt α/β T-cell rather than B-cell immunity. Affected patients typically develop HHV infections in the context of other infectious diseases. However, this is not always the case, as illustrated by inborn errors of SAP-dependent T-cell immunity to EBV-infected B cells. The related inborn errors of innate immunity disrupt leukocytes other than T and B cells, non-hematopoietic cells, or both. Patients typically develop only a single type of infection due to HHV, although, again, this is not always the case, as illustrated by inborn errors of TLR3 immunity resulting in HSV1 encephalitis in some patients and influenza pneumonitis in others. Most severe HHV infections in otherwise healthy patients remains unexplained. The forward human genetic dissection of isolated and syndromic HHV-driven illnesses will establish the molecular and cellular basis of protective immunity to HHVs, paving the way for novel diagnosis and management strategies.

Fatal Cytomegalovirus Infection in an Adult with Inherited NOS2 Deficiency

BACKGROUND

Cytomegalovirus (CMV) can cause severe disease in children and adults with a variety of inherited or acquired T-cell immunodeficiencies, who are prone to multiple infections. It can also rarely cause disease in otherwise healthy persons. The pathogenesis of idiopathic CMV disease is unknown. Inbred mice that lack the gene encoding nitric oxide synthase 2 (Nos2) are susceptible to the related murine CMV infection.

METHODS

We studied a previously healthy 51-year-old man from Iran who after acute CMV infection had an onset of progressive CMV disease that led to his death 29 months later. We hypothesized that the patient may have had a novel type of inborn error of immunity. Thus, we performed whole-exome sequencing and tested candidate mutant alleles experimentally.

RESULTS

We found a homozygous frameshift mutation in NOS2 encoding a truncated NOS2 protein that did not produce nitric oxide, which determined that the patient had autosomal recessive NOS2 deficiency. Moreover, all NOS2 variants that we found in homozygosity in public databases encoded functional proteins, as did all other variants with an allele frequency greater than 0.001.

CONCLUSIONS

These findings suggest that inherited NOS2 deficiency was clinically silent in this patient until lethal infection with CMV. Moreover, NOS2 appeared to be redundant for control of other pathogens in this patient. (Funded by the National Center for Advancing Translational Sciences and others.).

Human cytomegalovirus pneumonia in an immunocompetent patient: a very uncommon but treatable condition

Human cytomegalovirus (CMV) is a double-stranded DNA virus that can cause widespread severe infection in immunocompromised individuals but is more typically a subclinical infection in immunocompetent individuals. Rarely, it can cause a serious infection in immunocompetent individuals. Here, we describe a 36-year-old otherwise healthy male who presented with fever, cough and malaise who was diagnosed with CMV pneumonia. He made a rapid recovery after initiation of ganciclovir and has been doing well on follow-up visits. We performed a comprehensive review of CMV pneumonia in immunocompetent individuals and have summarised the prior 16 reported cases of CMV pneumonia in immunocompetent patients. This article highlights the importance of considering CMV as a cause of pneumonia even in immunocompetent individuals, especially when the more common causes have been excluded. Early diagnosis allows prompt treatment and potentially complete recovery.

Cytomegalovirus (CMV) Pneumonitis: Cell Tropism, Inflammation, and Immunity

Human cytomegalovirus (HCMV) is an opportunistic pathogen causing disease mainly in immunocompromised patients or after congenital infection. HCMV infection of the respiratory tract leads to pneumonitis in the immunocompromised host, which is often associated with a bad clinical course. The related mouse cytomegalovirus (MCMV) likewise exhibits a distinct tropism for the lung and thus provides an elegant model to study host-pathogen interaction. Accordingly, fundamental features of cytomegalovirus (CMV) pneumonitis have been discovered in mice that correlate with clinical data obtained from humans. Recent studies have provided insight into MCMV cell tropism and localized inflammation after infection of the respiratory tract. Accordingly, the nodular inflammatory focus (NIF) has been identified as the anatomical correlate of immune control in lungs. Several hematopoietic cells involved in antiviral immunity reside in NIFs and their key effector molecules have been deciphered. Here, we review what has been learned from the mouse model with focus on the microanatomy of infection sites and antiviral immunity in MCMV pneumonitis.

