Measurement of corticotropin-releasing factor (CRF), CRF-binding protein (CRF-BP), and CRF/CRF-BP complex in human plasma by two-site enzyme-linked immunoabsorbant assay.

The actions of human corticotropin-releasing factor (hCRF) in brain, pituitary, and plasma are modulated by a 37-kDa protein [CRF-binding protein (CRF-BP)] that binds to hCRF and neutralizes the peptide's biological activity, suggesting that only the free unbound peptide is biologically active. To accurately predict the biological consequences resulting from changes in total hCRF levels, we have developed two-site enzyme-linked immunosorbent assays (ELISAs) for hCRF-BP, free hCRF, and the hCRF-BP/hCRF complex. The assays were validated by measuring each factor in 1) maternal plasma at times when CRF and hCRF-BP levels are altered, and 2) plasma from normal elderly human subjects who have undergone a hCRF stimulation test. The hCRF-BP ELISA has a sensitivity of 2.7 fmol and a range of detection from 2.7-8000 fmol. Both the hCRF and hCRF-BP/ hCRF assays have a sensitivity of 0.4 fmol, with a useful range of detection from 0.4-40 fmol. Maternal plasma hCRF-BP levels remained unaltered between the 16-21 and 34-39 month gestational age groups. However, levels rose from 0.88 +/- 0.069 nmol/L in the 16-21 month gestational age group to 1.01 +/- 0.09 nmol/L in the 28-33 month gestational age group. Bound hCRF levels dramatically rose from undetectable at 16-21 months of gestation to 200 +/- 69 and 442 +/- 106 pmol/L in the 28-33 and 34-39 month gestational age groups, respectively. In comparison, free hCRF levels remained low throughout gestation, but dramatically rose to 318 +/- 120 pmol/L from 34-39 months of gestation. Binding site occupancy on the hCRF-BP decreased when bound and free hCRF levels were elevated. After treating the third trimester plasma sample with the high affinity hCRF-BP ligand, alpha-helical CRF-(9-41), all of the bound hCRF was displaced from the binding protein, and free hCRF levels rose from 87 to 284 pmol/L. The plasma hCRF-BP level was 0.9 +/- 0.08 nmol/L in normal human volunteers (10 men and 9 women; mean +/- SD age, 74.2 +/- 7.7 yr), decreased to 60% of basal levels 15 min after a bolus injection of 1 microgram/kg synthetic hCRF, and gradually returned to preinjection levels after 120 min. Conversely, bound and free hCRF levels increased from undetectable levels before hCRF injection to 0.58 +/- 0.03 nmol/L at 15 min and then rapidly decreased to undetectable levels at 120 min. These data validate the ELISAs in combination with high affinity hCRF-BP ligands for measuring bound and free hCRF in human plasma and suggest the utility of these assays for further determining alterations in peripheral CRF in conditions such as pregnancy.

Adrenal responsivity in normal aging and mild to moderate Alzheimer's disease.

BACKGROUND: Enhanced levels of cortisol have been found in moderate to severe Alzheimer's disease (AD) and in major depression, while recent studies have suggested decreased levels of serum dehydroepiandrosterone sulfate (DHAS) in patients with dementia. In this study the responsivity of the adrenal cortex to stimulation with a new low dose adrenocorticotropin (ACTH) test was investigated in patients with AD and in normal aging. METHODS: Thirteen patients with mild to moderate AD, 12 healthy old controls, and 15 young controls (78.0 +/- 8.4, 76.7 +/- 7.0, and 28.3 +/- 4.1 years old, mean: +/- SD, respectively) received an intravenous bolus injection of 1 microgram ACTH. Serum cortisol and androgen levels were analyzed before and 5, 10, 20, 25, 30, 35, 40, 60, 90, 120, 180, and 240 minutes after injection. RESULTS: The cortisol responsivity did not differ between the three groups. An enhanced release of androgens was present in patients with AD. AD per se had an independent influence on androstenedione levels after ACTH stimulation after adjustments for age and gender in a general linear regression model. CONCLUSIONS: In contrast to major depression, increased cortisol release to ACTH stimulation does not seem to be a feature of AD. Abnormal androgen levels after ACTH stimulation are characteristic features of mild to moderate Alzheimer's disease.

