Presence of procoagulant peripheral blood mononuclear cells in severe COVID-19 patients relate to ventilation perfusion mismatch and precede pulmonary embolism

PURPOSE

Pulmonary emboli (PE) contribute substantially to coronavirus disease 2019 (COVID-19) related mortality and morbidity. Immune cell-mediated hyperinflammation drives the procoagulant state in COVID-19 patients, resulting in immunothrombosis. To study the role of peripheral blood mononuclear cells (PBMC) in the procoagulant state of COVID-19 patients, we performed a functional bioassay and related outcomes to the occurrence of PE. Secondary aims were to relate this functional assay to plasma D-dimer levels, ventilation perfusion mismatch and TF expression on monocyte subsets.

METHODS

PBMC from an ICU biobank were obtained from 20 patients with a computed tomography angiograph (CTA) proven PE and compared to 15 COVID-19 controls without a proven PE. Functional procoagulant properties of PBMC were measured using a modified fibrin generation time (MC-FGT) assay. Tissue factor (TF) expression on monocyte subsets were measured by flow cytometry. Additional clinical data were obtained from patient records including end-tidal to arterial carbon dioxide gradient.

RESULTS

MC-FGT levels were highest in the samples taken closest to the PE detection, similar to the end-tidal to arterial carbon dioxide gradient (ETCO2 - PaCO2), a measurement to quantify ventilation-perfusion mismatch. In patients without proven PE, peak MC-FGT relates to an increase in end-tidal to arterial carbon dioxide gradient. We identified non-classical, CD16 positive monocytes as the subset with increased TF expression.

CONCLUSION

We show that the procoagulant state of PBMC could aid in early detection of PE in COVID-19 ICU patients. Combined with end-tidal to ETCO2 - PaCO2 gradient, these tests could improve early detection of PE on the ICU.

A highly virulent variant of HIV-1 circulating in the Netherlands

We discovered a highly virulent variant of subtype-B HIV-1 in the Netherlands. One hundred nine individuals with this variant had a 0.54 to 0.74 log₁₀ increase (i.e., a ~3.5-fold to 5.5-fold increase) in viral load compared with, and exhibited CD4 cell decline twice as fast as, 6604 individuals with other subtype-B strains. Without treatment, advanced HIV-CD4 cell counts below 350 cells per cubic millimeter, with long-term clinical consequences-is expected to be reached, on average, 9 months after diagnosis for individuals in their thirties with this variant. Age, sex, suspected mode of transmission, and place of birth for the aforementioned 109 individuals were typical for HIV-positive people in the Netherlands, which suggests that the increased virulence is attributable to the viral strain. Genetic sequence analysis suggests that this variant arose in the 1990s from de novo mutation, not recombination, with increased transmissibility and an unfamiliar molecular mechanism of virulence.

COVID-19 related stigma and health-protective behaviours among adolescents in the Netherlands: An explorative study

The COVID-19 pandemic has forced many governments to impose social distancing measures upon its citizens, including in the Netherlands. Motivating adolescents to adhere to measures such as social distancing can be challenging, since adolescents are relatively more affected by them, while experiencing virtually no personal health benefit. In addition, the COVID-19 pandemic seems to impact the social environment of adolescents in schools, as some media sources have reported bullying and stigmatisation of students with an Asian appearance. This study aims to explore the experiences of adolescents regarding their Health-Protective Behaviour (HPB), as well as the prevalence and expression of stigma towards ethnic minorities within the context of the first wave of COVID-19 pandemic. We performed a cross-sectional mixed-methods study, including two independent online questionnaires. An adapted version of the "HPB" questionnaire (n = 528) and the "Measure of Disease-Related Stigma (MDRS)" questionnaire (n = 380), were administered to Dutch adolescents of 10-16 years old, attending primary or secondary school. Furthermore, 15 interviews were held with eight male and seven female adolescents. All data collection took place between March 17 and April 20, 2020. Results show that adolescents perceive COVID-19 as a threat to other peoples' health, rather than their own, and report adherence to public health measures in the interest of older and more vulnerable members of their community. We found no convincing evidence for widespread misinformation or stigmatising of certain ethnic groups among adolescents related to COVID-19 during this study. Participants acknowledged such behaviour happened in the early stages of the pandemic, before this study was initiated. Adolescents are a vital group for public health researchers to engage with during a pandemic, even when reaching them can be challenging.

