Assessment of health status in elderly patients with cancer

Background

Health status assessment of senior adults is one of the most important aspects of a treatment decision making process. A group of elderly cancer patients is very heterogeneous according to the health status – some of them are fit enough for aggressive treatment, but others are frail and vulnerable. Treatment for the latter group has to be adapted and carefully monitored.

Aim

To review and analyze relevant literature on the usage and optimization of Comprehensive Geriatric Assessment (CGA).

Materials and methods

Medline search of studies published between 2000 and 2011, containing key words: Comprehensive Geriatric Assessment, aging, cancer in senior adults, frailty.

Results

To recognize and address individual needs of senior adults, a special holistic approach has been developed – comprehensive geriatric assessment (CGA). This tool is a gold standard in gerontooncology, recommended by International Society of Geriatric Oncology. CGA evaluates all important health domains, from physiology to social and economical problems, using sets of different tests. Assessment has to be performed by a trained team, including a physician, nurse and social worker. CGA has been clinically validated in many studies, but it is still not clear whether CGA improves the outcome of treatment of the elderly with cancer.

Conclusions

Complexity and multidimensionality of CGA pose a logistic challenge for everyday clinical practice. Special senior programs, which could be developed inside comprehensive cancer center, focusing attention on seniors’ problems and needs seem to be a way forward for geriatric oncology.     

Primary care management for optimized antithrombotic treatment [PICANT]: study protocol for a cluster-randomized controlled trial

Background

Delirium occurs frequently in elderly hospitalised patients and is associated with higher mortality, increased length of hospital stay, functional decline, and admission to long-term care. Healthcare professionals frequently do not recognise delirium, indicating that education can play an important role in improving delirium care for hospitalised elderly. Previous studies have indicated that e-learning can provide an effective way of educating healthcare professionals and improving quality of care, though results are inconsistent.

Methods and design

This stepped wedge cluster randomised trial will assess the effects of a complementary delirium e-learning course on the implementation of quality improvement initiative, which aims to enhance the recognition and management of delirium in elderly patients. The trial will be conducted in 18 Dutch hospitals and last 11 months. Measurements will be taken in all participating wards using monthly record reviews, in order to monitor delivered care. These measurements will include the percentage of elderly patients who were screened for the risk of developing delirium, use of the Delirium Observation Screening scale, use of nursing or medical interventions, and the percentage of elderly patients who were diagnosed with delirium. Data regarding the e-learning course will be gathered as well. These data will include user characteristics, information regarding use of the course, delirium knowledge before and after using the course, and the attitude and intentions of nurses concerning delirium care.

Setting

The study will be conducted in internal medicine and surgical wards of eighteen hospitals that are at the beginning stages of implementing the Frail Elderly Project in the Netherlands.

Discussion

Better recognition of elderly patients at risk for delirium and subsequent care is expected from the introduction of an e-learning course for nurses that is complementary to an existing quality improvement project. This trial has the potential to demonstrate that e-learning can be a vital part of the implementation process, especially for quality improvement projects aimed at complex health issues such as delirium. The study will contribute to a growing body of knowledge concerning e-learning and the effects it can have on knowledge as well as delivered care.

Trial registration

Netherlands Trial Register (NTR): NTR2885     

Résultats fonctionnels de la radiofréquence par Prostiva? dans le traitement de l’hypertrophie bénigne de la prostate (HBP) non compliquée résistante aux traitements médicamenteux

Objective

To assess prospectively on objective and subjective parameters functional outcomes of prostatic thermotherapy by radiofrequency (Prostiva?) on urinary discomfort and sexual life in the treatment of uncomplicated symptomatic and resistant to drug treatment benign prostatic hypertrophy (BPH).

Patients and methods

Patients with eligibility criteria for this treatment published by HAS have been treated in our urology unit. They were called at one month for a clinical examination and analysis of objective data (maximum urine flow [Qmax], post-voiding residual, international prostate score symptom [IPSS]). They were contacted in December 2009 and submitted to a questionnaire on urinary symptoms (IPSS), quality of life (question 8 of IPSS), assessment of sexual function (IIEF, DAN SEX) and subjective assessment of treatment (Likert score).

