New recommendations on cerebral venous and dural sinus thrombosis from the German consensus-based (S2k) guideline.

Over the last years, new evidence has accumulated on multiple aspects of diagnosis and management of cerebral venous and dural sinus thrombosis (CVT) including identification of new risk factors, studies on interventional treatment as well as treatment with direct oral anticoagulants. Based on the GRADE questions of the European Stroke Organization guideline on this topic, the new German guideline on CVT is a consensus between expert representatives of Austria, Germany and Switzerland. New recommendations include:• CVT occurring in the first weeks after SARS-CoV-2 vaccination with vector vaccines may be associated with severe thrombocytopenia, indicating the presence of a prothrombotic immunogenic cause (Vaccine-induced immune thrombotic thrombocytopenia; VITT).• D-dimer testing to rule out CVT cannot be recommended and should therefore not be routinely performed.• Thrombophilia screening is not generally recommended in patients with CVT. It should be considered in young patients, in spontaneous CVT, in recurrent thrombosis and/or in case of a positive family history of venous thromboembolism, and if a change in therapy results from a positive finding.• Patients with CVT should preferably be treated with low molecular weight heparine (LMWH) instead of unfractionated heparine in the acute phase.• On an individual basis, endovascular recanalization in a neurointerventional center may be considered for patients who deteriorate under adequate anticoagulation.• Despite the overall low level of evidence, surgical decompression should be performed in patients with CVT, parenchymal lesions (congestive edema and/or hemorrhage) and impending incarceration to prevent death.• Following the acute phase, oral anticoagulation with direct oral anticoagulants instead of vitamin K antagonists should be given for 3 to 12 months to enhance recanalization and prevent recurrent CVT as well as extracerebral venous thrombosis.• Women with previous CVT in connection with the use of combined hormonal contraceptives or pregnancy shall refrain from continuing or restarting contraception with oestrogen-progestagen combinations due to an increased risk of recurrence if anticoagulation is no longer used.• Women with previous CVT and without contraindications should receive LMWH prophylaxis during pregnancy and for at least 6 weeks post partum.Although the level of evidence supporting these recommendations is mostly low, evidence from deep venous thrombosis as well as current clinical experience can justify the new recommendations.This article is an abridged translation of the German guideline, which is available online.

Lesion topography of posterior cerebral artery infarcts.

This study analyzed the topography of acute ischemic stroke in the posterior cerebral artery (PCA) territory. We studied 84 patients with unilateral ischemic PCA stroke. Patients were classified according to lesion levels as cortico-subcortical (superficial), combined (cortical and mesodiencephalic) or isolated thalamic. To receive a lesion map, data from acute MR and CT imaging were normalized and labelled automatically by mapping to stereotaxic anatomical atlases. Cortical lesions accounted for 41.7%, combined for 36.9%, and isolated thalamic lesions for 21.4%. The maximum overlay of ischemia and, thus, highest occurrence of PCA ischemic stroke was found in the ventral and medial occipito-temporal cortex and adjacent white matter association tracts. Dorsal and peripheral segments of the occipito-temporo-parietal region were only rarely lesioned. This configuration was similar in both hemispheres. Consistent with this lesion pattern, visual field defects (VFD) were the most frequent signs, followed by sensorimotor signs, dizziness and sopor, cognitive and oculomotor deficits, and ataxia. The three vascular subgroups differed not only by their anatomical lesion profile and lesion load, but also by their clinical manifestation; although patients with combined and thalamic lesions were sigificantly younger, they were more disabled than participants with cortical lesions. VFD were only found in cortical and combined, and oculomotor deficits only in mesodiencephalic lesions. White matter lesions were common in the cortico-subcortical and the combined group. Basal occipito-temporal and calcarine regions, and neighbouring white matter tracts have the highest risk of ischemia in acute PCA stroke.

Prevalence and differences of ideal cardiovascular health in urban and rural adolescents in the Region of Tyrol: results from the EVA Tyrol study.

