No effect of intravenous immunoglobulins on cytokine-producing lymphocytes in secondary progressive multiple sclerosis

Therapeutic approaches to multiple sclerosis: an update on failed, interrupted, or inconclusive trials of neuroprotective and alternative treatment strategies

Currently approved multiple sclerosis (MS) therapeutics have a mainly anti-inflammatory mode of action. However, a number of promising clinical trials have been initiated that either focus on neuroprotection or follow completely different treatment strategies. So far, all of these clinical trials have failed to show efficacy or had to be halted prematurely because of unexpected adverse events. Some others show results that are of unknown significance with regard to a reliable assessment of true efficacy versus safety. For example, trials addressing the highly promising sodium channel blockers are under close observation because of potential adverse effects after drug withdrawal. Previously failed therapeutic approaches in MS have indicated that there are discrepancies between the theoretical expectations and practical outcomes of different compounds. Learning from these failures helps to optimize future study designs and to reduce risks to patients. This review summarizes trials on MS treatments since 2001 that failed or were interrupted, attempts to analyze the underlying reasons for failure, and discusses the implications for our current view of MS pathogenesis, clinical practice, and the design of future studies. In order to maintain clarity, this review focuses on neuroprotective and various other treatment strategies. Clinical trials addressing anti-inflammatory research strategies are presented elsewhere.

Evidence for the use of intravenous immunoglobulins--a review of the literature

Intravenous immunoglobulins (IVIg) were first introduced in the middle of the twentieth century for the treatment of primary immunodeficiencies. In 1981, Paul Imbach noticed an improvement of immune-mediated thrombocytopenia, in patients receiving IVIg for immunodeficiencies. This opened a new era for the treatment of autoimmune conditions with IVIg. Since then, IVIg has become an important treatment option in a wide spectrum of diseases, including autoimmune and acute inflammatory conditions, most of them off-label (not included in the US Food and Drug Administration recommendation). A panel of immunologists and internists with experience in IVIg therapy reviewed the medical literature for published data concerning treatment with IVIg. The quality of evidence was assessed, and a summary of the available relevant literature in each disease was given. To our knowledge, this is the first all-inclusive comprehensive review, developed to assist the clinician when considering the use of IVIg in autoimmune diseases, immune deficiencies, and other conditions.

Rituximab levels in cerebrospinal fluid of patients with neurological autoimmune disorders

BACKGROUND

Rituximab, a monoclonal antibody against the B-cell-specific surface protein CD20, is being evaluated for treatment of multiple sclerosis and neuromyelitis optica. Both diseases are restricted to the brain and cerebrospinal fluid (CSF). Whereas the ability of rituximab to deplete B cells in peripheral blood and tissue is well known, little information is available about the ability of rituximab to penetrate the barriers separating brain and CSF from the serum compartment.

OBJECTIVE

To measure rituximab levels in serum and CSF of rituximab-treated patients and correlate them with CSF and response markers.

METHODS

Fourteen paired serum/CSF samples of patients with autoimmune nervous system disorder were analyzed for up to 43 weeks after rituximab application.

RESULTS

Rituximab remains detectable within the CSF after i.v. application for up to 24 weeks. Furthermore, levels of rituximab in CSF correlate significantly with the integrity of the blood CSF barrier.

Rituximab in a patient with multiple sclerosis--effect on B cells, plasma cells and intrathecal IgG synthesis

OBJECTIVE

To study the time course of immunoglobulin, B and plasma cells in the blood and cerebrospinal fluid (CSF) before and during rituximab treatment in a patient with severe relapsing-remitting multiple sclerosis (MS) in relation to clinical and MRI findings.

METHODS

Immunoglobulins in the CSF were measured by nephelometry and detected by isoelectrical focussing. CSF and blood cell subtypes from seven time points were analysed by flow cytometry.

RESULTS

Treatment with rituximab induced a dramatic and sustained improvement in clinical and MRI findings over a follow-up period of 20 months. By contrast, the initially completely suppressed B and plasma cells in both the blood and CSF reappeared after 5 and 10 months, CSF cells being the first to reappear. Interestingly, intrathecal IgG synthesis persisted throughout the study period.

DISCUSSION

Although highly effective in this case, the clinical effect in larger series and the mechanism of rituximab in MS deserves further evaluation.