[Human T-cell lymphotropic virus type 1 (HTLV-1): a forgotten pathogen]

HTLV-1 is a retrovirus endemic to different parts of the world that causes a variety of symptoms, ranging from asymptomatic infection to severe diseases such as lymphoma/leukaemia and myelopathy. HTLV-1 is transmitted from mother to child through breastfeeding, sexually and via blood and organ donation. We describe 3 patients as examples of the distinct clinical problems related to HTLV-1: a 53-year-old woman with HTLV-1-associated myelopathy, a 43-year-old woman with acute T-cell lymphoma and a 34-year-old pregnant woman who is an asymptomatic carrier. It is not known how many people are infected in the Netherlands, but it is probably more prevalent among immigrants from the Caribbean and Surinam and likely to be underdiagnosed. Diagnosis is important because it alters treatment and because measures to prevent transmission can be implemented, e.g. refraining from breastfeeding and safe sex precautions.

High Treatment Uptake in Human Immunodeficiency Virus/Hepatitis C Virus-Coinfected Patients After Unrestricted Access to Direct-Acting Antivirals in the Netherlands

Background

The Netherlands has provided unrestricted access to direct-acting antivirals (DAAs) since November 2015. We analyzed the nationwide hepatitis C virus (HCV) treatment uptake among patients coinfected with human immunodeficiency virus (HIV) and HCV.

Methods

Data were obtained from the ATHENA HIV observational cohort in which >98% of HIV-infected patients ever registered since 1998 are included. Patients were included if they ever had 1 positive HCV RNA result, did not have spontaneous clearance, and were known to still be in care. Treatment uptake and outcome were assessed. When patients were treated more than once, data were included from only the most recent treatment episode. Data were updated until February 2017. In addition, each treatment center was queried in April 2017 for a data update on DAA treatment and achieved sustained virological response.

Results

Of 23574 HIV-infected patients ever linked to care, 1471 HCV-coinfected patients (69% men who have sex with men, 15% persons who [formerly] injected drugs, and 15% with another HIV transmission route) fulfilled the inclusion criteria. Of these, 87% (1284 of 1471) had ever initiated HCV treatment between 2000 and 2017, 76% (1124 of 1471) had their HCV infection cured; DAA treatment results were pending in 6% (92 of 1471). Among men who have sex with men, 83% (844 of 1022) had their HCV infection cured, and DAA treatment results were pending in 6% (66 of 1022). Overall, 187 patients had never initiated treatment, DAAs had failed in 14, and a pegylated interferon-alfa-based regimen had failed in 54.

Conclusions

Fifteen months after unrestricted DAA availability the majority of HIV/HCV-coinfected patients in the Netherlands have their HCV infection cured (76%) or are awaiting DAA treatment results (6%). This rapid treatment scale-up may contribute to future HCV elimination among these patients.

Dutch healthcare professionals' opinion on vaccination and education to prevent infections in immunocompromised patients: A mixed-method study with recommendations for daily practice

BACKGROUND

The fast-growing population of immunocompromised patients (ICP) is more vulnerable to infectious diseases, demanding strategies to protect them. These strategies seem inconsistent in available guidelines and in practices. We aim to evaluate healthcare professionals' (HCP) opinions on vaccination to reduce the number and severity of infections in ICP.

METHODS

A mixed-method study, with an exploratory sequential design, was performed. Medical specialists from various departments in a tertiary care center in the Netherlands were invited for semi-structured interviews to explore their perspective on preventive care of ICP. Topics that play a substantial role in daily practice for ICP were translated into a survey to gain insight into what extent opinions were generalizable to Erasmus Medical Center.

RESULTS

Surveys were completed by 689 HCP (43% of the invitees), 269 of them treated at least two ICP weekly on average and were considered eligible for further analysis. Quantitative data showed that according to 80 percent of HCP, preventive care for ICP can be improved. Education was chosen by 40 percent as the most important intervention to reduce the number and severity of infections. Vaccinations were valued as important by seventeen percent of HCP. Except for influenza, vaccinations were not regularly discussed during routine consultations. Difficulties to administer vaccinations were experienced by 75 percent of HCP.

CONCLUSION

According to our respondents, education is the most promising intervention to reduce the number and severity of infections in ICP. To reach a higher vaccine uptake, we recommend HCP to address vaccinations more frequently during consultations and to search for solutions to alleviate barriers to vaccinate.

