Current Understanding of Cytomegalovirus Reactivation in Critical Illness

Exploring the relationship between HCMV serostatus and outcomes in COVID-19 sepsis

Background

Sepsis, a life-threatening condition caused by the dysregulated host response to infection, is a major global health concern. Understanding the impact of viral or bacterial pathogens in sepsis is crucial for improving patient outcomes. This study aimed to investigate the human cytomegalovirus (HCMV) seropositivity as a risk factor for development of sepsis in patients with COVID-19.

Methods

A multicenter observational study enrolled 95 intensive care patients with COVID-19-induced sepsis and 80 post-surgery individuals as controls. HCMV serostatus was determined using an ELISA test. Comprehensive clinical data, including demographics, comorbidities, and 30-day mortality, were collected. Statistical analyses evaluated the association between HCMV seropositivity and COVID-19 induced sepsis.

Results

The prevalence of HCMV seropositivity did not significantly differ between COVID-19-induced sepsis patients (78%) and controls (71%, p = 0.382) in the entire cohort. However, among patients aged ≤60 years, HCMV seropositivity was significantly higher in COVID-19 sepsis patients compared to controls (86% vs 61%, respectively; p = 0.030). Nevertheless, HCMV serostatus did not affect 30-day survival.

Discussion

These findings confirm the association between HCMV seropositivity and COVID-19 sepsis in non-geriatric patients. However, the lack of an independent effect on 30-day survival can be explained by the cross-reactivity of HCMV specific CD8+ T-cells towards SARS-CoV-2 peptides, which might confer some protection to HCMV seropositive patients. The inclusion of a post-surgery control group strengthens the generalizability of the findings. Further research is needed to elucidate the underlying mechanisms of this association, explore different patient populations, and identify interventions for optimizing patient management.

Conclusion

This study validates the association between HCMV seropositivity and severe COVID-19-induced sepsis in non-geriatric patients, contributing to the growing body of evidence on viral pathogens in sepsis. Although HCMV serostatus did not independently influence 30-day survival, future investigations should focus on unraveling the intricate interplay between HCMV, immune responses, and COVID-19. These insights will aid in risk stratification and the development of targeted interventions for viral sepsis.

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.

Reliability of Droplet Digital PCR Alone and in Combination with Interleukin-6 and Procalcitonin for Prognosis of Bloodstream Infection

Purpose

Bloodstream infection(BSI) is linked with high mortality, underscoring the significance of prompt etiological diagnosis for timely and precise treatment. This study aims to investigate the diagnostic value of droplet digital polymerase chain reaction(ddPCR) in combination with conventional inflammatory markers [interleukin-6(IL-6) and procalcitonin(PCT)] concerning disease progression and treatment prognosis in BSI patients. Furthermore, the study aims to explore a more efficient clinical application strategy.

Patients and Methods

This prospective case seried study centers on 176 patients suspected of or confirmed with BSI. Blood samples were collected to extract nucleic acids for identifying pathogens (bacteria, fungi, and viruses) and determining copy loads via ddPCR.

Results

The sensitivity of ddPCR was markedly higher compared to the culture method (74.71% vs 31.03%). A positive correlation existed between bacterial load and levels of inflammatory markers [IL-6 (P=0.0182), PCT (P=0.0029), and CRP (P=0.0005)]. In suspected BSI cases, the combination of ddPCR and inflammatory markers could predict sepsis risk [ROC: Area under the curve(AUC)=0.6071, P=0.0383]. Within confirmed BSI patients, the ddPCR bacterial load of those with SOFA<7 was lower than that of the SOFA≥7 (P=0.0334). ddPCR (OR: 1.789, P=0.035) monitoring combined with PCT (OR: 1.787, P=0.035) holded predictive value for SOFA progression (AUC=0.7913, P=0.0003). Similarly, BSI survivors displayed a lower burden than non-survivors (P=0.0170). Additionally, ddPCR combinated with IL-6 provided a more accurate and expedited insight into clinical outcomes prediction for BSI confirmed patients (AUC=0.7352, P=0.0030). Serial monitoring of bacterial load by ddPCR effectively mirrored the clinical course of BSI in patients. Notably, patients with positive ddPCR virus infection exhibited significantly reduced lymphocyte counts (P=0.0003).

