Potential determinants of antibody responses after vaccination against SARS-CoV-2 in older persons: the Doetinchem Cohort Study

BACKGROUND

Immune responses to vaccination vary widely between individuals. The aim of this study was to identify health-related variables potentially underlying the antibody responses to SARS-CoV-2 vaccination in older persons. We recruited participants in the long-running Doetinchem Cohort Study (DCS) who underwent vaccination as part of the national COVID-19 program, and measured antibody concentrations to SARS-CoV-2 Spike protein (S1) and Nucleoprotein (N) at baseline (T0), and a month after both the first vaccination (T1), and the second vaccination (T2). Associations between the antibody concentrations and demographic variables, including age, sex, socio-economic status (SES), comorbidities (cardiovascular diseases and immune mediated diseases), various health parameters (cardiometabolic markers, inflammation markers, kidney- and lung function) and a composite measure of frailty ('frailty index', ranging from 0 to 1) were tested using multivariate models.

RESULTS

We included 1457 persons aged 50 to 92 years old. Of these persons 1257 were infection naïve after their primary vaccination series. The majority (N = 954) of these individuals were vaccinated with two doses of BNT162b2 (Pfizer) and their data were used for further analysis. A higher frailty index was associated with lower anti-S1 antibody responses at T1 and T2 for both men (RT1 = -0.095, PT1 = 0.05; RT2 = -0.11, PT2 = 0.02) and women (RT1 = -0.24, PT1 < 0.01; RT2 = -0.15, PT2 < 0.01). After correcting for age and sex the frailty index was also associated with the relative increase in anti-S1 IgG concentrations between the two vaccinations (β = 1.6, P < 0.01). Within the construct of frailty, history of a cardiac catheterization, diabetes, gastrointestinal disease, a cognitive speed in the lowest decile of the population distribution, and impaired lung function were associated with lower antibody responses after both vaccinations.

CONCLUSIONS

Components of frailty play a key role in the primary vaccination response to the BNT162b2 vaccine within an ageing population. Older persons with various comorbidities have a lowered immune response after their first vaccination, and while frail and sick older persons see a stronger increase after their second vaccination compared to healthy people, they still have a lower antibody response after their second vaccination.

High-risk subtypes of chronic lymphocytic leukemia are detectable as early as 16 years prior to diagnosis

Chronic lymphocytic leukemia (CLL) is preceded by monoclonal B-cell lymphocytosis (MBL), a CLL precursor state with a prevalence of up to 12% in aged individuals; however, the duration of MBL and the mechanisms of its evolution to CLL remain largely unknown. In this study, we sequenced the B-cell receptor (BcR) immunoglobulin heavy chain (IGH) gene repertoire of 124 patients with CLL and 118 matched controls in blood samples taken up to 22 years prior to diagnosis. Significant skewing in the BcR IGH gene repertoire was detected in the majority of patients, even before the occurrence of lymphocytosis and irrespective of the clonotypic IGH variable gene somatic hypermutation status. Furthermore, we identified dominant clonotypes belonging to major stereotyped subsets associated with poor prognosis up to 16 years before diagnosis in 14 patients with CLL. In 22 patients with longitudinal samples, the skewing of the BcR IGH gene repertoire increased significantly over time to diagnosis or remained stable at high levels. For 14 of 16 patients with available samples at diagnosis, the CLL clonotype was already present in the prediagnostic samples. Overall, our data indicate that the preclinical phase of CLL could be longer than previously thought, even in adverse-prognostic cases.

Inflammatory marker trajectories associated with frailty and ageing in a 20‐year longitudinal study

Objective

The aim of this exploratory study was to investigate the development of low‐grade inflammation during ageing and its relationship with frailty.

Methods

The trajectories of 18 inflammatory markers measured in blood samples, collected at 5‐year intervals over a period of 20 years from 144 individuals aged 65–75 years at the study endpoint, were related to the degree of frailty later in life.

Results

IFN‐γ‐related markers and platelet activation markers were found to change in synchrony. Chronically elevated levels of IL‐6 pathway markers, such as CRP and sIL‐6R, were associated with more frailty, poorer lung function and reduced physical strength. Being overweight was a possible driver of these associations. More and stronger associations were detected in women, such as a relation between increasing sCD14 levels and frailty, indicating a possible role for monocyte overactivation. Multivariate prediction of frailty confirmed the main results, but predictive accuracy was low.

