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G J Ligthart

Publications and source records attributed to G J Ligthart.

At least 19 recordsLinked to original sources
PubMed2000

The effect of geographic origin on the frequency of HLA antigens and their association with ageing.

The association between HLA antigens and ageing is not clear. Ageing in women was associated with B40 and DR5 in a recent study, but other studies yielded conflicting results. In none of the studies, however, did the young and elderly samples originate from the same homogeneous population. Homogeneity is dependent on geographic origin. The aim of this study was to investigate whether differences in geographic origin between age groups could explain the age-associated differences in the frequencies of B40 and DR5. The authors used the new design of a 'birth-place-restricted comparison' in which the origin of all subjects was ascertained. The total study population comprised 1010 young women aged 25-40 years and 660 elderly women aged 85 years and older. The 'birth-place-restricted comparison' included 66 young and 285 elderly women from one geographic area (Leiden, the Netherlands). Men were not included because ageing in men was not associated with HLA antigens in a recent study. In the total population, the frequency of B40 in young women of different origin varied between 16 and 28%, and the frequency of DR5 between 11 and 23%. Similar differences were observed in the elderly women. In the 'birth-place-restricted comparison', the frequency of B40 was 15% in the young women and 11% in the elderly women (difference 4%, 95% confidence interval, -5 to 13%). The frequency of DR5 was 20% in the young women, and 28% in the elderly women (difference 8%, 95% confidence interval, -4 to 19%). Thus, marked differences in HLA antigen frequency were found between populations of various geographic origins. Definition and ascertainment of the target population are therefore necessary in genetic studies of ageing. In such a 'birth-place-restricted comparison', the authors confirmed that ageing in women was negatively associated with HLA-B40 and positively associated with HLA-DR5.

Adult↗
PubMed1999

Dose-dependent antibody response to influenza H1N1 vaccine component in elderly nursing home patients.

The effects of an increased antigen dose on HI, IgG, IgA, and IgM antibody responses to influenza A/Taiwan/1/86 (H1N1) were investigated in 92 elderly nursing-home residents (mean age 81 years) and 104 young subjects (mean age 20 years). At a standard 10-microg dose, HI and IgG titer rises were lower in the elderly. HI titers did not improve at higher vaccine dosages. By contrast, influenza-specific IgG and IgA antibody responses were dose dependent in elderly subjects, but not in young. In the young subjects, IgM antibody responses were dose dependent. The improved antibody responses in the elderly as observed in IgG and IgA were not reflected in the HI response. Therefore, the evaluation of antibody production by HI only may lead to an underestimate of the immune response in elderly people.

Adult↗
PubMed1998

Blood pressure and mortality in elderly people aged 85 and older: community based study.

OBJECTIVE: To determine whether the inverse relation between blood pressure and all cause mortality in elderly people over 85 years of age can be explained by adjusting for health status, and to determine whether high blood pressure is a risk factor for mortality when the effects of poor health are accounted for. DESIGN: 5 to 7 year follow up of community residents aged 85 years and older. SETTING: Leiden, the Netherlands. SUBJECTS: 835 subjects whose blood pressure was recorded between 1987 and 1989. MAIN OUTCOME MEASURE: All cause mortality. RESULTS: An inverse relation between blood pressure and all cause mortality was observed. For diastolic blood pressure crude 5 year all cause mortality decreased from 88% (52/59) (95% confidence interval 79% to 95%) in those with diastolic blood pressures <65 mm Hg to 59% (27/46) (44% to 72%) in those with diastolic pressures >100 mm Hg. For systolic blood pressure crude 5 year all cause mortality decreased from 85% (95/112) (78% to 91%) in those with systolic pressures <125 mm Hg to 59% (13/22) (38% to 78%) in those with systolic pressures >200 mm Hg. This decrease was no longer significant after adjustment for indicators of poor health. No relation existed between blood pressure and mortality from cardiovascular causes or stroke after adjustment for age and sex, but after adjustment for age, sex, and indicators of poor health there was a positive relation between diastolic blood pressure and mortality from both cardiovascular causes and stroke. CONCLUSION: The inverse relation between blood pressure and all cause mortality in elderly people over 85 is associated with health status.

