Human cytomegalovirus infection of endothelial cells triggers platelet adhesion and aggregation

Porphyromonas gingivalis and Human Cytomegalovirus Co-Infection: A Potential Link Between Periodontal Disease and Oral Cancer Development

Periodontal disease (PD) is an inflammatory condition that can contribute to the development of oral cancer. Chronic inflammation from PD can lead to the release of inflammatory mediators and growth factors that promote tumorigenesis. Porphyromonas gingivalis (P. gingivalis) is one of several pathogens implicated in PD and its potential link to oral cancer. However, other viral infections, such as human cytomegalovirus (HCMV), can also contribute to chronic inflammation, creating a favorable environment for oral cancer development.

OBJECTIVES

The present literature review tries to investigate the possible influence of P. gingivalis and HCMV co-infection in fostering the development of oral cancer and chronic periodontitis.

METHODS

A comprehensive search was conducted in PubMed and Google Scholar, focusing on the relevance and significance of articles that examine the role of P. gingivalis and HCMV in periodontal disease and oral cancer.

RESULTS

The evidence suggests that P. gingivalis and HCMV may act synergistically to modulate host immunity, disrupt epithelial integrity, and interfere with key cellular pathways. These interactions may enhance tissue destruction and foster a microenvironment conducive to malignant transformation. However, most of these findings stem from in vitro models and small-scale clinical studies, limiting the generalizability and clinical relevance of current conclusions.

CONCLUSIONS

Although the proposed interaction between P. gingivalis and HCMV provides a compelling framework for understanding how microbial co-infections may influence oral cancer, the evidence remains preliminary and largely associative. To support these mechanistic hypotheses, future studies should give top priority to in vivo models, bigger patient cohorts, and longitudinal clinical studies.

Thrombotic Microangiopathy: A Devastating Complication After Lung Transplantation

Background

Thrombotic microangiopathy (TMA) following lung transplantation (LTx) is a rare but severe complication. The pathogenesis is poorly understood, and various risk factors have been suggested. In this study, we aimed to evaluate diagnostic accuracy, identify risk factors, and assess renal, pulmonary, and overall survival of TMA in this patient group.

Methods

We performed a case-control retrospective study of patients with TMA after LTX between January 1, 2000, and January 1, 2021. Controls were selected based on underlying lung disease, age, sex, cytomegalovirus risk, and immunosuppressive regimen. Overall survival data were collected for the whole lung transplant group.

Results

A total of 29 TMA cases (2.9%) were identified out of 1025 LTx. Median time to development of TMA was 5.9 mo, 76% occurred in the first 12 mo. In the TMA group a higher rate of HLA donor-specific antibodies (11% versus 1%; P = 0.05), a lower median time to onset of chronic lung allograft dysfunction (37 versus 91 mo; P = 0.0017), a higher rate of cytomegalovirus infection (45% versus 19%; P = 0.02), and a higher prevalence of end-stage renal disease (24% versus 6%; P = 0.03) and overall death (97% versus 44%; P < 0.0001) was found. Diagnostic assessment of TMA was complete in 48% of patients, with Coombs testing missing in 52% and a disintegrin and metalloproteinase with thrombospondin type 1 motif 13 activity not assessed in 59%.

Conclusions

TMA poses a significant risk of end-stage renal disease and mortality after LTx. Challenges remain in standardizing diagnostic criteria and understanding its pathogenesis, underscoring the need for unified protocols in diagnosis and standardized screening. This study identifies potential risk factors and temporal patterns for TMA occurrence, providing crucial insights for future treatment strategies.

The Interplay Between Immunity, Inflammation and Endothelial Dysfunction

The endothelium is pivotal in multiple physiological processes, such as maintaining vascular homeostasis, metabolism, platelet function, and oxidative stress. Emerging evidence in the past decade highlighted the immunomodulatory function of endothelium, serving as a link between innate, adaptive immunity and inflammation. This review examines the regulation of the immune-inflammatory axis by the endothelium, discusses physiological immune functions, and explores pathophysiological processes leading to endothelial dysfunction in various metabolic disturbances, including hyperglycemia, obesity, hypertension, and dyslipidaemia. The final section focuses on the novel, repurposed, and emerging therapeutic targets that address the immune-inflammatory axis in endothelial dysfunction.

Enhanced levels of IL-6 and PAI-1 and decreased levels of MMP-3 in cytomegalovirus seropositive patients with prior myocardial infarction

Background

Efforts to understand atherosclerosis, a major cause of ischemic heart disease, have linked several lifestyle factors to increased risk for developing cardiovascular disease. Some studies suggest that cytomegalovirus (CMV), a widely prevalent herpesvirus, is reactivated in atherosclerotic plaques and associated with higher cardiovascular mortality risk. We aimed to explore whether CMV seropositivity and CMV-IgG antibody levels correlate with relevant biomarkers in a cohort of patients with myocardial infarction (MI) and matched controls.

Methods and results

We analyzed a dataset from 324 survivors of MI treated in Stockholm between 1996 and 2001. Blood samples collected three months after MI were used to measure protective Apo B100 autoantibodies, metabolic, and inflammatory biomarkers. CMV serology was performed on stored serum samples. Correlation analyses were conducted between biomarkers and CMV serostatus in 324 patients and age- and sex-matched controls. While CMV seroprevalence was equal, the CMV-IgG levels were higher in controls. Among various factors examined, CMV seropositive MI patients had elevated levels of plasminogen activator inhibitor-1 (PAI-1) and interleukin-6, along with lower levels of MMP-3, than CMV seronegative MI patients. CMV-IgG levels correlated positively with PAI-1 levels in patients. Although CMV seropositivity was associated with increased proinsulin levels, there was no correlation with diabetes diagnosis.

Conclusions

Our findings suggest an enhanced inflammatory and prothrombotic state in CMV seropositive patients after MI. Notably, patients had lower levels of CMV IgG than controls.

What intensivists need to know about cytomegalovirus infection in immunocompromised ICU patients

PURPOSE

Advances in therapeutic care are leading to an increase in the number of patients living with overt immunosuppression. These patients are at risk of cytomegalovirus (CMV) infection and disease that can lead to or develop during ICU admission. This manuscript aims to describe the clinical presentation, risk factors, and management of CMV infection and disease in this patient population.

METHODS

We conducted a literature search in PubMed up to April 2024, focusing on CMV infection and disease in patients with overt immunosuppression (hematopoietic stem cell and solid organ transplantation, solid or hematologic malignancies, HIV infection, immunosuppressive drugs, including corticosteroids, and primary immunodeficiencies) admitted to the intensive care unit (ICU). As there is limited ICU-specific data on CMV in immunosuppressed patients, many of the findings were extrapolated from the general literature.

RESULTS

CMV infection and disease in immunocompromised critically ill patients is associated with increased mortality and presents significant management challenges. Clinical manifestations are diverse, shaped by the underlying immune deficiency and primary disease. Pneumonia and encephalitis are among the most severe CMV end-organ diseases. CMV infection may also increase the risk of secondary infections and induce life-threatening conditions, such as thrombotic microangiopathy. Importantly, CMV reactivation is not synonymous with CMV disease, and qPCR testing of body fluids cannot reliably differentiate between viral shedding and tissue-invasive infection, which requires histopathological confirmation. Ganciclovir is commonly the first-line anti-viral, though maribavir shows potential for patients unresponsive to other antivirals. Identifying patients who require prophylactic or preemptive antiviral therapy is essential.