PURPOSE: Early adoption of a healthy lifestyle has positive effects on cardiovascular health (CVH) in adulthood. In this study, we aimed to assess CVH metrics in a cohort of healthy teenagers with focus on differences between rural and urban areas. METHODS: The Early Vascular Aging (EVA) Tyrol study is a population-based non-randomized controlled trial, which prospectively enrolled 14- to 19-year-old adolescents in North Tyrol, Austria and South Tyrol, Italy between 2015 and 2018. Data from the baseline and control group (prior to health intervention) are included in the current analysis. CVH determinants (smoking, body mass index, physical activity, dietary patterns, systolic and diastolic blood pressure, total cholesterol and fasting blood glucose) were assessed and analyzed for urban and rural subgroups separately by univariate testing. Significant variables were added in a generalized linear model adjusted for living in urban or rural area with age and sex as covariates. Ideal CVH is defined according to the guidelines of the American Heart Association. RESULTS: 2031 healthy adolescents were enrolled in the present study (56.2% female, mean age 16.5 years). 792 adolescents (39.0%) were from urban and 1239 (61.0%) from rural areas. In 1.3% of adolescents living in urban vs. 1.7% living in rural areas all CVH determinants were in an ideal range. Compared to the rural group, urban adolescents reported significantly longer periods of moderate to vigorous-intensive activity (median 50.0 min/day (interquartile range 30-80) vs. median 40.0 min/day (interquartile range 25-60), p < 0.01). This observation remained significant in a generalized linear model (p < 0.01). There were no significant differences between the study groups regarding all other CVH metrics. CONCLUSION: The low prevalence of ideal CVH for adolescents living in urban as well as rural areas highlights the need for early health intervention. Geographic differences must be taken into account when defining targeted subgroups for health intervention programs.

Familial hypercholesterolaemia in patients with ischaemic stroke or transient ischaemic attack.

BACKGROUND AND PURPOSE: Identification of patients with familial hypercholesterolaemia (FH) is a prerequisite for the appropriate management of their excess cardiovascular risk. It is currently unknown how many patients with acute ischaemic stroke or transient ischaemic attack (TIA) are affected by FH and whether systematic screening for FH is warranted in these patients. METHODS: The prevalence of a clinical diagnosis of FH was estimated in a large representative series of patients with acute ischaemic stroke or TIA (ABCD2 score ≥ 3) using the Dutch Lipid Clinic Network Algorithm (DLCNA; possible FH ≥3, probable/definite FH ≥6). RESULTS: Out of 1054 patients included in the present analysis, 14 had probable/definite FH (1.3%; 95% confidence interval 0.6-2.0) and 107 possible FH (10.2%; 8.4-12.0) corresponding to an overall prevalence of potential FH of 11.5%. Prevalences were even higher in patients with stroke/TIA manifestation before age 55 in men or 60 in women (3.1%, 0.6-5.6; and 13.1%, 8.3-17.9) and those with a prior history of cardiovascular disease (2.6%, 0.9-4.3; and 15.1%, 11.3-18.9). Of note, in two-thirds of our patients with probable/definite and possible FH, stroke or TIA was the initial clinical disease manifestation. CONCLUSIONS: The frequency of potential FH, based on clinical criteria, in patients with acute ischaemic stroke or TIA was 11.5% and that of probable/definite FH (1.3%) was similar to recently reported counts for patients with acute coronary syndrome (1.6%). FH screening using the DLCNA is feasible in clinical routine and should be considered as part of the usual diagnostic work-up.

Residual Thromboembolic Material in Cerebral Arteries after Endovascular Stroke Therapy Can Be Identified by Dual-Energy CT.

