Association between cytomegalovirus infection and venous thromboembolism

Interrelationship between COVID-19 and Coagulopathy: Pathophysiological and Clinical Evidence

Since the first description of COVID-19 infection, among clinical manifestations of the disease, including fever, dyspnea, cough, and fatigue, it was observed a high incidence of thromboembolic events potentially evolving towards acute respiratory distress syndrome (ARDS) and COVID-19-associated-coagulopathy (CAC). The hypercoagulation state is based on an interaction between thrombosis and inflammation. The so-called CAC represents a key aspect in the genesis of organ damage from SARS-CoV-2. The prothrombotic status of COVID-19 can be explained by the increase in coagulation levels of D-dimer, lymphocytes, fibrinogen, interleukin 6 (IL-6), and prothrombin time. Several mechanisms have been hypothesized to explain this hypercoagulable process such as inflammatory cytokine storm, platelet activation, endothelial dysfunction, and stasis for a long time. The purpose of this narrative review is to provide an overview of the current knowledge on the pathogenic mechanisms of coagulopathy that may characterize COVID-19 infection and inform on new areas of research. New vascular therapeutic strategies are also reviewed.

Multicenter study on recent portal venous system thrombosis associated with cytomegalovirus disease

BACKGROUND & AIMS

Recent non-malignant non-cirrhotic portal venous system thrombosis (PVT) is a rare condition. Among risk factors for PVT, cytomegalovirus (CMV) disease is usually listed based on a small number of reported cases. The aim of this study was to determine the characteristics and outcomes of PVT associated with CMV disease.

METHODS

We conducted a French multicenter retrospective study comparing patients with recent PVT and CMV disease ("CMV positive"; n = 23) to patients with recent PVT for whom CMV testing was negative ("CMV negative"; n = 53) or unavailable ("CMV unknown"; n = 297).

RESULTS

Compared to patients from the "CMV negative" and "CMV unknown" groups, patients from the "CMV positive" group were younger, more frequently had fever, and had higher heart rate, lymphocyte count and serum ALT levels (p ≤0.01 for all). The prevalence of immunosuppression did not differ between the 3 groups (4%, 4% and 6%, respectively). Extension of PVT was similar between the 3 groups. Thirteen out of 23 "CMV positive" patients had another risk factor for thrombosis. Besides CMV disease, the number of risk factors for thrombosis was similar between the 3 groups. Heterozygosity for the prothrombin G20210A gene variant was more frequent in "CMV positive" patients (22%) than in the "CMV negative" (4%, p = 0.01) and "CMV unknown" (8%, p = 0.03) groups. Recanalization rate was not influenced by CMV status.

CONCLUSIONS

In patients with recent PVT, features of mononucleosis syndrome should raise suspicion of CMV disease. CMV disease does not influence thrombosis extension nor recanalization. More than half of "CMV positive" patients have another risk factor for thrombosis, with a particular link to the prothrombin G20210A gene variant.

LAY SUMMARY

Patients with cytomegalovirus (CMV)-associated portal venous system thrombosis have similar thrombosis extension and evolution as patients without CMV disease. However, patients with CMV-associated portal venous system thrombosis more frequently have the prothrombin G20210A gene variant, suggesting that these entities act synergistically to promote thrombosis.

Donor Graft Cytomegalovirus Serostatus and the Risk of Arterial and Venous Thrombotic Events in Seronegative Recipients After Non-Thoracic Solid Organ Transplantation

BACKGROUND

Cytomegalovirus (CMV) is the most common opportunistic pathogen, following solid organ transplantation (SOT), that leads to direct and indirect effects. The aim of this study was to assess the impact of CMV exposure at transplantation on the rate of posttransplant thrombotic events (TEs).

METHODS

We conducted a retrospective cohort study of patients transplanted at the University of Alberta Hospital between July 2005 and January 2018. We included adult SOT CMV-seronegative recipients at transplantation who received an allograft from either a seropositive donor (D+/R-) or a seronegative donor (D-/R-).