Identifying patients with bacterial infections using a combination of C-reactive protein, procalcitonin, TRAIL, and IP-10 in the emergency department: a prospective observational cohort study

OBJECTIVES

The aim was to effectively reduce the unnecessary use of broad spectrum antibiotics in the emergency department (ED), patients with bacterial infections need to be identified accurately. We investigated the diagnostic value of a combination of biomarkers for bacterial infections, C-reactive protein (CRP), and procalcitonin (PCT), together with biomarkers for viral infections, tumour necrosis factor-related apoptosis-inducing ligand (TRAIL), and interferon-gamma-induced protein-10 (IP-10), in identifying suspected and confirmed bacterial infections in a general ED population with fever.

METHODS

This is a sub-study in the HiTEMP cohort. Patients with fever were included during ED triage, and blood samples were obtained. Using both diagnostics and expert panel analysis, all patients were classified as having either suspected or confirmed bacterial infections, or non-bacterial disease. Using multivariable logistic regression analysis, three biomarker models were analysed: model 1, CRP, TRAIL, IP-10; model 2, PCT, TRAIL, IP-10; and model 3, CRP, PCT, TRAIL, IP-10.

RESULTS

A total of 315 patients were included, of whom 228 patients had a suspected or confirmed bacterial infection. The areas under the curve for the combined models were the following: model 1, 0.730 (95% CI 0.665-0.795); model 2, 0.748 (95% CI 0.685-0.811); and model 3, 0.767(95% CI 0.704-0.829).

CONCLUSIONS

These findings show that a combination of CRP, PCT, TRAIL and IP-10 can identify bacterial infections with higher accuracy than single biomarkers and combinations of a single bacterial biomarkers combined with TRAIL and IP-10.

Work-related stigma and disclosure: A daily challenge for people living with HIV

BACKGROUND

Stigma and disclosure are important work-related issues for people living with HIV (PLWH). To gain better understanding and improve the position of PLWH in the labor market, further insight in these issues is needed.

OBJECTIVE

This study reviews the scientific evidence related to work-related stigma and disclosure.

METHODS

A sensitive literature search was performed in the databases of Medline, Embase, Cochrane Library, Cinahl and Psychinfo for articles published between 1996 and 2016. All studies on PLWH in western countries and investigating disclosure or stigma in relation to work were included.

RESULTS

Of the 866 identified studies, 19 met the inclusion criteria: 4 addressed both disclosure and stigma (2 quantitative), 9 addressed only disclosure (4 quantitative) and 7 studies addressed only stigma (4 quantitative).

CONCLUSION

This review provides a unique overview of the research on work-related disclosure and stigma, which will enable health care providers to support PWLH to make well-considered decisions. However, the available literature was heterogeneous and in most studies the topics of our interest were secondary outcomes and provided only basic insight.

Late Presentation of HIV Infection in the Netherlands: Reasons for Late Diagnoses and Impact on Vocational Functioning

Late diagnosis of HIV remains a major challenge in the HIV epidemic. In Europe, about 50% of all people living with HIV are diagnosed late after infection has occurred. Insight into the reasons for late diagnoses is necessary to increase the number of early diagnoses and optimize treatment options. This qualitative study explored the experiences of 34 late-presenters through in-depth semi-structured interviews. A variety of reasons for late diagnoses emerged from our data and led to a division into four groups, characterized by two dimensions. Regarding vocational functioning, the consequences of late diagnoses were health-related problems prior to and since diagnosis, and problems concealing the HIV status. Healthcare providers should offer HIV tests to groups at risk, and be alert for clinical HIV indicator conditions. It is recommended to increase awareness of HIV transmission routes, symptoms and tests, and the benefits of early testing and early entry to HIV care.

Climate Factors as Important Determinants of Dengue Incidence in Curaçao

Macro- and microclimates may have variable impact on dengue incidence in different settings. We estimated the short-term impact and delayed effects of climate variables on dengue morbidity in Curaçao. Monthly dengue incidence data from 1999 to 2009 were included to estimate the short-term influences of climate variables by employing wavelet analysis, generalized additive models (GAM) and distributed lag nonlinear models (DLNM) on rainfall, temperature and relative humidity in relation to dengue incidence. Dengue incidence showed a significant irregular 4-year multi-annual cycle associated with climate variables. Based on GAM, temperature showed a U-shape, while humidity and rainfall exhibited a dome-shaped association, suggesting that deviation from mean temperature increases and deviation from mean humidity and rainfall decreases dengue incidence, respectively. Rainfall was associated with an immediate increase in dengue incidence of 4.1% (95% CI: 2.2-8.1%) after a 10-mm increase, with a maximum increase of 6.5% (95% CI: 3.2-10.0%) after 1.5 month lag. A 1 °C decrease of mean temperature was associated with a RR of 17.4% (95% CI: 11.2-27.0%); the effect was inversed for a 1°C increase of mean temperature (RR= 0.457, 95% CI: 0.278-0.752). Climate variables are important determinants of dengue incidence and provide insight into its short-term effects. An increase in mean temperature was associated with lower dengue incidence, whereas lower temperatures were associated with higher dengue incidence.

