Peter Rieckmann

Pentoxifylline, a phosphodiesterase inhibitor, induces immune deviation in patients with multiple sclerosis

The outcome of immune responses can be predicted by the lymphokine production pattern of the participating cells. Cytokines of the T helper type 1 (Th1) cells mediate inflammatory responses and delayed-type hypersensitivity (DTH), whereas Th2-like T cells predominantly produce cytokines, which stimulate antibody production by B cells. Immunoregulatory therapy of autoimmune diseases with unknown antigens may be achieved by inhibiting the production of inflammatory cytokines and induction of protective cytokines of Th2-like T cells. To determine the immunoregulatory capacity of the phosphodiesterase inhibitor pentoxifylline (PTX), which is known to suppress the production of tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma), this drug was used in mitogen and antigen-stimulated lymphocyte cultures as well as in patients with multiple sclerosis. PTX significantly decreased TNF-alpha and interleukin-12 (IL-12), whereas it increased IL-4 and IL-10 production. In addition, PTX inhibited cell proliferation, which was associated with a marked reduction in CD25 (IL-2 receptor alpha-chain) and CD54 (intercellular adhesion molecule-1; ICAM-1) expression. Increasing doses of PTX significantly reduced TNF-alpha and IL-12 mRNA expression of blood mononuclear cells, but increased IL-4 and IL-10 expression in eight patients with relapsing-remitting multiple sclerosis. These results indicate that PTX modulates immune reactions favouring a Th2-like response and may therefore be useful for the treatment of autoimmune diseases with a dominant Th1-like T cell response.

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.

A Longitudinal Prospective Study of Soluble Adhesion Molecules in Acute Stroke

BACKGROUND AND PURPOSE Activation of endothelial cells is a consequence of cerebral ischemia and leads to the expression of adhesion molecules such as intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), and E-selectin, which can be released into the blood. This study aimed to define the kinetics of soluble adhesion molecule serum levels after cerebral ischemia and their correlation with the extent of neurological deficits, clinical outcome, and infarct volume as measured on CT scans. Methods-Plasma levels of soluble (s) ICAM-1, sVCAM-1, and sE-selectin were repeatedly determined by ELISA in 38 patients during a period of 14 days after acute cerebral ischemia. RESULTS Soluble adhesion molecule levels demonstrated considerable variability. Overall, concentrations revealed characteristic and significant changes after completed strokes but not after transient ischemic attacks. In patients with completed stroke (n=26) but not in patients with transient ischemic attacks (n=12), sICAM-1 peaked within 24 hours (P=0.04), sVCAM-1 reached a maximum after 5 days (P=0.02), and sE-selectin levels decreased after 5 days (P=0.002). There was no clear-cut correlation of soluble adhesion molecule levels with infarct volume or clinical disability. The initial increase of sE-selectin levels was higher in more disabled patients (P=0.02). sICAM-1 levels were higher in patients with signs of infection (n=9; P=0.03). CONCLUSIONS As a result of large interindividual variability influenced by ischemia-independent factors, soluble adhesion molecules are not reliable candidates as surrogate markers in acute cerebral ischemia. The characteristic profile of individual soluble adhesion molecules after completed stroke supports prior hypotheses of their involvement in the pathogenesis of acute cerebral ischemia, but this needs to be clarified in detail.

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)

Fasciculations : clinical, electromyographic, and ultrasonographic assessment

Widespread fasciculations are an important clinical sign in, for example, degenerative lower motor neuron diseases (LMND). Usually they are detected by clinical inspection and electromyography. Recently myosonography has been proposed for the detection of fasciculations. This prospective study compares the value of these three modes of examination in patients with degenerative LMND. Seventy healthy control persons and 34 patients (11 women, 23 men; aged 43–78 years; median age 60.5) with LMND were included in the study. All participants were subjected to thorough visual screening for the presence of fasciculations. Fourteen muscles were examined bilaterally by myosonography and a median of 8 muscles were screened electromyographically (only in the patients); the investigators were blinded to the other findings. Clinical inspection and ultrasonography exhibited fasciculations in up to 5 and 8 muscles, respectively, in 8 healthy persons. Ultrasonography demonstrated fasciculations in all patients, clinical inspection in all but 2, and electromyography in 26 of 33 patients (1 patient was not examined electromyographically). Comparing the three methods, clinical observation revealed fasciculations in 42%, electromyography in 39%, and ultrasonography in 67% of all muscles. Thus, ultrasonography was significantly more sensitive than the other techniques (P < 0.001). The interrater agreement (correlation coefficient)r in respect of the presence or absence of fasciculation was 0.71 for the clinical, 0.85 for the electromyographic and 0.84 for the myosonographic examinations. Ultrasonography and electromyography were more reliable than the clinical examination (P < 0.001 andP < 0.01, respectively). Our study indicates that ultrasonography is more sensitive than clinical and electromyographic examination in visualizing fasciculations in patients with LMND. Additionally, it is more reliable than clinical examination.

