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Background: Spontaneous intracranial hypotension (SIH) is increasingly recognized as a clinically variable and likely underdiagnosed syndrome caused by non-traumatic CSF leaks. The aim of this study was to correlate the findings of imaging studies – magnetic resonance imaging (MRI), radionuclide cisternography – with clinical features and CSF pressure in SIH in order to improve the diagnostic yield and management in patients with SIH. Methods: Clinical case study of 10 consecutive cases of SIH, MRI, radio-isotope cisternography. Results: 5 out of 10 patientshad unusual clinical symptoms of SIH(2 subdural haematomas, 1 gait ataxia, 1 tinnitus, 1 haemodialysis-associated headache). In 7 patients pachymeningeal gadolinium enhancement was detected in MRI accompanied by a reduced CSF opening pressure. In contrast, the 3 patients with normal MRI also had a normal CSF pressure. Radio-isotope cisternography was abnormal in all patients tested. There was no correlation between the severity of clinical symptoms and MRI or radionuclide cisternography findings. Conclusions: The spectrum of clinical symptoms and imaging findings in SIH is highly variable. There- fore the diagnosis of SIH is often delayed. Radio-isotope cisternography is an important additional diagnostic method to detect CSF leaks or pathological kinetics of radio-isotope movement particularly in cases with normal MRI findings.

SUMMARY Glatiramer acetate (GA) is effective in the treatment of Multiple Sclerosis (MS) presumably by the induction of an immunoregulatory T-cell response. We have previously shown that GA directly induces the Th2 cytokines IL-13 and IL-5 in T-cells in vitro. In the present study we compared the in vitro response to GA in healthy controls, untreated and GA-treated MS patients and tested whether the induction of IL-13 and IL-5 secretion is also detectable in the serum of 25 MS patients treated with GA. Patients were grouped into clinical responders and nonresponders in order to determine a possible correlation with the immunological response. As a result we found a significant increase of IL-13 in the serum of clinical GA-responders whereas IL-13 was not detectable in controls, untreated MS (P

Dendritic cells (DCs) are key regulators of immune responses and have been associated with autoimmunity in animal models and human disease. The effects of interferon beta (IFN-beta), an immunomodulatory cytokine used in multiple sclerosis (MS) therapy, on DCs are not well understood. Monocyte-derived DCs at different stages of maturation were stimulated with IFN-beta and DC-phenotype and stimulatory function were measured. IFN-beta inhibited the development of DCs at early stages but enhanced DC maturation. Moreover, IFN-beta enhanced the capacity of DCs to stimulate autologous T-cells to secrete IL-13, IL-10 and IL-5. Thus, IFN-beta has both immunostimulatory and immunosuppressive effects on DCs depending on the stage of maturation.

Interferon-beta (IFN-beta) is an effective treatment for a subgroup of patients with multiple sclerosis (MS). The mechanism of action as well as the pathophysiological basis of responsiveness to IFN-beta is not well understood. To improve treatment considerations in MS patients predictive markers for response to IFN-beta therapy at early timepoints are needed. Here we correlated changes in serum cytokine levels (IL-13, IL-10, IL-5, IL-4, IFN-gamma) with the clinical response to IFN-beta treatment. Serum cytokine levels of 77 untreated and 43 IFN-beta treated relapsing-remitting MS patients (RRMS) were measured by ELISA, including longitudinal measurements in 17 patients. We found a significant upregulation of IL-10 and IL-5 serum cytokine levels during IFN-beta therapy. However, clinical response was only associated with IL-10 serum levels (p=0.038; positive predictive value 0.95, negative predictive value 0.43) but not with IL-5. The predictive power was increased by a combined testing of IL-10 with expression of co-signaling molecules on monocytes, that were previously shown to change during IFN-beta therapy. In a subgroup of 17 patients testing of 4 markers had a positive and negative predictive value of 1.0 for at least 2 of these markers being positive in treatment responders. The results suggest that serum IL-10 is useful to predict treatment response to IFN-beta particularly in combination with a panel of other IFN-beta dependent parameters.