Age Distribution↗
PubMed1998

Altered antibody response to influenza H1N1 vaccine in healthy elderly people as determined by HI, ELISA, and neutralization assay.

To determine the influence of ageing per se as well as of priming histories on the antibody response to influenza vaccination, haemagglutination inhibition (HI), ELISA IgG, IgA, IgM and neutralizing antibody titres were studied in 43 healthy young subjects (mean age 23 years) and 55 healthy elderly people (mean age 79 years). The HI and ELISA lgG responses to the A/Guizhou/54/89 strain (H3N2) for which both the young and the elderly had similar priming histories were equal. By contrast, the HI and IgG responses to A/Taiwan/1/86 (H1N1), where the priming histories were different, were lower in the elderly (P < 0.05). Influenza-specific IgA responses in the elderly tended to be higher for all vaccine strains. Influenza-specific postvaccination IgM titres were similar or tended to be higher in the elderly. A subgroup of elderly subjects (18%) who did not express HI activity to the A/Taiwan/1/86 (H1N1) vaccine strain, reacted in the HI assay with the closely related A/Singapore/6/86 (H1N1) strain. These elderly people, however, produced lgG antibodies which neutralized A/Taiwan/1/86 virus in vitro. It is concluded that the elderly are capable of mounting antibody responses similar to those observed in the young. Moreover, the observed age-related differences in antibody responses to H1N1 strains are probably not due to ageing of the immune system itself, but are determined by differences in priming histories.

Adult↗
PubMed1997

The association between human leucocyte antigens (HLA) and mortality in community residents aged 85 and older.

OBJECTIVE: The association between Human Leucocyte Antigens (HLA) and aging was investigated. It is possible that HLA antigens are associated with longevity, either indirectly through disease associations or directly through involvement in the aging mechanism. DESIGN: Community-based follow-up study. SETTING: Leiden, the Netherlands. PARTICIPANTS: A total of 919 subjects were HLA typed in this community-based study. All subjects were aged 85 and older and were white. Seventy-two percent of the cohort was female. MEASUREMENTS: Age- and sex-adjusted Mortality Rate Ratios (MRR) were estimated for 79 antigens by the subject-years method. HLA-A, -B and -C typing was performed with the standard NIH lymphocytotoxicity test, HLA-DR and -DQ typing was performed with the two-color fluorescence test. Homozygosity for HLA-A, -B, and -DR was defined as only one detectable antigen at a locus. RESULTS: The mean follow-up period (SD) was 5.0 (0.6) years. At the end of the follow-up, 70% of the subjects had died. The MRR (95% CI) for B60 was 0.96 (0.75-1.23), and for DR11 it was 0.82 (0.66-1.01). For A2 and A26 only, the MRR (95% CI) was significantly different from 1: 0.85 (0.73-0.99), P = .04 and 1.45 (1.06-1.99), P = .02, respectively (P values not corrected for the number of antigens tested). Homozygosity was not associated with mortality. CONCLUSIONS: HLA was not associated with mortality after the age of 85. Therefore, direct involvement of HLA in aging is unlikely. We suggest that the findings of previous studies are attributable to methodological shortcomings such as small sample size and differences in genetic background of the subjects.

Aged↗
PubMed1997

Immunosenescence revisited. Does it have any clinical significance?

Immunosenescence refers to the influence of aging on the immune system. Numerous problems are encountered in studying this topic, the main one being the influence of concomitant disease. Despite the great efforts that have been devoted to research in this field, the results of studies performed to date have not been convincing and, until now, no sound scientific evidence has emerged to show that immunosenescence is clinically significant. The only possible exceptions to this are the discovery of a selective defect in cell-mediated immunity and the reactivation of varicella zoster virus. Therefore, many more, and better designed, studies will have to be conducted before the full clinical impact of immunosenescence can be delineated.

Aged↗
PubMed1996

Correlation between the antibody response to influenza vaccine and helper T cell subsets in healthy aging.

