Tobias Böttcher

Prevalence of Fabry disease in patients with cryptogenic stroke: a prospective study

BACKGROUND Strokes are an important cause of morbidity and mortality in young adults. However, in most cases the cause of the stroke remains unclear. Anderson-Fabry disease is an X-linked recessive lysosomal storage disease resulting from deficient alpha-galactosidase and causes an endothelial vasculopathy followed by cerebral ischaemia. To determine the importance of Fabry disease in young people with stroke, we measured the frequency of unrecognised Fabry disease in a cohort of acute stroke patients. METHODS Between February, 2001, and December, 2004, 721 German adults aged 18 to 55 years suffering from acute cryptogenic stroke were screened for Fabry disease. The plasma alpha-galactosidase activity in men was measured followed by sequencing of the entire alpha-GAL gene in those with low enzyme activity. By contrast, the entire alpha-GAL gene was genetically screened for mutations in women even if enzyme activity was normal. FINDINGS 21 of 432 (4.9%) male stroke patients and seven of 289 (2.4%) women had a biologically significant mutation within the alpha-GAL gene. The mean age at onset of symptomatic cerebrovascular disease was 38.4 years (SD 13.0) in the male stroke patients and 40.3 years (13.1) in the female group. The higher frequency of infarctions in the vertebrobasilar area correlated with more pronounced changes in the vertebrobasilar vessels like dolichoectatic pathology (42.9%vs 6.8%). INTERPRETATION We have shown a high frequency of Fabry disease in a cohort of patients with cryptogenic stroke, which corresponds to about 1.2% in young stroke patients. Fabry disease must be considered in all cases of unexplained stroke in young patients, especially in those with the combination of infarction in the vertebrobasilar artery system and proteinuria.

Reduced Release of Pneumolysin by Streptococcus pneumoniae In Vitro and In Vivo after Treatment with Nonbacteriolytic Antibiotics in Comparison to Ceftriaxone

ABSTRACT Pneumolysin, a virulence factor of Streptococcus pneumoniae with cytotoxic and proinflammatory activities, occurs at concentrations from 0.85 to 180 ng/ml in cerebrospinal fluid (CSF) of meningitis patients. In pneumococcal cultures and in a rabbit meningitis model, the concentrations of pneumolysin in supernatant and CSF were lower after addition of nonbacteriolytic bactericidal antibiotics (rifampin and clindamycin) than after incubation with ceftriaxone.

Differential regulation of Toll-like receptor mRNAs in experimental murine central nervous system infections

Toll-like receptors (TLR) play a key role in the recognition of microbial components. We investigated the differential regulation of TLR mRNA expression in bacterial and viral mouse models of central nervous system infection. Streptococcus pneumoniae meningitis led to an enhanced expression of TLR2, TLR4 and TLR9 mRNA. In Escherichia coli meningitis, TLR2, TLR4 and TLR7 mRNA expression was increased and Herpes simplex encephalitis caused a rise of TLR4 mRNA. In organotypic hippocampal cultures treatment with S. pneumoniae R6 led to increased expression of TLR2 and TLR3 mRNA. Our data provide evidence that regulation of TLR mRNA is not fully specific for the molecular patterns of the infectious pathogen. The TLR mRNA regulation observed probably represents a combination of specific response to the causative pathogen and non-specific activation of the innate immune system.

Rifampin Reduces Production of Reactive Oxygen Species of Cerebrospinal Fluid Phagocytes and Hippocampal Neuronal Apoptosis in Experimental Streptococcus pneumoniae Meningitis

