Klaus Felgenhauer

SOLUBLE FORMS OF INTERCELLULAR ADHESION MOLECULE-1 (ICAM-1) BLOCK LYMPHOCYTE ATTACHMENT TO CEREBRAL ENDOTHELIAL CELLS

Serum levels of circulating ICAM-1 are increased in various disorders including inflammatory diseases of the central nervous system (CNS). We recently described an association between high sICAM-1 levels in the serum of patients with multiple sclerosis and disease activity. The functional consequences of increased circulating adhesion molecules are not fully understood. This may simply arise as a consequence of inflammation or may have immune modulating properties. ICAM-1 plays an important role in the recruitment of activated lymphocytes to sites of inflammation within the CNS. We therefore tested the ability of soluble forms of ICAM-1 to prevent adhesion of activated lymphocytes to cerebral endothelial cells. Mitogen-activated blood mononuclear cells (PBMC) as well as PBMCs from patients with active multiple sclerosis adhered to cerebral endothelial cell cultures in vitro. This adhesion could be blocked if lymphocytes were preincubated with a recombinant form of soluble ICAM-1. In addition, serum from patients with active multiple sclerosis and high sICAM-1 levels blocked adhesion in a dose-dependent manner which was abrogated by pre-adsorption to an anti ICAM-1 antibody. Since soluble forms of ICAM-1 are able to block lymphocyte adhesion to cerebral endothelial cells, they may provide new therapeutic tools to interfere with the pathogenesis of inflammatory diseases of the CNS.

Matrix metalloproteinase-9 is elevated in serum of patients with amyotrophic lateral sclerosis

SMatrix metalloproteinase-9 (MMP-9) and its specific inhibitor, tissue inhibitor of matrix metalloproteinase-1 (TIMP-1), were analysed by enzyme-linked immunosorbent assay (ELISA) and by zymography in serum and cerebrospinal fluid (CSF) of patients with amyotrophic lateral sclerosis (ALS). In contrast to patients with inflammatory diseases, MMP-9 levels were not elevated in CSF of ALS patients. In serum, however, compared to healthy donors, MMP-9 was significantly (p = 0.0003) increased up to levels as high as those of viral meningoence-phalitis (VM) or bacterial meningitis (BM) patients. MMP-9 levels remained elevated during long-term observation of ALS patients. In the absence of an inflammatory response, the results indicate that the increase of MMP-9 in serum of ALS patients might be caused by upregulation of MMP-9 in denervated muscles or in degenerating peripheral nerves following motor neurone loss.

The diagnostic significance of antibody specificity indices in multiple sclerosis and herpes virus induced diseases of the nervous system

SummaryThe antibody specificity index (ASI) indicates the cerebrospinal fluid (CSF)/serum difference of antibody amounts per weight unit IgG (normal < 1.5). It has proven to be the most sensitive inflammation parameter in CSF analysis so far, more sensitive than the Western blot, the “oligoclonal” response, and the empirical differentiation of CSF immunoglobulins. By this diagnostic criterion, several benign viral meningitis cases were found to be caused by the varicella/zoster virus. The diagnostic relevance of local zoster antibody synthesis was greatest in ganglionitis cases, e.g., in zoster oticus sine herpete (facial paresis) and acute radicular syndromes of the elderly. The diagnostic significance of the local immune response against measles, rubella, and zoster antigens (MRZ response) was ascertained further. Together with oligoclonal gamma-globulin fractionation, there is now only 1 out of 100 multiple sclerosis (MS) patients left who has been found to have a normal CSF.

Soluble intercellular adhesion molecule-1 in cerebrospinal fluid: An indicator for the inflammatory impairment of the blood-cerebrospinal fluid barrier