Challenges and Clinical Implications of the Diagnosis of Cytomegalovirus Lung Infection in Children

PURPOSE OF REVIEW

Pulmonary cytomegalovirus (CMV) infection is a potential lethal disease in children, but it remains a diagnostic challenge. The differentiation between latent CMV infections with viral shedding and active infections is difficult and may lead to false positives in bronchoalvolar lavage (BAL) PCR detection. This review summarizes current diagnostic approaches for CMV lung infection in children including progress in the identification of underlying immune defects linked to this condition.

RECENT FINDINGS

There is increasing literature supporting that the combined assessment of host risk factors and lung disease pattern is essential for the diagnosis of pulmonary CMV infection in children. The most important host risk factor is an immunecompromised state that has expanded from primary or acquired immunodeficiency (e.g., HIV) to include a myriad of immune-dysregulation syndromes (e.g., CTLA4, PIK3 defects). Newborns, paricularly those born premature, are also a high-risk group. At the pulmonary level, active CMV infection is typically characterized by alveolar compromise leading to hypoxemia, ground-glass opacities, and intra-alveolar infiltrates with CMV inclusions in lung biopsy. The identification of active CMV lung infection should trigger additional evaluation of immune defects (primary or secondary) impairing T and NK cell function or innate antiviral responses as well as other immune dysregulation disorders. Lung CMV infections in children are more prevalent in immunocompromised hosts and premature newborns. Lung CMV infections should prompt further investigation into conditions altering immune mechanisms usually in place to contain CMV infections. Common clinical and radiological patterns such as hypoxemia and ground-glass pulmonary opacities may allow early identification and treatment of CMV lung infection and underlying causes in the pediatric population.

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.

Severe systemic cytomegalovirus infection in an immunocompetent patient outside the intensive care unit: a case report

BACKGROUND

Cytomegalovirus is responsible for an opportunistic infection that can be life threatening in immunocompromised patients, while it is usually mild or completely asymptomatic in immunocompetent subjects. In the recent years, however, some cases of severe cytomegalovirus infection in immunocompetent patients have been reported, showing this to be a less rare occurrence than previously reported.

CASE PRESENTATION

We report the case of an 83-year-old man, admitted to our hospital for gastroenteritis, complicated by dehydration and severe prothrombin time prolongation due to oral anticoagulant therapy accumulation, who developed hospital-acquired pneumonia; neither of these illnesses responded to several lines of antibiotic therapy. All microbiologic tests were negative, except cytomegalovirus DNA test in blood, which showed high viral load. Antiviral therapy with ganciclovir was then started and a quick favourable response followed. A state of immunodeficiency was excluded, based on normal CD4 count and patient's clinical history.

CONCLUSION

Different risk factors for severe cytomegalovirus disease in immunocompetent patients may exist, besides the ones already known, which could be responsible for severe cytomegalovirus disease in immunocompetent patients; thus, these patients should be tested for cytomegalovirus infection, if the clinical picture is compatible, to avoid delay in diagnosis and allow prompt start of specific therapy.

Influenza and Viral Pneumonia

Influenza and other respiratory viruses are commonly identified in patients with community-acquired pneumonia, hospital-acquired pneumonia, and in immunocompromised patients with pneumonia. Clinically, it is difficult to differentiate viral from bacterial pneumonia. Similarly, the radiological findings of viral infection are nonspecific. The advent of polymerase chain reaction testing has enormously facilitated the identification of respiratory viruses, which has important implications for infection control measures and treatment. Currently, treatment options for patients with viral infection are limited, but there is ongoing research on the development and clinical testing of new treatment regimens and strategies.