To investigate the effects of the altered composition of the helper T cell compartment in ageing on the humoral response to influenza vaccine, we investigated correlations between helper T cell subsets and anti-influenza antibody responses in 23 JUNIEUR healthy young and 41 SENIEUR healthy elderly subjects. Naive helper T cell numbers (CD4+ CD45RA+) were negatively correlated with antibody production to two of the four strains investigated in JUNIEURS only. By contrast, memory helper T cell numbers (CD4+CD45ROhi) were positively correlated with in vivo IgG antibody titres to three of the four vaccine strains. Age-related differences in the composition of the helper T cell compartment, however, did not explain the lower IgG antibody response that was observed to two of the four vaccine strains examined.

Adult↗
PubMed1996

Influenza vaccination for all elderly.

In the elderly, incidence, morbidity, complications, and mortality due to influenza are greatly underestimated. There are several reasons why influenza vaccination is unjustly denied to many elderly. In a number of countries such as the United Kingdom and The Netherlands, health authorities do not recommend to vaccinate all elderly persons above a certain age, and influenza vaccination is offered only to those with conventional risk factors such as cardiac or pulmonary disease. However, conventional risk factors are often not present or are not recognized in the elderly. There now is convincing evidence that age in itself leads to increased vulnerability and thus is a risk factor for influenza and its complications. It no longer seems justified not to vaccinate all elderly, including the healthy, against influenza.

Aged↗
PubMed1995

[Influenza vaccine in 85-and-over aged: motivation of elderly and family physicians to vaccinate or not].

OBJECTIVE: To determine on what grounds persons over 85 years are or are not vaccinated against influenza. DESIGN: Descriptive. SETTING: Gerontological Research Centre and Department of General Practice Medicine, University of Leiden, the Netherlands. METHOD: A random sample (n = 331) of the general population of Leiden aged 85 years or older and not institutionalized were interviewed. Early in October 1993, 163 interviews were suitable for analysis (response rate 54%). An analysis of non-responders revealed no significant difference as regards gender and housing, but persons aged 90 and older were under-represented. The general practitioners (n = 41) of the 163 elderly persons were interviewed about these persons (response: n = 127; 78%) and about influenza vaccination in general (response: n = 33; 82%). RESULTS: The vaccination coverage rates were 51% according to the elderly and 56% according to the GPs; those of elderly people with an indication (48% according to themselves and 64% according to the GP) 52% and 67%, respectively. Reasons for elderly people not to accept vaccination were that they considered vaccination unnecessary, that they felt well and wanted to avoid possible adverse effects. A doctor's recommendation to have vaccination done was a positive influence. GPs' motives not to vaccinate were absence of an indication and the elderly person's wish. CONCLUSION: Only two-thirds of those over 85 not living in a nursing home with an indication for influenza vaccination were indeed vaccinated. Information about the possible damage done by influenza and about the pros and cons of vaccination, together with a doctor's advice to be vaccinated appeared to have a positive effect on the vaccination coverage.

Aged↗
PubMed1995

Three-year follow-up of Mini-Mental State Examination score in community residents aged 85 and over.

The objective of this study was to describe over time the course of cognitive function of elderly without cognitive impairment and of elderly with different stages of impairment, and to assess if the change in cognitive function was dependent on the initial level of function. The Mini-Mental State Examination (MMSE) was used at two time points. The first assessment (MMSE-1) was part of a community-based study and was obtained from 871 subjects. For the second assessment (MMSE-2) a sample of 166 subjects was drawn from the subjects alive at follow-up who had an MMSE-1 score. This sample was stratified by MMSE-1 score to avoid oversampling of subjects with high MMSE-1 scores. A second MMSE score was obtained from 134 elderly, whereas 18 subjects refused participation and 14 subjects were not traceable. The median age at first assessment was 89 years (25th percentile 87, 75th percentile 92), the mean follow-up period (S.D.) was 3.3 (0.5) years. The median change in MMSE score was minus 4 points (95% confidence interval (CI) -7 to -2) and the slope of the regression line of MMSE-2 on MMSE-1 was 1.1 (95% CI 0.9-1.3). It is likely that the slope was underestimated due to a floor effect, regression to the mean and missing observations. However, the probability of decline decreased if MMSE-1 was higher. Nevertheless, the probability ranged from 27 to 59% for subjects with the highest MMSE-1 scores aged 85 and 95 years respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1995

A community based study of the incidence of dementia in subjects aged 85 years and over.