Seoul hantavirus in brown rats in the Netherlands: implications for physicians--Epidemiology, clinical aspects, treatment and diagnostics

The recent discovery of Seoul hantavirus (SEOV) presence in wild rat populations in the Netherlands has direct implications for Dutch clinicians and hantavirus diagnostics. SEOV is amongst the Old World hantaviruses which cause haemorrhagic fever and renal syndrome (HFRS) in humans. HFRS is characterised by a classical triad of fever, acute kidney injury and haemorrhage, but can show different signs and symptoms in specific cases. SEOV is transmitted from infected rats to humans by inhalation of aerosolised excreta. When compared with the known circulating hantaviruses in the Netherlands, Puumala (PUUV) and Tula (TULV), SEOV causes a more severe form of HFRS. Data from cohort studies undertaken in China and Northern Europe show differences in signs and symptoms at onset of disease, (haemorrhagic) complications and mortality. Furthermore, routine diagnostics currently available for hantavirus diagnosis in the Netherlands are not optimised for SEOV detection. The clinical outcome of an SEOV and PUUV infection will greatly benefit from an early diagnosis which will reduce the costs of unnecessary tests and treatments as well. The discovery of SEOV circulation in the Netherlands follows recent findings of SEOV infections in both rodents and humans in England, Wales, France, Belgium and Sweden, indicating the emerging character of SEOV and a high importance of this hantavirus for Public Health in large areas of Europe. Here, we review the current knowledge on the clinical manifestation of SEOV versus PUUV infections in humans, the treatment of clinical cases and diagnostics.

Employment-related concerns of HIV-positive people in the Netherlands: input for a multidisciplinary guideline

PURPOSE

Finding and keeping employment is difficult for people with HIV. To improve supportive care for people with HIV and employment-related problems, a multidisciplinary guideline was developed in the Netherlands in 2010/2011. To identify the employment-related concerns of people with HIV and to formulate the key questions for the guideline, we conducted a qualitative study. The results of this study are described in this article.

METHODS

This study was performed in three HIV-treatment centers in the Netherlands. In total 18 participants participated in three focus-group interviews and nine participants were interviewed individually. The data were transcribed ad verbatim and were analyzed according to the principle of constant comparison.

RESULTS

Our findings indicate that people with HIV in the Netherlands face many work-related concerns. The themes which emerged from this study were disclosure, stigma and discrimination, knowledge about HIV, physical and psychological factors, working conditions, absenteeism, reintegration, and dismissal and counselling.

CONCLUSIONS

This study provides insight into employment-related concerns for people with HIV living in a Western country. It formed the basis for the key questions which were addressed in a multidisciplinary, evidence-based guideline "HIV and work". Finally, it gives leads for further scientific research and opportunities for improving the vocational guidance of people with HIV.

Ebola virus disease: a review on epidemiology, symptoms, treatment and pathogenesis

Currently, West Africa is facing the largest outbreak of Ebola virus disease (EVD) in history. The virus causing this outbreak, the Zaire Ebolavirus (EBOV), belongs to the genus Ebolavirus which together with the genus Marburgvirus forms the family of the Filoviridae. EBOV is one of the most virulent pathogens among the viral haemorrhagic fevers, and case fatality rates up to 90% have been reported. Mortality is the result of multi-organ failure and severe bleeding complications. By 18 September 2014, the WHO reported of 5335 cases (confirmed, suspected and probable) with 2622 deaths, resulting in a case fatality rate of around 50%. This review aims to provide an overview of EVD for clinicians, with the emphasis on pathogenesis, clinical manifestations, and treatment options.

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.

Epidemiology of febrile diseases in the emergency department of a Caribbean island: the Curaçao experience

OBJECTIVE

The aetiology of febrile diseases in tropical countries often remains poorly characterized. We aim to describe the aetiology and outcome of febrile illnesses at the Emergency Department (ED) in Curaçao.

