Unusual clinical presentation of cervical extradural meningioma detected with neuromuscular ultrasound: A case report

Extradural meningiomas are rare in the cervical region. A total of 70-77% of reported cases have occurred in the thoracic region. Tumors that occur in the cervical region may invade the adjacent nerve root and brachial plexus. Typically, diagnoses of extradural meningioma are made after patients present with signs of myelopathy, such as progressive paresis and numbness. In the current study, a 64-year-old male patient presented with neck pain, numbness and mild weakness in the left hand over a 6-month period. The general neurological examination was unremarkable, except for mild grasping weakness on the left side. Needle electromyography revealed complex repetitive discharges in the left 5 and 6th cervical paraspinal muscles. Neuromuscular ultrasound revealed a lesion over the left 7th cervical root, which enabled the early detection of an extradural meningioma before notable focal neurological defects developed. The patient underwent a subtotal tumor excision, followed by radiotherapy for residual tumor. Histopathological examination confirmed atypical meningioma.

Magnetic Resonance Images Implicate That Glymphatic Alterations Mediate Cognitive Dysfunction in Alzheimer Disease

OBJECTIVE

The glymphatic system cleans amyloid and tau proteins from the brain in animal studies of Alzheimer disease (AD). However, there is no direct evidence showing this in humans.

METHODS

Participants (n = 50, 62.6 ± 5.4 years old, 36 women) with AD and normal controls underwent amyloid positron emission tomography (PET), tau PET, structural T1-weighted magnetic resonance imaging, and neuropsychological evaluation. Whole-brain glymphatic activity was measured by diffusion tensor image analysis along the perivascular space (DTI-ALPS).

RESULTS

ALPS-indexes showed negative correlations with deposition of amyloid and tau on PET images and positive correlations with cognitive scores even after adjusting for age, sex, years of education, and APOE4 genotype covariates in multiple AD-related brain regions (all p < 0.05). Mediation analysis showed that ALPS-index acted as a significant mediator between regional standardized uptake value ratios of amyloid and tau images and cognitive dysfunction even after correcting for multiple covariates in AD-related brain regions. These regions are responsible for attention, memory, and executive function, which are vulnerable to sleep deprivation.

INTERPRETATION

Glymphatic system activity may act as a significant mediator in AD-related cognitive dysfunction even after adjusting for multiple covariates and gray matter volumes. ALPS-index may provide useful disease progression or treatment biomarkers for patients with AD as an indicator of modulation of glymphatic activity. ANN NEUROL 2023;93:164-174.

Association of Sleep, Neuropsychological Performance, and Gray Matter Volume With Glymphatic Function in Community-Dwelling Older Adults

BACKGROUND AND OBJECTIVES

The glymphatic system, which is robustly enabled during some stages of sleep, is a fluid-transport pathway that clears cerebral waste products. Most contemporary knowledge regarding the glymphatic system is inferred from rodent experiments and human research is limited. Our objective is to explore the associations between human glymphatic function, sleep, neuropsychological performance, and cerebral gray matter volumes.

METHODS

This cross-sectional study included individuals 60 years or older who had participated in the Integrating Systemic Data of Geriatric Medicine to Explore the Solution for Health Aging study between September 2019 and October 2020. Community-dwelling older adults were enrolled at 2 different sites. Participants with dementia, major depressive disorders, and other major organ system abnormalities were excluded. Sleep profile was accessed using questionnaires and polysomnography. Administered neuropsychological test batteries included Everyday Cognition (ECog) and the Consortium to Establish a Registry for Alzheimer's Disease Neuropsychological Battery (CERAD-NB). Gray matter volumes were estimated based on MRI. Diffusion tensor imaging analysis along the perivascular space (DTI-ALPS) index was used as the MRI marker of glymphatic function.

RESULTS

A total of 84 participants (mean [SD] age 73.3 [7.1] years, 47 [56.0%] women) were analyzed. Multivariate linear regression model determined that age (unstandardized β, -0.0025 [SE 0.0001]; p = 0.02), N2 sleep duration (unstandardized β, 0.0002 [SE 0.0001]; p = 0.04), and the apnea-hypopnea index (unstandardized β, -0.0011 [SE 0.0005]; p = 0.03) were independently associated with DTI-ALPS. Higher DTI-ALPS was associated with better ECog language scores (unstandardized β, -0.59 [SE 0.28]; p = 0.04) and better CERAD-NB word list learning delayed recall subtest scores (unstandardized β, 6.17 [SE 2.31]; p = 0.009) after covarying for age and education. Higher DTI-ALPS was also associated with higher gray matter volume (unstandardized β, 107.00 [SE 43.65]; p = 0.02) after controlling for age, sex, and total intracranial volume.

DISCUSSION

Significant associations were identified between glymphatic function and sleep, stressing the importance of sleep for brain health. This study also revealed associations between DTI-ALPS, neuropsychological performance, and cerebral gray matter volumes, suggesting the potential of DTI-ALPS as a biomarker for cognitive disorders.

Glymphatic Dysfunction in Patients With Ischemic Stroke

Objectives: Rodent experiments have provided some insight into the changes of glymphatic function in ischemic stroke. The diffusion tensor image analysis along the perivascular space (DTI-ALPS) method offers an opportunity for the noninvasive investigation of the glymphatic system in patients with ischemic stroke. We aimed to investigate the changes of glymphatic function in ischemic stroke and the factors associated with the changes. Materials and Methods: A total of 50 patients (mean age 56.7 years; 30 men) and 44 normal subjects (mean age 53.3 years; 23 men) who had preoperative diffusion-tensor imaging for calculation of the analysis along the perivascular space (ALPS) index were retrospectively included. Information collected from each patient included sex, age, time since stroke onset, infarct location, hemorrhagic change, infarct volume, infarct apparent diffusion coefficient (ADC), infarct fractional anisotropy (FA), and ALPS index of both hemispheres. Interhemispheric differences in ALPS index (infarct side vs. contralateral normal side) were assessed with a paired t-test in all patients. ALPS index was normalized by calculating ALPS ratios (right-to-left and left-to-right) for comparisons between patients and normal subjects. Comparisons of ALPS ratios between patients and normal subjects were performed using analysis of covariance with adjustments for age and sex. Linear regression analyses were performed to identify factors associated with the ALPS index. Results: In patients, the mean ALPS index ipsilateral to infarct was 1.162 ± 0.126, significantly lower (P < 0.001) than that of the contralateral side (1.335 ± 0.160). The right-to-left ALPS index ratio of patients with right cerebral infarct was 0.84 ± 0.08, significantly lower (P < 0.001) than that of normal subjects (0.95 ± 0.07). The left-to-right ALPS ratio of patients with left cerebral infarct was 0.92 ± 0.09, significantly (P < 0.001) lower than that of normal subjects (1.05 ± 0.08). On multiple linear regression analysis, time since stroke onset (β = 0.794, P < 0.001) was the only factor associated with the ALPS index. Conclusion: The ALPS index showed lower values in ischemic stroke suggesting impaired glymphatic function. Following initial impairment, the ALPS index increased with the time since stroke onset, which is suggestive of glymphatic function recovery.

