Unusual thromboses associated with protein S deficiency in patients with acquired immunodeficiency syndrome: case reports and review of the literature

Cerebral Venous Thrombosis as The Sole Presenting Manifestation of Human Immunodeficiency Virus and Hepatitis B Virus Co-Infection

BACKGROUND

Cerebral venous thrombosis (CVT) following either human immunodeficiency virus (HIV) infection or hepatitis B virus (HBV) infection is a very rare condition. Moreover, it has never been reported as the presenting manifestation of HIV and HBV co-infection, even more so when the patient had a normal CD4 count and no demonstrable opportunistic infections. We aimed to report the first case of an adult Indian male, an intravenous drug abuser who developed CVT as the presenting manifestation of HIV-HBV co-infection.

METHODS

Patient data were obtained from medical records from the Bangur Institute of Neurosciences, Institute of Post Graduate Medical Education and Research & SSKM Hospital, Kolkata, West Bengal, India.

RESULTS

A 25-year-old male with a history of intravenous drug abuse and a normal CD4 count developed CVT as the presenting manifestation of HIV-HBV co-infection. His CD4 count was normal, and he had no demonstrable opportunistic infections. He had an uneventful recovery of the condition (CVT) following the institution of conventional anticoagulation therapy alongside anti-retroviral therapy.

CONCLUSION

Whether illicit drug abuse or HIV/HBV infection itself or all in combination led to this thrombotic event cannot be precisely established. Notwithstanding, we recommend serologic testing for HIV and HBV in patients suffering from CVT with high-risk behavior.

Profile of 26 HIV Seropositive individuals with Cerebral Venous Thrombosis

BACKGROUND

HIV infection has been found to be prothrombotic condition. However, venous thromboembolism associated with HIV is restricted to peripheral vasculature with few reports of cerebral venous thrombosis (CVT).

OBJECTIVE

To examine the clinical manifestations of CVT among HIV seropositive individuals and explore the possible etiological factors.

METHODS AND RESULTS

It is a prospective study of 26 (M:F-18:8) patients of CVT associated with HIV seropositive status. Their age and duration of illness was 33.8±6.8years and 11.3±8.5days respectively. Headache and vomiting was the most common symptom followed by seizures. Drowsiness with GCS (Glasgow coma score) ranging from 9-14 was present in two-thirds of the patients. Serum homocysteine was elevated in 70% of patients. Vitamin B12 was low in 12.5% and insufficient levels in 25%. 88.5% of the patients recovered completely to GCS 15/15 in 2-7days during follow up; 11.5% patients expired during the acute state.

CONCLUSION

This study represents the largest series of CVT in HIV seropositive individuals. There is increased risk of thrombosis due to elevated homocysteine and low Vitamin B12. They have better sensorium inspite of extensive radiological involvement.

Systemic and cell-specific mechanisms of vasculopathy induced by human immunodeficiency virus and highly active antiretroviral therapy

OBJECTIVE

Patients infected with human immunodeficiency virus (HIV) have higher rates of dyslipidemia, atherosclerosis, and chronic inflammation that can damage the vascular system compared with the general population. This can be attributed both to HIV itself and to highly active antiretroviral therapy (HAART) they receive. This review outlines the mechanisms by which HIV and HIV medications can cause vascular complications and identifies strategic areas of research to treat these dysfunctions.

REVIEW

HIV and HAART affect the vascular system through several mechanisms that target systemic or metabolic systems and specific cells. HIV causes dyslipidemia and chronic immune activation, which can contribute to atherosclerosis. In addition, HIV damages macrophages, endothelial cells, smooth muscle cells, and platelets, and this damage also plays a role in the development of atherosclerosis. HAART, particularly protease inhibitors, interferes with cholesterol metabolism and can affect macrophages, endothelial cells, and smooth muscle cells. The metabolic changes and cell damage induced by HIV and HAART put HIV patients at increased risk for atherosclerosis, dyslipidemia, and serious cardiovascular events such as myocardial infarction and stroke.