Conclusion

In summary, we documented temporal changes in and between inflammatory markers in an ageing population over a period of 20 years, and related these to clinically relevant health outcomes.

Impaired JAK-STAT pathway signaling in leukocytes of the frail elderly

Background

Elderly often show reduced immune functioning and can develop chronic low-grade inflammation. Why some elderly are more prone to become frail is unknown. We investigated whether frailty is associated with altered cytokine signaling through the JAK-STAT pathway in leukocytes of 34 individuals aged 65–74 years. In addition, we investigated how this relation is affected by chronic low-grade inflammation during the previous 20 years. Cytokine signaling was quantified by measuring intracellular STAT1, STAT3, and STAT5 phosphorylation in monocytes, B cells, CD4⁺ T cells and CD8⁺ T cells upon stimulation with IL-2, IL-6, IL-10, IFNα and IFNγ, using phospho-flow cytometry. Presence of chronic low-grade inflammation was investigated by evaluating 18 different plasma inflammatory markers that had been measured repeatedly in the same individuals over the previous 20 years. Frailty was assessed as a score on a frailty index.

Results

We found that lower cytokine-induced pSTAT responsiveness in the various cell subsets was seen with higher frailty scores in both men and women, indicative of dysfunctional pSTAT responses in frailer individuals. Associations differed between men and women, with frailer women showing lower pSTAT1 responses in monocytes and frailer men showing lower pSTAT5 responses in CD4⁺ and CD8⁺ T cells. Notably, lower IL-10-induced pSTAT3 responses in men were related to both higher frailty scores and higher CRP levels over the past 20 years. This might indicate poor resolution of low-grade inflammation due to defective regulatory pSTAT signaling in older men.

Conclusions

Our results emphasize the importance of preserved JAK-STAT pathway signaling in healthy aging and reveal cellular pSTAT levels as a candidate biomarker of frailty.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12979-021-00261-w.

A New Pipeline for the Normalization and Pooling of Metabolomics Data

Pooling metabolomics data across studies is often desirable to increase the statistical power of the analysis. However, this can raise methodological challenges as several preanalytical and analytical factors could introduce differences in measured concentrations and variability between datasets. Specifically, different studies may use variable sample types (e.g., serum versus plasma) collected, treated, and stored according to different protocols, and assayed in different laboratories using different instruments. To address these issues, a new pipeline was developed to normalize and pool metabolomics data through a set of sequential steps: (i) exclusions of the least informative observations and metabolites and removal of outliers; imputation of missing data; (ii) identification of the main sources of variability through principal component partial R-square (PC-PR2) analysis; (iii) application of linear mixed models to remove unwanted variability, including samples' originating study and batch, and preserve biological variations while accounting for potential differences in the residual variances across studies. This pipeline was applied to targeted metabolomics data acquired using Biocrates AbsoluteIDQ kits in eight case-control studies nested within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Comprehensive examination of metabolomics measurements indicated that the pipeline improved the comparability of data across the studies. Our pipeline can be adapted to normalize other molecular data, including biomarkers as well as proteomics data, and could be used for pooling molecular datasets, for example in international consortia, to limit biases introduced by inter-study variability. This versatility of the pipeline makes our work of potential interest to molecular epidemiologists.

Limited effect of duration of CMV infection on adaptive immunity and frailty: insights from a 27-year-long longitudinal study

Objectives

Cytomegalovirus infection is thought to affect the immune system and to impact general health during ageing. Higher CMV‐specific antibody levels in the elderly are generally assumed to reflect experienced viral reactivation during life. Furthermore, high levels of terminally differentiated and CMV‐specific T cells are hallmarks of CMV infection, which are thought to expand over time, a process also referred to as memory inflation.

Methods

We studied CMV‐specific antibody levels over ~ 27 years in 268 individuals (aged 60–89 years at study endpoint), and to link duration of CMV infection to T‐cell numbers, CMV‐specific T‐cell functions, frailty and cardiovascular disease at study endpoint.

