Plasma cell depletion with bortezomib in the treatment of refractory N-methyl-d-aspartate (NMDA) receptor antibody encephalitis. Rational developments in neuroimmunological treatment.

BACKGROUND AND PURPOSE: The aim was to assess the therapeutic potential of bortezomib in the treatment of refractory N-methyl-d-aspartate receptor (NMDAR) antibody encephalitis and its potential in other immune-mediated, B-cell-driven neurological diseases. METHODS: Two cases of severe NMDAR antibody encephalitis, resistant to first and second line therapy with steroids, intravenous immunoglobulins, plasma exchange, cyclophosphamide and rituximab, were treated with four and five cycles of 1.3 mg/m2 bortezomib at 350 and 330 days following initial presentation. RESULTS: Both patients showed significant clinical improvement with reductions of NMDAR antibody titres following bortezomib treatment. This is the first case in the literature where the NMDAR antibody level was undetectable following treatment with bortezomib. CONCLUSION: Bortezomib's unique ability to target long-lived autoreactive plasma cells appears to be a useful adjunct to standard second line immunosuppressive therapy in treatment-refractory NMDAR antibody encephalitis. The drug's pharmacodynamics, cell targeting and mechanism of action are reviewed, and it is postulated that bortezomib may be useful in a host of B-cell-driven neuroimmunological diseases.

First use of alemtuzumab in Balo's concentric sclerosis: a case report.

Balo's concentric sclerosis (BCS) is a rare demyelinating disorder of the central nervous system. The humanised monoclonal antibody alemtuzumab has shown efficacy in another demyelinating disorder, relapsing-remitting multiple sclerosis. We aimed to explore its efficacy in treatment-refractory BCS. A 52-year-old male with radiologically confirmed progressive BCS resistant to steroids, plasmapharesis and cyclophosphamide was administered a standard protocol of alemtuzumab. Treatment failed to slow his decline; he died 6 months after administration. Why alemtuzumab induced no clinical or radiological impact may be multifactorial. We review the evidence directing BCS therapy and propose the next steps for exploring this potentially fatal condition.

Human fetal neural precursor cells can up-regulate MHC class I and class II expression and elicit CD4 and CD8 T cell proliferation.

The use of allogeneic fetal neural precursor cells (NPCs) as a cell replacement therapy in neurodegenerative disorders holds great promise. However, previous studies concerning the possibility of alloimmune rejection of the transplanted cells have been inconclusive. Here, we used flow cytometry to quantify the expression of major histocompatibility complex (MHC) molecules by human NPCs, obtained from the cortex or ventral mesencephalon of fetuses with gestational ages between 7 and 11 weeks. MHC class I was undetectable on the surface of freshly isolated primary fetal tissue from either location, but increased over time in proliferating NPC cultures; after 7days in vitro, MHC class I was detectable on most cells. Following differentiation, MHC class I expression persisted on non-neuronal cells. MHC class II levels remained low at all time points but were inducible by pro-inflammatory cytokines, whereas the co-stimulatory molecules, CD80 and CD86, remained undetectable. Nonetheless, CD4+ and CD8+ T cells proliferated when peripheral blood mononuclear cells (PBMCs) were cultured with allogeneic NPCs. Weaker responses were obtained when NPCs were co-cultured with purified allogeneic responder T cells, suggesting that indirect allorecognition contributed significantly to PBMC responses. In conclusion, differentiating human NPCs are immunogenic in vitro, suggesting that they may trigger immune rejection unless transplant recipients are immunosuppressed.

A method to isolate and cryopreserve cerebrospinal fluid mononuclear cells from external ventricular drains to investigate immunological processes in acute brain injuries.

The inflammatory response to acute brain injuries is a key contributor to subsequent outcome. The study of local central nervous system inflammatory responses is hindered by raised intracranial pressure precluding cerebrospinal fluid sampling by lumbar puncture. External ventricular drains are sited in some acute brain injury patients to divert cerebrospinal fluid and thus reduce intracranial pressure, and represent a potential route to safely gather large volumes of cerebrospinal fluid for immunological studies. In this manuscript we show that mononuclear cells can be isolated from cerebrospinal fluid collected from external ventricular drains, and that the large volumes of cerebrospinal fluid available yield sufficient mononuclear cells to allow cryopreservation. Prolonged storage of cerebrospinal fluid in the external ventricular drain collection bag can alter the phenotype of cells recovered, but the predicted effect of this can be estimated for a given flow cytometry panel by assessing the changes in peripheral blood mononuclear cells exposed to the same conditions. The described method will allow clinical studies of acute brain injuries to investigate the immunological processes occurring within the central nervous system compartment, rather than relying on changes in the peripheral circulation.