CONCLUSIONS

HIV patients have increased risk of developing potentially life-threatening cardiovascular pathology, which cannot be explained by traditional cardiovascular risk factors alone. More research is needed into therapies to target this HIV-specific vasculopathy.

Impact of HIV infection on the haemostatic response during sepsis and malaria

Patients positive for the human immunodeficiency virus (HIV) are more susceptible to sepsis and malaria, two conditions known to activate the coagulation system. As chronic HIV infection also influences haemostatic mechanisms, we determined the influence of HIV co-infection on coagulation, anticoagulation and the endothelium during sepsis or malaria. We performed a prospective observational study in 325 subjects with or without HIV infection (103 with sepsis, 127 with malaria and 95 asymptomatic controls) in an HIV endemic area in Central Africa. We measured plasma biomarkers indicative of activation of distinct haemostatic mechanisms. Sepsis and malaria had similar effects with elevated markers of coagulation, reduced anticoagulation markers and activation of endothelium. In particular, asymptomatic HIV infection reduced the plasma levels of the anticoagulant co-factor free protein S, and increased activation of the vascular endothelium, which were not normalized by combination antiretroviral therapy. HIV co-infection during sepsis and malaria caused more profound changes in free protein S and von Willebrand factor in sepsis and malaria, and ADAMTS13 in sepsis, while not influencing sepsis- or malaria-induced coagulation activation. These results show for the first time that HIV infection augments selective haemostatic changes during sepsis and malaria, which may contribute to the enhanced morbidity of these conditions in HIV patients.

Warfarin therapy in the HIV medical home model: low rates of therapeutic anticoagulation despite adherence and differences in dosing based on specific antiretrovirals

To determine the indications for, rates of therapeutic anticoagulation during, and complications of warfarin therapy in HIV-infected individuals, in whom long-term anticoagulation is frequently indicated. To identify risk factors for nonoptimal anticoagulation and to determine if warfarin dosing is differentially affected by specific antiretroviral agents. Retrospective study of a dedicated anticoagulation program at one of the largest clinics for HIV-infected individuals in the United States. Seventy-three HIV-infected individuals on warfarin were followed for a total of 911 visits. The rate of therapeutic internation normalized ratio (INR) levels was 34.5% when including only visits at which patients were assessed to be adherent with warfarin. In multivariable analysis, injection drug use at baseline was an independent risk factor for subtherapeutic INR (odds ratio [OR] 2.4, 95% confidence interval [CI] 1.3-4.7, p=0.01). Additionally, warfarin adherence was protective of both subtherapeutic (OR 0.4, 95% CI 0.2-0.6, p<0.0001) and supratherapeutic (OR 0.5, 95% CI 0.3-0.9, p=0.02) INR status. Efavirenz-based antiretroviral regimens were associated with lower weekly warfarin doses (46 mg) to maintain therapeutic INR compared to lopinavir/ritonavir-based regimens (68 mg; p=0.01) and atazanavir/ritonavir-based regimens (71 mg; p=0.007). Consistently therapeutic warfarin therapy is difficult to achieve in HIV-infected individuals, even with a dedicated anticoagulation program. Adherence to warfarin therapy is important but rates of therapeutic INR levels are nonetheless low. Lower warfarin dosing was required for efavirenz compared to two commonly used protease inhibitor-based regimens. Because of these factors, the emergence of new oral anticoagulants is an important development for HIV-infected individuals who require long term anticoagulation therapy.

Factor VIII concentration is greater in female than male patients with HIV infection

The purpose of the present study was comparing plasma markers of coagulation between men and women in both HIV-infected patients and controls. Fifty-eight HIV-infected patients and 58 healthy participants who were individually matched with patients in age and sex were included in the study. We simultaneously collected blood samples for CD4+ T cell count, CD8+ T cell count, platelets count, hemoglobin, partial thromboplastin time (PTT), prothrombin time, international normalized ratio and blood type measurements. We used fresh plasma of the studied population to measure factor VIII, fibrinogen, antithrombin, protein C and protein S levels. CD4+ T cell count, CD8+ T cell count, platelet count, PTT, plasma fibrinogen, antithrombin, protein C and protein S levels were significantly lower, and plasma factor VIII levels were significantly higher in HIV patients. Factor VIII levels were significantly higher in HIV-infected women than HIV-infected men [200 (181-258) vs. 170 (150-194), p < 0.05]. This difference remained significant [219.7 (195.8-248.7) vs. 158 (136.5-180.3), p < 0.001] after multiple adjustments for age, CD8+ and CD4+ T cell count, using general linear model. Plasma factor VIII concentration was significantly higher in HIV-infected women after stratifying the patients into O, B, A and AB blood groups when there was not any gender difference in controls. We suggest that there is a sexual dimorphism in factor VIII concentration in HIV-infected patients.