Results

In our study, 136/268 individuals were long‐term CMV seropositive and 19 seroconverted during follow‐up (seroconversion rate: 0.56%/year). CMV‐specific antibody levels increased slightly over time. However, we did not find an association between duration of CMV infection and CMV‐specific antibody levels at study endpoint. No clear association between duration of CMV infection and the size and function of the memory T‐cell pool was observed. Elevated CMV‐specific antibody levels were associated with the prevalence of cardiovascular disease but not with frailty. Age at CMV seroconversion was positively associated with CMV‐specific antibody levels, memory CD4⁺ T‐cell numbers and frailty.

Conclusion

Cytomegalovirus‐specific memory T cells develop shortly after CMV seroconversion but do not seem to further increase over time. Age‐related effects other than duration of CMV infection seem to contribute to CMV‐induced changes in the immune system. Although CMV‐specific immunity is not evidently linked to frailty, it tends to associate with higher prevalence of cardiovascular disease.

In-depth immune cellular profiling reveals sex-specific associations with frailty

Background

With advancing age, the composition of leukocyte subpopulations in peripheral blood is known to change, but how this change differs between men and women and how it relates to frailty is poorly understood. Our aim in this exploratory study was to investigate whether frailty is associated with changes in immune cell subpopulations and whether this differs between men and women. Therefore, we performed in-depth immune cellular profiling by enumerating a total of 37 subpopulations of T cells, B cells, NK cells, monocytes, and neutrophils in peripheral blood of 289 elderly people between 60-87 years of age. Associations between frailty and each immune cell subpopulation were tested separately in men and women and were adjusted for age and CMV serostatus. In addition, a random forest algorithm was used to predict a participant’s frailty score based on enumeration of immune cell subpopulations.

Results

In the association study, frailty was found to be associated with increased numbers of neutrophils in both men and in women. Frailer women, but not men, showed higher numbers of total and CD16^- monocytes, and lower numbers of both CD56⁺ T cells and late differentiated CD4⁺ TemRA cells. The random forest algorithm confirmed all the findings of the association studies in men and women. In men, the predictive accuracy of the algorithm was too low (5.5%) to warrant additional conclusions on top of the ones derived from the association study. In women however, the predictive accuracy was higher (23.1%), additionally revealing that total T cell numbers and total lymphocyte numbers also contribute in predicting frailty.

Conclusions

In-depth immune cellular profiling revealed consistent associations of frailty with elevated numbers of myeloid cell subpopulations in both men and women. Furthermore, additional associations were found between frailty and lower numbers of some T cell subpopulations, in women only. Thus, our study indicates sex-specific associations of immune subpopulations with frailty. We hope that our study will prompt further investigation into the sex-specific immune mechanisms associated with the development of frailty.

[Undesirable medicalisation: on the nature and background of too much medicine]

Over recent years there has been renewed focus on medicalisation. Amongst other things, this is the result of the realisation that expansion of the medical domain can also have undesirable effects. However, the line between justified medical interventions and overdiagnosis is difficult to draw. The first step in regaining control of undesirable medicalisation is to identify and quantify the processes behind it and the situations in clinical practice in which it may occur. In this article we discuss different types of medicalisation and, on the basis of this, we give an indication of the frequency with which medicalisation occurs. Finally, we discuss the mechanisms that facilitate medicalisation.

Explaining the Decline in Coronary Heart Disease Mortality in the Netherlands between 1997 and 2007

Objective

We set out to determine what proportion of the mortality decline from 1997 to 2007 in coronary heart disease (CHD) in the Netherlands could be attributed to advances in medical treatment and to improvements in population-wide cardiovascular risk factors.

Methods

We used the IMPACT-SEC model. Nationwide information was obtained on changes between 1997 and 2007 in the use of 42 treatments and in cardiovascular risk factor levels in adults, aged 25 or over. The primary outcome was the number of CHD deaths prevented or postponed.

