Effectiveness of autologous haematopoietic stem cell transplantation versus natalizumab in progressive multiple sclerosis.

BACKGROUND: Natalizumab was not shown to modify disability in progressive multiple sclerosis (MS). This matched observational study compared the effectiveness of autologous haematopoietic stem cell transplantation (AHSCT) with natalizumab in progressive MS. METHODS: Patients with primary/secondary progressive MS from seven AHSCT MS centres and the MSBase registry, treated with AHSCT or natalizumab, were matched on a propensity score derived from sex, age, Expanded Disability Status Scale (EDSS), number of relapses 12/24 months before baseline, time from MS onset, the most effective prior therapy and country. The pairwise-censored groups were compared on hazards of 6-month confirmed EDSS worsening and improvement, relapses and annualised relapse rates (ARRs), using Andersen-Gill proportional hazards models and conditional negative binomial model. RESULTS: 39 patients treated with AHSCT (37 with secondary progressive MS, mean age 37 years, EDSS 5.7, 28% with recent disability progression, ARR 0.54 during the preceding year) were matched with 65 patients treated with natalizumab. The study found no evidence for difference in hazards of confirmed EDSS worsening (HR 1.49, 95% CI 0.70 to 3.14) and improvement (HR 1.50, 95% CI 0.22 to 10.29) between AHSCT and natalizumab over up to 4 years. The relapse activity was also similar while treated with AHSCT and natalizumab (ARR: mean±SD 0.08±0.28 vs 0.08±0.25; HR 1.05, 95% CI 0.39 to 2.82). In the AHSCT group, 3 patients experienced febrile neutropenia during mobilisation, 9 patients experienced serum sickness, 6 patients required intensive care unit admission and 36 patients experienced complications after discharge. No treatment-related deaths were reported. CONCLUSION: This study does not support the use of AHSCT to control disability in progressive MS with advanced disability and low relapse activity.

Neutropaenia complications from Ocrelizumab and Rituximab treatment.

Ocrelizumab is an anti-CD20 monoclonal antibody (mAb) that has been shown in phase 3 clinical trials to reduce relapses and disease progression in multiple sclerosis (MS) patients. Prior to the approval of ocrelizumab, rituximab, a chimeric anti-CD20 mAb was used to treat MS. Rituximab is still used to treat MS in many countries outside of Australia and remains mainstay of treatment of many non-MS neuroimmunological and systemic inflammatory diseases. Rituximab is currently used in neuromyelitis optica spectrum disorder (NMOSD) and autoimmune encephalitis, in addition to its widespread usage in hematological malignancies and systemic inflammatory diseases. Ocrelizumab is currently approved in Australia for treatment of relapsing-remitting MS (RRMS). Neutropaenia is a rare complication of both ocrelizumab and rituximab treatment. This case series reports 12 patients who have experienced neutropaenia following ocrelizumab or rituximab treatment and aims to characterize the clinical parameters of neutropaenia experienced by these patients, including the severity and duration of neutropaenia, length of hospital admission, the types of subsequent infections experienced and types of treatment necessary before patients reached count recovery. The unpredictability of neutropaenia and potential for serious infections highlight the need for continued hematological monitoring for patients on B-cell depleting therapies and calls for careful patient counselling to provide guidance on whether to continue such therapies in patients who have experienced related neutropaenia.

Detailed immunophenotyping of the hematopoietic graft from patients with multiple sclerosis undergoing autologous hematopoietic stem cell transplant.