Semi-quantitative analysis of cytokine gene expression in blood and cerebrospinal fluid cells by reverse transcriptase polymerase chain reaction

An easy, reproducible and semi-quantitative, non-radioactive method for the analysis of mRNA expression for various cytokines, (i.e., Interleukin (IL)-1β, IL-4, IL-6, tumor necrosis factor (TNF)-α, lymphotoxin (LT), transforming growth factor (TGF)-β, interferon (IFN)-γ and endothelin-1 (ET-1)) in cells from cerebrospinal fluid (CSF) and peripheral blood mononuclear cells (PBMC) has been established. By means of polymerase chain reaction primers that cover a splice junction, amplification of contaminating DNA was omitted. Densitometric scanning of ethidium bromide-stained agarose gels proved to be very sensitive for semiquantitative analysis of PCR products. Serial tenfold dilutions of cDNA revealed a log-linear regression from 106 to 102 cells under optimal cycle conditions. The intra- and inter-assay variability of the method was below 10%. With this assay, the cytokine expression pattern of as few as 104 mononuclear cells from blood or CSF was determined. This method made it possible to detect differences in the cytokine gene expression pattern of mononuclear cells from patients with different neurological diseases. CSF cells from 43 patients with various neurological diseases were analyzed. TNF-α, LT, and IL-1 mRNA were prominent in the CSF cells of most patients with bacterial meningitis. TNF-α, LT, IFN-γ and IL-6 mRNAs were detected in patients with active multiple sclerosis, whereas TNF-α, IL-6, and endothelin-1 mRNA expression was found frequently in patients with HIV encephalitis. Pro-inflammatory cytokines were rarely detected in CSF cells from patients with non-inflammatory diseases of the central nervous system. In blood mononuclear cells from patients with multiple sclerosis, TNF-α mRNA expression was associated with disease activity. The sensitivity, specificity, velocity and reliability of this assay considerably facilitates the analysis of cytokine production in mononuclear cells even in conditions where only a limited number of cells is available for analysis.

A soluble form of tumour necrosis factor receptor in cerebrospinal fluid and serum of HTLV-I-associated myelopathy and other neurological diseases

Paired samples of cerebrospinal fluid (CSF) and serum from 17 patients with human T-cell lymphotrophic virus I (HTLVI)-associated myelopathy, 5 patients with multiple sclerosis and 11 controls with non-inflammatory disorders (migraine, idiopathic epilepsy and myelopathy of unknown aetiology) were examined by enzyme-linked immunosorbent assay for the presence of the 60-kDa soluble form of tumour necrosis factor receptor (sTNF-R). The results were compared with blood-CSF barrier function, cell count and the intrathecal synthesis of HTLVI antibodies. No correlation could be demonstrated. High levels of sTNF-R were found in CSF of patients with HTLV-I-associated myelopathy and multiple sclerosis. In addition, intrathecal sTNF-R was also detected in the patients with non-inflammatory diseases, indicating that sTNF-R is definitively a normal constituent of CSF.

Specificity of intrathecal IgG synthesis for HTLV-1 core and envelope proteins in HAM/TSP

Introduction– In patients with human T‐cell lymphotropic virus type 1 (HTLV‐1) associated myelopathy/tropical spastic paraparesis (HAM/TSP), we investigated the significance of HTLV‐1 specific antibodies in the cerebrospinal fluid (CSF). Material and methods– The quantities of HTLV‐1 specific immunoglobulin G (IgG) in paired CSF and serum were evaluated by a sensitive enzyme immunoassay (EIA). The specificity of antiviral IgG was determined by radioimmunoprecipitation of HTLV‐1 antigens. Results– In 17 of 20 HAM/TSP patients, quantitative evaluation by EIA supplied evidence for antiviral IgG synthesis within the CNS. Radioimmunoprecipitation demonstrated IgG antibodies against HTLV‐1 envelope and core proteins in all HAM/TSP CSF and sera tested. Regarding the 3 sample pairs indeterminate in EIA for intrathecal synthesis, 2 showed stronger precipitation of HTLV‐1 antigens by CSF IgG than by equal amounts of serum IgG. Conclusion– Intrathecal antibody synthesis specific for both HTLV‐1 core and envelope antigens is common in HAM/TSP, thus providing conclusive evidence for an immune response to HTLV‐1 within the CNS.