Conclusion

In a clinical context, qualitative ddPCR results and quantitative continuous monitoring can more precisely assess sepsis progression and treatment prognosis in BSI patients. Furthermore, ddPCR results offer quicker and more accurate reference points for clinical antibacterial and antiviral interventions.

Antimicrobial Stewardship in Immunocompromised Patients: Current State and Future Opportunities

Immunocompromised (IC) patients are high risk for complications due to a high rate of antibiotic exposure. Antimicrobial stewardship interventions targeted to IC patients can be challenging due to limited data in this population and a high risk of severe infection-related outcomes. Here, the authors review immunocompromised antimicrobial stewardship barriers, metrics, and opportunities for antimicrobial use and testing optimization. Last, the authors highlight future steps in the field.

Human Cytomegalovirus Immunoglobulin G Response and Pulmonary Tuberculosis in Adolescents: A Case-Control Study

Background

Emerging evidence suggests a link between infection with herpes viruses, particularly human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV), and progression to tuberculosis disease.

Methods

An unmatched case-control study was conducted among adolescents aged 10-19 years enrolled in an observational study (Teen TB) between November 2020 and November 2021, in Cape Town, South Africa. Fifty individuals with pulmonary tuberculosis and 51 healthy tuberculosis-exposed individuals without tuberculosis were included. Demographics and clinical data were obtained, and serum samples collected at enrolment were tested for HCMV immunoglobulin G (IgG) and EBV nuclear antigen (EBNA) IgG using 2 automated enzyme immunoassays. Odds ratios were estimated using unconditional logistic regression.

Results

The median age of 101 participants was 15 years (interquartile range, 13-17 years); 55 (54%) were female. All participants were HCMV IgG seropositive, and 95% were EBNA IgG seropositive. Individuals with tuberculosis had higher HCMV IgG titers than healthy controls (P = .04). Individuals with upper-tertile HCMV IgG titers had 3.67 times greater odds of pulmonary tuberculosis than those with IgG titers in the lower tertile (95% confidence interval, 1.05-12.84; P = .04). There was a trend for increasing odds of pulmonary tuberculosis with increasing titers of HCMV IgG (P = .04). In contrast, there was no association between tuberculosis and higher EBNA IgG values.

Conclusions

There is a high prevalence of sensitization to HCMV and EBV among adolescents in this high-tuberculosis-burden setting. Higher HCMV IgG titers were associated with pulmonary tuberculosis in adolescents.

Evaluation of risk factors for cytomegalovirus DNAemia after end of regular prophylaxis after heart transplantation

BACKGROUND

Cytomegalovirus (CMV) infections after heart transplantation (HTx) can cause cardiac allograft vasculopathy. Consequently, monitoring and prophylaxis for cytomegalovirus deoxyribonucleic acid (CMV-DNAemia) within the first weeks after HTx is recommended.

METHODS

All patients who underwent HTx between September 2010 and 2021 surviving the first 90 days (n = 196) were retrospectively reviewed. The patients were divided on the prevalence of CMV-DNAemia during the first postoperative year after the end of the prophylaxis. A total of n = 35 (20.1%) developed CMV-DNAemia (CMV group) and were compared to patients without CMV-DNAemia (controls, n = 139). The remaining patients (n = 22) were excluded due to incomplete data.

RESULTS

Positive donors and negative recipients (D+/R-) and negative donors and positive recipients (D-/R+) serology was significantly increased and D-/R- decreased in the CMV group (p < .01). Furthermore, the mean age was 57.7 ± 8.7 years but only 53.6 ± 10.0 years for controls (p = .03). Additionally, the intensive care unit (p = .02) and total hospital stay (p = .03) after HTx were approximately 50% longer. Interestingly, the incidence of CMV-DNAemia during prophylaxis was only numerically increased in the CMV group (5.7%, respectively, 0.7%, p = .10), the same effect was also observed for postoperative infections. Multivariate analyses confirmed that D+/R- and D-/R+ CMV immunoglobulin G match were independent risk factors for postprophylaxis CMV-DNAemia.

CONCLUSION

Our data should raise awareness of CMV-DNAemia after the termination of regular prophylaxis, as this affects one in five HTx patients. Especially old recipients as well as D+/R- and D-/R+ serology share an elevated risk of late CMV-DNAemia. For these patients, prolongation, or repetition of CMV prophylaxis, including antiviral drugs and CMV immunoglobulins, may be considered.