METHODS

From April 2008 - April 2009, all adult febrile patients (T> 38.5 degrees C) at the ED of the St Elisabeth Hospital, Curaçao, Netherlands Antilles, were included. Clinical data were recorded, routine laboratory measurements and blood cultures were taken. Final diagnoses were made at discharge by an independent physician and in retrospect by the main investigator

RESULTS

Four hundred and three patients were included: 223 patients (55.6%) were hospitalized, 32 patients (7.9%) died and 18 patients (4.5%) were admitted to the Intensive Care Unit. In 129 febrile patients (32.0%), infection was proven; 84.4% of patients had bacterial (29.0% urinary tract infection, 23.2% pneumonia infection), 5.6% viral and 10.0% parasitic or fungal infections. Twenty-one patients (5.2%) were discharged with a non-infectious diagnosis and 172 patients (42.7%) without a clear diagnosis.

CONCLUSION

A high mortality rate of 7.9% was observed. We found a high prevalence of bacterial infections, with pneumonia and urinary tract infections as the most common causes of fever. One in 20 patients did not have an infectious disease.

One-year epidemiology of fever at the Emergency Department

BACKGROUND

Although fever is recognised as a major presentation symptom at Emergency Departments (EDs) and is often used as a rationale for the institution of antibiotics, few studies describing patients with fever as the sole inclusion criterion at the ED of a general hospital have been performed. The objective of this study is to describe epidemiology of non-surgical febrile patients at the ED and to identify risk factors for adverse outcome.

METHODS

Blood, sputum, urine and faeces cultures, urine sediments and throat swaps for viral diagnostics were obtained from febrile ED patients. Outcome parameters were bacterial/viral infection, non-bacterial/non-viral infection, non-infectious febrile disease; mortality, hospital admission, admission to the intensive care unit (ICU) and length of hospital stay.

RESULTS

213 Patients were included (87.8% were hospitalised, 8.5% were admitted to ICU, 4.2% died). In 75 patients (35.2%), bacterial infection was confirmed; in 78 patients (36.6%) bacterial infection was suspected. In nine patients (4.2%), viral diagnosis was confirmed; in six patients (2.8%), a viral condition was suspected. The most frequently encountered infection was bacterial pneumonia (58 patients, 27.2%). Only older age was correlated with mortality (ρ=0.176, p=0.01).

CONCLUSION

A majority of the febrile patients were admitted to the hospital, mostly for bacterial infection. An overall mortality rate of 4.2% was registered. Only a few risk factors for adverse outcome could be identified in this cohort. Overall, the outcome of patients presenting with fever at the ED is rather benign.

The diagnostic role of procalcitonin and other biomarkers in discriminating infectious from non-infectious fever

Fever is not only observed in the course of a bacterial or viral infection, but can be a symptom of, for instance, auto-immune, malignant or thromboembolic disease. Determining the etiology of fever in a fast and reliable way is of pivotal importance, as different causes of fever may ask for different therapies. Neither clinical signs and symptoms, nor traditional biomarkers, such as CRP, leukocytes and ESR have sufficient sensitivity and specificity to guide treatment decisions. In this review we focus on the value of traditional and newer biomarkers in non-infectious febrile diseases. Procalcitonin (PCT) seems to be the most helpful laboratory marker for the differentiation of causes of fever, particularly in autoimmune, autoinflammatory and malignant diseases.

Coagulation disorders in patients with severe leptospirosis are associated with severe bleeding and mortality

OBJECTIVE

To determine the involvement of coagulation in bleeding and poor outcome in patients with severe leptospirosis.

METHODS

In a prospective study, parameters of the coagulation system were measured on admission and during follow-up in 52 consecutive patients with severe leptospirosis.