CONCLUSIONS

CMV infection and disease in critically ill immunocompromised patients pose a unique challenge for intensivists. The broad spectrum of clinical presentations and the difficulty in distinguishing CMV-related symptoms from other causes require a high level of clinical suspicion. Accurate interpretation of nucleic acid load levels and careful evaluation of CMV's pathogenic role when it is found are critical. Further studies focusing specifically on CMV infection and disease in critically ill immunocompromised patients are needed to optimize management strategies.

Comprehensive Analysis of Thrombotic Microangiopathy Following Renal Transplantation

Background: Thrombotic microangiopathy is a severe complication of renal transplantation. Little is known about risk factors, incidence of autoantibodies against complement components, and prognosis. Methods: Clinical and laboratory data were retrospectively collected for 13 patients diagnosed with post-transplant thrombotic microangiopathy (PT-TMA) in 2011-2018. Enzyme-linked immunosorbent assay (ELISA) results were compared to transplant recipients without PT-TMA and healthy controls. Results: Nine patients (69%) had potential PT-TMA risk factors other than exposure to calcineurin inhibitors (CNIs). Stratification by time to PT-TMA yielded two groups. Patients diagnosed within 6 months of transplantation (n = 6) were characterized by positive donor-specific antibody (DSA) test, complement-associated renal disease, and acute rejection. Two had IgG and IgA autoantibodies to complement Factors H and I, respectively. Patients diagnosed ≥ 3 years after transplantation (n = 7) had a high rate of infection. Renal biopsy yielded dense deposits in 6 patients, and only one with primary immune complex renal disease. Within 2 years, graft failure requiring dialysis occurred in 6 patients (46%). Three patients with early-onset PT-TMA showed improved renal function and remained stable under eculizumab treatment. Epstein-Barr virus (EBV)-associated post-transplant lymphoproliferative disorder (EPTLD) developed in 3 patients, 2 of whom had received eculizumab for more than 5 years. Five patients (39%) died during follow-up. Conclusion: In this study, PT-TMA was associated with other risk factors besides CNI exposure, with differences by time of onset from transplantation. Prognosis was generally poor but better for early-onset PT-TMA managed with eculizumab. The development of late EPTLD in 3 patients raises concerns.

Viral coagulation: pushing the envelope

Many virus types affect the blood clotting system with correlations to pathology that range widely from thrombosis to hemorrhage linking to inflammation. Here we overview the intricate crosstalk induced by infection between proteins on the virus encoded by either the host or virus genomes, coagulation proteins, platelets, leukocytes, and endothelial cells. For blood-borne viruses with an outer covering acquired from the host cell, the envelope, a key player may be the cell-derived trigger of coagulation on the virus surface, tissue factor (TF). TF is a multifunctional transmembrane cofactor that accelerates factor (F)VIIa-dependent activation of FX to FXa, leading to clot formation. However, the nascent TF/FVIIa/FXa complex also facilitates G protein-coupled modulation of cells via protease-activated receptor 2. As a viral envelope constituent, TF can bypass the physiological modes of regulation, thereby initiating the activation of neighboring platelets, leukocytes, and endothelial cells. A thromboinflammatory environment is predicted due to feedback amplification in response to cellular release of cytokines, procoagulant proteins, neutrophil extracellular traps, and stimulus-induced accessibility of adhesive receptors, resulting in cellular aggregates. The pathobiological effects of thromboinflammation ultimately contribute to innate and adaptive immunity for viral clearance. In contrast, the preceding stages of viral infection may be enhanced via the TF-protease axis.

Posttransplant complications: molecular mechanisms and therapeutic interventions

Posttransplantation complications pose a major challenge to the long-term survival and quality of life of organ transplant recipients. These complications encompass immune-mediated complications, infectious complications, metabolic complications, and malignancies, with each type influenced by various risk factors and pathological mechanisms. The molecular mechanisms underlying posttransplantation complications involve a complex interplay of immunological, metabolic, and oncogenic processes, including innate and adaptive immune activation, immunosuppressant side effects, and viral reactivation. Here, we provide a comprehensive overview of the clinical features, risk factors, and molecular mechanisms of major posttransplantation complications. We systematically summarize the current understanding of the immunological basis of allograft rejection and graft-versus-host disease, the metabolic dysregulation associated with immunosuppressive agents, and the role of oncogenic viruses in posttransplantation malignancies. Furthermore, we discuss potential prevention and intervention strategies based on these mechanistic insights, highlighting the importance of optimizing immunosuppressive regimens, enhancing infection prophylaxis, and implementing targeted therapies. We also emphasize the need for future research to develop individualized complication control strategies under the guidance of precision medicine, ultimately improving the prognosis and quality of life of transplant recipients.

TMA in Kidney Transplantation

Thrombotic microangiopathy (TMA) is a rare and devastating complication of kidney transplantation, which often leads to graft failure. Posttransplant TMA (PT-TMA) may occur either de novo or as a recurrence of the disease. De novo TMA can be triggered by immunosuppressant drugs, antibody-mediated rejection, viral infections, and ischemia/reperfusion injury in patients with no evidence of the disease before transplantation. Recurrent TMA may occur in the kidney grafts of patients with a history of atypical hemolytic uremic syndrome (aHUS) in the native kidneys. Studies have shown that some patients with aHUS carry genetic abnormalities that affect genes that code for complement regulators (CFH, MCP, CFI) and components (C3 and CFB), whereas in 10% of patients (mostly children), anti-FH autoantibodies have been reported. The incidence of aHUS recurrence is determined by the underlying genetic or acquired complement abnormality. Although treatment of the causative agents is usually the first line of treatment for de novo PT-TMA, this approach might be insufficient. Plasma exchange typically resolves hematologic abnormalities but does not improve kidney function. Targeted complement inhibition is an effective treatment for recurrent TMA and may be effective in de novo PT-TMA as well, but it is necessary to establish which patients can benefit from different therapeutic options and when and how these can be applied.

Cytomegalovirus and Cardiovascular Disease: A Hypothetical Role for Viral G-Protein-Coupled Receptors in Hypertension

Cytomegalovirus (CMV) is a member of the β-herpesviruses and is ubiquitous, infecting 50%-99% of the human population depending on ethnic and socioeconomic conditions. CMV establishes lifelong, latent infections in their host. Spontaneous reactivation of CMV is usually asymptomatic, but reactivation events in immunocompromised or immunosuppressed individuals can lead to severe morbidity and mortality. Moreover, herpesvirus infections have been associated with several cardiovascular and post-transplant diseases (stroke, atherosclerosis, post-transplant vasculopathy, and hypertension). Herpesviruses, including CMV, encode viral G-protein-coupled receptors (vGPCRs) that alter the host cell by hijacking signaling pathways that play important roles in the viral life cycle and these cardiovascular diseases. In this brief review, we discuss the pharmacology and signaling properties of these vGPCRs, and their contribution to hypertension. Overall, these vGPCRs can be considered attractive targets moving forward in the development of novel hypertensive therapies.

Sepsis - it is all about the platelets

Sepsis is accompanied by thrombocytopenia and the severity of the thrombocytopenia is associated with mortality. This thrombocytopenia is characteristic of disseminated intravascular coagulation (DIC), the sepsis-associated coagulopathy. Many of the pathogens, both bacterial and viral, that cause sepsis also directly activate platelets, which suggests that pathogen-induced platelet activation leads to systemic thrombosis and drives the multi-organ failure of DIC. In this paper we review the mechanisms of platelet activation by pathogens and the evidence for a role for anti-platelet agents in the management of sepsis.