Results

From December 2006 to January 2009, 20 patients (median age: 63 years) were treated with Prostiva?. Four patients had acute retention of urine in the immediate postoperative needing a urinary catheterization in emergency. We made a systematic evaluation of all patients at one month and in December 2009. The median follow-up was 20.6 months (12?C37 months). There was a significant improvement of IPSS (?6.7 points; IC95= [?10.3; ?3.1]), an improvement of sexuality functions, quality of life data, and a sense of global improvement of urinary symptoms (+ 1.8 = improved on the Likert score). Four patients were considered as failures: three patients resumed drug therapy, one patient received a prostate resection.

Conclusion

Our single centre study performed in selected patients according to the criteria of HAS consolidated the results of published studies. Results were positive on urinary symptoms, with a low morbidity and a positive subjective evaluation on symptoms. It demonstrated the safety of thermotherapy on patients?? sexuality and even better, the positive impact of the treatment on erections and satisfaction relations.     

Eerste ervaringen met patiënt gerapporteerde uitkomstmaten in de geriatrie

Background

There are difficulties in expressing the value of geriatric care in outcome measures such as recovery or mortality rates. Rather, the goal of geriatric care is to maintain quality of life and functionality. As such, patient reported outcome measures (PROMs) may be more effective in measuring the value healthcare creates in geriatric patients. In 2015 the Dutch Geriatrics Society asked their Committee Quality of Care Measurement to select a suitable PROM for the purpose of measuring the outcomes of geriatric hospital care.

Methods/results

The goal of this PROM is to measure outcomes of an hospital admission in the perspective of the elderly patient who was admitted to a geriatric ward. A group of caregivers in geriatric care identified four possible PROMs in the literature and based on selection criteria the TOPICS-MDS was chosen as most suitable. To increase the feasibility of implementation in daily practice, an item reduction study was performed and this resulted in a short form: TOPICS-SF. Two pilot studies in three hospitals took place on a geriatric ward. A response of 62% was observed during the first pilot with TOPICS-MDS and a response of 37% was observed during the second pilot with TOPICS-SF. The Katz-15 improved during hospital stay and during one month at home after discharge.

Conclusion

The TOPICS-SF has been selected as PROM for the older patient receiving geriatric care and is feasible in practice. More research in different settings and with different moments of measurements is needed to evaluate the responsiveness of TOPICS-SF and the conditions for feasible implementation in daily practice.

     

Factoren die van invloed zijn op het verwijzen van patiënten van het verpleeghuis naar het ziekenhuis

Introduction

Hospitalisation may cause negative effects on elderly patients. Therefore, it is important that referral and admission of older nursing home patients is well-considered. The aim of this study is to investigate the factors that affect the decision making process.

Method

Questionnaire survey among elderly care physicians and physicians following the elderly care physician training program.

Results

Of the 1,540 surveys, 200 were returned (response rate of 13%). Over 60% of the respondents had referred a nursing home patient to the hospital in the previous month. A stay at a geriatric rehabilitation ward, suspicion of a fracture, a good quality of life, a patient’s or family’s wish for referral, no treatment restrictions, and follow-up appointments in the hospital were factors which made referral to the hospital more likely according to the respondents. Medical specialist consultation and the in hospital presence of a physician specialised in geriatric care were considered to be important. Referral was less likely if a patient was diagnosed with dementia, had a low quality of life or had treatment restrictions.

Conclusion

Both patient-related and non-patient-related factors influence hospital referral of nursing home patients. Further research is needed to determine whether these different factors contribute to the different outcomes of a hospital admission, to facilitate proper decision-making for elderly care physicians.

     

Analyzes of genome-wide association follow-up study for calving traits in dairy cattle

Background

Genomic islands play an important role in medical, methylation and biological studies. To explore the region, we propose a CpG islands prediction analysis platform for genome sequence exploration (CpGPAP).

Results

CpGPAP is a web-based application that provides a user-friendly interface for predicting CpG islands in genome sequences or in user input sequences. The prediction algorithms supported in CpGPAP include complementary particle swarm optimization (CPSO), a complementary genetic algorithm (CGA) and other methods (CpGPlot, CpGProD and CpGIS) found in the literature. The CpGPAP platform is easy to use and has three main features (1) selection of the prediction algorithm; (2) graphic visualization of results; and (3) application of related tools and dataset downloads. These features allow the user to easily view CpG island results and download the relevant island data. CpGPAP is freely available at http://bio.kuas.edu.tw/CpGPAP/.

Conclusions

The platform's supported algorithms (CPSO and CGA) provide a higher sensitivity and a higher correlation coefficient when compared to CpGPlot, CpGProD, CpGIS, and CpGcluster over an entire chromosome.     