RESULTS

All patients showed coagulation disorders, such as prolonged prothrombin time (PT) and activated partial thromboplastin time, marked procoagulant activity [thrombin-antithrombin (TAT) complexes, prothrombin fragment 1+2, D-dimer], reduced levels of anticoagulant markers (protein C, antithrombin) and increased (anti-) fibrinolytic activity [plasmin-antiplasmin (PAP) complexes, plasminogen activator inhibitor-1]. These disorders were more pronounced in patients who died eventually. PT prolongation was associated with mortality (OR 1.4, 95% CI: 1.0-1.8, P = 0.04). Bleeding occurred in 31 subjects (60%). Of these, 24 had mild bleeding and seven had severe haemorrhages. Thrombocytopenia (platelets </=100 x 10(9)/l) was significantly associated with clinical bleeding (OR 4.6, 95% CI: 1.3-16). A subanalysis of patients with and without severe bleeding revealed a more pronounced imbalance of the coagulation system in patients with severe bleeding, as reflected by a significant association with PT (OR 1.4, 95% CI: 1.0-1.8, P = 0.05) and the TAT/PAP ratio (OR 1.3, 95% CI: 1.0-1.6, P = 0.05), which is an indicator of the balance between coagulation and fibrinolysis. Overt disseminated intravascular coagulation (DIC) was found in 10 (22%) of the 46 patients for whom the score could be calculated. There was no significant association between DIC scores, bleeding diathesis or poor outcome.

CONCLUSION

The coagulation system was strongly activated in patients with leptospirosis. This was more pronounced in the deceased and in patients with severe bleeding than in than the survivors and in those without severe bleeding.

Effect of HIV viral load, CD4 cell count and antiretroviral therapy on human papillomavirus prevalence in urine samples of HIV-infected men

HIV-infected patients are at increased risk for persistent human papillomavirus (HPV) infection, the major cause of anogenital cancer. The present study describes the HPV prevalence in urine samples of 243 HIV-infected men and a control group of 231 men. HPV DNA was amplified by the SPF10 polymerase chain reaction primer set. The overall HPV prevalence in HIV-infected men was 27.5% compared with 12.6% in controls (P < 0.01). Infections with high-risk and multiple HPV genotypes were present in both groups. Differences were not statistically significant. A multivariate logistic regression model showed a decreased HPV prevalence associated with use of a nucleoside and a non-nucleoside reverse transcriptase inhibitor combination (P = 0.03). A trend was observed towards a higher HPV prevalence and a lower CD4 cell count. Further prospective studies are needed to determine the role of HPV DNA testing in urine in future screening programmes for anal cancer in men.

Quantification of HIV protease inhibitors and non-nucleoside reverse transcriptase inhibitors in peripheral blood mononuclear cell lysate using liquid chromatography coupled with tandem mass spectrometry

For pharmacokinetic monitoring, measurement of antiretroviral agents in plasma is the gold standard. However, human immunodeficiency virus protease inhibitors (PIs) or non-nucleoside reverse transcriptase inhibitors (NNRTIs) exert their action within the infected cell. Cell-associated concentrations may therefore more adequately reflect therapy outcome. Therefore, for the quantification of nine PIs (amprenavir, atazanavir, darunavir, indinavir, lopinavir, nelfinavir, ritonavir, saquinavir and tipranavir), 1 active PI metabolite (nelfinavir M8) and 2 NNRTIs (efavirenz and nevirapine) in lysate of peripheral blood mononuclear cells (PBMCs) an assay was developed and validated, using liquid chromatography coupled with tandem mass spectrometry. Analytes were extracted from a PBMC pellet by means of a one-step extraction with 50% methanol containing the internal standards D6-indinavir, D5-saquinavir, 13C6-efavirenz and dibenzepine. Chromatographic separation was performed on a reversed phase C18 column (150mmx2.0mm, particle size 5microm) with a quick stepwise gradient using an acetate buffer (pH 5) and methanol, at a flow rate of 0.25mL/min. The analytical run time was 10min. The triple quadrupole mass spectrometer was operated in the positive ion-mode and multiple reaction monitoring was used for drug quantification. The method was validated over a range of 1-500ng/mL in PBMC lysate for all analytes. The method was proven to be specific, accurate, precise and robust. The mean precision and accuracy was less than +/-12% at all concentration levels. Using the developed assay and a previously developed assay for these analytes in plasma, the relationship between plasma and intracellular pharmacokinetics and their relationship with therapy outcome can now be determined.

[A patient with feigned mental incompetence requiring medical treatment]

A woman at the presumed age of 60 years was suspected of malingering cognitive impairment, due to her social circumstances (illegal residency) and was consequently unable to give permission for treatment. She was suffering from locally advanced mammary carcinoma, diagnosed according to the Breast Imaging Reporting and Data System in stage 5. In order to assess mental incompetence, an algorithm from the Royal Dutch Medical Association (KNMG) is a useful tool. The algorithm contains questions for determining whether a patient is able to make choices, if he/she understands medical information and can apply this to his/her own situation and whether he/she is able to logically consider the choice. Mental incompetence is a legally defined status - there is no straightforward relation between mental incompetence and the underlying diagnosis, in this case malingering. Since feigning mental incompetence has its own limitations, the subjective judgment of the physician is important. In the case presented, medical treatment i.e. chemotherapy was started in accordance with the Dutch Medical Treatment Contracts Act (WGBO) for a patient with cognitive impairment. Compulsory treatment was not necessary because the patient did not resist either physically or verbally. If a critical situation is to be prevented or is threatening, then there is no difference between genuine or feigned mental incompetence.