Bacterial compounds induce the production of reactive oxygen species (ROS) in meningitis. Rifampin releases smaller quantities of proinflammatory compounds from Streptococcus pneumoniae than do beta-lactam antibiotics. Therefore, rabbits infected intracisternally with S. pneumoniae were treated intravenously either with rifampin 5 mg/kg/h or ceftriaxone 10 mg/kg/h (n=9 each). Before initiation of antibiotic treatment, a strong positive correlation between ROS production of cerebrospinal fluid (CSF) phagocyte populations and bacterial CSF titers was observed (granulocytes: rs=.90, P<.0001; monocytes: rs=.81, P<.0001). CSF leukocytes from rifampin-treated rabbits produced less ROS (monocytes at 2 h after initiation of treatment: P=.045; at 5 h: P=.014; granulocytes at 5 h: P=.036) than did leukocytes from animals receiving ceftriaxone. The CSF malondialdehyde concentrations and the density of apoptotic neurons in the dentate gyrus were lower in rifampin- than in ceftriaxone-treated animals (P=.002 and.005). The use of rifampin to reduce the release of ROS and to decrease secondary brain injury appears promising.

Glucosylsphingosine Is a Highly Sensitive and Specific Biomarker for Primary Diagnostic and Follow-Up Monitoring in Gaucher Disease in a Non-Jewish, Caucasian Cohort of Gaucher Disease Patients

Background Gaucher disease (GD) is the most common lysosomal storage disorder (LSD). Based on a deficient β-glucocerebrosidase it leads to an accumulation of glucosylceramide. Standard diagnostic procedures include measurement of enzyme activity, genetic testing as well as analysis of chitotriosidase and CCL18/PARC as biomarkers. Even though chitotriosidase is the most well-established biomarker in GD, it is not specific for GD. Furthermore, it may be false negative in a significant percentage of GD patients due to mutation. Additionally, chitotriosidase reflects the changes in the course of the disease belatedly. This further enhances the need for a reliable biomarker, especially for the monitoring of the disease and the impact of potential treatments. Methodology Here, we evaluated the sensitivity and specificity of the previously reported biomarker Glucosylsphingosine with regard to different control groups (healthy control vs. GD carriers vs. other LSDs). Findings Only GD patients displayed elevated levels of Glucosylsphingosine higher than 12 ng/ml whereas the comparison controls groups revealed concentrations below the pathological cut-off, verifying the specificity of Glucosylsphingosine as a biomarker for GD. In addition, we evaluated the biomarker before and during enzyme replacement therapy (ERT) in 19 patients, demonstrating a decrease in Glucosylsphingosine over time with the most pronounced reduction within the first 6 months of ERT. Furthermore, our data reveals a correlation between the medical consequence of specific mutations and Glucosylsphingosine. Interpretation In summary, Glucosylsphingosine is a very promising, reliable and specific biomarker for GD.

Matrix metalloproteinase-9 deficiency impairs host defense mechanisms against Streptococcus pneumoniae in a mouse model of bacterial meningitis.

Matrix metalloproteinase-9 (MMP-9) appears to contribute to blood-brain barrier damage and neuronal injury in bacterial meningitis. To further explore the function of MMP-9 in meningeal inflammation, we injected 10(4) colony forming units (CFU) of a Streptoccocus pneumoniae type 3 strain into the right forebrain of MMP-9 deficient mice (MMP-9(-/-), n=16) and wild-type controls (129 x B6, n=15). The clinical course of the disease, leukocyte recruitment into the subarachnoid space and bacterial titers in the brain did not differ. Yet, clearance of the bacteria from blood (log CFU/ml 4.7 [3.8/5.4] vs. 3.6 [3.0/4.0]; P=0.005) and spleen homogenates (log CFU/ml 5.3 [4.8/5.5] vs. 4.0 [2.8/4.7]; P=0.01) was reduced in MMP-9 deficient mice. A reduced systemic bacterial clearance of MMP-9(-/-) mice was confirmed in experimental S. pneumoniae peritonitis/sepsis. This implies a compromised systemic, but not intracerebral host response against S. pneumoniae in MMP-9 deficiency.