BACKGROUND AND PURPOSE: Dual-energy CT features the opportunity to differentiate among up to 3 different materials because the absorption of x-rays depends on the applied tube voltage and the atomic number of the material. For example, it is possible to distinguish between blood-brain barrier disruption and an intracerebral hemorrhage following treatment for a stroke. The aim of this study was to evaluate whether dual-energy CT is capable of distinguishing intra-arterial contrast agent from residually clotted vessels immediately after endovascular stroke therapy. MATERIALS AND METHODS: Sixteen patients (9 women, 7 men; mean age, 63.6 ± 13.09 years) were examined. Measurements were made on the postinterventional dual-energy CT virtual noncontrast, iodine map, and "weighted" brain window (weighted dual-energy) series. Postinterventional conventional angiography was used as the criterion standard method. RESULTS: A residual clot was found in 10 patients. On the virtual noncontrast series, the Hounsfield attenuation of the clotted arteries was higher than that in the corresponding perfused contralateral arteries (53.72 ± 9.42 HU versus 41.64 ± 7.87 HU; P < .05). The latter had higher absorption values on the weighted dual-energy series than on the virtual noncontrast series (49.37 ± 7.44 HU versus 41.64 ± 7.87 HU; P < .05). The sensitivity for the detection of a residual clot was 90%; the specificity was 83.3%, and the accuracy was 87.5%. Interrater agreement was good (κ = 0.733). CONCLUSIONS: Dual-energy CT may be valuable in the detection of clot persistence or early re-thrombosis without the necessity of additional contrast administration. However, its relevance for the prediction of outcomes remains to be determined in further studies.

Very urgent carotid endarterectomy does not increase the procedural risk.

OBJECTIVES: The timing of CEA for symptomatic internal carotid artery (ICA) stenosis remains a matter of controversy. Recent registry data showed a significantly increased risk, especially in the very early days after the onset of symptoms. In this study the outcome of CEA in the hyperacute phase has been investigated. METHODS: The outcome of CEA for symptomatic ICA stenosis between January 2004 and December 2013 has been retrospectively analyzed. Patients were divided into four timing groups: surgery within 0 and 2 days, between 3 and 7 days, 8 and 14 days, and thereafter. The post-operative 30 day stroke and death rates were assessed. RESULTS: A total of 761 symptomatic patients (40.1% with transient ischemic attack [TIA], 21.3% with amaurosis fugax, and 38.6% with ischemic stroke) were included, with an overall peri-operative stroke and death rate of 3.3%. A stroke and death rate of 4.4% (9/206) for surgery within 0 and 2 days, 1.8% (4/219) between 3 and 7 days, 4.4% (6/136) between 8 and 14 days, and 2.5% (5/200) in the period thereafter (p = .25 for the difference between the groups) was observed. The timing of surgery did not influence the peri-operative outcome in a multivariate regression analysis (OR 0.93 [0.63-1.36], p = .71). CONCLUSIONS: These data show that very urgent surgery in symptomatic patients can be performed without increased procedural risk. Given the fact that ruptured plaques with neurological symptoms carry the highest risk of a recurrent ischemic event in the first 2 days, treating patients as soon as possible to offer the highest benefit in stroke prevention is recommended.

Pentraxin 3 (PTX3) plasma levels and carotid intima media thickness progression in the general population.

BACKGROUND AND AIM: Pentraxin 3 (PTX3) is an essential component of the humoral arm of innate immunity and, like C-reactive protein, is independently associated with the risk of developing vascular events. Aim of this study was to investigate, in two large population-based surveys, the Bruneck Study and the PLIC Study, whether PTX3 plasma levels predict the progression of common carotid artery intima-media thickness (CCA-IMT), a surrogate marker of atherosclerosis, in the general population during 5 or 6 years of follow-up. RESULTS: In the Bruneck Study, PTX3 plasma levels did not predict a faster progression of CCA-IMT either in the carotid artery or in the femoral artery. This finding was confirmed in the PLIC Study where subjects within the highest tertile of PTX3 did not show an increased progression of CCA-IMT. PTX3 plasma levels were also not associated with the fastest maximum IMT progression. In summary, in more than 2400 subjects from the general population, PTX3 plasma level is neither an independent predictor of progression of subclinical atherosclerosis in different arterial territories, including carotid and femoral arteries nor of incident cardiovascular events. CONCLUSION: These findings support the relevance of investigating the predictive value of PTX3 plasma levels only in specific settings, like overt CVD, heart failure or acute myocardial infarction.