The aim was to investigate the incidence rate of dementia for community residents aged 85 years and over. It was a two wave community study of 224 subjects (community residents including those residing in a nursing home) older than 85 years, restudied 4.1 years after a community prevalence study. A two stage method was used, comprising the mini mental state examination followed in a stratified sample by the geriatric mental state schedule (A3)/AGECAT. Incidence rates were based on person-years at risk. The overall incidence of dementia was 6.9 (95% confidence interval (95% CI) 4.8-9.1) per 100 person-years at risk. The incidence was significantly higher for women than for men; respectively 8.9 (95% CI 5.9-11.9) v 2.7 (95% CI 0.5-4.9) per 100 person-years at risk. In the fastest growing age group seven out of 100 persons develop dementia each year. Women, who constitute two thirds of the oldest old, seem to have a higher risk. Further research is needed into the risk factors for dementia in this age group.

Aged↗
PubMed1994

Sleep and ageing: the effect of institutionalization on subjective and objective characteristics of sleep.

To assess the impact of institutionalization on sleep/wake characteristics of elderly people, we compared subjective (study I: n = 160) and objective (study II: n = 30) sleep/wake measures of non-demented institutionalized subjects and age-matched non-institutionalized controls. We also evaluated the prevalence and causes of various sleep disturbances. The three living conditions, i.e. independently living (IL), service home (SH) and nursing home (NH) were respectively assumed to have minimal, moderate and maximal effects upon the timing, the amount and the quality of the sleep/wake behaviour of the persons involved. Study I showed that a higher level of institutionalization was significantly (p < 0.05) associated with phase-advanced sleep/wake patterns, increased amounts of time spent in bed during the 24-hour period and increased usage of prescribed sedative-hypnotic drugs. Poor sleep quality and disturbed sleep onset occurred significantly mostly in the SH group. No differences between groups were demonstrated with respect to the prevalence of disturbed sleep maintenance, parasomnias and difficulty with awakening and their possible causes, except for environmental noise which was exclusively reported by institutionalized subjects. No differences between groups for any of the objective measures were found (study II). Overall, our findings are in line with previous findings on this topic, although the observed high rate of poor sleep quality and sleep disturbances and their associated causes as observed in institutionalized subjects also occurs in an age-matched non-institutionalized population.

Activities of Daily Living↗
PubMed1994

Age-related increase in the fraction of CD27-CD4+ T cells and IL-4 production as a feature of CD4+ T cell differentiation in vivo.

The influence of ageing on phenotype and function of CD4+ T cells was studied by comparing young (19-28 years of age) and aged (75-84 years of age) donors that were selected using the SENIEUR protocol to exclude underlying disease. An age-related increase was observed in the relative number of memory cells, not only on the basis of a decreased CD45RA and increased CD45RO expression, but also on the basis of a decrease in the fraction of CD27+CD4+ T cells. Our observation that the absolute number of CD45RO+CD4+ T cells was increased, while absolute numbers of CD27-CD4+ T cells remained unchanged in aged donors, indicates that the latter subset does not merely reflect the size of the CD45RO+CD4+ T cell pool. The increased fraction of memory cells in the aged was functionally reflected in an increased IL-4 production and T cell proliferation, when cells were activated with the combination of anti-CD2 and anti-CD28, whereas IL-2 production was comparable between both groups. No differences were observed with respect to proliferative T cell responses or IL-2 production using plate-bound anti-CD3 or phytohaemagglutinin (PHA). The observation that IL-4 production correlated with the fraction of memory cells in young donors but not in aged donors suggests different functional characteristics of this subset in aged donors.

Adult↗