Acquired protein S deficiency leads to obliterative portal venopathy and to compensatory nodular regenerative hyperplasia in HIV-infected patients

OBJECTIVE

To identify the mechanism of nodular regenerative hyperplasia in HIV-infected patients.

DESIGN

Case-control study.

SETTING

The hepatology and the infectious disease units of two tertiary care centers in France.

PATIENTS

We compared 13 consecutive HIV-positive patients with unexplained nodular regenerative hyperplasia to 16 consecutive HIV-positive patients without nodular regenerative hyperplasia, to eight HIV-negative patients with nodular regenerative hyperplasia from an identified cause and to 10 anonymous healthy blood donors.

MAIN OUTCOME MEASURE

Patients and controls were screened for diminished protein S activity and antiprotein S immunoglobulin G (IgG) antibodies. The antiprotein S activity of purified IgG from patients and controls was assessed in a functional test of activation of protein C in which protein S serves as a cofactor. A full liver CT portography was realized on the liver explant of a case patient.

RESULTS

The CT portography disclosed diffuse obliterative portal venopathy. Levels of protein S activity were lower among patients with HIV-associated nodular regenerative hyperplasia when compared with HIV-positive patients without nodular regenerative hyperplasia and when compared with HIV-negative patients with nodular regenerative hyperplasia (P < 0.005 for all comparisons). HIV-positive patients with nodular regenerative hyperplasia had significantly higher levels of antiprotein S IgG than HIV-positive patients without nodular regenerative hyperplasia and healthy controls. Purified IgG from patients with HIV-associated nodular regenerative hyperplasia specifically inhibited the protein S-dependent protein C activation.

CONCLUSION

Acquired autoimmune protein S paucity and secondary thrombophilia appear to be causes of obliterative portal venopathy and compensatory nodular regenerative hyperplasia in HIV-positive patients.

Review: thromboses among HIV-infected patients during the highly active antiretroviral therapy era

Venous thrombotic events (VTEs) may occur at higher rates among patients with HIV; some studies suggest that highly active antiretroviral therapy (HAART) may increase the risk for these potentially life-threatening events. We performed a retrospective study among patients with HIV to evaluate the incidence and risk factors for VTEs during the HAART era. A literature review was performed examining VTEs in the pre- and post-HAART eras. Seventeen (3.7%) of 465 patients with HIV experienced a VTE. The overall incidence rate of deep VTEs among HIV-positive persons was 377 cases per 100,000 person-years, a fourfold higher rate compared to age-matched males in the general population. The median age at VTE was 36 years (range, 27-68). Patients with a thrombosis compared to those without had significantly lower current CD4 (153 versus 520 cells/mm(3), p < 0.001) and nadir (76 versus 276 cells/mm(3), p < 0.001) CD4 counts, higher viral loads (3.6 versus 1.7 log(10) copies per milliliter, p = 0.003), and more likely to have a diagnosis of AIDS (76% versus 32%, p < 0.001); there were no differences in demographics, hyperlipidemia, current use of HAART, the duration of HAART or protease inhibitor (PI) exposure. A review of the literature noted 129 VTE cases; mean age was 40 years, mean CD4 count was 181 cells/mm(3), the majority of patients were not receiving HAART, and the most common risk factor was an ongoing infection. Thrombotic events are occurring among patients with HIV despite their relatively young ages. Advanced HIV disease is a risk factor for development of thromboses, possibly due to an increased inflammatory state or the presence of concurrent comorbidities such as infections. HAART or PI therapy does not appear to play a significant role in the occurrence of VTEs.