Venous thromboembolism in viral diseases: A comprehensive literature review

Venous thromboembolism (VTE) is known to be a common respiratory and/or cardiovascular complication in hospitalized patients with viral infections. Numerous studies have proven human immunodeficiency virus infection to be a prothrombotic condition. An elevated VTE risk has been observed in critically ill H1N1 influenza patients. VTE risk is remarkably higher in patients infected with the Hepatitis C virus in contrast to uninfected subjects. The elevation of D-dimer levels supported the association between Chikungunya and the Zika virus and the rise of clinical VTE risk. Varicella-zoster virus is a risk factor for both cellulitis and the consequent invasive bacterial disease which may take part in thrombotic initiation. Eventually, hospitalized patients infected with the coronavirus disease of 2019 (COVID-19), the cause of the ongoing worldwide pandemic, could mainly suffer from an anomalous risk of coagulation activation with enhanced venous thrombosis events and poor quality clinical course. Although the risk of VTE in nonhospitalized COVID-19 patients is not known yet, there are a large number of guidelines and studies on thromboprophylaxis administration for COVID-19 cases. This study aims to take a detailed look at the effect of viral diseases on VTE, the epidemiology of VTE in viral diseases, and the diagnosis and treatment of VTE.

Risk factors for transplant-associated thrombotic microangiopathy (TA-TMA): a systematic review and meta-analysis

INTRODUCTION

Transplant-associated thrombotic microangiopathy (TA-TMA) is a severe hematopoietic stem cell transplantation complication with high mortality and a poor patient prognosis. The pathogenesis of TA-TMA is not yet clear. In previous studies, the conclusions of different centers remain controversial. We conducted a systematic review and meta-analysis of nine selected risk factors that might be associated with the onset of TA-TMA.

MATERIALS AND METHODS

PubMed databases were searched from their inception up to 15 September 2021, for relevant studies. The articles included unprocessed data related to one or more of the risk factors discussed in this meta-analysis, including recipient gender, donor type, graft source, pretreatment, infection, aGVHD, diagnosis, total body irradiation (TBI), and CMV infection. The outcome is the incidence rate (IR) of TA-TMA.

RESULTS AND CONCLUSIONS

According to the sixteen articles included, risk factors included in this Meta-analysis included gender, unrelated donor source (95% CI: 1.29-2.01), graft source from peripheral blood stem cell (PBSC)(95% CI: 0.48-0.97), RIC/NMA, class II-IV aGVHD (95% CI: 2.22-4.78), nonmalignant disease, TBI. However, inconsistent diagnostic criteria for TA-TMA and the limited number of studies have an impact on the results of the study. More prospective cohort studies and More accurate diagnostic criteria are needed.

Early graft loss due to acute thrombotic microangiopathy accompanied by complement gene variants in living-related kidney transplantation: case series report

Background

Recently, early graft loss has become very rare in living-related kidney transplantation (LKT) as a result of decreased risk of hyperacute rejection and improvements in immunosuppressive regimens. Post-transplant acute thrombotic microangiopathy (TMA) is a rare, multi-factorial disease that often occurs shortly after kidney transplantation and is usually resistant to treatment with dismal renal outcomes. The complement genetic variants may accelerate the development of TMA. However, the complement genetic test was seldom performed in unknown native kidney disease recipients scheduled for LKT.

Case presentation

We reported three cases of unknown native kidney diseases who had fulminant TMA in the allograft shortly after LKT. Both the donors and the recipients were noted to carry complement genetic variants, which were identified by genetic testing after transplantation. However, all recipients were refractory to treatment and had allograft loss within 3 months after LKT.

Conclusion

This case series highlights the suggestion to screen complement gene variants in both the donors and the recipients with unknown native kidney diseases scheduled for LKT.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02868-7.

A Rare Case of Acute Infectious Purpura Fulminans Caused by Klebsiella Pneumoniae and Human Herpesvirus Type 5

Background

Purpura fulminans (PF), a rare, life-threatening disorder, is a hematological emergency in which there is skin necrosis, disseminated intravascular coagulation (DIC), and protein C deficiency. In PF, the skin necrosis and DIC are secondary to protein C deficiency. This may progress rapidly to multiorgan failure caused by the thrombotic occlusion of small- and medium-sized blood vessels.

Case Report

This article presents the case of a 22-year-old male with fever as well as necrotic and purpuric skin lesions. The ultrasound and computed tomography scans revealed infections in the skin wounds as well as venous microthrombosis and thrombosis in multiple intracranial and pulmonary vessels. The laboratory tests showed signs of sepsis, thrombocytopenia, an abnormal decrease in protein C and antithrombin III, DIC, multiple organ and system failures, gastric varices, and gastrointestinal hemorrhage. The blood, sputum, and secretions under the skin lesions were cultured and were positive for Klebsiella pneumoniae. The results of the high-throughput genetic testing of the pathogenic microorganism DNA were consistent. In addition, human herpesvirus type 5 was detected. The histopathological examination of the skin lesions revealed pathological features consistent with PF. After successful treatment by the departments of Dermatology, Emergency Critical Care Medicine, and the Intensive Care Unit, the patient was discharged after 67 days of hospitalization.

Conclusion

Adults with acquired protein C and/or S deficiency states, including certain bacterial and viral infections, who drink alcohol and take varieties of non-steroidal anti-inflammatory analgesics at the same time, may develop acute infectious PF. Clinicians should be aware of this for early diagnosis and treatment.

Genetic Predisposition of Anti-Cytomegalovirus Immunoglobulin G Levels and the Risk of 9 Cardiovascular Diseases

Background

Accumulating evidence has indicated that persistent human cytomegalovirus (HCMV) infection is associated with several cardiovascular diseases including atherosclerosis and coronary artery disease. However, whether there is a causal association between the level of anti-HCMV immune response and the risk of cardiovascular diseases remains unknown.

Methods

Single-nucleotide polymorphisms associated with anti-cytomegalovirus immunoglobulin (Ig) G levels were used as instrumental variables to estimate the causal effect of anti-cytomegalovirus IgG levels on 9 cardiovascular diseases (including atrial fibrillation, coronary artery disease, hypertension, heart failure, peripheral artery disease, pulmonary embolism, deep vein thrombosis of the lower extremities, rheumatic valve diseases, and non-rheumatic valve diseases). For each cardiovascular disease, Mendelian randomization (MR) analyses were performed. Inverse variance-weighted meta-analysis (IVW) with a random-effects model was used as a principal analysis. In addition to this, the weighted median approach and MR-Egger method were used for further sensitivity analysis.

Results

In the IVW analysis, genetically predicted anti-cytomegalovirus IgG levels were suggestively associated with coronary artery disease with an odds ratio (OR) of 1.076 [95% CI, 1.009–1.147; p = 0.025], peripheral artery disease (OR 1.709; 95% CI, 1.039–2.812; p = 0.035), and deep vein thrombosis (OR 1.002; 95% CI, 1.000–1.004; p = 0.025). In the further analysis, similar causal associations were obtained from weighted median analysis and MR-Egger analysis with lower precision. No notable heterogeneities and horizontal pleiotropies were observed (p > 0.05).