Cytomegalovirus acute infection with pulmonary involvement in an immunocompetent patient

Introduction

Cytomegalovirus (CMV) infection in healthy adults is usually asymptomatic or causes a mild mononucleosis syndrome, while severe infections are rare in immunocompetent patients and poorly documented. When described, gastrointestinal tract and the central nervous systems are the most frequent sites of severe CMV infection. Lung disease can occur, but it’s rare.

Clinical case

A 29 years old man presenting with a 2-weeks history of fever, headache, malaise, dry non-productive cough and thoracic pleuritic pain, without improvement after one-week therapy with levofloxacin. Blood exams showed lymphocytosis of almost 50%, nine percent of atypical lymphocytes and elevated transaminases. Thoracic CT-scan showed bilateral infiltrate with internal air bronchogram. Blood serology showed positivity for CMV IgG and IgM, with low CMV IgG avidity. Serum and bronchoalveolar detection of CMV by polymerase chain reaction (PCR) technique was also positive. Cultures were all negative. The patient became increasingly hypoxemic and the liver transaminases worsening, the reason for which ganciclovir was started. He made a full recovery and was discharged seven days later with oral valganciclovir, completing a 3 weeks antiviral course at home.

Discussion

CMV pneumonia is a rare condition, however it’s one of the three most common cause of severe viral community acquired pneumonia (CAP), along with influenza and adenovirus. CMV pneumonia should be considered in patients with atypical lymphocytes and mildly elevated serum transaminases.

Conclusion

In immunocompetent hosts, even with severe CMV-CAP, the prognosis is good. However, antiviral treatment should be considered in the rare occasion of severe CMV infection. Nevertheless, more studies are needed to clarify the clinical benefit of antiviral treatment.

Cytomegalovirus infection in immunocompetent adults: Is observation still the best strategy?

Cytomegalovirus (CMV) infection in immunocompetent patients generally resolves with few sequelae. However, it can cause severe and relapsing symptoms that can last for several weeks. Due to the self-limiting nature of CMV disease in immunocompetent individuals, criteria for specific antiviral therapy in this cohort are not well established. Additionally the adverse effect profile of currently available anti-CMV therapy limits its use in specific patient populations .We describe 3 immunocompetent adults who developed symptomatic CMV infection and were ill for several weeks. All patients had positive CMV viral assays and ultimately received anti-CMV therapy with significant improvement in symptoms within a few days of starting therapy. Choosing appropriate candidates for anti-CMV therapy, among mmunocompetent individuals, requires further research.

Immune Reconstitution Inflammatory Syndrome and Cytomegalovirus Pneumonia Case Report: Highlights and Missing Links in Classification Criteria and Standardized Treatment

BACKGROUND

Cytomegalovirus (CMV) pulmonary involvement is rarely associated with IRIS; therefore, limited information is available.

CASE PRESENTATION

Here, we describe the case of a 43-year-old HIV-infected male who developed an unusual case of IRIS after cytomegalovirus (CMV) pneumonia. Clinically there was a progressive and paradoxical worsening of respiratory distress, despite being treated for CMV after initiation with antiretroviral therapy. Chest X-ray revealed disseminated infiltrates in both lungs; chest CT-scan showed generalized lung involvement and mediastinal adenopathy. Pulmonary biopsy confirmed CMV pneumonia with the observation of typical viral inclusions on pneumocytes.

CONCLUSIONS

CMV pneumonia can be associated with the development of IRIS requiring treatment with immunosuppressant's and immunomodulatory drugs.

Acute Cytomegalovirus (CMV) Infection Associated with Hemophagocytic Lymphohistiocytosis (HLH) in an Immunocompetent Host Meeting All Eight HLH 2004 Diagnostic Criteria

Hemophagocytic lymphohistiocytosis (HLH) is a rare and often deadly syndrome characterized by severe inflammation and cytokine dysregulation. The disease is defined by the HLH-2004 criteria, requiring five of eight findings, and is further differentiated into either primary or secondary causes. Primary HLH tends to be of genetic etiology, while secondary HLH results from other insults such as infection. Secondary HLH is most commonly associated with viral infections in immunocompromised patients. Acute cytomegalovirus (CMV) associated HLH in the immunocompetent host is exceedingly rare and only documented in four case reports to date. We describe the fifth documented case of CMV-associated HLH in an immunocompetent patient, and furthermore, we demonstrate that this patient is the first published case of its type to satisfy all eight of HLH-2004 criteria.