Results

The age-standardized CHD mortality fell by 48% from 269 to 141 per 100.000, with remarkably similar relative declines across socioeconomic groups. This resulted in 11,200 fewer CHD deaths in 2007 than expected. The model was able to explain 72% of the mortality decline. Approximately 37% (95% CI: 10%-80%) of the decline was attributable to changes in acute phase and secondary prevention treatments: the largest contributions came from treating patients in the community with heart failure (11%) or chronic angina (9%). Approximately 36% (24%-67%) was attributable to decreases in risk factors: blood pressure (30%), total cholesterol levels (10%), smoking (5%) and physical inactivity (1%). Ten% more deaths could have been prevented if body mass index and diabetes would not have increased. Overall, these findings did not vary across socioeconomic groups, although within socioeconomic groups the contribution of risk factors differed.

Conclusion

CHD mortality has recently halved in The Netherlands. Equally large contributions have come from the increased use of acute and secondary prevention treatments and from improvements in population risk factors (including primary prevention treatments). Increases in obesity and diabetes represent a major challenge for future prevention policies.

A Window on Geographic Variation in Health Care: Insights from EuroHOPE

The aim of EuroHOPE was to provide new evidence on the performance of healthcare systems, using a disease-based approach, linkable patient-level data and internationally standardized methods. This paper summarizes its main results. In the seven EuroHOPE countries, the Acute Myocardial Infarction (AMI), stroke and hip fracture patient populations were similar with regard to age, sex and comorbidity. However, non-negligible geographic variation in mortality and resource use was found to exist. Survival rates varied to similar extents between countries and regions for AMI, stroke, hip fracture and very low birth weight. Geographic variation in length of stay differed according to type of disease. Regression analyses showed that only a small part of geographic variation could be explained by demand and supply side factors. Furthermore, the impact of these factors varied between countries. The findings show that there is room for improvement in performance at all levels of analysis and call for more in-depth disease-based research. In using international patient-level data and a standardized methodology, the EuroHOPE approach provides a promising stepping-stone for future investigations in this field. Still, more detailed patient and provider information, including outside of hospital care, and better data sharing arrangements are needed to reach a more comprehensive understanding of geographic variations in health care.

Comparing ischaemic stroke in six European countries. The EuroHOPE register study

BACKGROUND AND PURPOSE

The incidence of hospitalizations, treatment and case fatality of ischaemic stroke were assessed utilizing a comprehensive multinational database to attempt to compare the healthcare systems in six European countries, aiming also to identify the limitations and make suggestions for future improvements in the between-country comparisons.

METHODS

National registers of hospital discharges for ischaemic stroke identified by International Classification of Diseases codes 433-434 (ICD-9) and code I63 (ICD-10), medication purchases and mortality were linked at the patient level in each of the participating countries and regions: Finland, Hungary, Italy, the Netherlands, Scotland and Sweden. Patients with an index admission in 2007 were followed for 1 year.

RESULTS

In all, 64,170 patients with a disease code for ischaemic stroke were identified. The number of patients registered per 100,000 European standard population ranged from 77 in Scotland to 407 in Hungary. Large differences were observed in medication use. The age- and sex-adjusted all-cause case fatality amongst hospitalized patients at 1 year from stroke was highest in Hungary at 31.0% (95% confidence interval 30.5-31.5). Regional differences in age- and sex-adjusted 1-year case fatality within countries were largest in Hungary (range 23.6%-37.6%) and smallest in the Netherlands (20.5%-27.3%).

CONCLUSIONS

It is feasible to link population-wide register data amongst European countries to describe incidence of hospitalizations, treatment patterns and case fatality of ischaemic stroke on a national level. However, the coverage and validity of administrative register data for ischaemic stroke should be developed further, and population-based and clinical stroke registers should be created to allow better control of case mix.

Gender differences in adult congenital heart disease

Objective. To assess gender differences in morbidity, mortality and patient management among adults born with a heart defect.Methods and results. The database of the European Heart Survey on adult congenital heart disease was explored. This contains data on 4110 patients with one of eight congenital heart defects followed retrospectively for a median of 5.1 years. The existence of gender differences was assessed by considering mortality and a few 'overall' measures of morbidity. Adjusting for type of defect and age, it was found that cumulative mortality was greater in the male population (hazard ratio 1.63 (95% CI 1.12 to 2.38); p=0.011)). A significantly greater proportion of females had functional limitations (NYHA functional class >1; 37% vs. 29% of men; p=0.003). However, males were more likely to be on chronic medication during follow-up (59% vs. 55% of women; p=0.001), and males underwent diagnostic procedures more frequently (1.58/patient-year vs. 1.48/patient-year for women; p<0.02). There was no significant difference in the proportions of patients who underwent at least one intervention during follow-up, and rates of outpatient (re-)visits were not different between the sexes.Conclusion. This exploratory assessment of a large international database found evidence that gender differences exist in morbidity and mortality among adult patients with congenital heart disease, as well as in medical management. Future studies in adult congenital heart disease should always take into account the effects of gender. (Neth Heart J 2009;17:414-7.).