Conclusions/Interpretation

Our findings first provide direct evidence that genetic predisposition of anti-cytomegalovirus IgG levels increases the risk of coronary artery disease, peripheral artery disease, and deep vein thrombosis.

Complement Mediated Endothelial Damage in Thrombotic Microangiopathies

Thrombotic microangiopathies (TMA) constitute a group of different disorders that have a common underlying mechanism: the endothelial damage. These disorders may exhibit different mechanisms of endothelial injury depending on the pathological trigger. However, over the last decades, the potential role of the complement system (CS) has gained prominence in their pathogenesis. This is partly due to the great efficacy of complement-inhibitors in atypical hemolytic syndrome (aHUS), a TMA form where the primary defect is an alternative complement pathway dysregulation over endothelial cells (genetic and/or adquired). Complement involvement has also been demonstrated in other forms of TMA, such as thrombotic thrombocytopenic purpura (TTP) and in Shiga toxin-producing Escherichia coli hemolytic uremic syndrome (STEC-HUS), as well as in secondary TMAs, in which complement activation occurs in the context of other diseases. However, at present, there is scarce evidence about the efficacy of complement-targeted therapies in these entities. The relationship between complement dysregulation and endothelial damage as the main causes of TMA will be reviewed here. Moreover, the different clinical trials evaluating the use of complement-inhibitors for the treatment of patients suffering from different TMA-associated disorders are summarized, as a clear example of the entry into a new era of personalized medicine in its management.

Platelets in Viral Infections - Brave Soldiers or Trojan Horses

Viral infections are often associated with platelet activation and haemostatic complications. In line, low platelet counts represent a hallmark for poor prognosis in many infectious diseases. The underlying cause of platelet dysfunction in viral infections is multifaceted and complex. While some viruses directly interact with platelets and/or megakaryocytes to modulate their function, also immune and inflammatory responses directly and indirectly favour platelet activation. Platelet activation results in increased platelet consumption and degradation, which contributes to thrombocytopenia in these patients. The role of platelets is often bi-phasic. Initial platelet hyper-activation is followed by a state of platelet exhaustion and/or hypo-responsiveness, which together with low platelet counts promotes bleeding events. Thereby infectious diseases not only increase the thrombotic but also the bleeding risk or both, which represents a most dreaded clinical complication. Treatment options in these patients are limited and new therapeutic strategies are urgently needed to prevent adverse outcome. This review summarizes the current literature on platelet-virus interactions and their impact on viral pathologies and discusses potential intervention strategies. As pandemics and concomitant haemostatic dysregulations will remain a recurrent threat, understanding the role of platelets in viral infections represents a timely and pivotal challenge.

Of vascular defense, hemostasis, cancer, and platelet biology: an evolutionary perspective

We have established considerable expertise in studying the role of platelets in cancer biology. From this expertise, we were keen to recognize the numerous venous-, arterial-, microvascular-, and macrovascular thrombotic events and immunologic disorders are caused by severe, acute-respiratory-syndrome coronavirus 2 (SARS-CoV-2) infections. With this offering, we explore the evolutionary connections that place platelets at the center of hemostasis, immunity, and adaptive phylogeny. Coevolutionary changes have also occurred in vertebrate viruses and their vertebrate hosts that reflect their respective evolutionary interactions. As mammals adapted from aquatic to terrestrial life and the heavy blood loss associated with placentalization-based live birth, platelets evolved phylogenetically from thrombocytes toward higher megakaryocyte-blebbing-based production rates and the lack of nuclei. With no nuclei and robust RNA synthesis, this adaptation may have influenced viral replication to become less efficient after virus particles are engulfed. Human platelets express numerous receptors that bind viral particles, which developed from archetypal origins to initiate aggregation and exocytic-release of thrombo-, immuno-, angiogenic-, growth-, and repair-stimulatory granule contents. Whether by direct, evolutionary, selective pressure, or not, these responses may help to contain virus spread, attract immune cells for eradication, and stimulate angiogenesis, growth, and wound repair after viral damage. Because mammalian and marsupial platelets became smaller and more plate-like their biophysical properties improved in function, which facilitated distribution near vessel walls in fluid-shear fields. This adaptation increased the probability that platelets could then interact with and engulf shedding virus particles. Platelets also generate circulating microvesicles that increase membrane surface-area encounters and mark viral targets. In order to match virus-production rates, billions of platelets are generated and turned over per day to continually provide active defenses and adaptation to suppress the spectrum of evolving threats like SARS-CoV-2.

How Immunosenescence and Inflammaging May Contribute to Hyperinflammatory Syndrome in COVID-19

Aging is characterized by the dynamic remodeling of the immune system designated “immunosenescence,” and is associated with altered hematopoiesis, thymic involution, and lifelong immune stimulation by multitudinous chronic stressors, including the cytomegalovirus (CMV). Such alterations may contribute to a lowered proportion of naïve T-cells and to reduced diversity of the T-cell repertoire. In the peripheral circulation, a shift occurs towards accumulations of T and B-cell populations with memory phenotypes, and to accumulation of putatively senescent and exhausted immune cells. The aging-related accumulations of functionally exhausted memory T lymphocytes, commonly secreting pro-inflammatory cytokines, together with mediators and factors of the innate immune system, are considered to contribute to the low-grade inflammation (inflammaging) often observed in elderly people. These senescent immune cells not only secrete inflammatory mediators, but are also able to negatively modulate their environments. In this review, we give a short summary of the ways that immunosenescence, inflammaging, and CMV infection may cause insufficient immune responses, contribute to the establishment of the hyperinflammatory syndrome and impact the severity of the coronavirus disease 2019 (COVID-19) in elderly people.

NK and CD8+ T cell phenotypes predict onset and control of CMV viremia after kidney transplant

CMV causes mostly asymptomatic but lifelong infection. Primary infection or reactivation in immunocompromised individuals can be life-threatening. CMV viremia often occurs in solid organ transplant recipients and associates with decreased graft survival and higher mortality. Furthering understanding of impaired immunity that allows CMV reactivation is critical to guiding antiviral therapy and examining the effect of CMV on solid organ transplant outcomes. This study characterized longitudinal immune responses to CMV in 31 kidney transplant recipients with CMV viremia and matched, nonviremic recipients. Recipients were sampled 3 and 12 months after transplant, with additional samples 1 week and 1 month after viremia. PBMCs were stained for NK and T cell markers. PBMC transcriptomes were characterized by RNA-Seq. Plasma proteins were quantified by Luminex. CD8⁺ T cell transcriptomes were characterized by single-cell RNA-Seq. Before viremia, patients had high levels of IL-15 with concurrent expansion of immature CD56^bright NK cells. After viremia, mature CD56^dim NK cells and CD28^–CD8⁺ T cells upregulating inhibitory and NK-associated receptors were expanded. Memory NK cells and NK-like CD28^–CD8⁺ T cells were associated with control of viremia. These findings suggest that signatures of innate activation may be prognostic for CMV reactivation after transplant, while CD8⁺ T cell functionality is critical for effective control of CMV.

Similarities between COVID-19 and systemic sclerosis early vasculopathy: A "viral" challenge for future research in scleroderma

OBJECTIVE

To review similarities between COVID-19 and systemic sclerosis (SSc) early vasculopathy to provide novel insights into both diseases.

METHODS

A narrative review of the literature supplemented with expert opinion.