Serum dehydroepiandrosterone sulfate in Alzheimer's disease and in multi-infarct dementia.

Circulating levels of dehydroepiandrosterone sulfate (DHEAS) and cortisol were studied in 86 patients with dementia; 45 with Alzheimer's disease and 41 with multi-infarct dementia. Compared to an elderly control group, after adjustment for age and sex, patients with Alzheimer's disease were found to have lower serum levels of DHEAS. We found a covariation between serum albumin and DHEAS levels, which may be of importance regarding peripheral hormone concentration in patients with dementia. These findings may provide evidence for a role of DHEAS in amnestic disorder in humans, either reflecting or contributing to the course of dementing diseases.

Increased glucocorticoid production and altered cortisol metabolism in women with mild to moderate Alzheimer's disease.

BACKGROUND: Abnormalities at several levels of the hypothalamic-pituitary-adrenal axis, which may promote glucocorticoid dependent neurodegeneration, have been reported in patients with Alzheimer's disease. In this study we have explored the possibility that peripheral cortisol metabolism is enhanced and glucocorticoid production is increased compensatory in patients with mild to moderate Alzheimer's disease. METHODS: Urinary excretion of cortisol and its principal conjugated metabolites was studied in ten women with mild to moderate Alzheimer's disease, seven healthy elderly women and seven young women. RESULTS: There was an age-related fall in glucocorticoid production (median, 2009 [range 1828--4201] vs. 9315 [range 3613--16,244] microg/24 hours in elderly vs. young control subjects). A-ring metabolism (i.e., the irreversible inactivation of cortisol by 5 alpha- and 5 beta-reductases) was reduced in old age. However, patients with Alzheimer's disease showed persistence of cortisol metabolite excretion. Glucocorticoid production was significantly increased in patients with Alzheimer's disease versus healthy elderly control subjects (median, 7269 [range 6005-15,335] vs. 2009 [range 1828--4201] microg/24 hours), and patients with Alzheimer's disease had increased A-ring reduction of cortisol. CONCLUSIONS: An increased glucocorticoid production is an early feature of Alzheimer's disease and may be secondary to enhanced metabolic clearance of cortisol by A-ring reduction.

Blunted adrenocorticotropin and increased adrenal steroid response to human corticotropin-releasing hormone in Alzheimer's disease.

Previous studies suggest disturbances in the central regulation of the hypothalamic-pituitary-adrenocortical axis (HPA) in advanced Alzheimer's disease (AD). In this study the reactivity of the HPA axis was evaluated by stimulation with corticotropin-releasing hormone (CRH) of patients with mild to moderate AD. Twenty-three patients with AD (aged 61-88 yr) and 19 healthy elderly (aged 62-84 yr) received an intravenous bolus injection of human CRH (1 microgram/kg) at 3:00 PM. CRH-stimulated plasma ACTH levels were significantly lower in AD patients, while serum cortisol, dehydroepiandrosterone, and androstenedione responses relative to the amount of ACTH released were higher in AD patients. Significant correlations were found between low basal plasma ACTH levels and temporal lobe atrophy (p=0.02) and between peak plasma ACTH levels and hippocampal atrophy (p = 0.01). These findings suggest abnormalities at several levels of HPA axis in AD.

A subtle disturbance in the feedback regulation of the hypothalamic-pituitary-adrenal axis in the early phase of Alzheimer's disease.

In an attempt to find if a disturbance in the function of the feedback regulation of the hypothalamic-pituitary-adrenal axis is an early feature in Alzheimer's disease (AD), 35 outpatients (mean age 76.8 years) with a mild to moderate AD were compared to 20 controls (mean age 73.8 years) in their response to different doses of dexamethasone. After 0.5 mg dexamethasone, serum cortisol levels were significantly less suppressed in patients with early AD (p = .03) and these patients were significantly more often dexamethasone nonsuppressors (serum cortisol > or = 138 nmol/l) than controls (14/35 vs. 2/20; p = .03). Nonsuppression to 1 mg dexamethasone did not differ between groups (2/35 vs. 0/20). Plasma adrenocorticotropin levels were significantly lower in patients with Alzheimer's disease (n = 16) after 0.5 mg as well as after 1.0 mg dexamethasone (p = .01 and p < .001, respectively). The relationship between cortisol resistance to dexamethasone suppression and pathophysiology of AD is discussed.