Repaired and open atrial septal defects type II in adulthood: An epidemiological study of a large European cohort

BACKGROUND

There is a lack of evidence regarding treatment options for adults with an atrial septal defect (ASD) who present with an open defect or with sequelae after closure of the defect. The aim of this study was to describe the clinical characteristics and treatment of a large cohort of adult patients born with an ASD type II.

METHODS AND RESULTS

Data on the clinical characteristics of 882 ASD II patients (mean follow-up of 4.2 years) included in the Euro Heart Survey on adult congenital heart disease were analysed. At baseline, the defects of 377 patients (mean age 39.2 (16.1) years; 65% females) had been closed, leaving 505 patients (mean age 41.1 (16.4) years; 68% females) with an open ASD. Hemodynamic abnormalities were more prevalent among patients with an open compared to those with a closed defect at baseline: pulmonary arterial hypertension 35% versus 13%; right ventricular (RV) dysfunction 31% versus 8%; and severe RV volume overload 18% versus 1% (all P-values<0.001). These prevalences increased with age, but hemodynamic parameters remained stable during follow-up in nearly all patients with a small defect. Also functional limitations were more common in those with open defects at baseline compared to those with closed defects (54% versus 25%). There was no difference in the prevalence of arrhythmia's. The best independent predictors of functional limitations appeared to be PAH (odds ratio 25.2 (5.8-109.6); P<0.001)) and RV volume overload (odds ratio 2.3 (1.5-3.4; P<0.001)) in a multivariable model. During follow-up, 9 patients died and in 294 patients the defect was closed, in 180 patients surgically, and in 114 patients by device. Among the latter group there were relatively more females (78% vs 66%; P=0.035). In the surgically closed group defects were more "severe". There were substantial differences according to country in the relative frequency of device closure versus surgical closure, as well as the size and hemodynamic severity of the defects closed.

CONCLUSION

The data from this study provide a cross-section of the kind of adult patients with an ASD that are seen at outpatient clinics for adult congenital heart disease throughout Europe. Taken together, non-operated patients fared significantly worse in all aspects of hemodynamics studied than the patients whose defects had been closed. In moderate or large defects, when not-operated, clinical parameters tend to worsen with time, and closure of such a defect-the sooner the better-seems always to be the preferred treatment option. In the majority of small defects, operation is not necessarily indicated.

Radiation exposure during follow-up of adults with congenital heart disease

BACKGROUND

Adult patients with congenital heart disease under follow-up often need to undergo diagnostic procedures which expose them to radiation.

AIM

To evaluate radiation doses in adult patients with congenital heart disease during follow-up.

METHODS

Data on diagnostic procedures were used from the European Heart Survey on adult congenital heart disease, a multicenter retrospective cohort study. Lesions included in the survey were Atrial Septal Defect, Ventricular Septal Defect, Fallot, Fontan, Coarctation, Transposition of the Great Arteries, Marfan, and Cyanotic lesions. A total of 4110 patients (52% female) with a mean age of 32 years (range 17-85) were included. The follow-up time ranged from 0 to 72 months, with a median of 61 months. There were a total of 18,403 patient-years of follow-up. During this time, a mean of 4.5 visits per patient took place. Radiation doses were calculated using the number of examinations in each patient's data file. Effective radiation doses are given in millisievert (mSv).

RESULTS

The average cumulative annual effective dose per patient was 0.46 mSv. The relative contributions to these doses were 3% by chest X-rays, 39% by computed tomography scans, 42% by angiography, and 16% by nuclear scans. Effective doses were higher in patients with Fontan, Coarctation, Marfan and Cyanotic lesions, as well as in patients with Atrial Septal Defects.