Eenzaamheid en zelfmanagementvaardigheden bij visueel beperkte ouderen

Objectives

To describe the degree of loneliness among the visually impaired elderly and to make a comparison with a matched reference group of the normally sighted elderly. In addition, we examined self-management abilities (SMAs) as determinants of loneliness among the visually impaired elderly.

Methods

In a cross-sectional study, 173 visually impaired elderly persons completed telephone interviews. Loneliness and SMAs were assessed with the Loneliness Scale of De Jong Gierveld and the SMAS-30, respectively.

Results

The prevalence of loneliness among the visually impaired elderly was higher compared to the reference group (50% vs 29%; p?<?.001). Multivariate hierarchical regression analysis showed that the SMA self-efficacy, partner status, and self-esteem were determinants of loneliness. Severity and duration of visual impairment had no effect on loneliness.

Discussion

The relationship between SMAs (i.e., self-efficacy) and loneliness is promising, since SMAs can be learned through training. Consequently, self-management training may reduce feelings of loneliness. An adapted version of this paper was published in Journal of Aging and Health, doi:10.1177/0898264311399758     

El anciano con enfermedad avanzada de órgano. Consideraciones desde la geriatría,la medicina paliativa y la bioética

Objective

To analyze the literature as regards the knowledge, skills and attitudes that these disciplines can provide in improving technical, ethical and human quality health care in the elderly with advanced organ failure, multimorbidity, frailty and progressive dementia.

Material and methods

A comprehensive review focused on available references on the interrelationship between geriatric medicine and palliative medicine, education in bioethics, prognostic tools, functional status, and the humanization of health care.

Results

Advance care planning, comprehensive geriatric assessment, the study of the values of the patient and their introduction in decision-making process, as well as the need to promote moral, care, and healthcare organizational ethics, are essential elements to achieve this objective.

Conclusions

Practitioners and healthcare organizations should seek excellence as a moral requirement. To achieve this, there is a priority to acquire virtues of care and fundamental concepts of geriatric and palliative medicine, assessing functional status, advance care planning and patient/family needs as essential issues to protect, care for and promote them in all care settings.     

Effecten van geriatrische COPD-revalidatie op ziekenhuisopnames en inspanningstolerantie: een retrospectief observationele studie

Introduction

Frail COPD patients are frequently not accepted for regular pulmonary rehabilitation programs due to low physical condition and functional limitations. Rehabilitation programs in nursing homes for geriatric patients with COPD have been developed. The effects of such programs are largely unknown.

Aims

To assess the course of COPD-related hospital admissions and exercise tolerance in a cohort of frail COPD patients participating in geriatric COPD rehabilitation.

Methods

Retrospective observational study with a follow up of 12 months after discharge from rehabilitation. COPD related hospital admission days were measured in the year before and after participating rehabilitation. Exercise tolerance was measured by the six minute walk test (6MWT) at admission and at discharge from rehabilitation.

Results

Fifty-eight participants accomplished the rehabilitation program. Twelve patients died in the first year after discharge. The median number of hospital admission days in the year before participating rehabilitation was 21 (IQR 10–33). The first year after discharge this was decreased to a median of 6 (IQR 0–12). The 6MWT increased from 194 (SD 85) meters at admission to 274 (SD 95) meters at discharge (mean difference 80 m, SD 72; p < 0.05).

Conclusions

Geriatric COPD rehabilitation in a nursing home setting seems to reduce hospital admissions in frail COPD patients and to increase exercise tolerance.

     

Prevalencia de sarcopenia en consultas de geriatría y residencias. Estudio ELLI

Background

There are few systematic studies on the prevalence of sarcopenia using the new diagnostic criteria in different geriatric care settings.

Objective

To estimate the prevalence of sarcopenia, using the European Working Group on Sarcopenia in Older People (EWGSOP) criteria in older subjects living in nursing homes and in those who attend geriatric outpatient clinics.

Material and methods

A single country multicentre study in two samples of older subjects: patients cared for in outpatient geriatric clinics, and individuals living in nursing homes. Data collected will include demographic variables, medical history, medication, geriatric syndromes, functional status (assessment of basic and instrumental activities of daily living), mobility, cognitive status, comorbidity, quality of life, nutritional status, and laboratory parameters. For the diagnosis of sarcopenia, 4 m walking speed, handgrip strength, and body composition measured by bioelectrical impedance analysis will be assessed.