The immunological response to traumatic brain injury.

Traumatic brain injury (TBI) is the leading cause of death and disability in young adults in the developed world. The accuracy of early outcome-prediction remains poor even when all known prognostic factors are considered, suggesting important currently unidentified variables. In addition, whilst survival and neurological outcomes have improved markedly with the utilisation of therapies that optimise physiology, no treatments specifically modulate the underlying pathophysiology. The immunological response to TBI represents both a potential contributor to outcome heterogeneity and a therapeutically tractable component of the acute disease process. Furthermore, chronic inflammation has been linked with neurodegeneration, and may mark a bridge between acute brain injury and the subsequent neurodegenerative process seen in a proportion of patients following TBI. Given the complexity of the immune response and its varying functions ranging from repair of injury to bystander damage of healthy tissue, attempts at immunomodulatory intervention must necessarily be highly targeted towards the maladaptive facets of the inflammatory process. In this review we aim to provide an integrated description of the immunological processes triggered by TBI in both humans and animal models, in particular considering the interplay between the innate immune system, danger-associated molecular patterns and loss of self-tolerance leading to adaptive autoimmunity.

An investigation of auto-reactivity after head injury.

Murine models of CNS injury show auto-reactive T cell responses directed at myelin antigens, associated with improved neuronal survival and functional recovery. This pilot study shows, for the first time, that similar immune responses against myelin occur in human traumatic brain injury (TBI), with an expansion of lymphocytes recognising myelin basic protein observed in 40% of patients studied. "Reactive" patients did not have greater contusion volume on imaging, but were younger than the "unreactive" subgroup and tended towards a more favorable outcome. These findings are consistent with the concept of "beneficial autoimmunity".

Quantitative MRI in patients with secondary progressive MS treated with monoclonal antibody Campath 1H.

BACKGROUND: To assess the long-term effect of the lymphocyte-depleting humanized monoclonal antibody Campath 1H on MR markers of disease activity and progression in secondary progressive MS patients. METHODS: Twenty-five patients participated in a crossover treatment trial with monthly run-in MR scans for 3 months, followed (after a single pulse of Campath 1H) by monthly MR scans from months 1 to 6 and again from months 12 to 18. MR analysis was performed to provide measurements of the number and volume of gadolinium (Gd)-enhancing lesions as well as the hypointense lesion volume on a T1-weighted sequence. In addition, serial measurements of T2 brain lesion volume, brain volume, and spinal cord cross-sectional area were made over the duration of the study. The relationship between clinical and MR measures of disease evolution was also assessed. RESULTS: Treatment was associated with a reduction in the number and volume of Gd-enhancing lesions (p < 0.01). Despite this, a decrease in brain volume was seen in 13 patients during the 18 months post-treatment. The mean pretreatment Gd-enhancing lesion volume was predictive of subsequent reduction in brain volume (r = 0.77, p = 0.002). Reduction in brain volume also correlated with the change in T1 hypointense lesion volume after treatment (r = 0.53, p < 0.01). A reduction in spinal cord area was also seen throughout the study duration, and this correlated with an increase in disability (r = 0.65, p = 0.01). CONCLUSION: Campath 1H treatment was associated with a sustained and marked reduction in the volume of Gd enhancement, indicating suppression of active inflammation. Nevertheless, many patients developed increasing brain and spinal cord atrophy, T1 hypointensity, and disability. This study highlights the potential role for novel MR techniques in monitoring the effect of treatment on the pathologic process in MS.

Analysis of the human serological response to Chlamydia trachomatis 60-kDa proteins by two-dimensional electrophoresis and immunoblotting.

Earlier analyses of sera from humans and animals with chlamydial infections demonstrated a strong immune response to proteins of approximately 60 kDa. We have used two-dimensional (2D) electrophoresis followed by immunoblotting to more accurately define patient responses to the chlamydial 60-kDa cysteine-rich envelope protein (OMP2) and to the 57-kDa stress protein (SP) implicated in immunopathological damage. OMP2 and SP were separated on 2D gels by their distinct isoelectric points and identified by fluorography of [35S]-labelled proteins and cross-reaction with anti-mycobacterial antiserum, respectively. The majority of patients sera showed a strong reaction both to OMP2 and the SP (18/20 and 17/20 sera, respectively). Fewer sera (9/20 and 10/20 sera, respectively) reacted with two other polypeptides also present in the 60-kDa range by this analysis.

Low-nutrient induction of abnormal chlamydial development: a novel component of chlamydial pathogenesis?