Functional recovery after ischemic stroke--a matter of age: data from the Austrian Stroke Unit Registry.

OBJECTIVE: To analyze the association between patient age and good functional outcome after ischemic stroke with special focus on young patients who were numerically underrepresented in previous evaluations. METHODS: Of 43,163 ischemic stroke patients prospectively enrolled in the Austrian Stroke Unit Registry, 6,084 (14.1%) were ≤55 years old. Functional outcome was available in a representative subsample of 14,256 patients free of prestroke disability, 2,223 of whom were 55 years or younger. Herein we analyzed the effects of age on good functional outcome 3 months after stroke (modified Rankin Scale score ≤2). RESULTS: Good outcome was achieved in 88.2% (unadjusted probability) of young stroke patients (≤55 years). In multivariable analysis, age emerged as a significant predictor of outcome independent of stroke severity, etiology, performance of thrombolysis, sex, risk factors, and stroke complications. When the age stratum 56-65 years was used as a reference, odds ratios (95% confidence interval [95% CI]) of good outcome were 3.4 (1.9-6.4), 2.2 (1.6-3.2), and 1.5 (1.2-1.9) for patients aged 18-35, 36-45, and 46-55 years and 0.70 (0.60-0.81), 0.32 (0.28-0.37), and 0.18 (0.14-0.22) for those aged 66-75, 76-85, and >85 years (p < 0.001). In absolute terms, the regression-adjusted probability of good outcome was highest in the age group 18-35 years and gradually declined by 3.1%-4.2% per decade until age 75 with a steep drop thereafter. Findings applied equally to sexes and patients with and without IV thrombolysis or diabetes. CONCLUSIONS: Age emerged as a highly significant inverse predictor of good functional outcome after ischemic stroke independent of stroke severity, characteristics, and complications with the age-outcome association exhibiting a nonlinear scale and extending to young stroke patients.

Basilar artery dissection: series of 12 consecutive cases and review of the literature.

BACKGROUND: Current knowledge on primary or isolated basilar artery dissection (IBAD) is limited to case vignettes and small patient series. OBJECTIVE: To delineate the frequency and clinical presentations of IBAD along with short-term outcome, specific prognosis and targeted management. METHODS: Data were derived from a series of 12 consecutive patients and a review of 88 cases reported in the literature. In all the cases, the dissection was confined to the basilar artery. RESULTS: Disease incidence was estimated at 0.25 per 100,000 person-years. IBAD accounted for roughly 1.0% of all subarachnoid hemorrhage events and for no less than 10.5 and 4.5% of posterior circulation and brain-supplying artery dissections, respectively. The main clinical presentations were subarachnoid hemorrhage (46%) and posterior circulation brain ischemia (42%). Subarachnoid hemorrhage typically manifested at a higher age than brain ischemia (mean age, 48.9 vs. 41.4 years) and was more prevalent among women. Rebleedings related to pseudoaneurysm formation in patients with subarachnoid hemorrhage and recurrent ischemia in stroke patients were common in the acute phase (26.1 and 33.3%, respectively) but were rare in the long term. The outcome was generally favorable in stroke patients but variable in subarachnoid hemorrhage (case fatality rate, 21.7%). The mainstay of therapy for subarachnoid hemorrhage related to IBAD was endovascular occlusion of the aneurysm pouch whereas stroke patients were usually put on anticoagulants. CONCLUSIONS: IBAD is probably an underrecognized disease with heterogeneous clinical presentation and prognosis. It should be considered as a differential diagnosis in peritruncal subarachnoid hemorrhage, classic subarachnoid hemorrhage and posterior circulation stroke, especially in young individuals. Case management is challenging and has to be tailored to each patient.