Results

Using the EWGSOP algorithm, the prevalence of sarcopenia in an elderly Spanish population will be estimated. In addition, concordance and correlation between the three parameters included in the definition (muscle mass, muscle strength, and physical performance) will be analysed, using the different existing cut-off points, and examining the diagnostic accuracy of each. Finally, demographic, anthropometric and functional data that define subjects with sarcopenia will be investigated.

Conclusions

The ELLI study should improve knowledge on the prevalence and characteristics of sarcopenia in older people in our population.     

Effects of multidisciplinary integrated care on quality of care in residential care facilities for elderly people: a cluster randomized trial

Background:

Sophisticated approaches are needed to improve the quality of care for elderly people living in residential care facilities. We determined the effects of multidisciplinary integrated care on the quality of care and quality of life for elderly people in residential care facilities.

Methods:

We performed a cluster randomized controlled trial involving 10 residential care facilities in the Netherlands that included 340 participating residents with physical or cognitive disabilities. Five of the facilities applied multidisciplinary integrated care, and five provided usual care. The intervention, inspired by the disease management model, consisted of a geriatric assessment of functional health every three months. The assessment included use of the Long-term Care Facility version of the Resident Assessment Instrument by trained nurse-assistants to guide the design of an individualized care plan; discussion of outcomes and care priorities with the family physician, the resident and his or her family; and monthly multidisciplinary meetings with the nurse-assistant, family physician, psychologist and geriatrician to discuss residents with complex needs. The primary outcome was the sum score of 32 risk-adjusted quality-of-care indicators.

Results:

Compared with the facilities that provided usual care, the intervention facilities had a significantly higher sum score of the 32 quality-of-care indicators (mean difference − 6.7, p = 0.009; a medium effect size of 0.72). They also had significantly higher scores for 11 of the 32 indicators of good care in the areas of communication, delirium, behaviour, continence, pain and use of antipsychotic agents.

Interpretation:

Multidisciplinary integrated care resulted in improved quality of care for elderly people in residential care facilities compared with usual care.

Trial registration:

www.controlled-trials.com trial register no. ISRCTN11076857.The quality of care provided in residential care facilities is under pressure worldwide.¹ Facilities are frequently understaffed, and the complexity of care needed by residents increases while expertise of staff does not necessarily keep pace.^2,3 Although most care organizations want to innovate and improve quality of care, many lack expertise or financial resources needed to do so.^4,5 Family physicians are responsible for medical care in residential care facilities in the Netherlands. However, they do not regard themselves as suited for systematic management of chronic diseases and disabilities associated with frail health.⁶About 10% of elderly people aged 75 or older in the Netherlands live in residential care facilities.^7,8 These facilities were established to offer sheltered living for elderly people who are disabled but still relatively healthy. Because of the growing elderly population, the characteristics of elderly people living in residential care facilities have become more comparable to those of people in nursing homes, who need complex care. Residential care facilities in the Netherlands are comparable to residential care facilities in Canada, are publicly funded and are subject to government inspection and approval. Over 70% of the residents need professional care, such as assistance with activities of daily living, nursing care (e.g., medication, wound care) and housekeeping. They have multiple chronic diseases and associated disabilities.^9–12Effective interventions for chronic illnesses generally rely on a multidisciplinary team approach. The elements of this approach include structured geriatric assessment, protocol-based regulation of medications, support for self-reliance and intensive follow-up. The closely related disease management model comprises coordination of care, steering of the care process and patient empowerment.¹³ This model is strongly recommended by Bodenheimer and colleagues to improve the health and quality of life of chronically ill patients.¹⁴ However, no studies have as yet been undertaken to evaluate the effects of disease management on functional health and quality of care for elderly people in residential care facilities who have physical or cognitive disabilities.We developed an approach to multidisciplinary integrated care inspired by the disease management model. The objective of our study was to determine the effects of multidisciplinary integrated care on quality of care and quality of life for elderly people in residential care facilities.     

Les prothèses gonflables dans le traitement de l'impuissance: résultats de 80 implantations

Objective

The goal of this study is the evaluation of the functionnal results and the complications of this type of surgery. Such questions have been poorly discussed in the literature.

Methods

We report our experience on 80 inflatable prostheses that were implanted between october 1987 and october 1994. The mean follow-up is 3 years and the assessment of the objective (mechanical functioning of the prosthesis and complications) and sujective results (sexuality of the patients) is carried out on 68 patients.

Results

The results are the following:

? 54.5% of functioning disturbances,

? 7% of infections,

? 27.5% of prosthesis removals.

