Cytomegalovirus in the intensive care unit: pathogen or passenger?

Reactivation of Epstein-Barr virus among intensive care patients: a prospective observational study

PURPOSE

Herpesvirus reactivation has been documented among patients in the intensive care unit (ICU) and is associated with increased morbidity and mortality, particularly for cytomegalovirus (CMV). Epstein-Barr virus (EBV) has been poorly studied despite >95% of the population being seropositive. Our preliminary study suggested an association between EBV reactivation and increased morbidity and mortality. This study aimed to investigate this association among patients admitted to the ICU.

METHODS

In this multicenter prospective study, polymerase chain reaction was performed to quantify EBV in patients upon ICU admission and then twice a week during their stay. Follow-up was 90 days.

RESULTS

The study included 129 patients; 70 (54.3%) had EBV reactivation. On day 90, there was no difference in mortality rates between patients with and without reactivation (25.7% vs 15.3%, p = 0.22). Patients with EBV reactivation at admission had increased mortality compared with those without reactivation and those with later reactivation. EBV reactivation was associated with increased morbidity. Patients with EBV reactivation had fewer ventilator-free days at day 28 than those without reactivation (18 [1-22] vs. 21 days [5-26], p = 0.037) and a higher incidence of acute respiratory distress syndrome (34.3% vs. 17%, p = 0.04), infections (92.9% vs. 78%, p = 0.03), and septic shock (58.6% vs. 32.2%, p = 0.004). More patients with EBV reactivation required renal replacement therapy (30% vs. 11.9%, p = 0.02). EBV reactivation was also associated with a more inflammatory immune profile.

CONCLUSION

While EBV reactivation was not associated with increased 90-day mortality, it was associated with significantly increased morbidity.

Activation of senescence in critically ill patients: mechanisms, consequences and therapeutic opportunities

Whereas aging is a whole-organism process, senescence is a cell mechanism that can be triggered by several stimuli. There is increasing evidence that critical conditions activate cell senescence programs irrespective of patient's age. In this review, we briefly describe the basic senescence pathways and the consequences of their activation in critically ill patients. The available evidence suggests a paradigm in which activation of senescence can be beneficial in the short term by rendering cells resistant to apoptosis, but also detrimental in a late phase by inducing a pro-inflammatory and pro-fibrotic state. Senescence can be a therapeutic target. The use of drugs that eliminate senescent cells (senolytics) or the senescence-associated phenotype (senomorphics) will require monitoring of these cell responses and identification of therapeutic windows to improve the outcome of critically ill patients.

Cytomegalovirus antigenemia in patients with autoimmune and non-autoimmune diseases in Beijing: A 10-year single hospital experience

Background

Primary cytomegalovirus (CMV) infection is prevalent worldwide and usually results in latency in immunocompetent populations. Reactivation of latent CMV can cause life-threatening complications in immunocompromised hosts.

Methods

We used the CMV Brite assay to test CMV antigenemia (pp65) in whole blood samples from 22,192 patients with or without autoimmune diseases in Beijing during 2008–2018.

Results

The overall prevalence of CMV antigenemia was 19.5% (9.7%, males; 26.0%, females). The prevalence of CMV antigenemia was 35.1%, 58.6% and 11.4% in whole patients with autoimmune diseases, in patients with systemic lupus erythematosus (SLE) and in patients with non-SLE autoimmune diseases, respectively. All patients with non-autoimmune diseases, patients with HIV/AIDS or transplantation were found to have 5.0%, 27% or 14.8%, respectively. Patients≤20 years with SLE had a significantly higher prevalence of CMV antigenemia than did all SLE patients, on average. Patients>51 years with non-SLE autoimmune diseases had a significantly higher prevalence than did all patients with non-SLE autoimmune diseases, on average. The prevalence of CMV antigenemia in patients admitted to intensive-care units (ICUs) were 9.2%, which was significantly higher than that among all patients with non-autoimmune diseases. Patients with SLE had 23.8% of negative conversion of CMV antigenemia, significantly lower than the percentage of patients with non-SLE autoimmune (64.3%) and non-autoimmune (61.0%) diseases. The mean number of days to negative conversion of CMV antigenemia in patients with SLE was 35.3±35.8 days, which was significantly longer than that in patients with non-SLE autoimmune diseases (15.4±11.9 days) and non-autoimmune diseases (13.6±7.7 days).

Conclusions

CMV antigenemia is found more likely in women than in men, more prevalently in patients with SLE than those with HIV/AIDS or transplant recipients, more frequently in patients admitted to ICUs. Patients with SLE had prolonged CMV antigenemia. The role of CMV appears important in SLE.

Cytomegalovirus infection and outcome in immunocompetent patients in the intensive care unit: a systematic review and meta-analysis

BACKGROUND

Cytomegalovirus (CMV) infection is common in immunocompetent patients in intensive care units (ICUs). However, whether CMV infection or CMV reactivation contributes to mortality of immunocompetent patients remains unclear.

METHODS

A literature search was conducted for relevant studies published before May 30, 2016. Studies reporting on CMV infection in immunocompetent patients in ICUs and containing 2 × 2 tables on CMV results and all-cause mortality were included.