Spectrum of neuroimaging mimics in children with COVID-19 infection

Coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2, has affected over 200 million people globally (including over 30 million people in the United States), with children comprising 12.9% of reported cases in the United States. In children, COVID-19 infection appears to be associated with mild respiratory symptoms; however, serious neurological complications may occur in conjunction with multisystem inflammatory syndrome. A wide spectrum of neurological diseases have been observed in children with COVID-19 infection including encephalitis, acute necrotizing encephalopathy, acute disseminated encephalomyelitis, cytotoxic lesion of the callosal splenium, posterior reversible encephalopathy syndrome, venous sinus thrombosis, vasculitis and infarction, Guillain-Barré syndrome, transverse myelitis, and myositis. This review describes the characteristic magnetic resonance neuroimaging features of these diseases and their differentiations from other imaging mimics. In addition, we review the possible pathophysiology underlying the association between these diseases and COVID-19-infection. As new SARS-CoV-2 variants emerge and COVID-19 infection continues to spread worldwide, pediatricians, radiologists, and first-line care givers should be aware of possible neurological diseases associated with COVID-19 infection when these reported neuroimaging patterns are observed in children during this pandemic.

Peritumoral Brain Edema in Metastases May Be Related to Glymphatic Dysfunction

Objectives

The proliferation of microvessels with increased permeability is thought to be the cause of peritumoral brain edema (PTBE) in metastases. The contribution of the glymphatic system to the formation of PTBE in brain metastases remains unexplored. We aimed to investigate if the PTBE volume of brain metastases is related to glymphatic dysfunction.

Materials and Methods

A total of 56 patients with brain metastases who had preoperative dynamic susceptibility contrast-enhanced perfusion-weighted imaging for calculation of tumor cerebral blood volume (CBV) and diffusion tensor imaging for calculations of tumor apparent diffusion coefficient (ADC), tumor fractional anisotropy (FA), and analysis along perivascular space (ALPS) index were analyzed. The volumes of PTBE, whole tumor, enhancing tumor, and necrotic and hemorrhagic portions were manually measured. Additional information collected for each patient included age, sex, primary cancer, metastasis location and number, and the presence of concurrent infratentorial tumors. Linear regression analyses were performed to identify factors associated with PTBE volume.

Results

Among 56 patients, 45 had solitary metastasis, 24 had right cerebral metastasis, 21 had left cerebral metastasis, 11 had bilateral cerebral metastases, and 11 had concurrent infratentorial metastases. On univariable linear regression analysis, PTBE volume correlated with whole tumor volume (β = -0.348, P = 0.009), hemorrhagic portion volume (β = -0.327, P = 0.014), tumor ADC (β = 0.530, P <.001), and ALPS index (β = -0.750, P <.001). The associations of PTBE volume with age, sex, tumor location, number of tumors, concurrent infratentorial tumor, enhancing tumor volume, necrotic portion volume, tumor FA, and tumor CBV were not significant. On multivariable linear regression analysis, tumor ADC (β = 0.303; P = 0.004) and ALPS index (β = -0.624; P < 0.001) were the two independent factors associated with PTBE volume.

Conclusion

Metastases with higher tumor ADC and lower ALPS index were associated with larger peritumoral brain edema volumes. The higher tumor ADC may be related to increased periarterial water influx into the tumor interstitium, while the lower ALPS index may indicate insufficient fluid clearance. The changes in both tumor ADC and ALPS index may imply glymphatic dysfunction, which is, at least, partially responsible for peritumoral brain edema formation.

Prediction of Malignant Transformation of WHO II Astrocytoma Using Mathematical Models Incorporating Apparent Diffusion Coefficient and Contrast Enhancement

Using only increasing contrast enhancement as a marker of malignant transformation (MT) in gliomas has low specificity and may affect interpretation of clinical outcomes. Therefore we developed a mathematical model to predict MT of low-grade gliomas (LGGs) by considering areas of reduced apparent diffusion coefficient (ADC) with increased contrast enhancement. Patients with contrast-enhancing LGGs who had contemporaneous ADC and histopathology were retrospectively analyzed. Multiple clinical factors and imaging factors (contrast-enhancement size, whole-tumor size, and ADC) were assessed for association with MT. Patients were split into training and validation groups for the development of a predictive model using logistic regression which was assessed with receiver operating characteristic analysis. Among 132 patients, (median age 46.5 years), 106 patients (64 MT) were assigned to the training group and 26 (20 MT) to the validation group. The predictive model comprised age (P = 0.110), radiotherapy (P = 0.168), contrast-enhancement size (P = 0.015), and ADC (P < 0.001). The predictive model (area-under-the-curve [AUC] 0.87) outperformed ADC (AUC 0.85) and contrast-enhancement size (AUC 0.67). The model had an accuracy of 84% for the training group and 85% respectively for the validation group. Our model incorporating ADC and contrast-enhancement size predicted MT in contrast-enhancing LGGs.

Factors Associated With Dysfunction of Glymphatic System in Patients With Glioma

Objectives

Rodent experiments have provided some insights into the changes of glymphatic function associated with glioma growth. The diffusion tensor image analysis along the perivascular space (DTI-ALPS) method offers an opportunity for the noninvasive investigation of the glymphatic system in patients with glioma. We aimed to investigate the factors associated with glymphatic function changes in patients with glioma.

Materials and Methods

A total of 201 glioma patients (mean age = 47.4 years, 116 men; 86 grade II, 52 grade III, and 63 grade IV) who had preoperative diffusion tensor imaging for calculation of the ALPS index were retrospectively included. Information collected from each patient included sex, age, tumor grade, isocitrate dehydrogenase 1 (IDH1) mutation status, peritumoral brain edema volume, tumor volume, and ALPS index. Group differences in the ALPS index according to sex, tumor grade, and IDH1 mutation status were assessed using analysis of covariance with age adjustment. Linear regression analyses were performed to identify the factors associated with the ALPS index.