RESULTS

There is clear evidence that the endothelium is at the centre stage in SSc and COVID-19, with endothelial cell activation/injury and dysfunction creating the crucial evolving step in the pathogenesis of both diseases. The angiotensin system has also been implicated in the early stages of both COVID-19 and SSc. Autoptic studies provide novel insights into the effects of SARS-CoV-2 on the endothelium. Normal endothelium and endothelial dysfunction in COVID-19 and SSc are discussed. It is debated whether SARS-CoV-2 infection triggers autoimmunity with production of autoantibodies which is of mechanistic interest because other viral illnesses are potentially involved in endothelial dysfunction and in SSc pathogenesis.

CONCLUSION

COVID-19 is due to a direct assault of SARS-CoV-2 on the vascular system as an acute infection, whereas SSc remains a chronic/sub-acute autoimmune disease of largely unknown etiology Further study and exploration of the SARS-CoV-2 pathogenic mechanisms might provide further useful milestones in the understanding of the early SSc pathogenesis.

The Use of Eculizumab in Tacrolimus-Induced Thrombotic Microangiopathy

Drug-induced thrombotic microangiopathy (DITMA) is a secondary cause of thrombotic microangiopathy and a potentially fatal inflammatory disease. DITMA has been attributed to a variety of drugs, particularly chemotherapeutic and immunosuppressive agents. Prompt diagnosis is critical for survival and treatment necessitates withdrawal of the offending drug; however, many cases require further treatment including plasmapheresis, immunosuppression, and anticoagulation. In this article, we report a cutaneous biopsy-proven case of tacrolimus-induced DITMA, which was successfully treated with eculizumab after failing the conventional standard of care.

Acute superior mesenteric vein thrombosis in the setting of cytomegalovirus mononucleosis: a case report and review of the literature

Cytomegalovirus is a viral genus of the overarching family Herpesviridae, and is of particular importance because of its relevance to human disease. This association is predominantly due to human cytomegalovirus, a well-studied pathogen. In addition to the mononucleosis syndrome that can occur during acute cytomegalovirus viraemia, this virion has been recurrently implicated as a provoking factor for thromboembolic disease in the published scientific literature. As physicians increasingly forgo extensive laboratory investigation in the setting of clinical hypercoagulability, it has also become evident that in some circumstances whether or not a particular investigation alters clinical management is not necessarily the only important question. Viraemia as a provoking factor for thrombosis stands as such an example. The aim of this Grand Round is to further explore the role of cytomegalovirus as it pertains to thromboembolic disease, especially in the present era of viral-associated thromboembolism.

Reactivation cytomegalovirus leading to acute myocardial infarction-A first reported case in an immunocompetent patient

Reactivation of cytomegalovirus (CMV) in immunocompetent patients may lead to increase morbidity and mortality. A clinical suspicion allows timely diagnosis, treatment, and favorable outcome. In a subject without apparent risk factors for acute myocardial infarction (AMI), CMV can be a possibility.

Does reactivation of cytomegalovirus contribute to severe COVID-19 disease?

The majority of people infected with SARS-CoV-2 are asymptomatic or have mild to moderate symptoms. However, for unknown reasons, about 15 % have severe pneumonia requiring hospital care and oxygen support, and about 5 % develop acute respiratory distress syndrome, septic shock, and multiorgan failure that result in a high mortality rate. The risk of severe COVID-19 is highest among those who are over 70 years of age. Why severe COVID-19 develops in some people but not others is not understood. Could some cases involve reactivation of latent cytomegalovirus (CMV)?

Stroke in critical COVID-19 patients: a cautionary tale from the frontlines

INTRODUCTION

Although Coronavirus Disease 2019 (COVID-19) is primarily a disease of the respiratory system in its transmission and clinical manifestations, physicians have also reported a tropism toward the nervous system.

METHODS

Neurological symptoms can occur as one of many systemic manifestations of a critical form of the disease or in isolation as the predominant presenting complaint.

RESULTS

We report a series of 6 patients who suffered significant cerebrovascular accidents while being treated for critical COVID-19 in the intensive care units of a quaternary care hospital in New York's Hudson valley.

CONCLUSIONS

This series demonstrates how a relatively rare but catastrophic neurological complication can occur in patients with COVID-19 while they are being managed for their more common problems such as respiratory and renal failure.

Degos-like lesions as a cutaneous manifestation of cytomegalovirus infection: A rare and serious complication in a patient with drug-induced hypersensitivity syndrome

Cytomegalovirus causes a myriad of clinical features, potentially affecting any organ system, significantly increasing morbidity and even mortality. Vascular endothelial cell infection by cytomegalovirus has been implicated in the development of vasculopathy, possibly accounting for the clinical association between cytomegalovirus and vascular thrombosis. In contrast with visceral organ involvement, the cutaneous manifestations of cytomegalovirus are variable and rarely described. Malignant atrophic papulosis, commonly known as Degos disease, is an unusual small vessel arteriopathy with a pathognomonic clinical appearance of atrophic porcelain-white central papules surrounded by telangiectatic erythema. As with the arterial occlusive process, Degos disease may be idiopathic or secondary to autoimmune disorders or viral infection. All in all, cytomegalovirus-related Degos-like presentation has never been described. This report describes a case in which disseminated cytomegalovirus disease developed 4 weeks after the onset of drug-induced hypersensitivity syndrome with prominent Degos-like skin lesions. Our case highlights a rare example of Degos-like lesions occurring due to cytomegalovirus disease and emphasizes the importance of early recognition of the characteristic cutaneous eruption as a diagnostic clue leading to the prompt management of this life-threatening infection.

Atypical Hemolytic Uremic Syndrome and Nephrotic Syndrome Associated with Cytomegalovirus Infection

Atypical hemolytic uremic syndrome (aHUS) is a rare disease. It results from the dysregulation of the alternative complement pathway on the cell surface which causes endothelial damage. Increasing evidence links, these abnormalities to mutations in genes of complement regulators or with autoantibodies against complement factors. These mutations have an incomplete penetrance and variable phenotype. Cytomegalovirus (CMV) is endemic throughout the world, and the incidence of severe CMV disease in immunocompetent adults appears to be greater than previously thought. aHUS and nephrotic syndromes associated with CMV infection are rare. Identification of triggers for aHUS manifestation in a genetically susceptible patient is extremely important since this permits a faster initiation of treatment and clinical improvement. We report a case of a man with a homozygotic deletion of CFHR3-1 whose initial presentation was aHUS and nephrotic syndromes associated with CMV infection.

Delicate Role of PD-L1/PD-1 Axis in Blood Vessel Inflammatory Diseases: Current Insight and Future Significance

Immune checkpoint molecules are the antigen-independent generator of secondary signals that aid in maintaining the homeostasis of the immune system. The programmed death ligand-1 (PD-L1)/PD-1 axis is one among the most extensively studied immune-inhibitory checkpoint molecules, which delivers a negative signal for T cell activation by binding to the PD-1 receptor. The general attributes of PD-L1's immune-suppressive qualities and novel mechanisms on the barrier functions of vascular endothelium to regulate blood vessel-related inflammatory diseases are concisely reviewed. Though targeting the PD-1/PD-L1 axis has received immense recognition-the Nobel Prize in clinical oncology was awarded in the year 2018 for this discovery-the use of therapeutic modulating strategies for the PD-L1/PD-1 pathway in chronic inflammatory blood vessel diseases is still limited to experimental models. However, studies using clinical specimens that support the role of PD-1 and PD-L1 in patients with underlying atherosclerosis are also detailed. Of note, delicate balances in the expression levels of PD-L1 that are needed to preserve T cell immunity and to curtail acute as well as chronic infections in underlying blood vessel diseases are discussed. A significant link exists between altered lipid and glucose metabolism in different cells and the expression of PD-1/PD-L1 molecules, and its possible implications on vascular inflammation are justified. This review summarizes the most recent insights concerning the role of the PD-L1/PD-1 axis in vascular inflammation and, in addition, provides an overview exploring the novel therapeutic approaches and challenges of manipulating these immune checkpoint proteins, PD-1 and PD-L1, for suppressing blood vessel inflammation.