Human cytomegalovirus seropositivity is associated with reduced patient survival during sepsis

BACKGROUND

Sepsis is one of the leading causes of death. Treatment attempts targeting the immune response regularly fail in clinical trials. As HCMV latency can modulate the immune response and changes the immune cell composition, we hypothesized that HCMV serostatus affects mortality in sepsis patients.

METHODS

We determined the HCMV serostatus (i.e., latency) of 410 prospectively enrolled patients of the multicenter SepsisDataNet.NRW study. Patients were recruited according to the SEPSIS-3 criteria and clinical data were recorded in an observational approach. We quantified 13 cytokines at Days 1, 4, and 8 after enrollment. Proteomics data were analyzed from the plasma samples of 171 patients.

RESULTS

The 30-day mortality was higher in HCMV-seropositive patients than in seronegative sepsis patients (38% vs. 25%, respectively; p = 0.008; HR, 1.656; 95% CI 1.135-2.417). This effect was observed independent of age (p = 0.010; HR, 1.673; 95% CI 1.131-2.477). The predictive value on the outcome of the increased concentrations of IL-6 was present only in the seropositive cohort (30-day mortality, 63% vs. 24%; HR 3.250; 95% CI 2.075-5.090; p < 0.001) with no significant differences in serum concentrations of IL-6 between the two groups. Procalcitonin and IL-10 exhibited the same behavior and were predictive of the outcome only in HCMV-seropositive patients.

CONCLUSION

We suggest that the predictive value of inflammation-associated biomarkers should be re-evaluated with regard to the HCMV serostatus. Targeting HCMV latency might open a new approach to selecting suitable patients for individualized treatment in sepsis.

Real-World Experience With CMV inSIGHT T Cell Immunity Testing in High-Risk Kidney and Pancreas Transplant Recipients

BACKGROUND

Cytomegalovirus (CMV)-specific cell-mediated immunity is important for control of CMV after transplant. Assays exist to measure this, but their place in therapy is unclear, particularly in CMV high-risk recipients, without pretransplant exposure.

OBJECTIVE

The objective of this study was to evaluate predictive potential of a positive assay to determine freedom from DNAemia and describe subsequent 3-month CMV outcomes.

METHODS

Adult CMV high-risk kidney and/or pancreas transplant recipients were included if a CMV inSIGHT T Cell Immunity Panel (TCIP, Eurofins Viracor) was ordered and resulted between 1 August, 2019 and 30 July, 2022.

RESULTS

Seventy-six patients were included in our study; 49 tested during prophylaxis and 27 during treatment. Most TCIP assays obtained in the prophylaxis cohort were negative (n = 46, 93.9%). Rate of post-TCIP CMV infection was 10.2%. In those tested during treatment, 33.3% were positive and rate of post-TCIP CMV recurrence was 22.2%. The positive predictive value of the assay to successfully predict immunity was 66.7% during both prophylaxis and treatment. There were 4 cases of TCIP predictive failure with progressive CMV replication. At time of replication, 2 patients had concomitant clinical confounders thought to influence immune control of viral replication. All patients had intensification of immunosuppression prior to recurrent replication, but after TCIP was collected.

CONCLUSION AND RELEVANCE

The data obtained from the TCIP are not static, immune control of CMV in latency can change and must be evaluated in clinical context. Timing of TCIP after transplant is significant, and patient-specific factors remain important to assess the likelihood of CMV in each unique patient-specific scenario. A CMV stewardship program can aid in application and interpretation of results.

The effects of cytomegalovirus on brain structure following sport-related concussion