Results

Group comparisons revealed that the ALPS index of grade II/III gliomas was significantly higher than that of grade IV gliomas (p < 0.001). The ALPS index of IDH1 mutant gliomas was significantly higher than that of IDH1 wild-type gliomas (p < 0.001). On multivariable linear regression analysis, IDH1 mutation (β = 0.308, p < 0.001) and peritumoral brain edema volume (β = −0.353, p < 0.001) were the two independent factors associated with the ALPS index.

Conclusion

IDH1 wild-type gliomas and gliomas with larger peritumoral brain edema volumes were associated with a lower ALPS index, which may reflect impaired glymphatic function.

Peritumoral Brain Edema in Meningiomas May Be Related to Glymphatic Dysfunction

The pathogenesis of peritumoral brain edema (PTBE) in meningiomas remains unclear. The glymphatic system is recently recognized as a pathway for waste clearance and maintaining fluid balance in the brain parenchymal interstitium. We aimed to investigate if the PTBE volume of meningiomas correlates with their glymphatic function. A total of 80 meningioma patients (mean age, 58.8 years; 37 men) and 44 normal subjects (mean age 53.3 years; 23 men) who had preoperative diffusion-tensor imaging for calculation of the analysis along the perivascular space (ALPS) index were retrospectively included. Information collected from each patient included sex, age, tumor grade, Ki-67 index, tumor location, tumor volume, PTBE volume and ALPS index. Comparisons of ALPS index among meningiomas without PTBE, meningiomas with PTBE, and normal subjects were performed using analysis of covariance with Bonferroni correction and adjustments for age and sex. Pearson correlation coefficient and multivariable linear regression analyses were performed to identify factors associated with PTBE volume. Group comparisons revealed that the ALPS index was significantly higher (P < 0.05) in meningiomas without PTBE vs. meningiomas with PTBE and normal subjects. On the other hand, ALPS index was not different between meningiomas with PTBE and normal subjects. On Pearson correlation and multivariable linear regression analyses, the ALPS index was the only factor significantly (P < 0.05) associated with PTBE volume. In conclusion, PTBE volume inversely correlated with ALPS index in meningiomas. PTBE formation in meningiomas may be related to glymphatic dysfunction.

Greater white matter hyperintensities and the association with executive function in suicide attempters with late-life depression

Late-life depression (LLD) is associated with greater risk of suicide and white matter hyperintensities (WMH), which are also found in suicide attempters regardless of age. Greater periventricular WMH are related to worse cognitive function. We investigated the spatial distribution of WMH in suicide attempters with LLD and its association with cognitive function. We recruited 114 participants with LLD (34 with history of suicide attempt and 80 without) and 47 older adult controls (individuals without LLD or history of suicide attempt). WMH were quantified by an automated segmentation algorithm and were classified into different regions. Suicide attempters with LLD had significantly higher global WMH (F3, 150 = 2.856, p = 0.039) and periventricular WMH (F3, 150 = 3.635, p = 0.014) compared to other groups. Suicide attempters with high WMH had significantly lower executive function, which could be an underlying mechanism for cognitive decline in older adults with suicidality.

Brain Abscess Apparent Diffusion Coefficient is Associated With Microbial Culture Yields

BACKGROUND

Obtaining pus for microbial cultures is one of the surgical aims in patients with brain abscess. Predictors of microbial yields are necessary as they help in treatment planning.

PURPOSE

To investigate the relationship between microbial culture yields of brain abscesses and their apparent diffusion coefficient (ADC) values and clinical characteristics.

STUDY TYPE

Retrospective.

SUBJECTS

Eighty-four patients diagnosed with brain abscess by surgery and histopathology (59 with positive abscess cultures).

FIELD STRENGTH/SEQUENCE

Diffusion-weighted, T2-weigthed, and contrast-enhanced T1-weighted imaging at 1.5 T and 3 T.

ASSESSMENT

Contrast-enhanced T1-weighted images were co-registered to ADC maps. Three neuroradiologists determined abscess imaging characteristics (distribution, location, and ventricular rupture), and two measured abscess volumes and ADC values. Clinical characteristics collected included sex, age, fever, underlying diseases, infection sources, white blood cell count, percentage of segmented neutrophils, C-reactive protein level, regimen and duration of empirical antibiotics, and types of surgery.

STATISTICAL TESTS

Interobserver differences were assessed with Fleiss kappa and intraclass correlation coefficients. The differences in clinical and imaging factors between the positive and negative culture groups were compared with Chi-square analysis or Student's t test. All factors were subjected to multivariable logistic regression analysis to assess their associations with microbial culture yields, and factors with statistical significance were evaluated with receiver operating characteristic curve analysis to assess their diagnostic performance in discriminating the two groups.

RESULTS

Mean ADC (×10^-6  mm² /s) of culture-negative abscesses (841 ± 173) was significantly higher (P < 0.05) than that of culture-positive abscesses (536 ± 90). On multivariable analysis, mean ADC was the only significant factor (P < 0.05) related to culture yields. With 660 as the cutoff value, the sensitivity, specificity, and accuracy of ADC for discriminating culture yields were 93.2%, 88.0%, and 91.7%, respectively.

DATA CONCLUSION

ADC could be used to discriminate between culture-positive and culture-negative abscesses.

EVIDENCE LEVEL

4 TECHNICAL EFFICACY: Stage 2.

Peritumoral brain edema volume in meningioma correlates with tumor fractional anisotropy but not apparent diffusion coefficient or cerebral blood volume

PURPOSE

Pathogenesis of peritumoral brain edema (PTBE) in meningiomas remains unclear. Associations between PTBE volume and diffusion or perfusion properties of meningioma have not been studied. We aimed to investigate if diffusion and perfusion properties of meningioma correlate with its PTBE volume.

METHODS

Seventy consecutive patients (mean age, 58.9 ± 13.7 years; 37 women) with meningiomas who had preoperative DTI and DSC-PWI were retrospectively analyzed. PTBE volume, tumor volume, and mean T2 signal, ADC, FA, and CBV of the tumor were measured. Between meningiomas with and without PTBE, patient age and sex, as well as T2 signal intensity, volume, ADC, FA, and CBV of tumors, were compared. In meningiomas with PTBE, correlations of PTBE volume with patient age and sex, as well as T2 signal intensity, volume, ADC, FA, and CBV of tumors, were analyzed. Multivariable linear regression analysis was performed to identify factors associated with PTBE volume.