Rapid and combined detection of Mycoplasma pneumoniae, Epstein-Barr virus and human cytomegalovirus using AllGlo quadruplex quantitative PCR

Acute respiratory infections (ARIs) cause substantial morbidity and mortality worldwide. The causes of ARI are dynamic, and co-infections of Mycoplasma pneumoniae, Epstein-Barr virus and human cytomegalovirus are recently developed causes of ARI. Here, we established a quadruplex quantitative PCR (qPCR) method to rapidly identify and simultaneously detect a single infection or co-infection of these three pathogens and an internal control in a single tube using AllGlo probes. The analysis demonstrated a wide linear range of detection from 101 to 108 copies per test and a low coefficient of variation of less than 5 %. The amplification efficiencies were all close to 1, and the correlation coefficients (r2) were all greater than 0.99. We found no significant difference in a comparative reagent test (P >0.05). Moreover, the results of tests on clinical samples using AllGlo quadruplex qPCR and TaqMan uniplex qPCR were in near-perfect agreement (κ =0.97). Clinically, the availability of this method will enable better differential diagnosis, disease surveillance and controlled outcomes.

Case report: severe cytomegalovirus primary infection in an immunocompetent adult with disseminated intravascular coagulation treated with valganciclovir

BACKGROUND

Disseminated intravascular coagulation (DIC) is a very rare complication of disseminated cytomegalovirus (CMV) infection. So far it is mainly described for immunocompromised patients.

CASE PRESENTATION

A 49-year-old immunocompetent Caucasian male presented with sudden onset of fever and DIC due to primary CMV infection, which was treated with Valganciclovir. CMV-specific IgG-avidity and epithelial cell-specific neutralisation-capacity developed five weeks after onset of symptoms. We describe the first case of an immunocompetent patient suffering from DIC due to a CMV primary infection successfully treated with Valganciclovir.

CONCLUSIONS

Primary CMV infection can occur accompanied with life threatening complications even in immunocompetent patients. Immediate treatment with Valganciclovir should be considered as an early treatment of choice in severe cases since specific neutralisation capacity might need several weeks to develop.

Cytomegalovirus-related hemorrhagic cystitis in an immunocompetent child

Cytomegalovirus (CMV) infections are mostly seen in immunocompromised patients. However, unusual manifestations or complications of acquired CMV infections in immunocompetent patients are rarely reported. CMV-related hemorrhagic cystitis is extremely rare but should be considered even in immunocompetent patients. We present a case of a 3-year-old immunocompetent boy with intermittent, terminal gross hematuria lasting for 1 month. There was no history of genitourinary trauma or stone disease. Urine analysis revealed hematuria with eumorphic red blood cells and no proteinuria. Urine culture was negative. Ultrasonography showed increased bladder wall thickness and irregularity at inferior of bladder. Cystoscopy revealed hyperemia and edema. Histopathological examination was consistent with CMV infection, viral DNA by polymerase chain reaction in peripheral blood and urine were positive. Clinical, laboratory, and imaging features pointed towards hemorrhagic cystitis due to CMV. He was followed-up with no treatment. After 1 month, repeated investigations showed complete resolution of finding. This is a rare description of an immunocompetent child with CMV-induced cystitis.

Pneumonitis due to cytomegalovirus during chronic methotrexate treatment

Although hypersensitivity pneumonitis is the most common pulmonary complication described during treatment with methotrexate, other complications like lymphoproliferative and infectious disease may be considered in the study of respiratory disease associated to methotrexate. The existence of an increased risk to developing infectious diseases may be similar to that observed during treatment with antagonists of tumor necrosis factor and corticosteroids, where Cytomegalovirus pneumonia is a serious complication; early diagnosis and treatment will prevent a potentially fatal outcome.