Abnormalities in adrenal androgens, but not of glucocorticoids, in early Alzheimer's disease.

In an attempt to evaluate possible adrenal abnormalities in Alzheimer's disease (AD), prestimulus levels and ACTH-stimulated serum levels of steroid hormones, corticosteroid-binding globulin (CBG), and insulin-like growth factor I (IGF-I) were measured in 18 patients with early AD (8 men, 10 women; 74.6 +/- 6.5 years, mean +/- SD) and 19 healthy controls (10 men, 9 women; 74.2 +/- 7.6 years, mean +/- SD). Steroid hormone levels were measured before and after an intravenous bolus injection of 250 micrograms ACTH. AD per se had an independent influence on hormone levels when evaluated in MANOVA models. AD patients had significantly higher prestimulus levels of dehydroepiandrosterone and androstenedione (p = .04 and p = .003, respectively) with accentuated differences after ACTH (p = .02 and p < .001 for peak responses, respectively). Serum levels of cortisol, CBG, free cortisol, 17 alpha-hydroxyprogesterone (17 alpha-OHP), and IGF-I did not differ between groups. These abnormalities may have implications for neuronal degeneration as well as for behavioural symptoms in AD.

Histochemical detection of 4-hydroxynonenal protein in Alzheimer amyloid.

The presence of lipid peroxidation product in amyloid deposits from seven patients with Alzheimer disease and nine with non-Alzheimer disease was examined immunohistochemically by means of an affinity purified anti-HNE antibody to hydroxynonenal (HNE), a marker of lipid peroxidation. A positive reaction was found in amyloid deposits in all the specimens examined: most of the perivascular areas (89%) where amyloid deposition was confirmed by Congo red staining, showed immunoreactivity with the antibody in the specimens of Alzheimer disease. Twenty-one percent of senile plaques which were also stained by Congo red staining reacted with this antibody. Several perivascular cells were also stained by anti-HNE antibody. In other neurons both in Alzheimer and non-Alzheimer disease patients, only a few percent reacted with this antibody and no statistical difference was observed between them. These results verify that lipid peroxidation via free radical injury occurs in amyloid deposits in Alzheimer amyloid. Since HNE has been identified as a cytotoxic metabolite of free radical injury, amyloid deposits in the tissue may exhibit a toxic effect during the generation process of HNE.

Peripheral blood lymphocyte subsets in polymyalgia rheumatica.

Peripheral blood lymphocytes from 23 patients with polymyalgia rheumatica (PMR) were characterized using monoclonal antibodies and flow cytometry in a two-year prospective study. There were no significant differences in absolute numbers or relative percentages of lymphocytes or CD3+, CD4+, CD8+ T cells or the CD4+ T cell functional subsets, virgin (CD4+CD45RA+) and memory (CD4+CD29+) T cells, in patients before or during corticosteroid treatment compared to controls. Previous reports on decreased levels of CD8+ T cells as a characteristic of PMR/giant cell arteritis was not confirmed. The absolute number and relative percentage of lymphocytes with natural killer cell activity, CD16+ CD56+ cells, were significantly lower in patients with active untreated PMR as well as during corticosteroid treatment compared to controls, but at the two-year follow-up the difference was less marked.

[Harmonization of dementia diagnoses--a necessary quality assurance]. / Harmonisering av demensdiagnoser--en nödvändig kvalitetssäkring.

Classification and registration of diseases is necessary in order to monitor the proliferation of diseases in a population. Despite the presence of an international framework for classification of diseases (ICD 10) which has been approved by the Swedish authorities, the guidelines provided are not observed in the area of dementia diseases. Different diagnoses can be used to describe the same condition, and "dementia unspecified" is sometimes employed when a specified diagnosis could have been used. In order to refine consensus regarding the use of different diagnoses in the dementia field, representatives for the Swedish University hospitals and medical faculties propose a unified description of a limited number of dementia diagnoses.

Abnormalities at different levels of the hypothalamic-pituitary-adrenocortical axis early after stroke.

