1
|
Dresser L, Chaar WA, Reder AT, Abuaf AF, Cipriani VP, Javed A. Effectiveness of rituximab versus oral immunosuppressive therapies in neuromyelitis optica spectrum disorder in a racially diverse cohort of subjects: A single-center retrospective study. Mult Scler Relat Disord 2023; 74:104718. [PMID: 37086634 DOI: 10.1016/j.msard.2023.104718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 04/11/2023] [Accepted: 04/12/2023] [Indexed: 04/24/2023]
Abstract
BACKGROUND Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune, inflammatory disorder characterized by severe relapses and high level of disability. In clinical trials of NMOSD, Black patients are under-represented, < 12%, compared to a relatively high prevalence of NMSOD in this population, 10/100,000. Despite the higher prevalence of NMOSD in Black and Asian patients, there is limited knowledge of the effectiveness of disease modifying treatments across racially diverse groups. OBJECTIVE To assess the effectiveness of rituximab and oral immunosuppressive agents in a cohort of NMOSD patients, the majority of whom are Black, in a real-world, clinical setting. METHODS A single-center retrospective study was conducted at the University of Chicago Medical Center. INCLUSION CRITERIA (1) diagnosis according to the 2015 International Panel for NMO Diagnosis (IPND) Criteria, (2) positive anti-aquaporin-4 antibodies on ELISA or cell-based tests, (3) initiation of immunosuppressant therapy within 5 years of disease onset, (4) first-line treatment with rituximab, mycophenolate (MMF), or azathioprine (AZA). Patients with negative anti-AQP4 titers were excluded. Kaplan-Meier survival analysis was used to estimate proportion of relapse-free patients following initiation of first line immunosuppressive therapy. A Cox proportional hazards regression model assessed the association of risk of relapsing with first-line immunosuppressive treatments with and without adjustments of pre-specified factors (age at disease onset, duration of disease, sex, race, CNS location of relapse). RESULTS 7 of 29 patients (24%) receiving rituximab experienced a relapse within the first 3 years of treatment vs. 13 of 23 patients (57%) receiving either AZA or MMF. Within the first 6 months of treatment, 2 (6.9%) patients treated with rituximab experienced a relapse vs. 7 (30.4%) patients treated with either MMF or AZA. In the 29 patients treated with rituximab, the 1-year and 3-year proportion of relapse-free patients was 88.8% and 70.9%. For the 23 patients treated with either AZA or MMF, the 1-year and 3-year proportion of relapse-free patients was 69.5% and 38.7%. In the univariate analysis, the risk of relapse was significantly higher in patients treated with AZA or MMF compared to those treated with rituximab (hazard ratio [HR] of 2.48 [0.99 - 6.21]; p = 0.046). CONCLUSION In this real-world study involving a majority of Black NMOSD patients, rituximab was relatively more effective in preventing relapses within 3 years of therapy initiation than AZA and MMF. Rituximab remains an effective option for treating NMOSD, especially when there are delays in treatment due to access and economic issues associated with newer treatments.
Collapse
Affiliation(s)
- Laura Dresser
- MS & Neuromuscular Center of Excellence, Tampa, FL, United States of America
| | - Widad Abou Chaar
- Department of Neurology, The University of Chicago, Chicago, IL, United States of America
| | - Anthony T Reder
- Department of Neurology, The University of Chicago, Chicago, IL, United States of America
| | - Amanda Frisosky Abuaf
- Department of Neurology, The University of Wisconsin, Madison, WI, United States of America
| | - Veronica P Cipriani
- Department of Neurology, The University of Chicago, Chicago, IL, United States of America
| | - Adil Javed
- Department of Neurology, The University of Chicago, Chicago, IL, United States of America.