BACKGROUND AIMS: Autologous hematopoietic stem cell transplantation (AHSCT) is a highly effective therapy for relapsing multiple sclerosis. Re-infused stem cells provide "rescue" from the pancytopenia induced by immuno-chemotherapy. To date, no study has analyzed the non-stem cell content of the leukapheresis product (graft) in regards to its influence on disease remission in AHSCT for multiple sclerosis (MS). METHODS: Detailed immunophenotyping of the stem cell graft was performed in a cohort of highly active patients with MS (n = 22) followed for a median of 6 years' post-AHSCT. RESULTS: Effector memory populations thought to house pathogenic clones including Th17 cells and central nervous system homing T cells were detected in the graft at similar proportions to pre-AHSCT. There was no association between absolute counts of these populations in the graft and treatment response. Only in responder patients was there evidence of a significant decrease in these putative pro-inflammatory populations by 3 months' post-transplant. Although there was no statistical difference in the number of T regulatory cells (Tregs) in the graft between responders and relapsing patients, the absolute count of Tregs in the graft correlated with circulating Tregs in the first 6 months post-AHSCT in responders alone. CONCLUSIONS: Our results collectively suggest that the early establishment of immune tolerance post-AHSCT appears to relate to a decrease in putative pathogenic cell populations following reinfusion, and that Treg load in the leukapheresis product is less relevant to treatment response than the early expansion of graft-derived Tregs. It therefore remains unclear whether employment of CD34 selection to manipulate the graft may offer additional benefit in remission rates post-AHSCT for MS. Cellular therapy targeted toward early Treg expansion may provide recourse for long-term remission rates in MS.

Diversification and expansion of the EBV-reactive cytotoxic T lymphocyte repertoire following autologous haematopoietic stem cell transplant for multiple sclerosis.

Both genetic susceptibility and environmental exposures are thought to be involved in multiple sclerosis (MS) pathogenesis. Of all viruses potentially relevant to MS aetiology, Epstein-Barr virus (EBV) is the best-studied. EBV is a B cell lymphotropic virus which is able to evade the immune system by establishing latent infection in memory B cells, and EBV reactivation is restricted by CD8 cytotoxic T cell (CTL) responses in immune competent individuals. Autologous haematopoietic stem cell transplantation (AHSCT) is considered to be the most effective therapy in the treatment of relapsing MS even though chemotherapy-induced lymphopenia can associate with the re-emergence of latent viruses. Despite the increasing interest in EBV and MS pathogenesis the relationship between AHSCT, EBV and viral immunity in people with MS has not been investigated to date. This study analysed immune responses to EBV in a well characterised cohort of 13 individuals with MS by utilising pre-AHSCT, and 6-, 12- and 24-month post AHSCT bio-banked peripheral blood mononuclear cells and plasma samples. It is demonstrated that the infused stem cell product contains latently EBV-infected memory B cells, and that EBV viremia occurs in the immune-compromised recipient post-transplant. High throughput TCR analysis detected expansion and diversification of the CD8 CTL responses reactive with EBV lytic and latent antigens from 6 to 24 months following AHSCT. Increased levels of latent EBV infection found within the B cell pool following treatment, as measured by EBV genomic detection, did not associate with disease relapse. This is the first study of EBV immunity following application of AHSCT in the treatment of MS and not only raises important questions about the role of EBV infection in MS pathogenesis, but is of clinical importance given the expanding clinical trials of adoptive EBV-specific CTLs in MS.

Comparative Effectiveness of Autologous Hematopoietic Stem Cell Transplant vs Fingolimod, Natalizumab, and Ocrelizumab in Highly Active Relapsing-Remitting Multiple Sclerosis.