Platelet-endothelial associations may promote cytomegalovirus replication in the salivary gland in mice

Platelet decline is a feature of many acute viral infections, including cytomegalovirus (CMV) infection in humans and mice. Platelet sequestration in association with other cells, including endothelium and circulating leukocytes, can contribute to this decline and influence the immune response to and pathogenesis of viral infection. We sought to determine if platelet-endothelial associations (PEAs) contribute to platelet decline during acute murine CMV (mCMV) infection, and if these associations affect viral load and production. Male BALB/c mice were infected with mCMV (Smith strain), euthanized at timepoints throughout acute infection and compared to uninfected controls. An increase in PEA formation was confirmed in the salivary gland at all post-inoculation timepoints using immunohistochemistry for CD41+ platelets co-localizing with CD34+ vessels. Platelet depletion did not change amount of viral DNA or timecourse of infection, as measured by qPCR. However, platelet depletion reduced viral titer of mCMV in the salivary glands while undepleted controls demonstrated robust replication in the tissue by plaque assay. Thus, platelet associations with endothelium may enhance the ability of mCMV to replicate within the salivary gland. Further work is needed to determine the mechanisms behind this effect and if pharmacologic inhibition of PEAs may reduce CMV production in acutely infected patients.

Novel Strategies to Combat CMV-Related Cardiovascular Disease

Cytomegalovirus (CMV), a ubiquitous human pathogen that is never cleared from the host, has long been thought to be relatively innocuous in immunocompetent adults, but causes severe complications including blindness, end-organ disease, and death in newborns and in immuno-compromised individuals, such as organ transplant recipients and those suffering from AIDS. Yet even in persons with intact immunity, CMV infection is associated with profound stimulation of immune and inflammatory pathways. Carriers of CMV infection also have an elevated risk of developing cardiovascular complications. In this review, we define the proposed mechanisms of how CMV contributes to cardiovascular disease (CVD), describe current approaches to target CMV, and discuss how these strategies may or may not alleviate cardiovascular complications in those with CMV infection. In addition, we discuss the special situation of CMV coinfection in people with HIV infection receiving antiretroviral therapy, and describe how these 2 viral infections may interact to potentiate CVD in this especially vulnerable population.

The role of human cytomegalovirus in atherosclerosis: a systematic review

Atherosclerosis is a progressive vascular disease with increasing morbidity and mortality year by year in modern society. Human cytomegalovirus (HCMV) infection is closely associated with the development of atherosclerosis. HCMV infection may accelerate graft atherosclerosis and the development of transplant vasculopathy in organ transplantation. However, our current understanding of HCMV-associated atherosclerosis remains limited and is mainly based on clinical observations. The underlying mechanism of the involvement of HCMV infection in atherogenesis remains unclear. Here, we summarized current knowledge regarding the multiple influences of HCMV on a diverse range of infected cells, including vascular endothelial cells, vascular smooth muscle cells, monocytes, macrophages, and T cells. In addition, we described potential HCMV-induced molecular mechanisms, such as oxidative stress, endoplasmic reticulum stress, autophagy, lipid metabolism, and miRNA regulation, which are involved in the development of HCMV-associated atherogenesis. Gaining an improved understanding of these mechanisms will facilitate the development of novel and effective therapeutic strategies for the treatment of HCMV-related cardiovascular disease.

Productive Cytomegalovirus Infection Is Associated With Impaired Endothelial Function in ST-Elevation Myocardial Infarction

BACKGROUND

An association between productive cytomegalovirus infection and atherosclerosis was shown recently in several trials, including a previous study of ours. However, the mechanism involved in this association is still under investigation. Here, we addressed the interaction between productive cytomegalovirus infection and endothelial function in patients with ST-elevation myocardial infarction (STEMI).

METHODS

We analyzed the presence of cytomegaloviral DNA in plasma and endothelial function in 33 patients with STEMI and 33 volunteers without cardiovascular diseases, using real-time polymerase chain reaction (PCR) and a noninvasive test of flow-mediated dilation.

RESULTS

Both the frequency of presence and the load of cytomegaloviral DNA were higher in plasma of patients with STEMI than those in controls. This difference was independent of other cardiovascular risk factors (7.38 [1.36-40.07]; P = 0.02). The results of the flow-mediated dilation test were lower in patients in STEMI than in controls (5.0% [2.65%-3.09%] vs 12. %5 [7.5%-15.15%]; P = 0.004) and correlated negatively with the cytomegaloviral DNA load (Spearman R = -0.407; P = 0.019) independently of other cardiovascular risk factors.

CONCLUSIONS

Productive cytomegalovirus infection in patients with STEMI correlated negatively with endothelial function independently of other cardiovascular risk factors. The impact of cytomegalovirus on endothelial function may explain the role of cytomegalovirus in cardiovascular prognosis.

Environmental Triggers of Autoreactive Responses: Induction of Antiphospholipid Antibody Formation

Antiphospholipid antibodies (aPLs) comprise a diverse family of autoantibodies targeted against proteins with the affinity toward negatively charged phospholipids or protein-phospholipid complexes. Their clinical significance, including prothrombotic potential of anti-cardiolipin antibodies (aCLs), anti-β2-glycoprotein I antibodies (aβ2-GPIs), and lupus anti-coagulant (LA), is well-established. However, the ontogeny of these pathogenic aPLs remains less clear. While transient appearance of aPLs could be induced by various environmental factors, in genetically predisposed individuals these factors may eventually lead to the development of the antiphospholipid syndrome (APS). Since the first description of APS, it has been found that a wide variety of microbial and viral agents influence aPLs production and contribute to clinical manifestations of APS. Many theories attempted to explain the pathogenic potential of different environmental factors as well as a phenomenon termed molecular mimicry between β2-GPI molecule and infection-relevant structures. In this review, we summarize and critically assess the pathogenic and non-pathogenic formation of aPLs and its contribution to the development of APS.

Antiphospholipid antibody syndrome with thrombotic splenic infarcts associated with acute cytomegalovirus infection

INTRODUCTION

We describe a case of acute cytomegalovirus (CMV) infection complicated by acquired antiphospholipid antibodies and splenic thrombi. We discuss the associations between CMV infection and thrombosis risk and correlation with antiphospolipid antibodies.

CASE PRESENTATION

A previously healthy 32-year-old woman is hospitalized for acute abdominal pain and fever and found to have multiple splenic infarcts on an abdominal computed tomography (CT) scan. An infectious work-up is negative except for acute CMV, and a hypercoagulable work-up is only positive for antiphospholipid antibodies. The patient is discharged and placed on anti-coagulation therapy for 6 months.