Comparison of (68)Ga-DOTA-Tyr(3)-octreotide and (18)F-fluoro-L-dihydroxyphenylalanine positron emission tomography in neuroendocrine tumor patients.

AIM: (68)Ga-DOTA-Tyr3-octreotide positron emission tomography ((68)Ga-DOTA-TOC PET) and (18)F-fluoro-L-dihydroxyphenylalanine PET ((18)F-DOPA PET) are emerging modalities for imaging of neuroendocrine tumors. This study reports our initial experiences with these two PET modalities on initial diagnosis, staging and restaging in NET patients. METHODS: Fifteen patients with NET underwent both (68)Ga-DOTA-TOC and (18)F-DOPA PET as well as computed tomography (CT). Image findings were compared on a patient-basis (pathological uptake: yes/no) as well as on a lesion-basis. Contrast-enhanced CT and histological follow-up served as gold standard. Furthermore, imaging results were matched with tumor marker levels and quantitative tracer uptake by the tumor lesions. RESULTS: When comparing (68)Ga-DOTA-TOC and (18)F-DOPA PET, each modality showed a sensitivity of 64% and a specificity of 100% on a patient-based analysis. (68)Ga-DOTA-TOC PET and (18)F-DOPA PET showed equal findings in 7 out of 15 patients and disagreement in 8 patients. (68)Ga-DOTA-TOC revealed more metastases than (18)F-DOPA PET in 6 patients, while (18)F-DOPA PET detected more metastases than (68)Ga-DOTA-TOC in 4 patients. By (68)Ga-DOTA-TOC PET, 208 malignant lesions were detected, while by (18)F-DOPA only 86 lesions were found, and in CT 124, respectively. CONCLUSIONS: (68)Ga-DOTA-TOC and (18)F-DOPA PET are useful tools in the detection and staging of NET lesions. Our initial results allow the conclusion that (68)Ga-DOTA-TOC PET may have a stronger clinical impact in NET patients, as it does not only offer diagnostic information, but is decisive for the further treatment management, i. e. PRRT, as well.

Early clinical worsening in patients with TIA or minor stroke: the Austrian Stroke Unit Registry.

OBJECTIVE: TIA is associated with a substantial short-term risk of stroke and is thus increasingly recognized as an unstable condition necessitating full medical attention. Our study sought to assess the rate of and predictors for early deterioration after TIA or minor stroke in a large nationwide survey among Austrian stroke units. METHODS: Of the 29,287 patients prospectively enrolled in the Austrian Stroke Unit Registry (2003-2008), 8,291 presenting with a TIA or minor ischemic stroke, defined by an NIH Stroke Scale (NIHSS) score <4, were included in the current evaluation. Worsening was defined as clinical deterioration during stroke unit stay by > or = 2 points on the NIHSS. RESULTS: A total of 374 patients (4.5%) experienced early clinical worsening during a mean stroke unit stay of 2.97 days (median 2 [interquartile range,1-4] days). In a multivariate stepwise regression analysis hypertension, diabetes, cardiac decompensation, acute infection, and stroke etiology emerged as independent risk predictors for early deterioration. The ABCD2 score could be estimated in a subgroup of 3,886 subjects and closely correlated with the risk of neurologic worsening. CONCLUSIONS: Our study revealed a high rate of early clinical deterioration (4.5%) among 8,291 patients with TIA or minor stroke despite immediate admission to specialized stroke units. Predictors for neurologic deterioration apart from diabetes, hypertension, and the estimated ABCD2 score were stroke etiology, reinforcing the relevance of an immediate diagnostic workup, and coexistent acute infection and cardiac decompensation, both conditions necessitating adequate attention in the emergency setting.

Burden of atherosclerosis and risk of venous thromboembolism in patients with migraine.