A soluble form of the intercellular adhesion molecule-1 (sICAM-1) was measured in paired cerebrospinal fluid (CSF)/blood samples from 123 patients with different neurological diseases. Mean levels of circulating ICAM-1 in the blood were mean +/- SD = 423 +/- 184.6 ng ml-1 (range 44-1115 ng ml-1). Considerable differences of sICAM-1 in the CSF of patients were observed between disease groups. In acute bacterial meningitis, sICAM-1 levels as high as 1/5 of the serum concentration were detected in the CSF (n = 24; mean +/- SD = 33.0 +/- 23.7 ng ml-1; range: 4.8-93.9 ng ml-1). These changes coincided with a severe blood-CSF barrier dysfunction as indicated by a high CSF/blood ratio for albumin (mean +/- SD = 46.7 +/- 52.2; range: 16.8-249.3). In patients with polyradiculitis (n = 9; mean +/- SD = 14.5 +/- 11.9 ng ml-1; range: 2.6-43.7 ng ml-1) a similar covariation between the albumin and sICAM CSF/blood ratios was detected. In patients with multiple sclerosis (n = 9; mean +/- SD = 5 +/- 4.3; range: 0-12.7 ng ml-1) or HIV infection with neurological symptoms (n = 18; mean +/- SD = 4.9 +/- 3.2; range; 1-11.9 ng ml-1) low levels of sICAM-1 were detected in the CSF associated with intact blood-CSF barrier function in most patients. Among 13 patients with viral meningitis, only four had detectable levels of sICAM-1 in their CSF (mean +/- SD = 1.0 +/- 1.5 ng ml-1; range: 0-3.7).(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical relevance of the quantification of apolipoprotein E in cerebrospinal fluid

Apolipoprotein E was measured in paired sera and cerebrospinal fluid samples from 483 neurological patients. The average apolipoprotein E concentration was 7.5 (+/- 3.1) mg/l in cerebrospinal fluid and 93.5 (+/- 29.7) mg/l in serum. Mean apolipoprotein B concentrations in 88 patients were 0.77 +/- 3.4 mg/l in cerebrospinal fluid and 1.06 +/- 0.31 g/l in serum. The apolipoprotein E concentration in cerebrospinal fluid was much greater than expected for passive diffusion from serum. By contrast to apolipoprotein B, there was no correlation between the apolipoprotein E cerebrospinal fluid/serum concentration quotient and the albumin concentration quotient. This suggests that apolipoprotein E in cerebrospinal fluid, unlike apolipoprotein B, is locally synthesized and that the use of a cerebrospinal fluid/serum concentration quotient is unnecessary. In a control group (n = 64) the mean cerebrospinal fluid apolipoprotein E value (+/- SD) was 5.9 (1.6) mg/l. Elevated cerebrospinal fluid apolipoprotein E concentrations were observed in acute (n = 22, 12.5 +/- 6.2 mg/l) and chronic inflammatory central nervous system diseases (n = 15, 10.4 +/- 2.4 mg/l).

Choroid plexus: the major site of mRNA expression for the β-trace protein (prostaglandin D synthase) in human brain

Expression of beta-trace protein (beta-trace), recently identified as glutathion-independent prostaglandin D synthase (prostaglandin-H2 D-isomerase; EC 5.3.99.2), was localized in paraffin sections of the human brain by in situ hybridization using digoxigenin-labeled antisense cRNA probes. The mRNA for beta-trace was predominantly found in the epithelial cells of the choroid plexus. Hybridization signals were also obtained in some oligodendrocytes, particularly in the white matter. In the leptomeninges, specific signals were found in meningeal macrophages and in single cells of the arachnoid barrier layer. The cells exhibiting hybridization signals with the antisense cRNA probes for beta-trace were identified by counterstaining with antibodies directed against specific cell markers. Additionally, beta-trace mRNA was localized in tubular epithelial and basal cells of the human epididymis and in different cell types within the seminiferous epithelium of the testis.

Matrix metalloproteinase-9 (MMP-9) in human cerebrospinal fluid (CSF): elevated levels are primarily related to CSF cell count