Importance: Autologous hematopoietic stem cell transplant (AHSCT) is available for treatment of highly active multiple sclerosis (MS). Objective: To compare the effectiveness of AHSCT vs fingolimod, natalizumab, and ocrelizumab in relapsing-remitting MS by emulating pairwise trials. Design, Setting, and Participants: This comparative treatment effectiveness study included 6 specialist MS centers with AHSCT programs and international MSBase registry between 2006 and 2021. The study included patients with relapsing-remitting MS treated with AHSCT, fingolimod, natalizumab, or ocrelizumab with 2 or more years study follow-up including 2 or more disability assessments. Patients were matched on a propensity score derived from clinical and demographic characteristics. Exposure: AHSCT vs fingolimod, natalizumab, or ocrelizumab. Main outcomes: Pairwise-censored groups were compared on annualized relapse rates (ARR) and freedom from relapses and 6-month confirmed Expanded Disability Status Scale (EDSS) score worsening and improvement. Results: Of 4915 individuals, 167 were treated with AHSCT; 2558, fingolimod; 1490, natalizumab; and 700, ocrelizumab. The prematch AHSCT cohort was younger and with greater disability than the fingolimod, natalizumab, and ocrelizumab cohorts; the matched groups were closely aligned. The proportion of women ranged from 65% to 70%, and the mean (SD) age ranged from 35.3 (9.4) to 37.1 (10.6) years. The mean (SD) disease duration ranged from 7.9 (5.6) to 8.7 (5.4) years, EDSS score ranged from 3.5 (1.6) to 3.9 (1.9), and frequency of relapses ranged from 0.77 (0.94) to 0.86 (0.89) in the preceding year. Compared with the fingolimod group (769 [30.0%]), AHSCT (144 [86.2%]) was associated with fewer relapses (ARR: mean [SD], 0.09 [0.30] vs 0.20 [0.44]), similar risk of disability worsening (hazard ratio [HR], 1.70; 95% CI, 0.91-3.17), and higher chance of disability improvement (HR, 2.70; 95% CI, 1.71-4.26) over 5 years. Compared with natalizumab (730 [49.0%]), AHSCT (146 [87.4%]) was associated with marginally lower ARR (mean [SD], 0.08 [0.31] vs 0.10 [0.34]), similar risk of disability worsening (HR, 1.06; 95% CI, 0.54-2.09), and higher chance of disability improvement (HR, 2.68; 95% CI, 1.72-4.18) over 5 years. AHSCT (110 [65.9%]) and ocrelizumab (343 [49.0%]) were associated with similar ARR (mean [SD], 0.09 [0.34] vs 0.06 [0.32]), disability worsening (HR, 1.77; 95% CI, 0.61-5.08), and disability improvement (HR, 1.37; 95% CI, 0.66-2.82) over 3 years. AHSCT-related mortality occurred in 1 of 159 patients (0.6%). Conclusion: In this study, the association of AHSCT with preventing relapses and facilitating recovery from disability was considerably superior to fingolimod and marginally superior to natalizumab. This study did not find evidence for difference in the effectiveness of AHSCT and ocrelizumab over a shorter available follow-up time.

From bedside to bench: how existing therapies inform the relationship between Epstein-Barr virus and multiple sclerosis.

Therapy for relapsing-remitting multiple sclerosis (MS) has advanced dramatically despite incomplete understanding of the cause of the condition. Current treatment involves inducing broad effects on immune cell populations with consequent off-target side effects, and no treatment can completely prevent disability progression. Further therapeutic advancement will require a better understanding of the pathobiology of MS. Interest in the role of Epstein-Barr virus (EBV) in multiple sclerosis has intensified based on strong epidemiological evidence of an association between EBV seroprevalence and MS. Hypotheses proposed to explain the biological relationship between EBV and MS include molecular mimicry, EBV immortalised autoreactive B cells and infection of glial cells by EBV. Examining the interaction between EBV and immunotherapies that have demonstrated efficacy in MS offers clues to the validity of these hypotheses. The efficacy of B cell depleting therapies could be consistent with a hypothesis that EBV-infected B cells drive MS; however, loss of T cell control of B cells does not exacerbate MS. A number of MS therapies invoke change in EBV-specific T cell populations, but pathogenic EBV-specific T cells with cross-reactivity to CNS antigen have not been identified. Immune reconstitution therapies induce EBV viraemia and expansion of EBV-specific T cell clones, but this does not correlate with relapse. Much remains unknown regarding the role of EBV in MS pathogenesis. We discuss future translational research that could fill important knowledge gaps.

Glioblastoma cells have increased capacity to repair radiation-induced DNA damage after migration to the olfactory bulb.

BACKGROUND: The invasive nature of GBM combined with the diversity of brain microenvironments creates the potential for a topographic heterogeneity in GBM radioresponse. Investigating the mechanisms responsible for a microenvironment-induced differential GBM response to radiation may provide insights into the molecules and processes mediating GBM radioresistance. METHODS: Using a model system in which human GBM stem-like cells implanted into the right striatum of nude mice migrate throughout the right hemisphere (RH) to the olfactory bulb (OB), the radiation-induced DNA damage response was evaluated in each location according to γH2AX and 53BP1 foci and cell cycle phase distribution as determined by flow cytometry and immunohistochemistry. RNAseq was used to compare transcriptomes of tumor cells growing in the OB and the RH. Protein expression and neuron-tumor interaction were defined by immunohistochemistry and confocal microscopy. RESULTS: After irradiation, there was a more rapid dispersal of γH2AX and 53BP1 foci in the OB versus in the RH, indicative of increased double strand break repair capacity in the OB and consistent with the OB providing a radioprotective niche. With respect to the cell cycle, by 6 h after irradiation there was a significant loss of mitotic tumor cells in both locations suggesting a similar activation of the G2/M checkpoint. However, by 24 h post-irradiation there was an accumulation of G2 phase cells in the OB, which continued out to at least 96 h. Transcriptome analysis showed that tumor cells in the OB had higher expression levels of DNA repair genes involved in non-homologous end joining and genes related to the spindle assembly checkpoint. Tumor cells in the OB were also found to have an increased frequency of soma-soma contact with neurons. CONCLUSION: GBM cells that have migrated to the OB have an increased capacity to repair radiation-induced double strand breaks and altered cell cycle regulation. These results correspond to an upregulation of genes involved in DNA damage repair and cell cycle control. Because the murine OB provides a source of radioresistant tumor cells not evident in other experimental systems, it may serve as a model for investigating the mechanisms mediating GBM radioresistance.