RESULTS

On univariable analysis, meningiomas without PTBE were more frequently found in women (P = 0.033) and demonstrated lower ADC (P = 0.020), higher FA (P < 0.001), and lower CBV (P < 0.001). PTBE volume of meningiomas correlated with tumor ADC (r = 0.444; P = 0.001), tumor FA (r = - 0.655; P < 0.001), and tumor CBV (r = 0.402; P = 0.003). On multivariable analysis, tumor FA was the only factor associated with PTBE volume (P < 0.001).

CONCLUSION

PTBE volume in meningioma correlates with tumor FA. DTI may help to understand the mechanism of PTBE in meningiomas.

MRS as an Aid to Diagnose Malignant Transformation in Low-Grade Gliomas with Increasing Contrast Enhancement

BACKGROUND AND PURPOSE

Increased contrast enhancement has been used as a marker of malignant transformation in low-grade gliomas. This marker has been found to have limited accuracy because many low-grade gliomas with increased contrast enhancement remain grade II. We aimed to investigate whether MR spectroscopy can contribute to the diagnosis of malignant transformation in low-grade gliomas with increased contrast enhancement.

MATERIALS AND METHODS

Patients with low-grade gliomas who had contemporaneous MR spectroscopy and histopathology for tumor regions with increased contrast enhancement between 2004 and 2015 were retrospectively reviewed. Clinical data collected were sex and age, Karnofsky Performance Scale, histologic subtypes, isocitrate dehydrogenase 1 mutation status, disease duration, adjuvant therapy, and post-radiation therapy duration. Imaging data collected were contrast-enhancement size, whole-tumor size, MR spectroscopy metabolite ratios, and tumor grades of regions with increased contrast enhancement. Diagnostic values of these factors on malignant transformation of low-grade gliomas were statistically analyzed.

RESULTS

A total of 86 patients with 96 MR spectroscopy studies were included. Tumor grades associated with increased contrast enhancement were grade II (n = 42), grade III (n = 27), and grade IV (n = 27). On multivariate analysis, the NAA/Cho ratio was the only significant factor (P < .001; OR, 7.1; 95% CI, 3.2-16.1) diagnostic of malignant transformation. With 0.222 as the cutoff value, the sensitivity, specificity, and accuracy of NAA/Cho for diagnosing malignant transformation were 94.4%, 83.3%, and 89.6%, respectively.

CONCLUSIONS

MR spectroscopy complements conventional MR imaging in the diagnosis of malignant transformation in a subgroup of low-grade gliomas with increased contrast enhancement.

Can we predict intraoperative blood loss in meningioma patients? Application of dynamic susceptibility contrast-enhanced magnetic resonance imaging

PURPOSE

To evaluate the potential of quantitative dynamic susceptibility contrast (DSC) perfusion MR imaging parameters as imaging biomarkers for predicting intraoperative blood loss in meningioma.

METHODS

Fifty-one non-embolized meningioma patients who had undergone preoperative DSC perfusion MR imaging were retrospectively included. The corrected relative cerebral blood volume (rCBV) and leakage coefficient (K₂) of the entire enhanced tumor were obtained using leakage correction. Tumor volume, location, grade, and other clinical variables, were also analyzed. To investigate the vascularity and vascular permeability of meningiomas, and their correlation with predicting estimated blood loss (EBL) using preoperative DSC perfusion MR imaging, the authors proposed an index reflecting the inherent tendency of meningiomas to bleed after controlling volume (i.e., EBL/cm³). Simple regression was performed to identify predictors of EBL/cm³; subsequently, the relevant variables included in the stepwise multiple linear regression.

RESULTS

On univariate analysis, EBL/cm³ was correlated with rCBV (r=0.677; P<0.001), K₂ (r=0.294; P=0.036), and tumor volume (r=-0.312, P=0.026). EBL/cm³ was not correlated with age (P=0.873), sex (P=0.404), tumor location (P=0.327), or histological grade (P=0.230). On multiple linear regression, rCBV (β=0.663 [0.463-0.864], B=1.293 [0.903-1.684; P<0.001) and K₂ (β=0.260 [0.060-0.460], B=2.277 [0.523-4.031], P=0.012), were the only independent predictors of EBL/cm³.

CONCLUSION

The rCBV and K₂ derived from DSC perfusion MR imaging in meningiomas may serve as feasible tools for clinicians to predict intraoperative blood loss and facilitate surgical planning.

Activation of Protein C and Its Distribution between Its Inhibitors, Protein C Inhibitor, α1-Antitrypsin and α2-Macroglobulin, in Patients with Disseminated intravascular Coagulation

Activation and inactivation of protein C during the clinical course of disseminated intravascular coagulation (DIC) was studied in three patients by qualitative (Western blotting) and quantitative (ELISA) analysis and the intensity of procoagulant activity monitored by the measurement of thrombin and factor Xa antithrombin III complexes. In one patient, inhibitor complexes of APC with protein C inhibitor (PCI) and α1-antitrypsin (α1-AT) were observed and the latter predominated at presentation. Both disappeared during the development of remission but the loss of α1-AT complexes preceded PCI complexes which on Western blotting appeared to increase in intensity prior to disappearance. The two other patients bled to death from uncontrollable haemorrhage. In both cases, APC/inhibitor complexes with α2-macroglobulin (α2-M) in addition to PCI and αr-AT were detected and persisted until death. Although PCI appeared to be the primary inhibitor in all three cases, α1-antitrypsin and particularly α2-macroglobulin appeared to assume greater roles in the two fatal cases. These data are similar to previous findings in an experimental animal model of DIC that suggested that α2-macroglobulin and α1-antitrypsin become more important inhibitors of APC as the primary inhibitor PCI is consumed in the face of a sustained procoagulant challenge.

Accuracy of circulating histones in predicting persistent organ failure and mortality in patients with acute pancreatitis

BACKGROUND

Early prediction of acute pancreatitis severity remains a challenge. Circulating levels of histones are raised early in mouse models and correlate with disease severity. It was hypothesized that circulating histones predict persistent organ failure in patients with acute pancreatitis.

METHODS

Consecutive patients with acute pancreatitis fulfilling inclusion criteria admitted to Royal Liverpool University Hospital were enrolled prospectively between June 2010 and March 2014. Blood samples were obtained within 48 h of abdominal pain onset and relevant clinical data during the hospital stay were collected. Healthy volunteers were enrolled as controls. The primary endpoint was occurrence of persistent organ failure. The predictive values of circulating histones, clinical scores and other biomarkers were determined.