The neurotrophic herpes virus cytomegalovirus is a known cause of neuropathology in utero and in immunocompromised populations. Cytomegalovirus is reactivated by stress and inflammation, possibly explaining the emerging evidence linking it to subtle brain changes in the context of more minor disturbances of immune function. Even mild forms of traumatic brain injury, including sport-related concussion, are major physiological stressors that produce neuroinflammation. In theory, concussion could predispose to the reactivation of cytomegalovirus and amplify the effects of physical injury on brain structure. However, to our knowledge this hypothesis remains untested. This study evaluated the effect of cytomegalovirus serostatus on white and grey matter structure in a prospective study of athletes with concussion and matched contact-sport controls. Athletes who sustained concussion (n = 88) completed MRI at 1, 8, 15 and 45 days post-injury; matched uninjured athletes (n = 73) completed similar visits. Cytomegalovirus serostatus was determined by measuring serum IgG antibodies (n = 30 concussed athletes and n = 21 controls were seropositive). Inverse probability of treatment weighting was used to adjust for confounding factors between athletes with and without cytomegalovirus. White matter microstructure was assessed using diffusion kurtosis imaging metrics in regions previously shown to be sensitive to concussion. T1-weighted images were used to quantify mean cortical thickness and total surface area. Concussion-related symptoms, psychological distress, and serum concentration of C-reactive protein at 1 day post-injury were included as exploratory outcomes. Planned contrasts compared the effects of cytomegalovirus seropositivity in athletes with concussion and controls, separately. There was a significant effect of cytomegalovirus on axial and radial kurtosis in athletes with concussion but not controls. Cytomegalovirus positive athletes with concussion showed greater axial (P = 0.007, d = 0.44) and radial (P = 0.010, d = 0.41) kurtosis than cytomegalovirus negative athletes with concussion. Similarly, there was a significant association of cytomegalovirus with cortical thickness in athletes with concussion but not controls. Cytomegalovirus positive athletes with concussion had reduced mean cortical thickness of the right hemisphere (P = 0.009, d = 0.42) compared with cytomegalovirus negative athletes with concussion and showed a similar trend for the left hemisphere (P = 0.036, d = 0.33). There was no significant effect of cytomegalovirus on kurtosis fractional anisotropy, surface area, symptoms and C-reactive protein. The results raise the possibility that cytomegalovirus infection contributes to structural brain abnormalities in the aftermath of concussion perhaps via an amplification of concussion-associated neuroinflammation. More work is needed to identify the biological pathways underlying this process and to clarify the clinical relevance of this putative viral effect.

Superinfections in COVID-19 patients receiving extracorporeal membrane oxygenation support

BACKGROUND

The risk of superinfections and associations with mortality among patients with corona virus disease 2019 (COVID-19) receiving veno-venous extracorporeal membrane oxygenation (VV-ECMO) is poorly elucidated.

METHOD

We identified all patients with COVID-19 treated with VV-ECMO >24 h at Rigshospitalet, Denmark from March 2020 to December 2021. Data were obtained by review of medical files. Associations between superinfections and mortality were assessed by logistic regression analyses adjusted for sex and age.

RESULTS

Fifty patients, median age 53 years (interquartile range [IQR] 45-59), 66% male, were included. Median time on VV-ECMO was 14.5 days (IQR 6.3-23.5), 42% were discharged from hospital alive. Bacteremia, ventilator associated pneumonia (VAP), invasive candidiasis, pulmonary aspergillosis, herpes simplex virus, and cytomegalovirus (CMV) were detected in 38%, 42%, 12%, 12%, 14%, and 20% of patients, respectively. No patients with pulmonary aspergillosis survived. CMV was associated with increased risk of death, odds ratio 12.6 (95% confidence interval 1.9-257, p = .05), whereas we found no associations between other superinfections and risk of death.

CONCLUSION

Bacteremia and VAP are common but does not seem to affect mortality, whereas pulmonary aspergillosis and CMV are associated with poor prognosis among COVID-19 patients treated with VV-ECMO.

Cytomegalovirus viremia and advanced HIV disease: is there an argument for anti-CMV treatment?

INTRODUCTION

The role of cytomegalovirus (CMV) infection as a co-factor in HIV disease has been a topic of considerable interest since the beginning of the HIV pandemic. CMV is believed to function both as a co-factor in the progression of HIV infection, and as a contributor to enhanced disease for other opportunistic infections.

AREAS COVERED

In this special article, we review several recent studies that have enhanced our understanding of the role that CMV infection plays in the natural history of other HIV-related opportunistic infections. We review the clinical evidence that demonstrates how CMV viremia has emerged as an independent risk factor for the progression of infections such as those caused by C. neoformans and M. tuberculosis. We outline the biological underpinnings of the various hypotheses by which CMV, as an immunomodulatory virus, may modify the natural history of HIV-related infections.