Protocol and Methodology of the Stroke in Young Fabry Patients (sifap1) Study: A Prospective Multicenter European Study of 5,024 Young Stroke Patients Aged 18–55 Years

Background: Stroke in the young has not been thoroughly investigated with most previous studies based on a small number of patients from single centers. Furthermore, recent reports indicate that Fabry disease may be a significant cause for young stroke. The primary aim of our study was to determine the prevalence of Fabry disease in young stroke patients, while the secondary aim was to describe patterns of stroke in young patients. Methods: We initiated the Stroke in Young Fabry Patients (sifap1) study as a multinational prospective European study of stroke patients aged 18–55 years and collected a broad range of clinical, laboratory, and radiological data using stringent standardized methods. All patients were tested for Fabry disease and blood was stored for future genetic testing. Results: We managed to enroll 5,024 eligible young stroke patients in 15 countries and 47 centers across Europe between April 2007 and January 2010. The median number of patients included per center was 98 with a range between 8 and 315. The average duration of patient recruitment per center was 22 months, ranging between 5 and 33 months. The database was closed in July 2010. This paper describes protocol and methodology of the sifap1 study. Conclusion: The sifap1 study included the largest series of young stroke patients so far and will allow for analyses on a large number of aspects of stroke in the young.

Clindamycin is neuroprotective in experimental Streptococcus pneumoniae meningitis compared with ceftriaxone

In animal models of Streptococcus pneumoniae meningitis, rifampin is neuroprotective in comparison to ceftriaxone. So far it is not clear whether this can be generalized for other protein synthesis‐inhibiting antimicrobial agents. We examined the effects of the bactericidal protein synthesis‐inhibiting clindamycin (n = 12) on the release of proinflammatory bacterial components, the formation of neurotoxic compounds and neuronal injury compared with the standard therapy with ceftriaxone (n = 12) in a rabbit model of pneumococcal meningitis. Analysis of the CSF and histological evaluation were combined with microdialysis from the hippocampal formation and the neocortex. Compared with ceftriaxone, clindamycin reduced the release of lipoteichoic acids from the bacteria (p = 0.004) into the CSF and the CSF leucocyte count (p = 0.011). This led to lower extracellular concentrations of hydroxyl radicals (p = 0.034) and glutamate (p = 0.016) in the hippocampal formation and a subsequent reduction of extracellular glycerol levels (p = 0.018) and neuronal apoptosis in the dentate gyrus (p = 0.008). The present data document beneficial effects of clindamycin compared with ceftriaxone on various parameters linked with the pathophysiology of pneumococcal meningitis and development of neuronal injury. This study suggests neuroprotection to be a group effect of bactericidal protein synthesis‐inhibiting antimicrobial agents compared with the standard therapy with β‐lactam antibiotics in meningitis.

Frequency of Fabry disease in patients with small‐fibre neuropathy of unknown aetiology: a pilot study

Background:  Early occurrence of small‐fibre neuropathy (SFN) is a common feature of Fabry disease (FD) – an X‐linked storage disorder caused by reduced activity of the α‐galactosidase A (α‐GAL). Although SFN may result from different disorders, the cause is often unclear. Therefore, we investigated the frequency of FD in patients with SFN of unknown aetiology.

Basilar Artery Diameter Is a Potential Screening Tool for Fabry Disease in Young Stroke Patients

Background: Fabry disease (FD) is a rare hereditary lysosomal storage disease that has been highlighted as a possible etiology of stroke at a young age. Enlarged basilar artery diameters (BADs) have been demonstrated in FD, and we hypothesize that they might be useful for the screening of FD in young stroke patients. The aim of this study was to compare BADs of young stroke patients without FD to those of FD patients and of healthy age-matched controls. Methods: BADs were measured using MR angiography in 3 age- and gender-matched groups: 25 FD patients (aged 36.5 ± 11.0 years), 26 non-FD stroke patients and 20 healthy controls. Results: Compared to the non-FD stroke patients, FD patients had significantly enlarged BADs. FD patients could be significantly separated from stroke patients by BADs (area under the curve = 0.89, 95% confidence interval 0.81–0.98). Eighty-six percent of all subjects could be correctly classified by BADs (sensitivity 84%, specificity 88.5%). Conclusions: Enlarged BADs were able to detect FD within a cohort of FD, stroke patients and healthy controls. BAD measurement could be an easily obtainable and sensitive screening tool for FD in young stroke patients.