Haematopoietic Stem Cell Transplantation Results in Extensive Remodelling of the Clonal T Cell Repertoire in Multiple Sclerosis.

Autologous haematopoietic stem cell transplantation (AHSCT) is a vital therapeutic option for patients with highly active multiple sclerosis (MS). Rates of remission suggest AHSCT is the most effective form of immunotherapy in controlling the disease. Despite an evolving understanding of the biology of immune reconstitution following AHSCT, the mechanism by which AHSCT enables sustained disease remission beyond the period of lymphopenia remains to be elucidated. Auto-reactive T cells are considered central to MS pathogenesis. Here, we analyse T cell reconstitution for 36 months following AHSCT in a cohort of highly active MS patients. Through longitudinal analysis of sorted naïve and memory T cell clones, we establish that AHSCT induces profound changes in the dominant T cell landscape of both CD4+ and CD8+ memory T cell clones. Lymphopenia induced homeostatic proliferation is followed by clonal attrition; with only 19% of dominant CD4 (p <0.025) and 13% of dominant CD8 (p <0.005) clones from the pre-transplant repertoire detected at 36 months. Recovery of a thymically-derived CD4 naïve T cell repertoire occurs at 12 months and is ongoing at 36 months, however diversity of the naïve populations is not increased from baseline suggesting the principal mechanism of durable remission from MS after AHSCT relates to depletion of putative auto-reactive clones. In a cohort of MS patients expressing the MS risk allele HLA DRB1*15:01, public clones are probed as potential biomarkers of disease. AHSCT appears to induce sustained periods of disease remission with dynamic changes in the clonal T cell repertoire out to 36 months post-transplant.

Sustained immunotolerance in multiple sclerosis after stem cell transplant.

OBJECTIVE: Autologous haematopoietic stem cell transplantation (AHSCT) has the potential to induce sustained periods of disease remission in multiple sclerosis (MS), which is an inflammatory disease of the central nervous system (CNS) characterised by demyelination and axonal degeneration. However, the mechanisms associated with durable treatment responses in MS require further elucidation. METHODS: To characterise the longer term immune reconstitution effects of AHSCT at 24 and 36 months (M) post-transplant, high-dimensional immunophenotyping of peripheral blood mononuclear cells from 22 MS patients was performed using two custom-designed 18-colour flow cytometry panels. RESULTS: The higher baseline frequencies of specific pro-inflammatory immune cells (T-helper-17 (Th17) cells, mucosal-associated invariant T-cells and CNS-homing T-conventional (T-conv) cells observed in MS patients were decreased post-AHSCT by 36M. This was accompanied by a post-AHSCT increase in frequencies and absolute counts of immunoregulatory CD56hi natural killer cells at 24M and terminally differentiated CD8+ CD28- CD57+ cells until 36M. A sustained increase in the proportion of naïve B-cells, with persistent depletion of memory B-cells and plasmablasts was observed until 36M. Reconstitution of the B-cell repertoire was accompanied by a reduction in the frequency of circulating T-follicular helper cells (cTfh) expressing programmed cell death-1 (PD1+ ) at 36M. Associations between frequency dynamics and clinical outcomes indicated only responder patients to exhibit a decrease in Th17, CNS-homing T-conv and PD1+ cTfh pro-inflammatory subsets at 36M, and an increase in CD39+ T-regulatory cells at 24M. INTERPRETATION: AHSCT induces substantial recalibration of pro-inflammatory and immunoregulatory components of the immune system of MS patients for up to 36M post-transplant.