The intracellular development of chlamydiae in McCoy cells incubated in Eagle's minimal essential medium lacking all 13 amino acids was examined both by fluorescence and electron microscopy and by infectivity titration. Aberrant development occurred in almost all inclusions of strains of Chlamydia trachomatis and C. psittaci with the production of abnormal forms which differed in size, shape and internal structure from normal reticulate and elementary body forms. Detailed analysis of the response of C. trachomatis L2 strain 434 to graded reductions in amino acid level showed that infectivity was reduced and morphological abnormality increased as amino acid concentrations were lowered from 33 to 0% of amino acids present in minimal essential medium. Reversion of inclusions to normal and reappearance of infectious forms occurred on restoration of amino acids and further incubation. It is suggested that aberrant development may account for the presence in vivo of non-cultivable chlamydiae and that such development can arise via tryptophan deprivation mediated by local release of interferon gamma.

Informed choice in cancer pain: empowering the patient.

Cancer and palliative care service users can often feel isolated and disempowered. (Tower, 1999). Physical changes, medical interventions and pain can mean that they no longer feel in control of their bodies or their futures. In recognition of this, many health professionals within cancer and palliative care have adopted the mantra of 'patient empowerment', but it is not always clear what it means for either the patients or the professionals. Empowerment is an interactive process that develops and increases power through cooperation, sharing and working together (Marquis and Huston, 2000), and it plays a central role in health professionals' personal and working lives. A person's ability to make decisions and choices demonstrates control of his or her own destiny. This article aims to direct health professionals' participation and involvement in restoring this ability to patients who have pain related to cancer.

Sample sizes for lesion magnetisation transfer ratio outcomes in remyelination trials for multiple sclerosis.

BACKGROUND: Enhancing remyelination in MS might improve function and protect axons from future damage. Lesion magnetisation transfer ratio (MTR) is sensitive to myelin content, and may be a useful measure for trials evaluating potential remyelinating agents. OBJECTIVE: Estimating sample sizes required for a parallel group, placebo-controlled trial in MS using change in mean MTR of all T2lesions as a primary outcome measure. METHODS: The primary sample size calculation was derived from data from a natural history study of relapsing remitting MS (n=18). The MTR values observed in demyelinated and remyelinated lesions in an ex vivo study were used to estimate the effect of remyelination on lesion MTR. The ex vivo data were also used to independently calculate sample sizes in order to inform the robustness of the in vivo estimates. RESULTS: Calculations suggest that 30% remyelination of T2 lesions could be detected with 80% power in 38 (95% confidence interval 12-96) patients per arm based on the in vivo data, and in 66 per arm based on the ex vivo data. CONCLUSION: The sample sizes derived are in a range that makes MTR a feasible outcome measure for proof-of-concept trials of putative therapies achieving remyelination in MS lesions.

Alemtuzumab more effective than interferon ß-1a at 5-year follow-up of CAMMS223 clinical trial.

OBJECTIVE: To report the long-term safety and efficacy results from CAMMS223 comparing alemtuzumab with interferon ß-1a in early, active relapsing-remitting multiple sclerosis (RRMS). What are the long-term effects of alemtuzumab treatment, received 36 to 48 months previously, on relapse and disability in early, active RRMS? This study provides evidence of the effectiveness of alemtuzumab in reducing the relapse rate and accumulation of disability compared with interferon ß-1a (IFNß-1a) through extended follow-up (up to 60 months from baseline). METHODS: Of 334 patients originally randomized, 198 participated in the extension phase (151 [68%] alemtuzumab and 47 [42%] IFNß-1a). Disability, relapses, and safety were assessed as in the original study period. Efficacy outcomes were analyzed from baseline of the original trial period to 60 months. Safety data extended beyond 60 months. RESULTS: Over 5 years, alemtuzumab lowered the risk of sustained accumulation of disability by 72% and the rate of relapse by 69% compared with IFNß-1a (both p < 0.0001). The annualized relapse rate from baseline to month 60 was 0.11 for alemtuzumab and 0.35 for IFNß-1a. Complete safety follow-up reflected 988 and 376 person-years for alemtuzumab and IFNß-1a patients, respectively. Serious infections were seen in 7% of alemtuzumab patients and 3% of IFNß-1a patients, and thyroid disorders were seen in 30% of alemtuzumab patients vs 4% of IFNß-1a patients. Immune thrombocytopenia occurred in 3% of alemtuzumab patients and 0.9% of IFNß-1a patients during the initial study period; no additional events were reported during the extension phase. One alemtuzumab patient developed Goodpasture disease 39 months after the second annual cycle of alemtuzumab. CONCLUSIONS: Through extended follow-up, alemtuzumab remained significantly more efficacious than IFNß-1a, with a safety profile consistent with previous reports. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that alemtuzumab is more effective than interferon ß-1a in reducing relapses and disability in patients with RRMS in a long-term follow-up of a rater-blinded, randomized clinical trial with 59.5% of patients participating in the extended follow-up period.