Cardiovascular manifestations in human immunodeficiency virus-infected patients

Human immunodeficiency virus (HIV) is now a pandemic. It afflicts multiple organs, including the cardiovascular system. This occurs by direct invasion as well as opportunistic infections complicating acquired immunodeficiency syndrome. The presence of newer highly active antiretroviral therapy has led to longer survival of patients infected with HIV, but the cardiac abnormalities related to HIV have remained less well characterized. It is now evident that cardiac involvement in patients with acquired immunodeficiency syndrome is relatively common. This includes coronary artery disease, dilated cardiomyopathy, pericardial effusion, pulmonary hypertension, and ill effects of highly active antiretroviral therapy in the form of lipodystrophy, lipoatrophy, and dyslipidemia. In fact, HIV can now be viewed as a potential risk factor for coronary artery disease, and the dilemma facing clinicians is how to quantify this risk. Awareness of accelerated coronary artery disease and dilated cardiomyopathy is critical to implement preventive measures early in the course of HIV. However, better guidelines are still needed on the basis of prospective randomized controlled studies involving large populations. In conclusion, this review describes cardiac abnormalities associated with HIV, including possible molecular mechanisms. The co-morbid sequelae, their presentation, and pharmacologic management are also discussed.

Venous thromboembolism in patients with HIV/AIDS: a case-control study

BACKGROUND

Retrospective cohort studies of HIV-infected patients suggest an incidence of venous thromboembolism (VTE) of 1% to 2%, which is 10 times that expected among people without HIV. We investigated the prevalence of established risk factors for VTE in this population and explored novel risk factors.

METHODS

We conducted a case-control study using patients in the Johns Hopkins University AIDS Service cohort. We used conditional logistic regression and paired t tests to test for covariates significantly associated with VTE.

RESULTS

We identified 160 patients with VTE diagnosed radiologically or with a clinical course consistent with VTE; 23% of the cases of VTE were diagnosed in hospitalized patients. The incidence of VTE was approximately 0.5% per patient-year. Patients with VTE and control patients did not differ by gender, but black patients were overrepresented among those with VTE (odds ratio [OR]=1.9, 95% confidence interval [CI]: 1.11 to 3.08) and patients with VTE were older than controls (mean: 39 vs. 37 years; P=0.001). Patients with VTE had lower CD4 counts (229 vs. 362 cells/mm; P<0.0001), higher HIV RNA titers (120,254 vs. 71,262 copies/mL; P=0.013), and lower hemoglobin concentrations (11.4 vs. 12.7 g/dL; P<0.0001) preceding the event than those without VTE. The use of highly active antiretroviral therapy was not associated with VTE. In multivariate analyses, independent risks for VTE were age, hospitalization in the past 3 months (OR=13, 95% CI: 6.4 to 27), central venous catheter use in the past 3 months (OR=6.0, 95% CI: 2.3 to 16), and a CD4 count<500 cells/mm (OR=3.0, 95% CI: 1.2 to 7.8).

CONCLUSIONS

The incidence of VTE in our cohort is similar to that reported in other cohorts of patients with HIV. Recent hospitalization was the risk factor most strongly associated with VTE.

[Thromboembolic events at the time of highly active antiretroviral therapies against human immunodeficiency virus]

PURPOSE

Vein thrombosis risk and pulmonary embolism seem to be more important among human immunodeficiency virus (HIV) infected patients.

METHOD

We performed a retrospective study including 780 HIV positive patients followed-up between January 2000 and June 2005 at the University Hospital of Clermont-Ferrand.

RESULTS

Among the 780 HIV-infected patients, six cases of thromboembolic events were identified including, four with pulmonary embolism. All the patients were receiving lopinavir/ritonavir combination.

CONCLUSION

Although uncommon, pulmonary embolism occurs more frequently among HIV positive patients than in general population. Clinicians must remain aware about the possibility of the occurrence of a thromboembolic event especially during the first few months after introduction of the antiretroviral therapy.