RESULTS

A total of 392 SOT recipients were included: 151 (39%) liver, 188 (48%) kidney, 45 (11%) pancreas, and 8 (2%) other transplants. The mean age was 47 years, 297 (76%) were males, and 181 (46%) had a CMV D+/R- donor. Patients in the CMV D+/R- cohort were slightly older (51 years versus 48 years in the D-/R- cohort; P = .036), while other variables, including cardiovascular risk factors and pretransplant TEs, were not different between groups. Overall, TEs occurred in 35 (19%) patients in the CMV D+/R- group, versus 21 (10%) in the CMV D-/R- group, at 5 years of follow-up (P = .008); the incidence rates per 100 transplant months were 5.12 and 1.02 in the CMV D+/R- and CMV D-/R- groups, respectively (P = .003). After adjusting for potential confounders with a Cox regression model, a CMV D+/R- transplantation was independently associated with an increased risk of a TE over 5 years (adjusted hazard ratio, 3.027; 95% confidence interval, 1.669-5.488).

CONCLUSIONS

A CMV D+/R- transplantation is associated with an increased risk of a TE posttransplantation.

Hyperthrombotic Milieu in COVID-19 Patients

COVID-19 infection has protean systemic manifestations. Experience from previous coronavirus outbreaks, including the current SARS-CoV-2, has shown an augmented risk of thrombosis of both macrovasculature and microvasculature. The former involves both arterial and venous beds manifesting as stroke, acute coronary syndrome and venous thromboembolic events. The microvascular thrombosis is an underappreciated complication of SARS-CoV-2 infection with profound implications on the development of multisystem organ failure. The telltale signs of perpetual on-going coagulation and fibrinolytic cascades underscore the presence of diffuse endothelial damage in the patients with COVID-19. These parameters serve as strong predictors of mortality. While summarizing the alterations of various components of thrombosis in patients with COVID-19, this review points to the emerging evidence that implicates the prominent role of the extrinsic coagulation cascade in COVID-19-related coagulopathy. These mechanisms are triggered by widespread endothelial cell damage (endotheliopathy), the dominant driver of macro- and micro-vascular thrombosis in these patients. We also summarize other mediators of thrombosis, clinically relevant nuances such as the occurrence of thromboembolic events despite thromboprophylaxis (breakthrough thrombosis), current understanding of systemic anticoagulation therapy and its risk-benefit ratio. We conclude by emphasizing a need to probe COVID-19-specific mechanisms of thrombosis to develop better risk markers and safer therapeutic targets.

Risk factors of venous thrombo-embolism during cytomegalovirus infection in immunocompetent individuals. A systematic review

Most of the effects and complications of cytomegalovirus (CMV) infection are still unknown, even though its tropism for the endothelium has been extensively investigated. In fact, CMV is suspected to be a cause of venous thrombo-embolism (VTE) since 1974, but there is still no consensus about the management of CMV-related thrombosis and how to prevent it. Cytomegalovirus-related thrombosis has been reported mostly in immunocompromised patients, rarely in immunocompetent individuals. In order to identify potential risk factors of CMV-related thrombosis, we performed a systematic review of the literature regarding immunocompetent patients with cytomegalovirus infection and thrombosis. We found 115 cases with a mean age of 37.36 years (SD ± 16.43 years). Almost half the female patients were assuming EP contraception at the time of the event, and almost half the patients were affected by a coagulation disorder. Interestingly, just two women and four men had no risk factor for thrombosis other than the CMV infection at the time of the event. In conclusion, coagulation disorders and EP contraception have to be taken into a great deal of consideration in patients with CMV infection, since they could be important risk factors for VTE. Knowing the correlation with coagulation disorders, the use of anticoagulation drugs cannot be considered overtreatment. It was not feasible to determine the usefulness of an antiviral treatment. Further studies, even randomized ones, are required to determine the usefulness of antiviral drugs and the real prevalence of CMV-related VTE.

Pulmonary Embolism in a Young Immunocompetent Adult Infected with Cytomegalovirus. Are Novel Oral Anticoagulants an Efficient Alternative?