CONCLUSION

Co-incident thrombosis and antiphospholipid antibody syndrome can occur with acute viral infections, including CMV. We discuss the viral infection-associated increased risk of developing blood clots and antiphospholipid antibodies as being either correlative with or causative of viral-induced thrombosis.

Zika Virus Infection Induces Elevation of Tissue Factor Production and Apoptosis on Human Umbilical Vein Endothelial Cells

Zika virus (ZIKV) infection is typically characterized by a mild disease presenting with fever, maculopapular rash, headache, fatigue, myalgia, and arthralgia. A recent animal study found that ZIKV-infected pregnant Ifnar ^-/-mice developed vascular damage in the placenta and reduced amount of fetal capillaries. Moreover, ZIKV infection causes segmental thrombosis in the umbilical cord of pregnant rhesus macaques. Furthermore, several case reports suggest that ZIKV infection cause coagulation disorders. These results suggest that ZIKV could cause an alteration in the host hemostatic response, however, the mechanism has not been investigated thus far. This paper aims to determine whether ZIKV infection on HUVECs induces apoptosis and elevation of tissue factor (TF) that leads to activation of secondary hemostasis. We infected HUVECs with two ZIKV strains and performed virus titration, immunostaining, and flow cytometry to confirm and quantify infection. We measured TF concentrations with flow cytometry and performed thrombin generation test (TGT) as a functional assay to assess secondary hemostasis. Furthermore, we determined the amount of cell death using flow cytometry. We also performed enzyme-linked immunosorbent assay (ELISA) to determine interleukin (IL)-6 and IL-8 production and conducted blocking experiments to associate these cytokines with TF expression. Both ZIKV strains infected and replicated to high titers in HUVECs. We found that infection induced elevation of TF expressions. We also showed that increased TF expression led to shortened TGT time. Moreover, the data revealed that infection induced apoptosis. In addition, there was a significant increase of IL-6 and IL-8 production in infected cells. Here we provide in vitro evidence that infection of HUVECs with ZIKV induces apoptosis and elevation of TF expression that leads to activation of secondary hemostasis.

Colon perforation due to antigenemia-negative cytomegalovirus gastroenteritis after liver transplantation: A case report and review of literature

BACKGROUND

Cytomegalovirus (CMV) remains a critical complication after solid-organ transplantation. The CMV antigenemia (AG) test is useful for monitoring CMV infection. Although the AG-positivity rate in CMV gastroenteritis is known to be low at onset, almost all cases become positive during the disease course. We treated a patient with transverse colon perforation due to AG-negative CMV gastroenteritis, following a living donor liver transplantation (LDLT).

CASE SUMMARY

The patient was a 52-year-old woman with decompensated liver cirrhosis as a result of autoimmune hepatitis who underwent a blood-type compatible LDLT with her second son as the donor. On day 20 after surgery, upper and lower gastrointestinal endoscopy (GE) revealed multiple gastric ulcers and transverse colon ulcers. The biopsy tissue immunostaining confirmed a diagnosis of CMV gastroenteritis. On day 28 after surgery, an abdominal computed tomography revealed transverse colon perforation, and simple lavage and drainage were performed along with an urgent ileostomy. Although the repeated remission and aggravation of CMV gastroenteritis and acute cellular rejection made the control of immunosuppression difficult, the upper GE eventually revealed an improvement in the gastric ulcers, and the biopsy samples were negative for CMV. The CMV-AG test remained negative, therefore, we had to evaluate the status of the CMV infection on the basis of the clinical symptoms and GE.

CONCLUSION

This case report suggests a monitoring method that could be useful for AG-negative CMV gastroenteritis after a solid-organ transplantation.

Cytomegalovirus Infection in Cardiovascular Diseases

Atherosclerosis underlies the development of many cardiovascular diseases that continue to hold a leading place among the causes of death in developed countries. The role of activated immune cells in atherosclerosis progression has been convincingly demonstrated, but the mechanism of their action remains poorly investigated. Since atherosclerosis is associated with chronic inflammatory response, involvement of viral and bacterial infections in atherogenesis has been examined. A special place among the infectious agents is held by human herpesviruses as the most common persistent viruses in human population coupled to chronic inflammation during atherosclerosis. We found that activation of cytomegalovirus (CMV, human herpesvirus 5) infection is associated with the emergence of acute coronary syndrome, which is in a good agreement with the data on productive CMV infection published elsewhere. In this review, we discuss the data obtained by us and other researchers regarding the role of cytomegalovirus infection and related potential mechanisms resulting in the expansion of atherosclerotic plaques during ischemic heart disease and stroke, including virus transfer to immune and endothelial cells via extracellular vesicles. In particular, the data presented in the review demonstrate that virus spreading in the vascular wall triggers immune system activation in atherosclerotic plaques and causes endothelial dysfunction. Moreover, productive CMV infection in patients with acute myocardial infarction correlates with the extent of endothelial dysfunction. The mechanisms described by us and other researchers may explain the role of CMV infection in atherosclerosis and development of ischemic heart disease.

Pathogen interactions with endothelial cells and the induction of innate and adaptive immunity

There are over 10 trillion endothelial cells (EC) that line the vasculature of the human body. These cells not only have specialized functions in the maintenance of homeostasis within the circulation and various tissues but they also have a major role in immune function. EC also represent an important replicative niche for a subset of viral, bacterial, and parasitic organisms that are present in the blood or lymph; however, there are major gaps in our knowledge regarding how pathogens interact with EC and how this influences disease outcome. In this article, we review the literature on EC-pathogen interactions and their role in innate and adaptive mechanisms of resistance to infection and highlight opportunities to address prominent knowledge gaps.

Micro RNAs from DNA Viruses are Found Widely in Plasma in a Large Observational Human Population

Viral infections associate with disease risk and select families of viruses encode miRNAs that control an efficient viral cycle. The association of viral miRNA expression with disease in a large human population has not been previously explored. We sequenced plasma RNA from 40 participants of the Framingham Heart Study (FHS, Offspring Cohort, Visit 8) and identified 3 viral miRNAs from 3 different human Herpesviridae. These miRNAs were mostly related to viral latency and have not been previously detected in human plasma. Viral miRNA expression was then screened in the plasma of 2763 participants of the remaining cohort utilizing high-throughput RT-qPCR. All 3 viral miRNAs associated with combinations of inflammatory or prothrombotic circulating biomarkers (sTNFRII, IL-6, sICAM1, OPG, P-selectin) but did not associate with hypertension, coronary heart disease or cancer. Using a large observational population, we demonstrate that the presence of select viral miRNAs in the human circulation associate with inflammatory biomarkers and possibly immune response, but fail to associate with overt disease. This study greatly extends smaller singular observations of viral miRNAs in the human circulation and suggests that select viral miRNAs, such as those for latency, may not impact disease manifestation.

Perforated jejunitis in a child with acute lymphoblastic leukemia treated with pegaspargase

Survival rates of children with acute lymphoblastic leukemia have improved since the incorporation of asparaginase in the treatment protocol, but the medication has potential serious complications, including vascular thrombosis. Here, we describe the case of a 13-year-old boy with pre-T-cell acute lymphoblastic leukemia whose treatment course was complicated by perforated jejunitis requiring resection of a portion of his small bowel. Pathologic assessment showed transmural ischemia, mesenteric venous and arterial thrombi, and scattered cytomegalovirus inclusion bodies. Pediatric mesenteric ischemia is rare, and its consideration in patients treated with asparaginase is discussed.