CONCLUSIONS

Exposure to radiation during follow-up of patients with adult congenital heart disease mainly stems from computed tomography scans and angiography. Patients with Fontan, Coarctation, Marfan and Cyanotic lesions are more likely to get high doses from computed tomography. In these lesions, therefore, particular care should be taken to use non-ionizing imaging procedures whenever possible.

Delivery of care for adult patients with congenital heart disease in Europe: results from the Euro Heart Survey

AIMS

The increasing number of adults with congenital heart disease (CHD) has prompted the development of recommendations for the management of these patients and for the organization of their healthcare. The aim of this report is to describe the delivery of care in Europe for adults with congenital cardiac anomalies.

METHODS AND RESULTS

As part of the Euro Heart Survey on Adult Congenital Heart Disease, we obtained data from 71 voluntarily participating centres that detailed their care practices for these patients. Forty-eight of these centres were specialist centres and 23 were non-specialist centres. We found that only 19% of the specialist centres complied with defined standards for optimal care structure. The criteria that appeared to be most difficult for all centres to achieve were performing 50 congenital heart operations or more per year and involving nurse specialists in the care of these patients.

CONCLUSION

This survey indicated that the provision of care in Europe for adults with congenital heart defects is suboptimal. To fully realize the benefits of cardiac surgery performed in infants and children, continuous effort must be applied by healthcare professionals in order to implement the recommendations on the organization of care for these patients.

Adherence to guidelines in the clinical care for adults with congenital heart disease: The Euro Heart Survey on Adult Congenital Heart Disease

AIMS

To investigate the role of guidelines in structuring the clinical care for adult patients with congenital heart disease (CHD), and to assess adherence to the guidelines in Europe.

METHODS AND RESULTS

A selected number of current guidelines were chosen pertaining to operative procedures, investigations, and the use of medication ('interventions'). The source for this analysis was the database of the Euro Heart Survey on adult CHD, which contains retrospectively collected data on 4110 patients followed-up for a median of 5.1 years. For each guideline investigated, patients were selected from the database for whom the particular guideline was relevant. The selected cases were classified according to two criteria: was there an indication for the particular intervention and did the intervention take place? In this manner, cases of 'undue treatment' and 'insufficient treatment' were identified. Adherence to guidelines was found to be good in the case of operative procedures and prophylactic drug treatment. However, regarding diagnostic procedures there had been adherence to guidelines in only slightly more than half of the cases.

CONCLUSION

Guidelines have an important role in the actual clinical care of adults with CHD. However, large outcome studies are needed to develop more precise guidelines.

The spectrum of adult congenital heart disease in Europe: morbidity and mortality in a 5 year follow-up period

AIMS

To describe clinical and demographic characteristics at baseline of a European cohort of adults with congenital heart disease (CHD) and to assess mortality and morbidity in a 5 year follow-up period.

METHODS AND RESULTS

Data collected as part of the Euro Heart Survey on adult CHD was analysed. This entailed information transcribed from the files of 4110 patients diagnosed with one of eight congenital heart conditions ('defects'), who consecutively visited the outpatient clinics of one of the participating centres in 1998. The patients were included retrospectively and followed until the end of 2003 for a median follow-up of 5.1 years. Notwithstanding their overall relatively good functional class and low mortality over the follow-up period, a considerable proportion of the patients had a history of endocarditis, arrhythmias, or vascular events. There were major differences between the eight defects, both in morbidity and regarding specific characteristics. Outcomes were worst in cyanotic defects and in the Fontan circulation, but a considerable proportion of the other patients also suffer from cardiac symptoms. In particular, arrhythmias are common.

CONCLUSION

The spectrum of adult CHD in Europe emerging from this survey is one of a predominantly young population with substantial morbidity but relatively low mortality in a 5 year period.

Modeling the cost-effectiveness and budgetary impact for subpopulations

There is currently a trend to increasing demand for health-economic and budgetary-impact data in the decision-making process in Europe. A parallel development is the tendency to restrict the prescription of new drugs to subpopulations that may depend on the results of the above health-economic analysis and financial analysis. We present modeling techniques for determining the optimal subpopulation considering the cost-effectiveness and budgetary impact of a new drug. The methodology consists of incorporating confounding variables into the Markov health states by means of health state specific regression equations for costs and utilities. The strategy is applied to a hypothetical Markov model for new product in Parkinson's disease. The results of the presented analyses suggest that within the registered range of indications a further restriction in the application for a new drug can be made from the point of view of cost-effectiveness and budgetary impact. These results can also be considered in the decision-making process.