BACKGROUND/AIM

Cytomegalovirus (CMV) infection is a common disease especially in young adults. Thromboembolism like deep vein thrombosis and pulmonary embolism is increased among patients with CMV infection. Most cases represent immunocompromised patients usually treated with low molecular weight heparin.

CASE REPORT

Herein, we describe a 25-year-old immunocompetent male who presented at the emergency department with sudden onset of chest pain. One month prior to admission, he had developed persistent fever and cough and the diagnosis of CMV infection had been established. After extensive workup, the diagnosis of pulmonary embolism after CMV infection was set and he was treated with rivaroxaban. During the next six months the patient continued on the same anticoagulant therapy with no other episode of pulmonary embolism at 1-year follow-up.

CONCLUSION

To our knowledge, this is the first case of CMV-associated pulmonary embolism treated with novel oral anticoagulants (NOACs). NOACs, such as rivaroxaban, seem to be safe and may represent an attractive alternative with promising results in this particular group of patients. Studies incorporating a greater cohort of patients are needed in order to draw safe conclusions regarding the relationship between NOACs and CMV infection.

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.

Thromboembolic events in patients with severe pandemic influenza A/H1N1

BACKGROUND

The 2009 pandemic influenza A/H1N1 developed as a novel swine influenza which caused more diseases among younger age groups than in the elderly. Severe hypoxemic respiratory failure from A/H1N1 pneumonia resulted in an increased need for ICU beds. Several risk groups were identified that were at a higher risk for adverse outcomes. Pregnant women were a particularly vulnerable group of patients The CDC reported on the first ten patients with severe illness and acute hypoxemic respiratory failure associated with A/H1N1 infection, none of whom were pregnant, but they noticed that half of the patients had a pulmonary embolism.

METHODS

During a four-month period from September to December 2009, 252 patients were admitted to our hospital with confirmed pandemic influenza H1N1 by real-time reverse transcriptase-polymerase chain reaction test (rRT-PCR). We cared for twenty patients (7.9%) admitted to MICU with severe A/H1N1. Results on Thrombotic events were identified in five (25%) of our critically ill patients.

CONCLUSIONS

We recommend that patients with severe influenza A/H1N1 pneumonitis and respiratory failure be administered DVT prophylaxis in particular if there are additional risk factors for TVE. Further prospective studies on the relationship of influenza A/H1N1 and VTE are needed.

Acute cytomegalovirus infection in liver transplant recipients: An independent risk for venous thromboembolism

Acute cytomegalovirus (CMV) infection is a commonly encountered complication in the post liver transplant setting. We present a case of a 71-year-old male with acute CMV infection, initially presenting with a gastrointestinal bleed due to acute CMV gastritis and later on complicated by acute venous thromboembolism occurring as an unprovoked event in the post liver transplant period. Traditional risk factors for venous thromboembolism have been well described in the medical literature. Sporadic cases of thromboembolism due to CMV infection in the immune compromised patients have been described, especially in the post kidney transplant patients. Liver transplant recipients are equally prone to CMV infection particularly in the first year after successful transplantation. Venous thromboembolism in this special population is particularly challenging due to the fact that these patients may have persistent thrombocytopenia and anticoagulation may be a challenge for the treating physician. Since liver transplantation is severely and universally limited by the availability of donor organs, we feel that this case report will provide valuable knowledge in the day to day management of these patients, whose clinical needs are complex and require a multidisciplinary approach in their care and management. Evidence and pathophysiology linking both the conditions is presented along with a brief discussion on the management, common scenarios encountered and potential impact in this special group of patients.

Review: Viral infections and mechanisms of thrombosis and bleeding

Viral infections are associated with coagulation disorders. All aspects of the coagulation cascade, primary hemostasis, coagulation, and fibrinolysis, can be affected. As a consequence, thrombosis and disseminated intravascular coagulation, hemorrhage, or both, may occur. Investigation of coagulation disorders as a consequence of different viral infections have not been performed uniformly. Common pathways are therefore not fully elucidated. In many severe viral infections there is no treatment other than supportive measures. A better understanding of the pathophysiology behind the association of viral infections and coagulation disorders is crucial for developing therapeutic strategies. This is of special importance in case of severe complications, such as those seen in hemorrhagic viral infections, the incidence of which is increasing worldwide. To date, only a few promising targets have been discovered, meaning the implementation in a clinical context is still hampered. This review discusses non‐hemorrhagic and hemorrhagic viruses for which sufficient data on the association with hemostasis and related clinical features is available. This will enable clinicians to interpret research data and place them into a perspective. J. Med. Virol. 84:1680–1696, 2012. © 2012 Wiley Periodicals, Inc.