[Severe pneumonia due to cytomegalovirus in chronic obstructive pulmonary disease]

Severe pneumonia due to cytomegalovirus in chronic obstructive pulmonary disease.

INTRODUCTION

We describe two cases of immunocompetent patients with chronic obstructive pulmonary disease (COPD) who developed severe cytomegalovirus (CMV) pneumonia. The clinical and radiological context and CMV replication in broncho-alveolar lavage suggested a diagnosis of CMV pneumonia.

CASE HISTORIES

We report two cases in patients with moderate chronic obstructive pulmonary disease not treated with long-term steroid therapy who developed bilateral pneumonia with hypoxaemia. The only pathogen identified was CMV with replication of the virus in the broncho-alveolar lavage. Investigation failed to detect any associated immune deficiency.

CONCLUSION

Severe cytomegalovirus pneumonia could be encouraged by the existence of chronic obstructive pulmonary disease due to local inflammatory changes.

Human cytomegalovirus manipulation of latently infected cells

Primary infection with human cytomegalovirus (HCMV) results in the establishment of a lifelong infection of the host which is aided by the ability of HCMV to undergo a latent infection. One site of HCMV latency in vivo is in haematopoietic progenitor cells, resident in the bone marrow, with genome carriage and reactivation being restricted to the cells of the myeloid lineage. Until recently, HCMV latency has been considered to be relatively quiescent with the virus being maintained essentially as a “silent partner” until conditions are met that trigger reactivation. However, advances in techniques to study global changes in gene expression have begun to show that HCMV latency is a highly active process which involves expression of specific latency-associated viral gene products which orchestrate major changes in the latently infected cell. These changes are argued to help maintain latent infection and to modulate the cellular environment to the benefit of latent virus. In this review, we will discuss these new findings and how they impact not only on our understanding of the biology of HCMV latency but also how they could provide tantalising glimpses into mechanisms that could become targets for the clearance of latent HCMV.

Prevalence of herpes and respiratory viruses in induced sputum among hospitalized children with non typical bacterial community-acquired pneumonia

Objective

Few comprehensive studies have searched for viruses in infants and young children with community-acquired pneumonia (CAP) in China. The aim of this study was to investigate the roles of human herpes viruses (HHVs) and other respiratory viruses in CAP not caused by typical bacterial infection and to determine their prevalence and clinical significance.

Methods

Induced sputum (IS) samples were collected from 354 hospitalised patients (infants, n = 205; children, n = 149) with respiratory illness (CAP or non-CAP) admitted to Wenling Hospital of China. We tested for HHVs and respiratory viruses using PCR-based assays. The epidemiological profiles were also analysed.

Results

High rate of virus detection (more than 98%) and co-infection (more than 80%) were found among IS samples from 354 hospitalised infants and children with respiratory illness in this study. Of 273 CAP samples tested, CMV (91.6%), HHV-6 (50.9%), RSV (37.4%), EBV (35.5%), HBoV (28.2%), HHV-7 (18.3%) and rhinovirus (17.2%) were the most commonly detected viruses. Of 81 non- CAP samples tested, CMV (63%), RSV (49.4%), HHV-6 (42%), EBV (24.7%), HHV-7 (13.6%) and HBoV (8.6%) were the dominant viruses detected. The prevalence of several viral agents (rhinovirus, bocavirus, adenovirus and CMV) among IS samples of CAP were significantly higher than that of non-CAP control group. We also found the prevalence of RSV coinfection with HHVs was also higher among CAP group than that of non-CAP control.

Conclusions

With sensitive molecular detection techniques and IS samples, high rates of viral identification were achieved in infants and young children with respiratory illness in a rural area of China. The clinical significance of rhinovirus, bocavirus, adenovirus and HHV (especially CMV) infections should receive greater attention in future treatment and prevention studies of CAP in infants and children.