EXPERT OPINION

Evidence suggests that active CMV replication, manifest as CMV viremia (DNAemia), may play a key role in driving progression of HIV-associated opportunistic infections. We propose that control of CMV replication, independent of the known benefit of HAART therapy on reducing CMV end-organ disease, could reduce the risk of disease and mortality attributable to opportunistic infections such as cryptococcosis and tuberculosis. This could be achieved by the targeted use of CMV antivirals. The advent of newer (and safer) orally bioavailable CMV antivirals has renewed interest in, and opportunities for, randomized controlled trials to evaluate CMV viremia as a modifiable risk factor in high-risk persons with HIV disease.

Cytomegalovirus reactivation in patients diagnosed with severe COVID-19: A point prevalence study in a general hospital

OBJECTIVE

To determine the prevalence of CMV reactivation in a population admitted for severe COVID-19 to a general hospital.

METHODS

Point prevalence study in all hospitalized patients with severe COVID-19 (admitted either to general wards or ICU). Determination of the presence of CMV DNA in circulating blood. COVID-19 was confirmed in patients with compatible clinical manifestations, usually with pneumonia and a positive nasopharyngeal PCR test.

RESULTS

We included 140 hospitalized patients with COVID-19 who consented to participate. A total of 16 patients (11.42%), had circulating CMV-DNA in peripheral blood at the time of the study. Patients with positive CMV viral load were mainly ICU patients (11/37 -29,7%) and only 5/103 cases (4,85%) were hospitalized into general wards. The accumulated doses of corticosteroids (prednisone equivalents) in the study day were (median and IQR) 987.50 mg (396.87-2,454.68) and 187.50 mg (75.00-818.12) respectively in CMV positive and negative patients (p < 0.001). A significant proportion of CMV positive patients were discovered because of the study and were clinically unsuspected by their physicians. The coinfected COVID-CMV positive population had a higher risk of accumulated secondary nosocomially-acquired infections and a worse prognosis.

CONCLUSIONS

CMV reactivation should be systematically searched in patients in COVID-19 cases admitted to the ICU.

Human Cytomegalovirus Infection of Epithelial Cells Increases SARS-CoV-2 Superinfection by Upregulating the ACE2 Receptor

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), has caused widespread morbidity and mortality since its onset in late 2019. Here, we demonstrate that prior infection with human cytomegalovirus (HCMV) substantially increases infection with SARS-CoV-2 in vitro. HCMV is a common herpesvirus carried by 40%-100% of the population, which can reactivate in the lung under inflammatory conditions, such as those resulting from SARS-CoV-2 infection. We show in both endothelial and epithelial cell types that HCMV infection upregulates ACE2, the SARS-CoV-2 cell entry receptor. These observations suggest that HCMV reactivation events in the lung of healthy HCMV carriers could exacerbate SARS-CoV-2 infection and subsequent COVID-19 symptoms. This effect could contribute to the disparity of disease severity seen in ethnic minorities and those with lower socioeconomic status, due to their higher CMV seroprevalence. Our results warrant further clinical investigation as to whether HCMV infection influences the pathogenesis of SARS-CoV-2.

Post COVID and Apheresis - Where are we Standing?

A continual increase in cases of Long/Post COVID constitutes a medical and socioeconomic challenge to health systems around the globe. While the true extent of this problem cannot yet be fully evaluated, recent data suggest that up to 20% of people with confirmed SARS-CoV-2 suffer from clinically relevant symptoms of Long/Post COVID several weeks to months after the acute phase. The clinical presentation is highly variable with the main symptoms being chronic fatigue, dyspnea, and cognitive symptoms. Extracorporeal apheresis has been suggested to alleviate symptoms of Post/COVID. Thus, numerous patients are currently treated with apheresis. However, at present there is no data from randomized controlled trials available to confirm the efficacy. Therefore, physicians rely on the experience of practitioners and centers performing this treatment. Here, we summarize clinical experience on extracorporeal apheresis in patients with Post/COVID from centers across Germany.