Cytomegalovirus-induced cutaneous microangiopathy manifesting as lower limb ischemia in a human immunodeficiency virus-infected patient

Cutaneous infections by cytomegalovirus (CMV) are rare and often difficult to diagnose both clinically and histopathologically. A wide range of different clinical manifestations have been described in the literature, especially in immunosuppressed patients. CMV-induced thrombosis has also been reported in these patients, and various mechanisms have been proposed to explain the role of CMV in the thrombotic process, including direct damage of the endothelial cells, activation of coagulation factors and inducing the production of antiphospholipid antibodies. We present the case of a human immunodeficiency virus (HIV)-infected woman who developed distal ischemic lesions of the lower extremities during a generalized CMV infection. We discuss the role of CMV and antiphospholipid antibodies in the pathogenesis of thrombosis in immunosuppressed patients.

Cytomegalovirus infection is associated with venous thromboembolism of immunocompetent adults--a case-control study

Cytomegalovirus (CMV) seems to contribute to the development of venous thromboembolism (VTE) in immunocompromised patients whereas literature data on the role in immunocompetent individuals are mainly limited to case reports. This study aimed to investigate if cytomegalovirus infection contributes to the development of VTE in immunocompetent individuals. CMV-IgG and CMV-IgM antibody titres, CMV-IgG avidity and CMV-DNA were identified in samples from 166 VTE patients and from 166 healthy blood donors matched for gender and age. CMV-IgG antibodies were found more frequently in VTE patients compared to controls [57.8% vs. 44.0%; adjusted OR 1.75 (95% CI 1.13-2.70); p = 0.016]. Accordingly, median CMV-IgG titres were significantly higher in the case group (89.4 vs. 1.8 AU/ml; p = 0.002). Although the overall rate was low, CMV-IgM antibodies were detected more often among cases than controls. The difference was significant in patients with an unprovoked VTE event [7.4% vs. 0.6%; adjusted OR 5.26 (95% CI 1.35-20.8); p = 0.017]. CMV-IgG antibodies of almost all VTE patients (98.9%) and controls (98.6%) were found to be of high avidity. The rate of positive CMV-DNA samples was low and not different between cases and controls. With the exception of age, no association was found between CMV seropositivity and established VTE risk factors within the VTE group. CMV infection seems to play a role in the development of VTE in immunocompetent patients. Recurrent infection might be more important than acute CMV infection.

Human cytomegalovirus infection is detected frequently in stillbirths and is associated with fetal thrombotic vasculopathy

BACKGROUND

Human cytomegalovirus (CMV) is the most common congenital infection in developed countries and is a known cause of intrauterine fetal death. We examined CMV infection in stillbirths and the relationship with histopathological findings at autopsy.

METHODS

We collected liver, kidney, and placenta specimens from 130 stillbirths. CMV DNA and protein were detected using polymerase chain reaction and immunohistochemistry, along with routine autopsy of stillborn infants.

RESULTS

Overall, CMV DNA was detected in 15% of singleton, >20-week stillborn infants. CMV DNA was detected in kidney (9%), liver (11%), and placenta (5%) specimens, with 75% of infections confirmed by immunohistochemistry. Fetal thrombotic vasculopathy was the only histopathological abnormality associated with CMV infection (in 60% CMV-infected vs 28% uninfected stillbirths P = .010).

CONCLUSIONS

Stillbirth has multiple etiologies. However, the detection of CMV DNA in 15% of fetal tissues or placentae suggests a strong association between CMV infection in pregnancy and stillbirth. Molecular testing during postmortem investigation has an important role to determine the contribution of CMV infection.