BACKGROUND AND PURPOSE: Hypercortisolism is common in stroke patients. The aim of this study was to investigate possible disturbances at different sites within the hypothalamic-pituitary-adrenal axis. We also studied possible associations between hypercortisolism and clinical manifestations of brain dysfunction. METHODS: Patients with an acute ischemic stroke (n = 16; mean +/- SD age, 71 +/- 11 years) were compared with healthy elderly subjects (n = 9). We performed a short adrenocorticotropic hormone (ACTH) test with 0.25 mg 1-24 ACTH injected intravenously and an overnight dexamethasone suppression test with 1 mg dexamethasone given orally at 11 PM. RESULTS: Serum cortisol levels after dexamethasone at 8 AM were significantly higher in stroke patients (p = 0.003). The area under the curve for the cortisol response to ACTH was elevated in seven (47%) of stroke patients, and the centered cumulative cortisol response was elevated in three (20%) patients. The area under the curve response correlated significantly to the presence of an acute confusional state and male sex in stroke patients (rs = 0.63 and rs = 0.62, respectively; p < 0.05), whereas the centered cumulative cortisol response diminished with increasing age (rs = -0.62; p < 0.05). Postdexamethasone cortisol levels were significantly correlated to the presence of an acute confusional state and to extensive limb paresis (rs = 0.66 and rs = 0.62, respectively; p < 0.05). CONCLUSIONS: There are abnormalities in the cortisol axis both at the central level and at the adrenal level early after stroke. Hypercortisolism is closely associated with cognitive disturbances and extensive motor impairment.

Decreased peripheral glucocorticoid sensitivity in Alzheimer's disease.

Both peripheral and central glucocorticoid sensitivity was examined in patients with Alzheimer's disease (AD; n = 13), glucocorticoid-treated patients (n = 8), healthy elderly controls (n = 10) and young controls (n = 9). We performed glucocorticoid receptor-mediated skin vasoconstrictor responses to clobetasol and low-dose dexamethasone suppression tests. Patients with AD showed skin blanching at a significantly higher clobetasol concentration than did healthy elderly controls (p = 0.002). There was no difference in skin blanching between patients with AD and patients treated with corticosteroids. Patients with AD had significantly higher post-dexamethasone serum cortisol levels than healthy elderly (p = 0.01). No association was found between skin blanching and dexamethasone suppressibility. Thus patients with AD have apparently independent reductions in both central nervous system and peripheral glucocorticoid sensitivity. These results predict an increase in glucocorticoid secretion in some patients, which might accelerate neuronal degeneration in the absence of features of overexposure to glucocorticoids in peripheral tissues.

Cortisol axis abnormalities early after stroke--relationships to cytokines and leptin.

OBJECTIVE: To assess the relationships between circulating levels of proinflammatory cytokines and adrenocortical hormones and leptin early after stroke. DESIGN: Blood samples were collected four times daily the first two days after stroke, twice daily the next 4 days and four times at day 7. Cognitive function and functional outcome was measured at admittance and at day 7. SETTING: Consecutive inclusion of patients admitted to the stroke unit at Umeâ University Hospital. SUBJECTS: Eight men and 4 women with acute stroke and 10 healthy volunteers. MAIN OUTCOME MEASURES: Levels and diurnal variations of plasma proinflammatory cytokines interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-alpha), serum adrenocortical hormones (cortisol and DHEA) and leptin, and MMSE, SSS, and ADL scores. RESULTS: A significant correlation was present between IL-6 and cortisol levels the first two days after stroke (P < 0.05). In patients with a disturbed diurnal rhythm of cortisol, cortisol and leptin levels were increased (68% and 81% increase, respectively), whilst DHEA levels were unaltered. Half of the patients displayed an abnormal diurnal rhythmicity of leptin at the end of the week. Median TNF-alpha levels for the first two days after stroke also correlated to median leptin levels at the end of the week (P < 0.05). Median IL-6 levels correlated to severity of paresis on days 1 and 7 and to MMSE scores on day 7 (P < 0.05). CONCLUSIONS: Neuroendocrine disturbances are common and often profound early after stroke. Cytokines seem to be important modulators of these disturbances, including diurnal rhythmicity of cortisol and leptin.