Matrix metalloproteinase-9 (MMP-9) was investigated by enzyme-linked immunosorbent assay (ELISA) and zymography in 111 paired CSF and serum samples from patients with various neurological disorders. In 20 patients with blood-brain barrier (BBB) impairment but normal CSF cell count, elevated levels of MMP-9 were not observed by ELISA measurement. Another 11 patients characterized in the same way, exhibited only slightly increased MMP-9 levels. In contrast, in 12 patients with intact BBB but elevated CSF cell count, MMP-9 was increased too. It was shown by the more sensitive zymography that MMP-9 increased if CSF cell count exceeded five cells per microl. Spearman rank statistics revealed that MMP-9 concentration in CSF correlated with CSF cell count (r=0.755; P<0.0001), but not with CSF/serum albumin ratio (Q(Alb)) (r=0.212; P=0.057), a measure for BBB impairment. Moreover, the CSF/serum MMP-9 ratio (Q(MMP-9)) did not correlate with Q(Alb)(r=0.192; P=0.100). By use of a Boyden chamber, in which granulocytes migrated through a reconstituted basement membrane, it was demonstrated that the MMP-9 concentration in the lower chamber correlated very significantly with the number of accumulated cells (r(2)=0.7692; P<0.0001). The meaning of the increase of MMP-9 in CSF is critically discussed.

Cisternal S100 protein and neuron-specific enolase are elevated and site-specific markers in intractable temporal lobe epilepsy.

In the brain, S100 protein and neuron-specific enolase (NSE) are mainly found in glial cells and neurons, respectively. We investigated concentrations of S100 protein and NSE in cisternal cerebrospinal fluid obtained during implantation of foramen ovale electrodes in eight patients with temporal lobe epilepsy (TLE). In addition, the meningeal markers cystatin-C and beta-trace as well as total protein were measured. Patients with trigeminal neuralgia (TN) undergoing glycerol rhizotomy served as controls. S100 protein and NSE levels ipsilateral to the site of seizure onset were significantly higher than in TN. Contralateral TLE values were also markedly but not significantly elevated. The meningeal markers cystatin-C and beta-trace protein as well as total protein did not differ in TLE and TN. We conclude that interictal temporal lobe dysfunction corresponds with neuronal and glial marker elevations in the extracellular space and that site-specific elevations may predict the site of seizure origin biochemically.

Chronic HIV encephalitis--I. Cerebrospinal fluid diagnosis.

SummaryTo establish a reliable procedure for the early detection of central nervous system involvement in HIV infection, paired cerebrospinal fluid and serum samples of 59 patients were analysed. Fifteen were HIV antibody positive without clinical symptoms (stage I), 12 had lymphadenopathy syndrome or AIDS-related complex (stage II), and 32 had AIDS (stage III). Intrathecal synthesis of HIV antibodies was determined by a modified ELISA. Antibodies in CSF and serum were evaluated at identical immunoglobulin G levels to correct for the actual blood-CSF-barrier permeability. A CSF/serum quotient above 1.5 is indicative of intrathecal antibody synthesis, which was found in 47% of the patients in stage I, 67% in stage II, and 84% in stage III. These findings indicate an early and frequent invasion of the CNS.

Correlation of soluble adhesion molecules in blood and cerebrospinal fluid with magnetic resonance imaging activity in patients with multiple sclerosis

Several studies have reported a positive correlation between levels of soluble adhesion molecules in serum or cerebrospinal fluid and cranial MRI activity. We performed a cross-sectional study in 46 patients with newly diagnosed MS and determined levels of soluble intercellular adhesion molecule-1 (sICAM-1) as well as vascular cell adhesion molecule-1 (sVCAM-1) in correlation to the number and area of gadolinium enhancing lesions on cranial magnetic resonance images (MRI). The data revealed a significant positive correlation between sVCAM-1 serum levels and gadolinium enhancing lesions. In addition, CSF to serum ratios for sICAM-1 and sVCAM-1 correlated to MRI activity. In patients with a single enhancing lesion (SEL) there was a negative correlation between the QsCAM and the distance of the SEL to the ventricles. As these adhesion molecules are stable and markers of disease activity in MS, we further investigated sVCAM-1 serum levels during treatment with interferon beta-1b (Betaferon®). Significant increases in serum levels for sVCAM-1 in patients receiving Betaferon were associated with a favourable treatment response after 1 year in 17 out of 19 patients and correlated to decreased MRI activity, whereas stable or reduced sVCAM-1 levels occured more often in non-responders (five out of six patients). Therefore it can be hypothezised that soluble adhesion molecules are released from cerebral endothelial cells as an early immunoregulatory activity of the immune system to reduce cellular traffic across the blood brain barrier and this is further enhanced by IFN-beta treatment.