RESULTS

Among 236 patients with acute pancreatitis, there were 156 (66·1 per cent), 57 (24·2 per cent) and 23 (9·7 per cent) with mild, moderate and severe disease respectively, according to the revised Atlanta classification. Forty-seven healthy volunteers were included. The area under the receiver operating characteristic (ROC) curve (AUC) for circulating histones in predicting persistent organ failure and mortality was 0·92 (95 per cent c.i. 0·85 to 0·99) and 0·96 (0·92 to 1·00) respectively; histones were at least as accurate as clinical scores or biochemical markers. For infected pancreatic necrosis and/or sepsis, the AUC was 0·78 (0·62 to 0·94). Histones did not predict or correlate with local pancreatic complications, but correlated negatively with leucocyte cell viability (r = -0·511, P = 0·001).

CONCLUSION

Quantitative assessment of circulating histones in plasma within 48 h of abdominal pain onset can predict persistent organ failure and mortality in patients with acute pancreatitis. Early death of immune cells may contribute to raised circulating histone levels in acute pancreatitis.

Early-Stage Glioblastomas: MR Imaging-Based Classification and Imaging Evidence of Progressive Growth

BACKGROUND AND PURPOSE

The serial imaging changes describing the growth of glioblastomas from small to large tumors are seldom reported. Our aim was to classify the imaging patterns of early-stage glioblastomas and to define the order of appearance of different imaging patterns that occur during the growth of small glioblastomas.

MATERIALS AND METHODS

Medical records and preoperative MR imaging studies of patients diagnosed with glioblastoma between 2006 and 2013 were reviewed. Patients were included if their MR imaging studies showed early-stage glioblastomas, defined as small MR imaging lesions detected early in the course of the disease, demonstrating abnormal signal intensity but the absence of classic imaging findings of glioblastoma. Each lesion was reviewed by 2 neuroradiologists independently for location, signal intensity, involvement of GM and/or WM, and contrast-enhancement pattern on MR imaging.

RESULTS

Twenty-six patients with 31 preoperative MR imaging studies met the inclusion criteria. Early-stage glioblastomas were classified into 3 types and were all hyperintense on FLAIR/T2-weighted images. Type I lesions predominantly involved cortical GM (n = 3). Type II (n = 12) and III (n = 16) lesions involved both cortical GM and subcortical WM. Focal contrast enhancement was present only in type III lesions at the gray-white junction. Interobserver agreement was excellent (κ = 0.95; P < .001) for lesion-type classification. Transformations of lesions from type I to type II and type II to type III were observed on follow-up MR imaging studies. The early-stage glioblastomas of 16 patients were pathologically confirmed after imaging progression to classic glioblastoma.

CONCLUSIONS

Cortical lesions may be the earliest MR imaging-detectable abnormality in some human glioblastomas. These cortical tumors may progress to involve WM.

Assessment of angiographic vascularity of meningiomas with dynamic susceptibility contrast-enhanced perfusion-weighted imaging and diffusion tensor imaging

BACKGROUND AND PURPOSE

The roles of DTI and dynamic susceptibility contrast-enhanced-PWI in predicting the angiographic vascularity of meningiomas have not been studied. We aimed to investigate if these 2 techniques could reflect the angiographic vascularity of meningiomas.

MATERIALS AND METHODS

Thirty-two consecutive patients with meningiomas who had preoperative dynamic susceptibility contrast-enhanced-PWI, DTI, and conventional angiography were retrospectively included. The correlations between angiographic vascularity of meningiomas, classified with a 4-point grading scale, and the clinical or imaging variables-age and sex of patient, as well as size, CBV, fractional anisotropy, and ADC of meningiomas-were analyzed. The meningiomas were dichotomized into high-vascularity and low-vascularity groups. The differences in clinical and imaging variables between the 2 groups were compared. Receiver operating characteristic curve analysis was used to determine the diagnostic performance of these variables.

RESULTS

In meningiomas, angiographic vascularity correlated positively with CBV but negatively with fractional anisotropy. High-vascularity meningiomas demonstrated significantly higher CBV but lower fractional anisotropy as compared with low-vascularity meningiomas. In differentiating between the 2 groups, the area under the curve values were 0.991 for CBV and 0.934 for fractional anisotropy on receiver operating characteristic curve analysis.

CONCLUSIONS

CBV and fractional anisotropy correlate well with angiographic vascularity of meningiomas. They may differentiate between low-vascularity and high-vascularity meningiomas.

Differentiation of primary central nervous system lymphomas and glioblastomas: comparisons of diagnostic performance of dynamic susceptibility contrast-enhanced perfusion MR imaging without and with contrast-leakage correction

BACKGROUND AND PURPOSE

Contrast leakage results in underestimation of the CBV of brain tumors. Our aim was to compare the diagnostic performance of DSC perfusion MR imaging without and with mathematic contrast-leakage correction in differentiating PCNSLs and glioblastomas.

MATERIALS AND METHODS

Perfusion parameters-CBV, corrected CBV, and leakage coefficient-were measured in enhancing tumor portions and contralateral NAWM of 15 PCNSLs and 20 glioblastomas, respectively. The ratios of CBV and corrected CBV were calculated by dividing the tumor values by those obtained from contralateral NAWM. A paired t test was used to compare tumor K2 and NAWM K2, as well as tumor CBV ratios without and with leakage correction. Comparisons of CBV, corrected CBV, and K2 between PCNSLs and glioblastomas were done by using a 2-sample t test. The diagnostic performance of DSC perfusion MR imaging without and with contrast-leakage correction was assessed with receiver operating characteristic curve analysis.

RESULTS

PCNSLs and glioblastomas demonstrated higher K2 than those in their contralateral NAWM. Corrected CBV ratios were significantly higher than the uncorrected ones for both tumors. PCNSLs had lower CBV ratios (P < .001), lower corrected CBV ratios (P < .001), and higher K2 (P = .001) compared with glioblastomas. In differentiating between PCNSLs and glioblastomas, the area under the curve of the CBV ratio, corrected CBV ratio, and K2 were 0.984, 0.940, and 0.788, respectively.

CONCLUSIONS

PCNSL can be differentiated from glioblastoma with CBV ratios, corrected CBV ratios, and K2. CBV without contrast-leakage correction seems to have the best diagnostic performance in differentiating the 2 tumors.

Intraventricular silicone oil

The authors report a case in which intravitreous silicone oil migrated into the ventricles. They note that intraventricular silicone oil can be misdiagnosed as intraventricular hemorrhage and neurosurgeons should be aware of this possibility.