Thrombosis associated with acute cytomegalovirus infection: a meta-analysis

BACKGROUND

Thrombosis associated with acute cytomegalovirus (CMV) infection has been reported in the medical literature almost 100 times thus far. Still, the clinical characteristics of patients with both conditions have never been systematically reviewed and described.

METHODS

A literature search was conducted for all (n=97) reports concerning thrombosis associated with acute CMV infection. The current knowledge concerning this unique association and previous clinical experience are presented here.

RESULTS

The incidence of thrombosis among acute CMV infection hospitalized patients was 6.4%, and the incidence of acute CMV infection among thrombosis hospitalized patients was 1.9-9.1%. Most (n=64; 65.9%) reported patients were immunocompetent. Mean age of reported patients was 39.7 ± 14.9 years. Female-male ratio was 1:1. DVT/PE, splanchnic vein thrombosis and splenic infarction were the most prevalent thromboses associated with acute CMV infection. While DVT/PE was more prevalent among immunocompromised patients, splanchnic vein thrombosis was more prevalent among immunocompetent patients. Inherited predispositions for thrombosis were significantly more prevalent among immunocompetent patients. Immunocompromised patients were treated with antiviral agents significantly more often. Duration of anticoagulation therapy varied significantly between reported patients. In-hospital mortality rates were 4.9-22.2%.

CONCLUSIONS

We believe physicians should be alert for symptoms and signs of thrombosis in patients with acute CMV infection, and for symptoms and signs of acute CMV infection in patients with thrombosis.

Inherited and acquired predispositions for thrombosis in immunocompetent patients with cytomegalovirus-associated thrombosis

BACKGROUND

Thrombosis is a rare complication of cytomegalovirus (CMV) infection in immunocompetent patients. The clinical circumstances of this complication have never been studied, to the best of our knowledge.

AIM

We reviewed all reports on CMV-associated thrombosis in immunocompetent adults found in the literature, in search for thrombosis risk factors other than CMV.

METHODS

Our search yielded 32 case reports and case series on CMV-associated thrombosis in immunocompetent adults. Reports on immunocompromised patients, infants and elderly patients were excluded. All reports were reviewed for other, acquired as well as inherited, predispositions for thrombosis.

RESULTS

Reports on 39 immunocompetent adults were reviewed, mean age for which was 34.9+/-10.8years. Overall, 14 (35.9%) patients had one or more acquired predispositions for thrombosis; 16 (45.7%) of the 35 patients that were investigated for inherited thrombophilias had one or more inherited predispositions for thrombosis. Only 12 (34.3%) patients were found to have no acquired or inherited predispositions for thrombosis other than CMV. The most common (n=13; 33.3%) acquired predisposition for thrombosis was daily use of oral contraceptives. The most common (n=6; 17.1%) inherited predisposition for thrombosis was factor V Leiden mutation.

CONCLUSIONS

Most immunocompetent adults with CMV-associated thrombosis have other acquired or inherited predispositions for thrombosis. Hence, addressing these predispositions in patients with CMV-associated thrombosis may be of great clinical importance.

Pulmonary embolism and portal vein thrombosis in an immunocompetent adolescent with acute cytomegalovirus hepatitis

Cytomegalovirus infection is usually asymptomatic or resembles infectious mononucleosis with fever, pharyngitis, arthralgias, lymphadenopathy, and atypical lymphocytosis. Even though primary CMV infection is usually self-limited in healthy individuals, significant complications can develop in immunocompromised patients. Venous or arterial thromboembolic phenomena are uncommon, yet very serious complications of CMV infection. Most published reports describe immunosupressed patients after organ transplantation or in the presence of HIV co-infection. However, thrombotic events in CMV infected immunocompetent individuals may occur. We describe the case of an immunocompetent adolescent with acute cytomegalovirus hepatitis that was complicated with pulmonary embolism and portal vein thrombosis. To our knowledge, this is the first reported case in which these two thrombotic phenomena occurred simultaneously in an adolescent with no obvious predisposing factors for thrombosis in the setting of an acute CMV infection.