BACKGROUND: Previous studies have yielded evidence of an enhanced risk of cardiovascular disease, especially stroke, among patients with migraine. Our understanding of the underlying mechanisms is far from complete. The aims of the present study were to investigate the potential association between migraine and atherosclerosis and to assess the risk of venous thromboembolism as a clinical surrogate for a procoagulant state in patients with migraine. METHODS: The examination was part of the population-based Bruneck Study. During the 2005 evaluation, 574 participants aged 55-94 years underwent neurologic and laboratory examinations involving a standardized headache interview and scanning of the carotid and femoral arteries to evaluate presence, severity, and progression (2000-2005) of atherosclerosis. RESULTS: A large number of well-founded and putative cardiovascular risk factors have emerged as being unrelated to migraine status. Prevalence, severity, and 5-year progression of carotid and femoral atherosclerosis did not differ significantly between migraineurs with and without aura and nonmigraineurs. In fact, there was even a tendency for atherosclerosis to be less pronounced among patients with migraine, and for the intima-media thickness to be lower (p = 0.029). As a novel finding migraineurs faced a significantly enhanced risk of venous thromboembolism (18.9% vs 7.6% in nonmigraineurs, age/sex-adjusted p = 0.031). CONCLUSION: This study is the first to compare the burden of atherosclerosis as quantified by high-resolution duplex ultrasound between migraineurs and nonmigraineurs in the general community, and provides solid evidence against the view that migraine predisposes to atherosclerosis. The higher risk for venous thromboembolism among migraineurs (prothrombotic state) awaits confirmation and elaboration in future research.

Recanalization after thrombolysis in stroke patients: predictors and prognostic implications.

OBJECTIVE: To estimate rates, predictors, and prognostic importance of recanalization in an unselected series of patients with stroke treated with IV thrombolysis. METHODS: We performed a CT angiography or transcranial Doppler (TCD) follow-up examination 24 hours after IV thrombolysis in 64 patients with documented occlusion of the intracranial internal carotid or middle cerebral artery (MCA). Complete recanalization was defined by a rating of 3 on the Thrombolysis in Myocardial Infarction or 4/5 on the Thrombolysis in Brain Ischemia grading scales. Information about risk factors, clinical features, and outcome was prospectively collected by standardized procedures. RESULTS: Complete recanalization was achieved in 36 of the 64 patients (56.3%). There was a nonsignificant trend of recanalization rates to decline with a more proximal site of occlusion: 68.4% (M2 segment of MCA), 53.1% (M1 segment), and 46.2% (carotid T) (p for trend = 0.28). Frequencies of vessel reopening were markedly reduced in subjects with diabetes (9.1% vs 66.0% in nondiabetics, p < 0.001) and less so in subjects with additional extracranial carotid occlusion (p = 0.03). Finally, complete recanalization predicted a favorable stroke outcome at day 90 independently of the information provided by age, NIH Stroke Scale, and onset-to-needle time. CONCLUSIONS: We found a high rate of vessel recanalization after IV thrombolysis occlusion. However, recanalization was infrequent in patients with diabetes and extracranial carotid occlusion. Information on recanalization was a powerful, early predictor for clinical outcome.

T-cell reactivity against HSP60 relates to early but not advanced atherosclerosis.

BACKGROUND: Anti-heat-shock protein 60 (HSP60) antibody-levels have been linked to carotid atherosclerosis and cardiovascular risk in a variety of studies. The potential role of cellular immune reactions against HSP60 has so far attracted little attention in epidemiological research. METHODS AND RESULTS: In vitro T-cell reactivity to various HSP60s and tuberculin was assessed in blood samples from a elderly subpopulation of the Bruneck study (100 men, 50-69 years) and the young participants of the ARMY study (141 men, 17-18 years), and analyzed for a potential association with common carotoid artery intima-media thickness (IMT). In vivo skin reaction against tuberculin was recorded in subjects of the Bruneck study and correlated with the in vitro proliferative response to tuberculin (P=0.004). T-cells isolated from peripheral blood of all individuals proliferated upon stimulation with HSP60s. In multivariate linear regression analysis adjusted for standard risk factors, T-cell stimulation was significantly related to IMT in the ARMY (P=0.005 for human HSP60 and P=0.064 for mycobacterial HSP60) but not in the Bruneck study. CONCLUSIONS: T-cell reactivity against HSP60s correlated with IMT in male youngsters but not in men aged 50 and over, indicating a more prominent role of specific cellular immunity to HSP60s in the young and very early stages of atherosclerosis.