Autoimmune disease after alemtuzumab treatment for multiple sclerosis in a multicenter cohort.

OBJECTIVE: To define the rate, timing, and clinical risk factors for the development of autoimmune disease (AID) after alemtuzumab treatment for multiple sclerosis (MS). METHODS: We analyzed prospective clinical and serologic data from 248 patients with MS treated with alemtuzumab, with median follow-up of 34.3 months (range 6.7-107.3). RESULTS: Novel AID developed in 22.2%. Thyroid AID was most frequent (15.7%). A range of hematologic, renal, and dermatologic AID were also observed as was asymptomatic development of novel autoantibodies. AID was seen from 2 weeks after initial treatment and was most frequent 12-18 months after first treatment. No new cases of AID were identified 60 months or more after initial treatment and risk of AID was independent of total alemtuzumab dose or interval of dosage. While established risk factors for AID including sex and age had no impact on AID frequency, both family history (odds ratio = 7.31, 95% confidence interval 3.02-17.68) of AID and a personal smoking history (odds ratio = 3.05, 95% confidence interval 1.50-6.19) were predictive of AID expression. CONCLUSIONS: Cumulative risk for AID in MS following alemtuzumab is 22.2%, most frequent between 12 and 18 months following first dose and evident for up to 5 years. Individual risk is modified by smoking and family history, which should be incorporated within the counseling process prior to treatment. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that the risk of AID after alemtuzumab treatment for MS is time-limited and modified by external factors.

Alemtuzumab in the treatment of IVIG-dependent chronic inflammatory demyelinating polyneuropathy.

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an idiopathic immune mediated neuropathy causing demyelination and conduction block thought to occur as the result of an aberrant autoimmune response resulting in peripheral nerve inflammation mediated by T cells and humoral factors. Diagnosis commonly prompts initial treatment with steroids or intravenous immunoglobulin (IVIG) on which 5-35% subsequently become dependent to maintain function. Despite a number of small scale trials, the role for alternative long-term immunosuppression remains unclear. Alemtuzumab is a humanised monoclonal antibody targeting the CD52 antigen present on the surface of lymphocytes and monocytes. A single intravenous infusion results in rapid and profound lymphopoenia lasting >12 months. We report its use and clinical outcome in a small series of patients with severe IVIG-dependent CIDP. Seven patients (4 Males; 3 Females) who had failed to respond to conventional immunosuppression were treated in 5 centres receiving 9 courses of alemtuzumab (dose range 60-150 mg). Following treatment, mean monthly IVIG use fell 26% from 202 to 149 g and IVIG administration frequency from 22 to 136 days. Two patients had prolonged remission, two patients had a partial response and no clear benefit was observed in the remaining three patients (2 Males, 1 Females). Responding patients had a younger age at onset (19.5 years) and shorter disease duration than non-responders. Three patients developed autoimmune disease following treatment. Alemtuzumab may offer an alternative treatment for a subset of early onset IVIG dependent CIDP patients failing conventional immunosuppressive agents, but concerns about toxicity may limit its use.

Spotlight on alemtuzumab.

Alemtuzumab, formally known as Campath-1H, is a humanized monoclonal antibody directed against CD52, a protein on the surface of lymphocytes and monocytes with unknown function. A single dose of alemtuzumab leads to a rapid, profound and prolonged lymphopenia. A Phase II trial has shown that alemtuzumab reduces the risk of relapse and accumulation of disability by over 70% compared with interferon beta in patients with early relapsing-remitting multiple sclerosis (MS). Alemtuzumab has been used in Cambridge as an experimental treatment for MS since 1991. In this review we summarize our experience; describing how this prototypical, "bench-to-bedside" therapy continues to inform basic science, revealing aspects of the pathogenesis of MS and lymphopeniaassociated autoimmunity.

Rationale for cytotoxic monoclonal antibodies in MS.

Monoclonal antibodies (MAbs) have been used to treat human disease for over 20 years, and have found a range of applications, predominantly in inflammatory and neoplastic disorders. They are attractive therapies due to their unique specificity and capacity for production on an industrial scale. Cytotoxic MAbs, those that trigger lysis of their cellular target, were first used to probe experimental allergic encephalomyelitis, the standard animal model of MS. Since then, antibodies with specificity for a variety of lymphocytic antigens have been used in MS, with variable results. On the basis of experience with the anti-CD52 antibody, alemtuzumab (Campath-1H), it has been postulated that clinical efficacy of some MAbs in MS may not result from cellular depletion, but from the immunomodulatory effect of the subsequent immune system reconstitution.