RESULTS

Eighteen studies involving 2398 immunocompetent patients admitted to ICUs were included in the meta-analysis. The overall rate of CMV infection was 27% (95%CI 22-34%, I² = 89%, n = 2398) and the CMV reactivation was 31% (95%CI 24-39%, I² = 74%, n = 666). The odds ratio (OR) for all-cause mortality among patients with CMV infection, compared with those without infection, was 2.16 (95%CI 1.70-2.74, I² = 10%, n = 2239). Moreover, upon exclusion of studies in which antiviral treatment was possibly or definitely provided to some patients, the association of mortality rate with CMV infection was also statistically significant (OR: 1.69, 95%CI 1.01-2.83, I² = 37%, n = 912,). For CMV seropositive patients, the OR for mortality in patients with CMV reactivation as compared with patients without CMV reactivation was 1.72 (95%CI 1.04-2.85, I² = 29%, n = 664). Patients with CMV infection required significantly longer mechanical ventilation (mean difference (MD): 9 days (95% CI 5-14, I² = 81%, n = 875)) and longer duration of ICU stay (MD: 12 days (95% CI 7-17, I² = 70%, n = 949)) than patients without CMV infection. When analysis was limited to detection in blood, CMV infection without antiviral drug treatment or reactivation was not significantly associated with higher mortality (OR: 1.69, 95%CI 0.81-3.54, I² = 52%, n = 722; OR: 1.49, I² = 63%, n = 469).

CONCLUSION

Critically ill patients without immunosuppression admitted to ICUs show a high rate of CMV infection. CMV infection during the natural unaltered course or reactivation in critically ill patients is associated with increased mortality, but have no effect on mortality when CMV in blood. More studies are needed to clarify the impact of CMV infection on clinical outcomes in those patients.

The role of viruses in nosocomial pneumonia

PURPOSE OF REVIEW

The frequency and impact of viruses among intensive care unit (ICU) nonimmunocompromised patients remains controversial. This review analyzes their place as causal pathogens in ventilator-associated pneumonia, as well as their effects on ICU patients' outcomes.

RECENT FINDINGS

Herpesviruses, namely herpes simplex virus (HSV) and cytomegalovirus (CMV), are the most frequent viruses detected among nonimmunosuppressed ICU patients, as confirmed by recent prospective studies. Patients infected with these viruses show increased morbidity and, especially for CMV, mortality. An increase of bacterial or fungal superinfections was observed in ICU patients with CMV reactivation. A therapeutic trial of acyclovir (HSV antiviral) in ICU patients was negative. Concerning CMV, pathogenicity was suggested by histologic assessment in ICU patients, and recent murine models with a positive effect of prophylaxis with ganciclovir that prevented postseptic CMV reactivation and secondary lung damage.

SUMMARY

Using efficient and rapid virologic diagnostic tests (antigenemia or PCR), the identification of viruses in ICU patients is frequent. Their role in the occurrence of ventilator-acquired pneumonia and their impact on patient outcome depend on the virus. There is sufficient evidence suggesting CMV pathogenicity to conduct an interventional randomized trial using anti-CMV drugs.

[Ventilator-associated viral pneumonia]

Viral infections (especially respiratory infections) are not rare in critically ill non-immunocompromised patients. Efficient and rapid virologic diagnosis tests such as polymerase chain reaction (PCR) are now widely available. Herpesviridae (herpes simplex virus and cytomegalovirus) are the most frequent viruses detected among non-immunocompromised patients admitted to the intensive care unit (ICU). However, causal relationships between detected viruses and outcomes are still debated, with a variable level of demonstration among the different viruses. The aim of this review was to assess the role of viruses in causing mechanical ventilation-acquired pneumonias in non-immunocompromised ICU adult patients. We also discuss the possible physiopathology of these viral infections, as well as the opportunity for therapeutic interventions.

Virological and immunological features of active cytomegalovirus infection in nonimmunosuppressed patients in a surgical and trauma intensive care unit

Cytomegalovirus (CMV) reactivation occurs frequently in critically ill patients. The natural course of CMV infection and the interaction between CMV and the adaptive immune system in this setting remain poorly defined. Fifty-three CMV-seropositive patients in a surgical and trauma intensive care unit were included in this study. The CMV DNA load in tracheal aspirates (TA) and plasma (PL) was monitored by qPCR. CMV-specific T-cell immunity was assessed by intracellular cytokine staining. Plasma TNF-alpha levels were determined by ELISA. CMV reactivation occurred in 39.7% of patients (23% had CMV DNA detected only in TA). The analysis of TA allowed an earlier diagnosis in 28% of patients. Clearance of CMV DNAemia preceded that of CMV DNA in TA in some episodes. Peak CMV DNA levels were significantly higher in TA than in PL (P = 0.02). CMV reactivation developed in the presence of CMV-specific T cells. Termination of CMV reactivation was associated with an expansion of functional CMV-specific T cells. Plasma levels of TNF-alpha did not allow for the prediction of the occurrence of CMV reactivation. CMV-specific T-cell immunity is preserved in most critically ill patients experiencing CMV reactivation. Analysis of respiratory specimens is imperative for an optimal monitoring of CMV reactivation in this setting.