Anti-HSP60 immunity is already associated with atherosclerosis early in life.

In this review, we first briefly introduce the reader to our autoimmune hypothesis for the development of atherosclerosis based on experimental and clinical data. This hypothesis postulates that humoral and cellular immunity against heat-shock protein 60 (HSP60), a phylogenetically highly conserved stress protein, is the mechanism that initiates atherogenesis. We then turn to our investigations of arterial specimens from children and young adults. These clearly show that mononuclear cell infiltrations of the intimal layer already occur before the emergence of clear-cut atherosclerotic lesions, a phenomenon we have termed vascular-associated lymphoid tissue (VALT). In early lesions analyzed within the framework of the Pathological Determinants of Atherosclerosis in Youth (PDAY) study, T lymphocytes proved to be a major cellular constituent. In the Bruneck Study, a large, prospective atherosclerosis-prevention study in adults aged 40 years and older, we found a highly significant correlation between serum anti-HSP60 antibody titers and the occurrence and extent of sonographically demonstrable atherosclerotic lesions. However, no such correlation emerged with respect to HSP60-reactive T cells in the peripheral blood. In contrast, the similar Atherosclerosis Risk-Factors in Male Youngsters (ARMY) study, performed on 17- to 18-year-old volunteers, showed a highly statistically significant correlation between arterial intima-media thickening and HSP60 reactivity among peripheral T cells and (less pronounced) anti-HSP60 antibodies, even at this young age. We take this as indirect evidence that both T cell and B cell immunity against HSP60 plays a major role in the earliest stages of the disease. Because VALT can already be observed in healthy children and young adults, we hypothesize that T cells initiate the disease and that humoral antibodies play a facilitating, accelerating role. Finally, we provide initial evidence that smoking, as the most important risk factor for atherogenesis, also exerts its disease-inducing and disease-promoting effects by inducing HSP60 expression by vascular endothelial cells.

CD4(+)CD8(+)TCR(low) thymocytes express low levels of glucocorticoid receptors while being sensitive to glucocorticoid-induced apoptosis.

While signaling by either the TCR or glucocorticoid receptor (GR) can induce apoptosis in thymocytes, recent studies have shown that combining these signals results in survival of CD4(+)CD8(+) thymocytes. Although glucocorticoids (GC) in this way may directly affect T cell selection, no data are available addressing GR expression in thymocyte subsets and in individual cells within subsets. We studied GR expression by combining immunofluorescence cell surface staining for CD4, CD8 and TCR with intracellular staining of GR in four-color cytometry. Significant differences of GR expression were observed in various thymocyte subsets, although a homogeneous distribution of GR expression in individual thymocyte subsets emerged. The highest GR expression was found in CD4(-)CD8(-)TCR(-) thymocytes, and decreased during development via the CD4(-)CD8(+)TCR(-) subpopulation into the CD4(+)CD8(+)TCR(low) subset. Interestingly, the latter population, although expressing less than half the GR density of CD4(-)CD8(-)TCR(-) cells, is the most sensitive subset to GC-induced apoptosis. Up-regulation of TCR expression by the CD4(+)CD8(+)TCR(low) subset to CD4(+)CD8(+)TCR(high) cells was accompanied by a parallel increase in GR expression. The latter finding and the presence of a homogeneous distribution of GR in each thymocyte subset provides an experimental basis for the concept that GR can antagonize TCR-mediated signals at a constant rate relative to TCR expression.