Effect of Cytomegalovirus on the Immune System: Implications for Aging and Mental Health

Human cytomegalovirus (HCMV) is a major modulator of the immune system leading to long-term changes in T-lymphocytes, macrophages, and natural killer (NK) cells among others. Perhaps because of this immunomodulatory capacity, HCMV infection has been linked with a host of deleterious effects including accelerated immune aging (premature mortality, increased expression of immunosenescence-linked markers, telomere shortening, speeding-up of epigenetic "clocks"), decreased vaccine immunogenicity, and greater vulnerability to infectious diseases (e.g., tuberculosis) or infectious disease-associated pathology (e.g., HIV). Perhaps not surprisingly given the long co-evolution between HCMV and humans, the virus has also been associated with beneficial effects, such as increased vaccine responsiveness, heterologous protection against infections, and protection against relapse in the context of leukemia. Here, we provide an overview of this literature. Ultimately, we focus on one other deleterious effect of HCMV, namely the emerging literature suggesting that HCMV plays a pathophysiological role in psychiatric illness, particularly depression and schizophrenia. We discuss this literature through the lens of psychological stress and inflammation, two well-established risk factors for psychiatric illness that are also known to predispose to reactivation of HCMV.

Efficacy of Oxymatrine Plus Antiviral in the Treatment of Sepsis and Its Effect on the Levels of Endotoxin and Inflammatory Factors

Objective

To assess the clinical efficacy of oxymatrine plus antiviral therapy in the treatment of sepsis and its effects on the levels of endotoxin and inflammatory factors. Methodology. 90 patients with sepsis were selected for retrospective analysis and were assigned to receive either conventional treatment (control group) or oxymatrine plus antiviral treatment (study group). The clinical endpoint was treatment efficacy.

Results

There were no significant differences in baseline patient profile between the two groups (P > 0.05). The study group showed a higher efficiency versus the control group (P < 0.05). Patients in the study group had a significantly shorter mechanical ventilation duration and ICU stay versus those in the control group (P < 0.05). Both groups had reduced Acute Physiology and Chronic Health Evaluation II (APACHE II) score, Marshall score, levels of endotoxin, tumor necrosis factor-α (TNF-α), interleukin (IL)-6, IL-8, C-reactive protein (CRP), and procalcitonin (PCT) after treatment, with lower results in the study group versus the control group (P < 0.05).

Conclusion

Oxymatrine plus antiviral therapy effectively improves clinical efficacy, reduces the levels of endotoxin and inflammatory factors, protects organ function, and boosts recovery. Further clinical trials are, however, required prior to general application in clinical practice.

Effect of Cytomegalovirus Infection on the Central Nervous System: Implications for Psychiatric Disorders

Cytomegalovirus (CMV) is a common herpesvirus that establishes lifelong latent infections and interacts extensively with the host immune system, potentially contributing to immune activation and inflammation. Given its proclivity for infecting the brain and its reactivation by inflammatory stimuli, CMV is well known for causing central nervous system complications in the immune-naïve (e.g., in utero) and in the immunocompromised (e.g., in neonates, individuals receiving transplants or cancer chemotherapy, or people living with HIV). However, its potentially pathogenic role in diseases that are characterized by more subtle immune dysregulation and inflammation such as psychiatric disorders is still a matter of debate. In this chapter, we briefly summarize the pathogenic role of CMV in immune-naïve and immunocompromised populations and then review the evidence (i.e., epidemiological studies, serological studies, postmortem studies, and recent neuroimaging studies) for a link between CMV infection and psychiatric disorders with a focus on mood disorders and schizophrenia. Finally, we discuss the potential mechanisms through which CMV may cause CNS dysfunction in the context of mental disorders and conclude with a summary of the current state of play as well as potential future research directions in this area.

Association Between Cytomegalovirus Infection and Tuberculosis Disease: A Systematic Review and Meta-Analysis of Epidemiological Studies

BACKGROUND

Tuberculosis is one of the leading causes of mortality worldwide from an infectious disease. This review aimed to investigate the association between prior cytomegalovirus infection and tuberculosis disease.

METHODS

Six bibliographic databases were searched from their respective inception to 31 December 2021. Data were pooled using random-effects meta-analysis.

RESULTS

Of 5476 identified articles, 15 satisfied the inclusion criteria with a total sample size of 38 618 patients. Pooled findings showed that individuals with cytomegalovirus infection had a higher risk of tuberculosis disease compared to those not infected with cytomegalovirus (odds ratio [OR], 3.20; 95% confidence interval [CI], 2.18-4.70). Age was the only covariate that exerted a significant effect on the result of the association. Meta-analysis of risk estimates reported in individual studies showed a marked and significant correlation of cytomegalovirus infection with active tuberculosis (adjusted hazard ratio, 2.92; 95% CI, 1.34-4.51; adjusted OR, 1.14; 95% CI, .71-1.57). A clear dose-response relation was inferred between the levels of cytomegalovirus antibodies and the risks of tuberculosis events (OR for high levels of cytomegalovirus antibodies, 4.07; OR for medium levels of cytomegalovirus antibodies, 3.58).