Class differentiation of immunoglobulin-containing cerebrospinal fluid cells in inflammatory diseases of the central nervous system

SummaryAn immunocytochemical technique allowing repeated use of antisera is applied to identify immunoglobulin-containing cells (ICC) of the IgG, IgA, and IgM class in the cerebrospinal fluid (CSF) of 298 patients with various neurological disorders. The demonstration of ICC in the CSF is highly indicative of an inflammatory disease (p<0.0001; Chi-square test). In the group of noninflammatory disorders ICC are only found in three cases of lymphomas, two dysgerminomas, and one glioblastoma. ICC of all classes are seen in acute viral and bacterial infections of the CNS including tick-borne meningopolyneuritis Bannwarth. IgG-positive ICC predominate in chronic inflammatory disorders like multiple sclerosis and HIV encephalitis. In HIV-positive patients IgA-or IgM-positive cells are strongly indicative of an opportunistic infection of the brain. Persistent high levels of ICC in three patients with bacterial meningitis are associated with a fatal outcome.

Zentrale Schmerzverarbeitung bei Morbus Parkinson

ZusammenfassungDer Morbus Parkinson (MP) geht mit einer Degeneration der dopaminergen Neurone in der Substantia nigra (SN) und einer daraus resultierenden Minderfunktion der nigrostriatalen Verbindungen mit den Basalganglien im Zentrum einher. Neben den motorischen Symptomen lassen sich bei einer beträchtlichen Anzahl an Parkinson-Patienten verschiedene Typen von Schmerz, beispielsweise dystoniebedingte muskuloskeletale Schmerzen oder zentrale Schmerzen, sowie Auffälligkeiten in der Schmerzverarbeitung beobachten, die sich möglicherweise in einer erhöhten Schmerzsensibilität manifestieren. Die genauen Ursachen hierfür sind jedoch unklar.Der vorliegende Artikel gibt daher einen Überblick über einschlägige Studien, die die Anomalien in der Schmerzverarbeitung beim MP größtenteils mittels elektrophysiologischer [Elektroenzephalogramm (EEG), sympathische Hautreaktion (SSR)] und psychophysikalischer Methoden [quantitative sensorische Testung (QST), RIII-Reflexschwelle] untersuchen.Auf Grundlage der Literatursichtung werden im Dopaminmangel begründete Dysfunktionen der endogenen Schmerzhemmung unter Beteiligung der Basalganglien, besonders des Striatums, aber auch mesolimbischer Areale als wichtige pathophysiologische Mechanismen der Auffälligkeiten in der Schmerzverarbeitung beim MP postuliert.AbstractParkinson’s disease (PD) is caused by degeneration of the dopaminergic neurons in the substantia nigra (SN) and a resulting dysfunction of the nigrostriatal pathways including the basal ganglia. Beside motor symptoms, different types of pain (e.g., dystonic musculoskeletal pain or central pain) occur in a considerable number of patients. In addition, abnormalities in pain processing have been observed in PD patients, which may present as increased pain sensitivity. The pathophysiological mechanisms involved in disturbed pain processing of PD, however, are still poorly understood.The present article gives an overview of the relevant experimental studies, investigating the abnormalities of pain processing in PD by means of electrophysiological [electroencephalography (EEG), sympathetic skin response (SSR)] and psychophysical methods [quantitative sensory testing (QST), RIII reflex threshold].Based on a review of the literature, it is postulated that dysfunction in endogenous pain inhibition caused by dopaminergic deficiency in the basal ganglia, especially in the striatum, but also in mesolimbic areas is a main pathophysiological mechanism involved in nociceptive abnormalities in PD.Parkinsons disease (PD) is caused by degeneration of the dopaminergic neurons in the substantia nigra (SN) and a resulting dysfunction of the nigrostriatal pathways including the basal ganglia. Beside motor symptoms, different types of pain (e.g., dystonic musculoskeletal pain or central pain) occur in a considerable number of patients. In addition, abnormalities in pain processing have been observed in PD patients, which may present as increased pain sensitivity. The pathophysiological mechanisms involved in disturbed pain processing of PD, however, are still poorly understood. The present article gives an overview of the relevant experimental studies, investigating the abnormalities of pain processing in PD by means of electrophysiological [electroencephalography (EEG), sympathetic skin response (SSR)] and psychophysical methods [quantitative sensory testing (QST), RIII reflex threshold]. Based on a review of the literature, it is postulated that dysfunction in endogenous pain inhibition caused by dopaminergic deficiency in the basal ganglia, especially in the striatum, but also in mesolimbic areas is a main pathophysiological mechanism involved in nociceptive abnormalities in PD.