Interferon-beta (IFN-β) reduces disease activity in a subgroup of patients with relapsing remitting multiple sclerosis (MS). The mechanism of action as well as the pathophysiological basis of responsiveness to IFN-β is not well understood. Since T-cell activation plays an important part in the pathophysiology of MS, we here investigated the effect of IFN-β on the expression of co-signaling pathways (CD28—CD80/CD86, CD154—CD40, ICOS—ICOSL, PD-1—PD-L1/2) in MS patients and correlated the results with the clinical response to IFN-β in individual patients. Expression of co-signaling molecules was measured by flow cytometry in vitro on peripheral blood mononuclear cells after incubation with IFN-β, and in vivo in whole blood samples of 32 untreated and 24 IFN-β treated MS patients, including 13 patients longitudinal. IFN-β treatment induced upregulation of CD40, CD80, CD86, PD-L1 and PD-L2 on monocytes as well as PD-L1 on CD4+-T-cells in vitro and in vivo. IFN-β treated MS patients were grouped into responders and non-responders on the basis of Kurtzkés EDSS (expanded disability status scale) progression and relapse rate. Upregulation of CD40, CD86 and PD-L2 on monocytes was associated with treatment response to IFN-β ( P < 0.001, P = 0.028 and P = 0.028, respectively). Our results show that IFN-β upregulates co-stimulatory as well as co-inhibitory molecules in vitro and in vivo implicating that modulation of the balance between positive and negative co-stimulatory signals might be an important part of the mechanism of action of IFN-β in MS. Upregulation of the expression of CD40, CD86 and PD-L2 may be useful as a predictive marker for clinical response to IFN-β treatment at early timepoints during IFN-β therapy. Multiple Sclerosis 2008; 14: 166—176. http://msj.sagepub.com

SUMMARYInterferon (IFN)-β reduces the biological activity of multiple sclerosis (MS), a presumably T cell-mediated autoimmune disease of central nervous system (CNS) myelin. Co-stimulatory molecules are necessary for full T cell activation and differential expression of co-stimulatory molecules on antigen-presenting cells is thought to influence the type of effector T cell response (Th1/Th2). In this study we investigated the effects of IFN-β on the expression of co-stimulatory molecules on lymphocytes and monocytes as a potential mechanism of action of IFN-β in MS. Peripheral blood mononuclear cells (PBMCs) were stimulated with IFN-β in vitro and expression of CD80, CD86, CD40 and HLA was examined by flow cytometry and reverse-transcription polymerase chain reaction. Whereas IFN-β had no effect on the expression of these molecules on T and B lymphocytes there was a significant increase on monocytes. Correspondingly, the expression of mRNA increased after 6–18 h. This in vitro response was also observed in untreated MS patients and patients receiving treatment with IFN-β. The increase of co-stimulatory molecules on monocytes was not mediated by interleukin (IL)-10. When IFN-β-stimulated monocytes were used to stimulate autologous T cells an increased secretion of IL-13 was observed. In biopsies taken from IFN-β-induced skin reactions after subcutaneous injection increased expression of CD80 mRNA was detected, indicating that IFN-β also up-regulates this co-stimulatory molecule in vivo. These data provide the background for further studies of IFN-β-induced changes of co-stimulatory molecules in MS patients.

In order to define possible mechanisms of immunomodulation by glatiramer acetate (GA), we investigated the primary in vitro cytokine response of peripheral blood mononuclear cells (PBMCs) and T-cell subpopulations. In PBMCs from healthy subjects and untreated patients with multiple sclerosis (MS) GA-induced T-cell proliferation and mRNA expression/cytokine, secretion of IL-13 and IL-5 but not of IL-10, TGF-beta or IL-12, IL-4 was detected at the mRNA level only. IFN-gamma was induced in a few subjects at very low concentrations. The response to GA was driven by the CD4(+)/CD45RA(+) T-cell subpopulation and was mediated by T-cell receptor (TCR) engagement as determined by anti-TCR blocking antibodies. The findings are compatible with the hypothesis that GA functions as partial or weak TCR-agonist activating naive T cells to produce the Th2 cytokines IL-13 and IL-5.