CONCLUSIONS

The results suggest an elevated risk of tuberculosis disease among individuals with a prior cytomegalovirus infection.

Cytomegalovirus blood reactivation in COVID-19 critically ill patients: risk factors and impact on mortality

PURPOSE

Cytomegalovirus (CMV) reactivation in immunocompetent critically ill patients is common and relates to a worsening outcome. In this large observational study, we evaluated the incidence and the risk factors associated with CMV reactivation and its effects on mortality in a large cohort of patients affected by coronavirus disease 2019 (COVID-19) admitted to the intensive care unit (ICU).

METHODS

Consecutive patients with confirmed SARS-CoV-2 infection and acute respiratory distress syndrome admitted to three ICUs from February 2020 to July 2021 were included. The patients were screened at ICU admission and once or twice per week for quantitative CMV-DNAemia in the blood. The risk factors associated with CMV blood reactivation and its association with mortality were estimated by adjusted Cox proportional hazards regression models.

RESULTS

CMV blood reactivation was observed in 88 patients (20.4%) of the 431 patients studied. Simplified Acute Physiology Score (SAPS) II score (HR 1031, 95% CI 1010-1053, p = 0.006), platelet count (HR 0.0996, 95% CI 0.993-0.999, p = 0.004), invasive mechanical ventilation (HR 2611, 95% CI 1223-5571, p = 0.013) and secondary bacterial infection (HR 5041; 95% CI 2852-8911, p < 0.0001) during ICU stay were related to CMV reactivation. Hospital mortality was higher in patients with (67.0%) than in patients without (24.5%) CMV reactivation but the adjusted analysis did not confirm this association (HR 1141, 95% CI 0.757-1721, p = 0.528).

CONCLUSION

The severity of illness and the occurrence of secondary bacterial infections were associated with an increased risk of CMV blood reactivation, which, however, does not seem to influence the outcome of COVID-19 ICU patients independently.

Understanding the interaction between cytomegalovirus and tuberculosis in children: The way forward

Over 1 million children develop tuberculosis (TB) each year, with a quarter dying. Multiple factors impact the risk of a child being exposed to Mycobacterium tuberculosis (Mtb), the risk of progressing to TB disease, and the risk of dying. However, an emerging body of evidence suggests that coinfection with cytomegalovirus (CMV), a ubiquitous herpes virus, impacts the host response to Mtb, potentially influencing the probability of disease progression, type of TB disease, performance of TB diagnostics, and disease outcome. It is also likely that infection with Mtb impacts CMV pathogenesis. Our current understanding of the burden of these 2 diseases in children, their immunological interactions, and the clinical consequence of coinfection is incomplete. It is also unclear how potential interventions might affect disease progression and outcome for TB or CMV. This article reviews the epidemiological, clinical, and immunological literature on CMV and TB in children and explores how the 2 pathogens interact, while also considering the impact of HIV on this relationship. It outlines areas of research uncertainty and makes practical suggestions as to potential studies that might address these gaps. Current research is hampered by inconsistent definitions, study designs, and laboratory practices, and more consistency and collaboration between researchers would lead to greater clarity. The ambitious targets outlined in the World Health Organization End TB Strategy will only be met through a better understanding of all aspects of child TB, including the substantial impact of coinfections.

SARS-CoV-2 and Cytomegalovirus Co-Infections-A Case Series of Critically Ill Patients

The SARS-CoV-2 pandemic has placed great strain on the most developed of health care systems, especially in the context of critical care. Although co-infections with cytomegalovirus (CMV) are frequent in the critically ill due to underlying immune suppression of multiple causes, the impact on COVID-19 patients remains unclear. Furthermore, severe COVID-19 has recently been associated with significant immune suppression, and this may in turn impact CMV reactivation, possibly contributing to clinical course. Nevertheless, multiple confounding factors in these patients will certainly challenge upcoming research. The authors present a case series of five patients admitted to the intensive care unit (ICU) in the context of respiratory failure due to severe COVID-19. All patients evolved with CMV reactivation during ICU stay.