This 58-year-old woman with a history of Type II diabetic mellitus and retinal detachment (resulting from diabetic retinopathy), which had been treated with intravitreous silicone tamponade, presented with dizziness and headache approximately 10 years after the intravitreous silicone treatment. Over the next 6 years she underwent 2 non–contrast-enhanced brain CT studies and 1 MRI study for evaluation of her symptoms. On CT scan, extension of the intraocular silicone along the optic nerve was evident. Two hyperdense nodules were observed freely floating in the right lateral and fourth ventricles, remaining in the nondependent portion of ventricles in both supine and prone positions. On T2-weighted MRI, the left orbital content and the intraventricular nodules all demonstrated chemical shift artifacts typically associated with silicone. The imaging findings were characteristic for intraventricular silicone after silicone oil tamponade. The patient's dizziness and headache were treated symptomatically and she was followed up at the outpatient department.

Migration of intravitreous silicone oil into the cerebral ventricles is a rare complication. Intraventricular silicone oil can mimic intraventricular hemorrhage. Radiographically, intraventricular silicone oil can be distinguished from hemorrhage as silicone oil tends to stay in the nondependent portion of the ventricle. Chemical shift artifacts on MRI may help establishing the diagnosis of intraventricular silicone oil. Currently, there is no consensus on surgical removal of intraventricular silicone oil, and in the majority of cases reported in the literature, the patients were asymptomatic.

Kimura's disease: clinical and imaging parameters for the prediction of disease recurrence

Kimura's disease is a rare chronic inflammatory disorder with a high rate of recurrence. The clinical and imaging features of Kimura's disease have been documented in the literature, but the relationship between these features and disease recurrence is still unclear. We conclude that disease duration of greater than 5 years, bilateral involvement, a lesion diameter of greater than 3 cm, a blood eosinophil count greater than 20%, and ill-defined lesions are predictive factors for the recurrence of Kimura's disease.

Differentiation of pyogenic brain abscesses from necrotic glioblastomas with use of susceptibility-weighted imaging

BACKGROUND AND PURPOSE

A common imaging finding in brain abscess and necrotic glioblastoma is a T2 hypointense margin. The features of this hypointense rim on SWI have not been previously described, to our knowledge. We aimed to differentiate abscesses from glioblastomas by assessing the morphology of their lesion margin by using SWI.

MATERIALS AND METHODS

T2WI and SWI were performed in 12 abscesses and 20 rim-enhancing glioblastomas. On T2WI and SWI, the prevalence and the border types (complete versus incomplete) of hypointense rims were qualitatively assessed. On SWI, the contour (smooth versus irregular) and the location of hypointense rims relative to the contrast-enhancing rims as well as the prevalence of the "dual rim sign," defined as 2 concentric rims at lesion margins with the outer one being hypointense and the inner one hyperintense relative to cavity contents, were also analyzed.

RESULTS

Prevalence and the border types of the hypointense rims on T2WI were not different between abscesses and glioblastomas. On SWI, there were significantly more hypointense rims that were complete (P < .001) and smooth (P < .001), having the same location as the contrast-enhancing rims (P < .001) for abscesses. A dual rim sign was present in 9 of 12 abscesses but absent in all glioblastomas (P < .001).

CONCLUSIONS

SWI may be helpful in differentiating pyogenic abscesses from necrotic glioblastomas. The dual rim sign is the most specific imaging feature distinguishing the 2.

Differentiation of tumefactive demyelinating lesions from high-grade gliomas with the use of diffusion tensor imaging

BACKGROUND AND PURPOSE

TDLs may be indistinguishable from high-grade gliomas on conventional MR imaging. The role of DTI in differentiating TDLs from high-grade gliomas is not clear, and quantitative comparison between the 2 has not been reported. Here we aimed to differentiate TDLs from high-grade gliomas by using DTI.

MATERIALS AND METHODS

DTI was performed in 8 TDLs and 13 high-grade gliomas. The presence of 3 findings (ie, intralesional hyperintensities on the FA map, restricted diffusion in the lesion periphery, and a perilesional hyperintense FA rim) was assessed by visual inspection. The FA and MD values were measured in the central nonenhancing portion, peripheral enhancing portion, and perilesional edema for each lesion and compared between the 2 groups respectively.

RESULTS

TDLs had a significantly higher incidence of intralesional hyperintensities on FA maps (P = .049) but a lower incidence of a perilesional hyperintense FA rim (P < .001), compared with those of high-grade gliomas on visual inspection. TDLs had significantly higher FA (P = .004) and lower MD (P = .001) values in the peripheral enhancing portions of the lesions compared with those of high-grade gliomas. In perilesional edema, FA values were significantly higher in high-grade gliomas (P = .001).

CONCLUSIONS

DTI is helpful in differentiating TDLs from high-grade gliomas by using visual inspection and quantitative analysis.

Differentiation of brain abscesses from necrotic glioblastomas and cystic metastatic brain tumors with diffusion tensor imaging

BACKGROUND AND PURPOSE

The differentiation of abscesses from glioblastomas and metastases may not always be possible on the basis of DWI. Our hypothesis was that differences in diffusion properties as detected by DTI allow differentiation of abscess from glioblastomas and metastasis. Furthermore, diagnostic performance of tensor metrics quantifying anisotropy or tensor shapes is better than that of ADC in measuring mean diffusivity for this purpose.

MATERIALS AND METHODS

DTI was performed in 15 abscesses, 15 necrotic glioblastomas, and 26 cystic metastases. In each lesion, manually segmented into 4 regions of interest (ie, cystic cavity, enhancing rim, and immediate [edema most adjacent to the enhancing rim] and distant zones of edema), FA, ADC, C(l), C(p), and C(s) values were measured and statistically compared among groups and evaluated with ROC curve analysis. The presence of a hyperintense FA rim (a rim of edematous tissue that was hyperintense on the FA map) was assessed visually.

RESULTS

Abscess was significantly different from glioblastoma for all tensor metrics measured in the cystic cavity and immediate zone of edema and for all except C(l) in the enhancing rim. Abscess was significantly different from metastasis for all tensor metrics measured in the cystic cavity and enhancing rim and for FA, ADC, and C(l) in immediate zone of edema. The incidence of a hyperintense FA rim was significantly higher in glioblastoma and metastasis compared with abscess. The 3 tensor metrics with the highest performance in differentiating abscess from glioblastoma and metastasis were FA, C(l), and C(s) of the cystic cavity.

CONCLUSIONS

DTI is able to differentiate abscess from glioblastoma and metastasis. FA, C(l), and C(s) outperformed ADC in diagnostic performance comparisons.