A cost-cost study comparing etanercept with infliximab in rheumatoid arthritis

OBJECTIVE

The objective of this study was to compare the total costs associated with the administration of two different tumour necrosis factor (TNF) strategies used in the treatment of rheumatoid arthritis (RA): etanercept, a soluble TNF receptor that can be administered at home by subcutaneous injection, versus infliximab, an antibody that requires an intravenous infusion in a hospital outpatient setting.

DESIGN AND SETTING

The main analytical framework of the study was a cost-cost analysis comparing the total annual costs associated with the administration of etanercept and infliximab in adult RA patients. The perspective of the study was that of the Dutch society. An economic model was constructed to determine the costs of both treatments. The cost evaluation included direct medical costs, direct nonmedical costs and indirect costs. The base-case analysis compared monotherapy with etanercept versus a combination therapy with infliximab and methotrexate. Data for the economic model came from published literature, expert opinion and official price and tariff lists. All costs were in 1999 values.

PATIENTS AND PARTICIPANTS

The analysis was performed for the adult RA population eligible for treatment with etanercept or infliximab in The Netherlands.

MAIN OUTCOME MEASURES AND RESULTS

The analysis showed that the total annual drug costs per patient do not differ substantially between infliximab and etanercept, with costs of Netherland guilders (NLG)31,526 (12,610 US dollars) and NLG31,334 (12,534 US dollars), respectively. However, the other medical costs (i.e. excluding the costs of the two drugs themselves) are substantially higher for infliximab due to the additional costs associated with administration in an outpatient clinic and the use of methotrexate [NLG 12,621 (5048 US dollars) versus NLG269 (107 US dollars) for etanercept]. The impact of direct nonmedical costs (transportation) and indirect costs were negligible. Overall treatment with infliximab is more expensive than treatment with etanercept with total costs of NLG45 115 (18,046 US dollars) and NLG3I,621 (12,648 US dollars), respectively (42.7% increase).

CONCLUSIONS

Based on the assumptions used in the model, we may conclude that the use of etanercept compares favourably with infliximab from a budgetary and health economic perspective: the total costs are substantially lower when the efficacy of etanercept is assumed to be at least equivalent to the efficacy of infliximab.

Blood transfusion

Blood transfusion became a relatively safe and practicable procedure following the discovery in 1900 of blood groups and the realization early in the first World War that citrate was a safe and effective anticoagulant. Transfusion may elicit the formation of antibodies in the recipient due to "foreign" antigens on the donor's red cells, white cells, or platelets. Application of the methods of molecular biology has characterized the antigens concerned and the genes that determine them. The concept of transfusing whole blood to remedy a deficiency of any constituent, for example, platelets, has been superseded by the idea of transfusing only that component of blood which is needed. Many viruses, for example, hepatitis viruses and human immunodeficiency viruses, can be transmitted by transfusion. The high degree of success in preventing their transmission is a scientific triumph.

Specific antisera against human blood cells applicable in the indirect immunofluorescence technique

The preparation of antisera against various cells of the human peripheral blood applicable in the indirect immunofluorescence technique (IIFT) is described. Such antisera will be a great interest for the study of cell-specific membrane antigens, for example during haematopoiesis. Purified erythrocytes, lymphocytes, neutrophils, monocytes, and thrombocytes from healthy donors were injected into rabbits. The antisera thus produced were not spontaneously specific. Only by extensive absorption of the crude antisera with purified cells from healthy donors was it possible to obtain antisera that were specific for erythrocytes, lymphocytes, and thrombocytes. By injection of small doses of leukocyte lysate and by absorption of the resulting antiserum with mononclear cells a specific antineutrophil serum was produced. So far it has not been possible to prepare a specific anti-monocyte antiserum. The specific antisera were applicable in the IIFT on paraformaldehyde-fixed cells in suspension and on cells on slides.