Response to treatment in NMOSD: the Australasian experience.

BACKGROUND: Neuromyelitis optica spectrum disorder (NMOSD) is associated with significant morbidity and mortality. Several therapies have been recommended for NMOSD and more recently clinical trials have demonstrated efficacy for three monoclonal antibody therapies. We present a retrospective observational study of treatment response in NMOSD. METHODS: This was a retrospective, unblinded, observational study of treatment efficacy for rituximab and traditional immunosuppressive therapy in patients with AQP4 antibody positive NMOSD. Treatment efficacy was assessed using annualised relapse rates (ARR), time to first relapse and expanded disability status scale (EDSS) scores. RESULTS: Complete relapse and treatment data were available for 43/68 (63%) of AQP4 antibody positive NMOSD cases covering 74 episodes of treatment. In a time to first relapse analysis rituximab showed a risk ratio of 0.23 (95% CI 0.08 - 0.65) when compared with no treatment and there was a non-significant reduction in ARR of 35% compared to pre-treatment. ß-interferon (p = 0.0002) and cyclophosphamide (p = 0.0034) were associated with an increased ARR compared to pre-treatment. Rituximab (median 4.0 [range 0.0 - 7.0]; p = 0.042) and traditional immunosuppressive therapy (median 4.0 [range 0.0 - 8.0]; p = 0.016) were associated with a lower final EDSS compared to ß-interferon (median 6.0 [range 4.0 - 7.5]). CONCLUSIONS: These data provide additional support for the use of rituximab in preference to traditional immunosuppressive agents and MS disease modifying therapies as first line treatment of NMOSD.

Enhanced expression of pentraxin-3 in glioblastoma cells correlates with increased invasion and IL8-VEGF signaling axis.

Glioblastoma (GB) is highly invasive and resistant to multimodal treatment partly due to distorted vasculature and exacerbated inflammation. The aggressiveness of brain tumors may be attributed to the dysregulated release of angiogenic and inflammatory factors. The glycoprotein pentraxin-3 (PTX3) is correlated with the severity of some cancers. However, the mechanism responsible for the invasive oncogenic role of PTX3 in GB malignancy remains unclear. In this study, we examined the role of PTX3 in GB growth, angiogenesis, and invasion using in vitro and in vivo GB models, proteomic profiling, molecular and biochemical approaches. Under in vitro conditions, PTX3 over-expression in U87 cells correlated with cell cycle progression, increased migratory potential, and proliferation under hypoxic conditions. Conditioned media containing PTX3 enhanced the angiogenic potential of endothelial cells. While silencing of PTX3 by siRNA decreased the proliferation, migration, and angiogenic potential of U87 cells in vitro. Importantly, PTX3 over-expression increased tumor growth, angiogenesis, and invasion in an orthotopic mouse model. Higher levels of PTX3 in these tumors were associated with the upregulation of inflammatory and angiogenic markers including interleukin-8 (IL-8) and vascular endothelial growth factor (VEGF), but decreased levels of thrombospondin-1, an anti-angiogenic factor. Mechanistically, exogenous production of PTX3 triggered an IKK/NFκB signaling pathway that enhances the expression of the motility genes AHGEF7 and Rac1. Taken together, PTX3 expression is dysregulated in GB. PTX3 may augment invasion through enhanced angiogenesis in the GB microenvironment through the IL8-VEGF axis. Thus, PTX3 may represent a potential therapeutic target to mitigate the aggressive behavior of gliomas.

MRI Patterns Distinguish AQP4 Antibody Positive Neuromyelitis Optica Spectrum Disorder From Multiple Sclerosis.