New approaches for measuring coagulation

Although specific assays of coagulation factors are essential for diagnostic purposes they only give partial information about an individual's haemostatic state. This can be better assessed by various global tests, and recent developments and evaluations of five such tests are described in this symposium: the PFA-100; waveform analysis; thrombin generation; overall haemostasis potential; thrombelastography. Each test has advantages in various applications, but the thrombin generation test and waveform analysis have been found most useful in haemophilia, whilst the PFA-100 is helpful in von Willebrand's disease.

Autocrine VEGF mediates the antiapoptotic effect of CD154 on CLL cells

CD154 is an important regulator of chronic lymphocytic leukaemia (CLL)-cell survival. In CLL, high serum levels of VEGF are a feature of advanced disease, and we and others have previously shown that CLL cells produce and secrete this growth factor. Since CD154 stimulates VEGF production in other cell types, and VEGF is known to promote cell survival, we examined whether the cytoprotection of CLL cells by CD154 involves VEGF. We report for the first time that treatment of CLL cells with CD154 results in increased VEGF production and demonstrate involvement of NF-kappaB in this process. Moreover, we show that CD154-induced CLL-cell survival is reduced by anti-VEGF-neutralising antibody and by inhibiting VEGF receptor (VEGFR) signalling with SU5416. However, addition of exogenous VEGF alone or blocking secreted autocrine VEGF had little or no effect on CLL-cell survival. We therefore conclude that CLL-cell cytoprotection in the presence of CD154 requires combined signalling by both CD40 and VEGFR. This combined signalling and resulting cytoprotection were shown to involve NF-kappaB activation and increased survivin production. In conclusion, our findings identify autocrine VEGF as an important mediator of the antiapoptotic effect of CD40 ligation, and thus provide new insights into CLL-cell rescue by CD154 in lymphoreticular tissues.

Combined hepatocellular-cholangiocarcinoma: a case report

Combined hepatocellular-cholangiocarcinoma (HCC-CC) is a rare primary liver tumour. We report a carrier of both HBV and HCV presenting with intermittent abdominal pain, fever, chillness and elevated á-fetoprotein (AFP) of 1197 ng/ml. Computed tomography showed an irregular hypodense mass in the left lateral segment of the liver with vague contrast enhancement and multiple regional lymphadenopathy. Hepatic angiogram showed that the mass was hypovascular and the left portal vein was occluded with a tapered end. Percutaneous ultrasound-guided core needle biopsy of the liver yielded HCC-CC. We suggest that HCC-CC should be considered in hypovascular liver tumours with striking elevation of serum AFP and multiple regional lymphadenopathy.

Temporal changes in factors associated with neutrophil elastase and coagulation in intensive care patients with a biphasic waveform and disseminated intravascular coagulation

Summary. The biphasic waveform is an early marker of disseminated intravascular coagulation (DIC). Neutrophil elastase (NE) cleaves coagulation factors; thus, elevated elastase levels or its dysregulation by alpha-1-protease inhibitor (Alpha1PI) may be linked to DIC. Time courses over a period were determined for factors associated with NE and coagulation in 14 Intensive Care Unit patients with a biphasic waveform who developed DIC. The data were analyzed using a random coefficient linear regression model to predict the variables' mean values on day 0 and their mean rates of change over the period in which the biphasic waveform appeared. The biphasic waveform was normal on day 0, maximized on day 1, and approached normal again by day 4. Alpha1PI/NE complex levels were 2.5-fold greater than normal for the entire period. The A1PI activity, antigen, and specific activity levels were normal on day 0 and increased thereafter by 21.0, 10.5, and 8.9% of normal per day, respectively. Factor II, V, VII, IX, and X activity levels were, respectively, 57, 46, 46, 77, and 46% of normal on day 0, whereas factor VIII and fibrinogen levels were normal. All coagulation factor levels trended upward with time but not significantly. The prothrombin time, but not the activated partial thromboplastin time, was prolonged, and the platelet counts and hematocrits were below normal on day 0 and remained so thereafter. We conclude that events associated with neutrophil activation, elastase release, and perturbations of coagulation precede both the appearance of the biphasic waveform and the diagnosis of DIC in these patients.

A longitudinal study of maternal dose response to low molecular weight heparin in pregnancy

OBJECTIVE

To assess the maternal response to low molecular weight heparin during pregnancy, by estimation of plasma anti-Xa activity, at three specified gestation points and in the nonpregnant state.

METHODS

A longitudinal, prospective, observational study was set in a tertiary referral recurrent miscarriage clinic. Twenty-four women, attending consecutively, were invited to participate and gave informed consent. Each woman had a history of recurring pregnancy loss and positive preconception screening for antiphospholipid syndrome. After confirmation of a viable pregnancy all subjects began taking 5000 IU of dalteparin once daily subcutaneously. Serial measurement of plasma anti-Xa activity after administration of dalteparin was performed at three standard gestation points (12, 24, and 36 weeks) and in the nonpregnant state (6 weeks postpartum).

RESULTS

Peak anti-Xa levels occurred at 4 hours postbolus in pregnancy, as compared with 2 hours in the nonpregnant state. The mean anti-Xa levels at 12, 24, and 36 weeks' gestation were significantly reduced, at 2 hours postinjection, as compared with the nonpregnant state (P <.001, P <.01, P <.001, respectively). The lowest dose-response curve was at 36 weeks' gestation. A repeated-measures analysis of variance found a significant difference (P <.05) between the 36-week group and the postterm group but not between any of the other groups.

CONCLUSION

During pregnancy, differences in the pharmacokinetics of low molecular weight heparin were observed, with an overall reduction in anti-Xa activity. On the basis of this study it is questionable to extrapolate dosing and lack of dose monitoring, in pregnant women, using data derived from a nonpregnant population.

Waveform analysis of clotting test optical profiles in the diagnosis and management of disseminated intravascular coagulation (DIC)

Transmittance waveform charts the changes in light transmittance on standard coagulation assays, such as the prothrombin time (PT) and activated partial thromboplastin time (APTT). Analysis and characterization of these data on photo-optical coagulation analysers provides additional qualitative and quantitative information to that obtained using the clotting time alone. The most thoroughly evaluated clinical application is that of the biphasic APTT waveform with disseminated intravascular coagulation (DIC). The degree of waveform abnormality correlates directly with the severity of haemostatic dysfunction and allows for both the prediction and monitoring from non-overt to overt DIC. As its performance is simple and rapid, this provides the means for targeting therapeutic intervention to an earlier stage of DIC. The recent identification that the mechanism underlying the biphasic waveform is a complex that exists in vivo between C reactive protein with very low density lipoprotein, provides potentially important insights into the molecular pathogenesis of DIC. Thus, in addition to the immediate clinical utility in diagnostic practice, it has important applications as a research tool. Preliminary experience in the application of this technology to the diagnosis and management of the haemophilias and the lupus anticoagulant syndrome has also provided evidence of the power and utility of waveform analysis in essentially simple clotting assays.