What role do coagulation disorders play in the pathogenesis of leptospirosis?

Leptospirosis is a zoonosis of worldwide distribution, spread by the urine of infected animals. It is a major public health problem, especially in developing countries, where circumstances for transmission are most favourable. The clinical picture varies from mild disease to a severe illness with haemostatic derangements and multiorgan failure eventually leading to death. Although the haemorrhagic complications of severe disease are serious, the pathophysiology is scarcely elucidated. The complex mechanisms involved in inflammation-induced coagulation activation are extensively studied in various infectious diseases, i.e. Gram-negative sepsis. Tissue factor-mediated coagulation activation, impairment of anticoagulant and fibrinolytic pathways in close concert with the cytokine network are thought to be important. But for human leptospirosis, data are limited. Because of the growing interest in this field, the impact of leptospirosis, and the availability of new therapeutic strategies, we reviewed the evidence regarding the role of coagulation in leptospirosis and provide suggestions for future research.

Population pharmacokinetics of lopinavir in combination with ritonavir in HIV-1-infected patients

AIMS

To develop a population pharmacokinetic model for lopinavir in combination with ritonavir, in which the interaction between both drugs was characterized, and in which relationships between patient characteristics and pharmacokinetics were identified.

METHODS

The pharmacokinetics of lopinavir in combination with ritonavir were described using NONMEM (version V, level 1.1). First, ritonavir data were fitted to a previously developed model to obtain individual Bayesian estimates of pharmacokinetic parameters. Hereafter, an integrated model for the description of the pharmacokinetics of lopinavir with ritonavir was designed.

RESULTS

From 122 outpatients 748 lopinavir and 748 ritonavir plasma concentrations were available for analysis. The interaction between the drugs was described by a time-independent inverse relationship between the exposure to ritonavir over a dosing-interval and the apparent clearance (CL/F) of lopinavir. The model parameters volume of distribution and absorption rate constant were 61.6 l (95% prediction interval (PI) 22.4, 83.7) and 0.564 h(-1) (95% PI 0.208, 0.947), respectively. The model yielded a theoretical value for the CL/F of lopinavir without ritonavir of 14.8 l h(-1) (95%PI 12.1, 20.1), which translates to a value of 5.73 l h(-1) in the presence of ritonavir. The only factor with significant effect on the pharmacokinetics was concurrent use of non-nucleoside reverse transcriptase inhibitors (NNRTI), which increased the CL/F of lopinavir by 39% (P < 0.001).

CONCLUSIONS

We have developed a model that has defined a time-independent inverse relationship between the exposure to ritonavir and the CL/F of lopinavir, and provided an adequate description of the pharmacokinetic parameters for the latter. Concomitant use of the NNRTIs efavirenz and nevirapine increased the CL/F of lopinavir.

[Acute respiratory tract infections and acute coronary syndromes]

Epidemiological research indicates a correlation between respiratory-tract infections and acute cardiovascular events. Chronic infections have been linked to the development of atherosclerosis. As a result of chronic infections a prolonged and elevated inflammatory activity arises. Inflammation and the associated vessel-wall damage play an important role in the pathophysiology of atherosclerosis. Acute infections have been linked to a transient increased risk of unstable angina pectoris and an acute myocardial infarct. The consequence of acute infections is a systemic inflammatory response which results in changes in the atherosclerotic plaque, thrombotic activation and a prothrombotic condition. The inflammatory response and prothrombotic condition reinforce each other. This can result in coagulation on ruptured atherosclerotic plaques and erosions in the vessel wall, which can give rise to the sudden constriction or blockage of coronary arteries.