Most of the patients considered they were satisfied although only 65% returned to a regular sexual activity.     

Decline of influenza-specific CD8+ T cell repertoire in healthy geriatric donors

Background

While influenza vaccination results in protective antibodies against primary infections, clearance of infection is primarily mediated through CD8⁺ T cells. Studying the CD8⁺ T cell response to influenza epitopes is crucial in understanding the disease associated morbidity and mortality especially in at risk populations such as the elderly. We compared the CD8⁺ T cell response to immunodominant and subdominant influenza epitopes in HLA-A2⁺ control, adult donors, aged 21-42, and in geriatric donors, aged 65 and older.

Results

We used a novel artificial Antigen Presenting Cell (aAPC) based stimulation assay to reveal responses that could not be detected by enzyme-linked immunosorbent spot (ELISpot). 14 younger control donors and 12 geriatric donors were enrolled in this study. The mean number of influenza-specific subdominant epitopes per control donor detected by ELISpot was only 1.4 while the mean detected by aAPC assay was 3.3 (p = 0.0096). Using the aAPC assay, 92% of the control donors responded to at least one subdominant epitopes, while 71% of control donors responded to more than one subdominant influenza-specific response. 66% of geriatric donors lacked a subdominant influenza-specific response and 33% of geriatric donors responded to only 1 subdominant epitope. The difference in subdominant response between age groups is statistically significant (p = 0.0003).

Conclusion

Geriatric donors lacked the broad, multi-specific response to subdominant epitopes seen in the control donors. Thus, we conclude that aging leads to a decrease in the subdominant influenza-specific CTL responses which may contribute to the increased morbidity and mortality in older individuals.     

Growth response of crops to soil microbial communities from conventional monocropping and tree-based intercropping systems

Background and aims

Recent studies have shown that tree-based intercropping (TBI) systems support a more diverse soil microbial community compared to conventional agricultural systems. However, it is unclear whether differences in soil microbial diversity between these two agricultural systems have a functional effect on crop growth.

Methods

In this study, we used a series of greenhouse experiments to test whether crops respond differently to the total soil microbial community (Experiment 1) and to arbuscular mycorrhizal (AM) fungal communities alone (Experiment 2) from conventionally monocropped (CM) and TBI systems.

Results

The crops had a similar growth response to the total soil microbial communities from both cropping systems. However, when compared to sterilized controls, barley (Hordeum vulgare) and canola (Brassica napus) exhibited a negative growth response to the total soil microbial communities, while soybean (Glycine max) was unaffected. During the AM fungal establishment phase of the second experiment, ‘nurse’ plants had a strong positive growth response to AM fungal inoculation, and significantly higher biomass when inoculated with AM fungi from the CM system compared to the TBI system. Soybean was the only crop species to exhibit a significant positive growth response to AM fungal inoculation. Similar to the total soil microbial communities, AM fungi from the two cropping systems did not differ in their effect on crop growth.

Conclusion

Overall, AM fungi from both cropping systems had a positive effect on the growth of plants that formed a functional symbiosis. However, the results from these experiments suggest that negative effects of non-AM fungal microbes are stronger than the beneficial effects of AM fungi from these cropping systems.     

Short-term effects of litter from 21 woody species on plant growth and root development

Background and aims

Plant litter has an important role in terrestrial ecosystems (Lambers et al. 2008). Our aim was to assess the short-term effect of litter from 21 woody species (deciduous and evergreens) on plant growth and root development.

Methods

We conducted a short-term experiment (10 weeks) under controlled conditions adding litter from 21 woody species to pots with Dactylis glomerata (target species). We determined plant biomass and root development and related these variables to decomposition rate and litter quality.

Results

Litter from two species enhanced plant growth whereas litter of five species inhibited it. Considering all species in the data set, plant growth was associated to litter with high decomposition rate and high litter quality: high Ca and N concentration and low polyphenols concentration. However, excluding from the analyses the two species that increased growth, litter inhibition effect on plant growth was related to the litter-polyphenols concentration. Plants growing with nutrient-richer litter had a lower proportion of fine roots which could be related to a litter mediated increase in soil nutrient.

Conclusions

Enhanced plant growth or, on the contrary, plant growth inhibition could be the result of a positive or, in turn, negative balance between nutrient and polyphenols concentration in litter.     