Laboratory testing in disseminated intravascular coagulation

The lack of improvement in the clinical prognosis of disseminated intravascular coagulation (DIC) poses searching questions on the value of current laboratory testing in this area. There is little immediate chance of advancement unless new tests or new modes of analyzing currently available tests place an emphasis on identifying the early phase of DIC. An equal emphasis is also required on practicality to ensure that recommendations are applicable to the routine clinical setting. These two priorities need to be fulfilled to facilitate earlier therapeutic intervention in the clinical trials required for formal assessment of promising and emerging new molecules from successful animal studies. This article therefore discusses the advantages and disadvantages of available assays in DIC with these perspectives in mind. It also proposes a format to bring together the necessary elements required to make an impact on ultimately delivering clinical improvement in this critical area.

Aberrant dimerization of von Willebrand factor as the result of mutations in the carboxy-terminal region: identification of 3 mutations in members of 3 different families with type 2A (phenotype IID) von Willebrand disease

The 3' end of the VWF gene was screened in the affected members of 3 different families with type 2A (phenotype IID) von Willebrand disease (vWD). Exons 49 to 52 of the VWF gene were amplified and screened for mutations by chemical cleavage mismatch detection. Mismatched bands were detected in exon 52 of 2 patients and in exon 51 of a third patient. Using direct DNA sequencing, a heterozygous G8562A transition leading to a Cys2008Tyr substitution was found in all the patients in family 1, and a T8561A transversion leading to a Cys2008Ser substitution was found in both patients from family 2. In a patient from a third family, an 8-base deletion from nucleotide 8437 to 8444 was identified in exon 51. The 2 mutations in exon 52 were reproduced by in vitro site-directed mutagenesis of full-length von Willebrand factor (vWF) cDNA and transiently expressed in COS-7 cells. The corresponding recombinant VWFs for these 2 mutations exhibited the typical aberrant vWF:Ag multimer pattern seen in the plasma of the patients. These 3 mutations demonstrate the importance of other carboxy-terminal cysteines in addition to the reported Cys2010 residue, in the normal dimerization of vWF, and their essential role in the assembly of normal multimeric vWF. (Blood. 2001;98:674-680)

Postnatal screening for thrombophilia in women with severe pregnancy complications

OBJECTIVE

To examine the prevalence of maternal thrombophilia in women with severe preeclampsia/eclampsia, placental abruption, fetal growth restriction, and unexplained stillbirth.

METHODS

We studied 102 women who had pregnancy complications and 44 healthy women with uncomplicated pregnancies. All women were tested 10 weeks postpartum for mutations of factor V Leiden, methylenetetrahydrofolate reductase (MTHFR) C677T, and G20210A prothrombin gene; deficiencies of protein C, protein S, and antithrombin III; and the presence of lupus anticoagulant and anticardiolipin antibodies. We aimed to recruit 100 cases and 300 controls to detect a 10% difference in thrombophilia between the groups. However, we were able to recruit only 44 controls.

RESULTS

Abnormal thrombophilia screen was found in 54 women with pregnancy complications (53%) and in 17 women (39%) with normal pregnancies (odds ratio [OR] 1.8; 95% confidence interval [CI] 0.87, 3.67). Mutations encoding for factor V Leiden, G20210A prothrombin gene, and MTHFR C677T (homozygous) were identified in 18% of women with complications compared with 16% of controls (OR 1.1; 95% CI 0.44, 2.94). Activated protein C resistance, not due to factor V Leiden mutation, was the most common thrombophilic defect, found in 26% of women with pregnancy complications compared with 18% of controls (OR 1.5; 95% CI 0.63, 3.73). Twenty women with complications (20%) had multiple thrombophilic defects compared with four controls (9%) (OR 2.4; 95% CI 0.78, 7.61).

CONCLUSION

In our cohort of women with pregnancy complications, maternal thrombophilia was less common than previously thought, and multiple thrombophilias were not a major additional risk factor.

Unexpected presentation of type 2N von Willebrand disease in pregnancy

The finding of low factor VIII levels in pregnancy immediately raises concern of haemophilia A carriage, especially with a history of bleeding in the maternal grandfather. However, the diagnosis of type 2N von Willebrand disease (2N vWD) should also be considered as illustrated here. This is also the first reported case of the management of 2N vWD in pregnancy.

In vitro and in vivo production of vascular endothelial growth factor by chronic lymphocytic leukemia cells

Expansion of primary solid tumors and their malignant dissemination are angiogenesis-dependent. Vascular endothelial growth factor (VEGF) is the key factor playing a pivotal role in solid tumor-induced angiogenesis. Recent studies indicate that angiogenesis may also be involved in the pathogenesis of certain hemic malignancies, including B-cell chronic lymphocytic leukemia (B-CLL). Mechanisms underlying angiogenesis in B-CLL and the role of VEGF in this process are incompletely understood. In this study, it was examined whether angiogenically functional VEGF is produced by B-CLL cells. Immunohistochemical staining with antibodies against VEGF and CD34, an endothelial cell marker, demonstrated the presence of VEGF protein and abundant blood vessels in infiltrated lymphoreticular tissues. Low levels of VEGF were detected by ELISA in the culture media of unstimulated cells; this was enhanced up to 7-fold by hypoxic stimulation. SDS-PAGE and Western blot analysis of the concentrated culture media showed 2 isoforms of VEGF protein with molecular weights of 28 and 42 kd, respectively. RNA hybridization showed that these cells expressed VEGF mRNA. Reverse transcription-polymerase chain reaction, combined with nucleotide sequence analysis, revealed that the predominantly expressed isoforms were VEGF121 and VEGF165. Moreover, (3)H-thymidine incorporation and an in vivo angiogenic assay demonstrated that the VEGF produced by CLL cells can induce angiogenesis by stimulating endothelial cell proliferation. In conclusion, this study shows that B-CLL cells produce VEGF and demonstrates the angiogenic effects of this growth factor, which may be relevant for the tissue phase of the disease.