Is chronic HIV infection associated with venous thrombotic disease? A systematic review

Infection with the human immunodeficiency virus (HIV) is still a major health problem world-wide. HIV infection has changed into a chronic infection with the chance of developing long-term complications. Vascular complications are frequently reported in the current literature. HIV and treatment by highly active antiretroviral therapy (HAART) are associated with many cardiovascular risk factors. An increased risk of arterial cardiovascular complications was found in a number of studies. However, data about the risk of venous thrombotic disease (VTE), including potentially fatal conditions as pulmonary embolism, were limited. In a systematic review of the literature, ten relevant epidemiological studies were identified that investigated the risk of venous thrombotic disease in HIV-infected patients. The incidence was increased two- to tenfold in comparison with a healthy population of the same age. However, these studies were mainly retrospective cohort studies that were prone to selection bias, confounding factors were not always mentioned and in all but three control populations were missing. An increased risk of venous thrombotic disease in HIV-infected patients could be explained by the presence of a hypercoagulable state, characterised by an increase in procoagulant factors, such as endothelial TF expression and thrombogenic properties of microparticles, and a decrease in anticoagulant factors, including AT III, HC II and the protein C pathway. Furthermore, the risk of VTE was associated with an increased risk of infections and autoimmune haemolytic anaemia, and was weakly associated with HAART. All together, quite some evidence pointed towards a relationship between HIV infection and venous thrombotic disease, but the association still needs to be established in properly designed epidemiological studies.

Dengue: an arthropod-borne disease of global importance

Dengue viruses cause a variable spectrum of disease that ranges from an undifferentiated fever to dengue fever to the potentially fatal dengue shock syndrome. Due to the increased incidence and geographical distribution of dengue in the last 50 years, dengue is becoming increasingly recognised as one of the world's major infectious diseases. This article will review clinical and diagnostic aspects of dengue virus infections. It also presents our current knowledge of the pathophysiology of severe dengue and addresses the importance of dengue virus infections in those travelling to parts of the world where dengue is endemic.

Evaluation of clinical pharmacist interventions on drug interactions in outpatient pharmaceutical HIV-care

OBJECTIVE

To evaluate the usefulness of intervention in drug interactions of antiretroviral drugs with coadministered agents by a clinical pharmacist in outpatient HIV-treatment.

METHODS

The study design included two intervention arms (A and B), which were both preceded by a control observation period. In arm A, a complete list of the currently used drugs, extracted from pharmacy records was provided to the treating physician. In arm B the same list was provided but with a notification when a drug interaction was present and an advice how to handle this. The infectious disease specialist obtained the information before the patient's visit to the outpatient clinic (time point 0). Three months prior (time point -3) and 3 months after (time point +3) the intervention, pharmacy records were also screened for drug interactions. The number of drug interactions (total and per patient) was determined at the three different time points (-3, 0, +3). In addition, drug interactions encountered at time points -3 and 0 were checked for their presence at time points 0 and +3, respectively, for both intervention arms.

RESULTS

Arms A and B included 115 and 105 patients, respectively. Patient characteristics of both intervention arms were similar at time point 0. The number of interactions and the number of patients with interactions were similar in both intervention arms at time point 0. There were 42 and 40 potential drug interactions in 30 and 24 patients in arms A and B, respectively. The reduction in the number of interactions per patient over time and after intervention was small but significant, and was equal in both intervention arms. The advice of the clinical pharmacist had thus no additional value.

CONCLUSION

Both interventions were effective in reducing the number of drug interactions per patient. The advice of a clinical pharmacist was, however, redundant in the studied setting.

Is clinical outcome of dengue-virus infections influenced by coagulation and fibrinolysis? A critical review of the evidence

Despite efforts to elucidate the pathogenesis of dengue fever, the progression into severe disease remains poorly understood. In-vitro findings suggest that coagulopathy and disturbances in fibrinolysis have a pivotal role in the pathophysiology. If disturbances in these processes are predictive of clinical outcome in this disease, there could be important consequences for both diagnosis and treatment. We have critically reviewed publications on this topic to assess whether there is an association between activation of coagulation and fibrinolysis and clinical outcome of dengue-virus infections. In general, the selected studies showed activation of both the coagulation and fibrinolytic systems in this infection. The activation was more pronounced in severe infections and in cases with a poor clinical outcome. However, the findings were not consistent, and owing to a lack of detailed information on characteristics of patients, disease, and study design, we could not ascertain whether inconsistencies were caused by differences in these characteristics, selection bias, or confounding factors. We conclude that an association between activation of coagulation and fibrinolysis and clinical outcome of dengue-virus infections is conceivable but has been inadequately assessed and that methodologically sound studies, complemented with complete and reliable reporting, are needed to show whether there is a true association.