Pyrosequencing reveals how pulses influence rhizobacterial communities with feedback on wheat growth in the semiarid Prairie

Background and Aims

Evidence shows that plants modify their microbial environment leading to the “crop rotation effect”, but little is known about the changes in rhizobacterial community structure and functionality associated with beneficial rotation effects.

Methods

Polymerase chain reaction (PCR) and 454 GS FLX amplicon pyrosequencing were used to describe the composition of the rhizobacterial community evolving under the influence of pea, a growth promoting rotation crop, and the influence of three genotypes of chickpea, a plant known as an inferior rotation crop. The growth promoting properties of these rhizobacterial communities were tested on wheat in greenhouse assays.

Results

The rhizobacterial communities selected by pea and the chickpea CDC Luna in 2008, a wet year, promoted durum wheat growth, but those selected by CDC Vanguard or CDC Frontier had no growth-promoting effect. In 2009, a dry year, the influence of plants was mitigated, indicated that moisture availability is a major driver of soil bacterial community dynamics.

Conclusion

The effect of pulse crops on soil biological quality varies with the crop species and genotypes, and certain chickpea genotypes may induce positive rotation effects on wheat. The strength of a rotation effect on soil biological quality is modulated by the abundance of precipitation.     

Environmental impacts of hybrid,plug-in hybrid,and battery electric vehicles—what can we learn from life cycle assessment?

Purpose

The purpose of this review article is to investigate the usefulness of different types of life cycle assessment (LCA) studies of electrified vehicles to provide robust and relevant stakeholder information. It presents synthesized conclusions based on 79 papers. Another objective is to search for explanations to divergence and “complexity” of results found by other overviewing papers in the research field, and to compile methodological learnings. The hypothesis was that such divergence could be explained by differences in goal and scope definitions of the reviewed LCA studies.

Methods

The review has set special attention to the goal and scope formulation of all included studies. First, completeness and clarity have been assessed in view of the ISO standard’s (ISO 2006a, b) recommendation for goal definition. Secondly, studies have been categorized based on technical and methodological scope, and searched for coherent conclusions.

Results and discussion

Comprehensive goal formulation according to the ISO standard (ISO 2006a, b) is absent in most reviewed studies. Few give any account of the time scope, indicating the temporal validity of results and conclusions. Furthermore, most studies focus on today’s electric vehicle technology, which is under strong development. Consequently, there is a lack of future time perspective, e.g., to advances in material processing, manufacturing of parts, and changes in electricity production. Nevertheless, robust assessment conclusions may still be identified. Most obvious is that electricity production is the main cause of environmental impact for externally chargeable vehicles. If, and only if, the charging electricity has very low emissions of fossil carbon, electric vehicles can reach their full potential in mitigating global warming. Consequently, it is surprising that almost no studies make this stipulation a main conclusion and try to convey it as a clear message to relevant stakeholders. Also, obtaining resources can be observed as a key area for future research. In mining, leakage of toxic substances from mine tailings has been highlighted. Efficient recycling, which is often assumed in LCA studies of electrified vehicles, may reduce demand for virgin resources and production energy. However, its realization remains a future challenge.

Conclusions

LCA studies with clearly stated purposes and time scope are key to stakeholder lessons and guidance. It is also necessary for quality assurance. LCA practitioners studying hybrid and electric vehicles are strongly recommended to provide comprehensive and clear goal and scope formulation in line with the ISO standard (ISO 2006a, b).     

Rapid detection of porcine circovirus type 2 using a TaqMan-based real-time PCR

Background

In assays for anti-hepatitis E virus (HEV) immunoglobulin M (IgM), large volumes of the patient's sera cannot be easily obtained for use as a positive control. In this study, we investigated an alternative chemical method in which rabbit anti-HEV IgG was conjugated with human IgM and was used as a positive control in the anti-HEV IgM assay. Rabbit anti-HEV IgG was isolated from immune sera by chromatography on protein A-Sepharose and was conjugated with human IgM by using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) as a crosslinker.

Results

The specific anti-HEV IgG antibody titer was 100,000 times that of the negative control, i.e., prebleed rabbit serum. The results of anti-HEV IgM enzyme-linked immunosobent assay showed that the antibody conjugate was similar to anti-HEV IgM antibodies produced in humans. The results of a stability experiment showed that the antibody conjugate was stable for use in external quality assessment or internal quality control trials.

Conclusions

We concluded that the chemically conjugated rabbit-human antibody could be used instead of the traditional serum control as a positive control in the anti-HEV IgM assay.