Neuromyelitis optica spectrum disorder (NMOSD) and multiple sclerosis (MS) are inflammatory diseases of the CNS. Overlap in the clinical and MRI features of NMOSD and MS means that distinguishing these conditions can be difficult. With the aim of evaluating the diagnostic utility of MRI features in distinguishing NMOSD from MS, we have conducted a cross-sectional analysis of imaging data and developed predictive models to distinguish the two conditions. NMOSD and MS MRI lesions were identified and defined through a literature search. Aquaporin-4 (AQP4) antibody positive NMOSD cases and age- and sex-matched MS cases were collected. MRI of orbits, brain and spine were reported by at least two blinded reviewers. MRI brain or spine was available for 166/168 (99%) of cases. Longitudinally extensive (OR = 203), "bright spotty" (OR = 93.8), whole (axial; OR = 57.8) or gadolinium (Gd) enhancing (OR = 28.6) spinal cord lesions, bilateral (OR = 31.3) or Gd-enhancing (OR = 15.4) optic nerve lesions, and nucleus tractus solitarius (OR = 19.2), periaqueductal (OR = 16.8) or hypothalamic (OR = 7.2) brain lesions were associated with NMOSD. Ovoid (OR = 0.029), Dawson's fingers (OR = 0.031), pyramidal corpus callosum (OR = 0.058), periventricular (OR = 0.136), temporal lobe (OR = 0.137) and T1 black holes (OR = 0.154) brain lesions were associated with MS. A score-based algorithm and a decision tree determined by machine learning accurately predicted more than 85% of both diagnoses using first available imaging alone. We have confirmed NMOSD and MS specific MRI features and combined these in predictive models that can accurately identify more than 85% of cases as either AQP4 seropositive NMOSD or MS.

Pregnancy post autologous stem cell transplant with BEAM conditioning for multiple sclerosis.

BACKGROUND: Given the increasing numbers of multiple sclerosis (MS) patients undergoing autologous haematopoietic stem cell transplant (AHSCT) worldwide, and with women of childbearing age overrepresented in the target population, it is increasingly important to review fertility and pregnancy outcomes following AHSCT. OBJECTIVE: To evaluate the rate of pregnancy and complications post-AHSCT for MS. METHOD: Retrospective evaluation of the rate of pregnancy and associated complications in a cohort of patients post-AHSCT with BEAM conditioning for MS since 2010 in a tertiary referral centre. RESULTS: In our ongoing Phase 2 trial of AHSCT for MS, 55 patients have undergone AHSCT with 30 females being of childbearing age at time of transplantation. Four pregnancies occurred following AHSCT. Two pregnancies were carried to term. No maternal or neonatal complications were reported in either case. Two pregnancies were not carried to term due to elective terminations. Both of these patients became pregnant unexpectedly 2 years following AHSCT. Of the 21 male patients, one patient has fathered three children since his AHSCT. There were no newborn complications. CONCLUSIONS: This is the first report to our knowledge on fertility outcomes in both sexes post-AHSCT for MS. Patients of both sexes should be counselled prior to treatment on infertility and contraceptive use.

Galectin-3 protects against ischemic stroke by promoting neuro-angiogenesis via apoptosis inhibition and Akt/Caspase regulation.

Post-stroke neurological deficits and mortality are often associated with vascular disruption and neuronal apoptosis. Galectin-3 (Gal3) is a potent pro-survival and angiogenic factor. However, little is known about its protective role in the cerebral ischemia/reperfusion (I/R) injury. We have previously shown significant up-regulation of Gal3 in the post-stroke rat brain, and that blocking of Gal3 with neutralizing antibody decreases the cerebral blood vessel density. Our current study demonstrates that intracerebral local delivery of the Gal3 into rat brain at the time of reperfusion exerts neuroprotection. Ischemic lesion volume and neuronal cell death were significantly reduced as compared with the vehicle-treated MCAO rat brains. Gal3 increased vessel density and neuronal survival after I/R in rat brains. Importantly, Gal3-treated groups showed significant improvement in motor and sensory functional recovery. Gal3 increased neuronal cell viability under in vitro oxygen-glucose deprivation conditions in association with increased phosphorylated-Akt, decreased phosphorylated-ERK1/2, and reduced caspase-3 activity. Gene expression analysis showed down regulation of pro-apoptotic and inflammatory genes including Fas-ligand, and upregulation of pro-survival and pro-angiogenic genes including Bcl-2, PECAM, and occludin. These results indicate a key role for Gal3 in neuro-vascular protection and functional recovery following ischemic stroke through modulation of angiogenic and apoptotic pathways.

Long-Term Suppression of Circulating Proinflammatory Cytokines in Multiple Sclerosis Patients Following Autologous Haematopoietic Stem Cell Transplantation.