Human cytomegalovirus infection and coronary heart disease: a systematic review

Background

Human cytomegalovirus (HCMV) infection is closely associated with coronary heart disease.

Main body of the abstract

In 1987, Adam et al. were the first to report an association between HCMV infection and atherosclerosis (AS), and later, many serum epidemiology and molecular biology studies showed that HCMV-infected endothelial cells play an important role in the development of AS. As patients with HCMV are generally susceptible to coronary heart disease, and with the increasing elderly population, a review of recent studies focusing on the relationships of HCMV infection and coronary heart disease is timely and necessary.

Short conclusion

The role of HCMV infection in the development of AS needs further study, since many remaining issues need to be explored and resolved. For example, whether HCMV promotes the development of coronary AS, and what the independent factors that lead to coronary artery AS by viral infection are. A comprehensive understanding of HCMV infection is needed in order to develop better strategies for preventing AS.

Thrombotic microangiopathy following haematopoietic stem cell transplant

Thrombotic microangiopathy is a potentially lethal complication of haematopoietic stem cell (bone marrow) transplantation. The pathophysiology is incompletely understood, although endothelial damage appears to be central. Platelet activation, neutrophil extracellular traps and complement activation appear to play key roles. Diagnosis may be difficult and universally accepted diagnostic criteria are not available. Treatment remains controversial. In some cases, withdrawal of calcineurin inhibitors is adequate. Rituximab and defibrotide also appear to have been used successfully. In severe cases, complement inhibitors such as eculizumab may play a valuable role. Further research is required to define the pathophysiology and determine both robust diagnostic criteria and the optimal treatment.

Down-regulation of single-stranded DNA-binding protein 1 expression induced by HCMV infection promotes lipid accumulation in cells

The objective of this study was to observe the infection of human cytomegalovirus (HCMV) to human umbilical vein endothelial cells, and its effect on the expression of single-stranded DNA-binding protein (SSBP1) and on lipid metabolism in endothelial cells. We screened the differential expression of mRNAs after HCMV infection by suppression subtractive hybridization and the expression levels of SSBP1 mRNA and protein after HCMV infection by real-time PCR and western blot. After verification of successful infection by indirect immunofluorescent staining and RT-PCR, we found a differential expression of lipid metabolism-related genes including LDLR, SCARB, CETP, HMGCR, ApoB and LPL induced by HCMV infection. The expression levels of SSBP1 mRNA and protein after HCMV infection were significantly down-regulated. Furthermore, we found that upregulation of SSBP1 inhibited the expression of atherosclerosis-associated LDLR, SCARB, HMGCR, CETP as well as the accumulation of lipids in the cells. The results showed that the inhibition of SSBP1 by HCMV infection promotes lipid accumulation in the cells.

The association between cytomegalovirus infection, obesity, and metabolic syndrome in U.S. adult females

OBJECTIVE

The purpose of this analysis was to determine whether cytomegalovirus (CMV) infection is associated with the prevalence of metabolic syndrome (MetS) and whether this relationship differs by BMI.

METHODS

Data from the 1999-2004 National Health and Nutrition Examination Survey (NHANES) were pooled (N = 2,532). Logistic regression was used for assessing the association between CMV and MetS, stratified by gender and BMI, categorized as normal weight, overweight, obesity, and extreme obesity, and adjusted for age, race/ethnicity, and poverty level.

RESULTS

In unadjusted analyses, CMV infection was significantly associated with MetS in females (OR: 1.50; 95% CI: 1.1-2.1) but not males. After adjusting for confounders, the odds of MetS were higher in CMV+ normal-weight females (aOR: 65.31; 95% CI: 6.8-625.6) but lower in CMV+ females with extreme obesity (aOR: 0.25; 95% CI: 0.1-0.9). CMV infection was associated with higher high-density lipoprotein cholesterol (HDL-C) and lower triglycerides in females with extreme obesity but lower HDL-C in normal-weight females.

CONCLUSIONS

CMV infection was found to be associated with unique MetS phenotypes that differ between BMI categories and gender. Seropositive normal-weight females had a higher prevalence of MetS and dyslipidemia, while infection in females with extreme obesity was associated with a more metabolically benign profile.

A Case of Miller Fisher Syndrome, Thromboembolic Disease, and Angioedema: Association or Coincidence?

BACKGROUND Miller Fisher Syndrome is characterized by the clinical triad of ophthalmoplegia, ataxia, and areflexia, and is considered to be a variant of Guillain-Barre Syndrome. Miller Fisher Syndrome is observed in approximately 1-5% of all Guillain-Barre cases in Western countries. Patients with Miller Fisher Syndrome usually have good recovery without residual deficits. Venous thromboembolism is a common complication of Guillain-Barre Syndrome and has also been reported in Miller Fisher Syndrome, but it has generally been reported in the presence of at least one prothrombotic risk factor such as immobility. A direct correlation between venous thromboembolism and Miller Fisher Syndrome or Guillain-Barre Syndrome has not been previously described. CASE REPORT We report the case of a 32-year-old Hispanic male who presented with acute, severe thromboembolic disease and concurrently demonstrated characteristic clinical features of Miller Fisher Syndrome including ophthalmoplegia, ataxia, and areflexia. Past medical and family history were negative for thromboembolic disease, and subsequent hypercoagulability workup was unremarkable. During the course of hospitalization, the patient also developed angioedema. CONCLUSIONS We describe a possible association between Miller Fisher Syndrome, thromboembolic disease, and angioedema.

The Cell Biology of Cytomegalovirus: Implications for Transplantation

Interpretation of clinical data regarding the impact of cytomegalovirus (CMV) infection on allograft function is complicated by the diversity of viral strains and substantial variability of cellular receptors and viral gene expression in different tissues. Variation also exists in nonspecific (monocytes and dendritic cells) and specific (NK cells, antibodies) responses that augment T cell antiviral activities. Innate immune signaling pathways and expanded pools of memory NK cells and γδ T cells also serve to amplify host responses to infection. The clinical impact of specific memory T cell anti-CMV responses that cross-react with graft antigens and alloantigens is uncertain but appears to contribute to graft injury and to the abrogation of allograft tolerance. These responses are modified by diverse immunosuppressive regimens and by underlying host immune deficits. The impact of CMV infection on the transplant recipient reflects cellular changes and corresponding host responses, the convergence of which has been termed the "indirect effects" of CMV infection. Future studies will clarify interactions between CMV infection and allograft injury and will guide interventions that may enhance clinical outcomes in transplantation.

Pulmonary embolism in an immunocompetent patient with acute cytomegalovirus colitis

Acute cytomegalovirus (CMV) infection occurs commonly in immunocompromised and immunocompetent patients, but is usually asymptomatic in the latter. Vascular events associated with acute CMV infection have been described, but are rare. Hence, such events are rarely reported in the literature. We report a case of pulmonary embolism secondary to acute CMV colitis in an immunocompetent 78-year-old man. The patient presented with fever and diarrhea. Colonic ulcers were diagnosed based on colonoscopy findings, and CMV was the proven etiology on pathological examination. The patient subsequently experienced acute respiratory failure. Pulmonary embolism was diagnosed based on the chest radiography and computed tomography findings. A diagnosis of acute CMV colitis complicated by pulmonary embolism was made. The patient was successfully treated with intravenous administration of unfractionated heparin and intravenous ganciclovir.