Autologous haematopoietic stem cell transplantation (AHSCT) is a therapeutic option for haematological malignancies, such as non-Hodgkin's lymphoma (NHL), and more recently, for autoimmune diseases, such as treatment-refractory multiple sclerosis (MS). The immunological mechanisms underlying remission in MS patients following AHSCT likely involve an anti-inflammatory shift in the milieu of circulating cytokines. We hypothesised that immunological tolerance in MS patients post-AHSCT is reflected by an increase in anti-inflammatory cytokines and a suppression of proinflammatory cytokines in the patient blood. We investigated this hypothesis using a multiplex-ELISA assay to compare the concentrations of secreted cytokine in the peripheral blood of MS patients and NHL patients undergoing AHSCT. In MS patients, we detected significant reductions in proinflammatory T helper (Th)17 cytokines interleukin (IL)-17, IL-23, IL-1ß, and IL-21, and Th1 cytokines interferon (IFN)γ and IL-12p70 in MS patients from day 8 to 24 months post-AHSCT. These changes were not observed in the NHL patients despite similar pre-conditioning treatment for AHSCT. Some proinflammatory cytokines show similar trends in both cohorts, such as IL-8 and tumour necrosis factor (TNF)-α, indicating a probable treatment-related AHSCT response. Anti-inflammatory cytokines (IL-10, IL-4, and IL-2) were only transiently reduced post-AHSCT, with only IL-10 exhibiting a significant surge at day 14 post-AHSCT. MS patients that relapsed post-AHSCT exhibited significantly elevated levels of IL-17 at 12 months post-AHSCT, unlike non-relapse patients which displayed sustained suppression of Th17 cytokines at all post-AHSCT timepoints up to 24 months. These findings suggest that suppression of Th17 cytokines is essential for the induction of long-term remission in MS patients following AHSCT.

The clinical profile of NMOSD in Australia and New Zealand.

Neuromyelitis optica spectrum disorders (NMOSD) are an inflammation of the central nervous system associated with autoantibodies to aquaporin-4. We have undertaken a clinic-based survey of NMOSD in the Australia and New Zealand populations with the aim of characterising the clinical features and establishing the value of recently revised diagnostic criteria. Cases of possible NMOSD and age and sex-matched controls with multiple sclerosis (MS) were referred from centres across Australia and New Zealand. Cases were classified as NMOSD if they met the 2015 IPND criteria and remained as suspected NMOSD if they did not. Clinical and paraclinical data were compared across the three groups. NMOSD was confirmed in 75 cases and 89 had suspected NMOSD. There were 101 controls with MS. Age at onset, relapse rates and EDSS scores were significantly higher in NMOSD than in MS. Lesions and symptoms referable to the optic nerve were more common in NMOSD whereas brainstem, cerebellar and cerebral lesions were more common in MS. Longitudinally extensive spinal cord lesions were seen in 48/71 (68%) of cases with NMOSD. Elevations of CSF, white cell count and protein were more common in NMOSD. We have confirmed a clinical pattern of NMOSD that has been seen in several geographical regions. We have demonstrated the clinical utility of the current diagnostic criteria. Distinct patterns of disease are evident in NMOSD and MS, but there remains a large number of patients with NMOSD-like features who do not meet the current diagnostic criteria for NMOSD and remain a diagnostic challenge.

B cell depletion therapy resulting in sustained remission of severe autoimmune complications following Alemtuzumab treatment of Multiple Sclerosis.

Secondary autoimmune disorders (AID) are a recognised complication of alemtuzumab treatment for multiple sclerosis. We have previously reported two female multiple sclerosis patients treated with alemtuzumab who developed rare but severe secondary AID; acquired haemophilia A and autoimmune encephalitis with seizures. Both cases proved to be refractory to treatment with conventional immuno-therapy. However, treatment of the patients with anti-CD20 therapy resulted in sustained remission. This observation validates anti-CD20 therapy as a potential treatment option in patients with autoimmune complications of alemtuzumab that are postulated to arise as a result of B cell hyperpopulation.

Prospective phase II clinical trial of autologous haematopoietic stem cell transplant for treatment refractory multiple sclerosis.

BACKGROUND: Autologous haematopoietic stem cell transplantation (AHSCT) has been explored as a therapeutic intervention in multiple sclerosis (MS) over the last two decades; however, prospective clinical trials of the most common myeloablative conditioning regimen, BEAM, are limited. Furthermore, patient selection, optimal chemotherapeutic regimen and immunological changes associated with disease response require ongoing exploration. We present the outcomes, safety and immune reconstitution (IR) of patients with active, treatment refractory MS. METHODS: This study was a single-centre, phase II clinical trial of AHSCT for patients with active relapsing remitting (RRMS) and secondary progressive MS (SPMS). Patients underwent AHSCT using BEAM (carmustine, etoposide, cytarabine, melphalan)+antithymocyte globulin chemotherapeutic regimen. OUTCOMES: The primary outcome was event-free survival (EFS); defined as no clinical or radiological relapses and no disability progression. Multiparameter flow cytometry was performed for evaluation of post-transplant IR in both MS and lymphoma patients receiving the same chemotherapy regimen. RESULTS: Thirty-five patients (20 RRMS, 15 SPMS) completed AHSCT, with a median follow-up of 36 months (range 12-66). The median Expanded Disability Status Scores (EDSS) was 6 (2-7) and patients had failed a median of 4 (2-7) disease modifying therapies. 66% failed treatment with natalizumab. EFS at 3 years was 60%, (70% RRMS). Sustained improvement in EDSS was seen in 15 (44%) of patients. There was no treatment-related mortality. A sustained rise in CD39+ T regulatory cells, immunosuppressive CD56hi natural killer cells and ablation of proinflammatory mucosal-associated invariant T cells was seen for 12 months following AHSCT in patients with MS. These changes did not occur in patients with lymphoma receiving the same chemotherapy for AHSCT. CONCLUSIONS: The EFS in our MS cohort is significantly greater than other high-efficacy immunosuppressive therapies and similar to other AHSCT studies despite a more heavily pretreated cohort. TRIAL REGISTRATION NUMBER: ACTRN12613000339752.

Autoimmune encephalitis following alemtuzumab treatment of multiple sclerosis.

Secondary autoimmune disorders are a recognised complication of alemtuzumab treatment for multiple sclerosis. We report a case of autoimmune encephalitis manifesting as a polymorphic epilepsia partialis continua / status epilepticus seven months after the second course of alemtuzumab in a patient with previous autoimmune hypothyroidism and immune thrombocytopenic purpura. An MRI revealed multifocal cortical abnormalities and neuronal loss was evident on biopsy. Although testing for anti-neuronal antibodies was negative, the patient responded well to immunotherapy including plasma exchange. This is the first reported presentation of an autoimmune encephalopathy secondary to alemtuzumab therapy.

Regenerating Immunotolerance in Multiple Sclerosis with Autologous Hematopoietic Stem Cell Transplant.

Multiple sclerosis (MS) is an inflammatory disorder of the central nervous system where evidence implicates an aberrant adaptive immune response in the accrual of neurological disability. The inflammatory phase of the disease responds to immunomodulation to varying degrees of efficacy; however, no therapy has been proven to arrest progression of disability. Recently, more intensive therapies, including immunoablation with autologous hematopoietic stem cell transplantation (AHSCT), have been offered as a treatment option to retard inflammatory disease, prior to patients becoming irreversibly disabled. Empirical clinical observations support the notion that the immune reconstitution (IR) that occurs following AHSCT is associated with a sustained therapeutic benefit; however, neither the pathogenesis of MS nor the mechanism by which AHSCT results in a therapeutic benefit has been clearly delineated. Although the antigenic target of the aberrant immune response in MS is not defined, accumulated data suggest that IR following AHSCT results in an immunotolerant state through deletion of pathogenic clones by a combination of direct ablation and induction of a lymphopenic state driving replicative senescence and clonal attrition. Restoration of immunoregulation is evidenced by changes in regulatory T cell populations following AHSCT and normalization of genetic signatures of immune homeostasis. Furthermore, some evidence exists that AHSCT may induce a rebooting of thymic function and regeneration of a diversified naïve T cell repertoire equipped to appropriately modulate the immune system in response to future antigenic challenge. In this review, we discuss the immunological mechanisms of IR therapies, focusing on AHSCT, as a means of recalibrating the dysfunctional immune response observed in MS.