| |
Collapse
|
2
|
Masha N, Kimbrough DJ, Eckstein CP, Hudak NM, Skeen MB, Hartsell FL, Lutz MW, Shah S. Neuromyelitis optica: Clinical course and potential prognostic indicators. Mult Scler Relat Disord 2023; 69:104414. [PMID: 36463620 DOI: 10.1016/j.msard.2022.104414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Revised: 11/08/2022] [Accepted: 11/13/2022] [Indexed: 11/21/2022]
Abstract
BACKGROUND Neuromyelitis optica spectrum disorder (NMOSD) is a rare autoimmune neurological disorder associated with antibodies to aquaporin-4 (AQP4). NMOSD has been thought to follow a progressive disease course, with step-wise accumulation of disability over time, even in patients undergoing immunosuppressive/immunomodulatory therapy. The influence of factors such as AQP4 seropositivity, AQP4 serum titer levels, and administration of plasmapheresis on NMOSD prognosis is, as yet, unclear. METHODS We performed a retrospective chart review of 53 persons with NMOSD at Duke University Hospital-collecting data on longitudinal disease course, imaging, demographics, and serum AQP4 titers (measured using the ELISA or FACS method). Most patients in our cohort were treated with high-dose corticosteroids and, following diagnosis, received maintenance immunosuppressive/immunomodulatory therapies. Longitudinal data on EDSS scores were used to calculate the slope of disability over time for each participant. We additionally investigated the correlation between initial AQP4 seropositivity, initial AQP4 serum titer levels, and treatment with plasmapheresis on disability progression for each participant. RESULTS Contrary to current views on NMOSD disease course, the majority of our participants showed either no change (31.9%) or improvement (27.1%) in disability over time. Our results additionally revealed no significant association between clinical prognosis and initial AQP4 seropositivity (p = 0.830), initial AQP4 serum titer levels (p = 0.338), or administration of plasmapheresis (p = 0.1149). CONCLUSIONS Our study presents a contemporary view of the clinical course of NMOSD and shows a more favorable view of its disease course than prior studies (performed before high-efficacy disease modifying therapies became widely-used for this patient population). Most patients in this study received treatment with high-dose corticosteroids following NMOSD flares, as well as a variety of maintenance immunosuppressive therapies. The results of this study cannot shed light on the disease course of untreated NMOSD. Our findings additionally challenge the theory that AQP4 seropositivity or serum titer levels at time of diagnosis may be used to effectively predict NMOSD prognosis. While we were unable to find evidence supporting a favorable effect of plasmapheresis administration on disease outcomes, further research is needed to determine the role plasmapheresis ought to play in the treatment of NMOSD.
Collapse
Affiliation(s)
- Nidhila Masha
- Duke University School of Medicine, 8 Searle Center Dr, Durham, NC 27710, USA.
| | - Dorlan J Kimbrough
- Department of Neurology, Duke University Medical Center, 40 Duke Medicine Cir Clinic 1L, Durham, NC 27710, USA
| | - Christopher P Eckstein
- Department of Neurology, Duke University Medical Center, 40 Duke Medicine Cir Clinic 1L, Durham, NC 27710, USA
| | - Nicholas M Hudak
- Department of Neurology, Duke University Medical Center, 40 Duke Medicine Cir Clinic 1L, Durham, NC 27710, USA
| | - Mark B Skeen
- Department of Neurology, Duke University Medical Center, 40 Duke Medicine Cir Clinic 1L, Durham, NC 27710, USA
| | - F Lee Hartsell
- Department of Neurology, Duke University Medical Center, 40 Duke Medicine Cir Clinic 1L, Durham, NC 27710, USA
| | - Michael W Lutz
- Department of Neurology, Duke University Medical Center, 40 Duke Medicine Cir Clinic 1L, Durham, NC 27710, USA
| | - Suma Shah
- Department of Neurology, Duke University Medical Center, 40 Duke Medicine Cir Clinic 1L, Durham, NC 27710, USA
| |
Collapse
|
3
|
Dinoto A, Sechi E, Flanagan EP, Ferrari S, Solla P, Mariotto S, Chen JJ. Serum and Cerebrospinal Fluid Biomarkers in Neuromyelitis Optica Spectrum Disorder and Myelin Oligodendrocyte Glycoprotein Associated Disease. Front Neurol 2022; 13:866824. [PMID: 35401423 PMCID: PMC8983882 DOI: 10.3389/fneur.2022.866824] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 02/28/2022] [Indexed: 12/20/2022] Open
Abstract
The term neuromyelitis optica spectrum disorder (NMOSD) describes a group of clinical-MRI syndromes characterized by longitudinally extensive transverse myelitis, optic neuritis, brainstem dysfunction and/or, less commonly, encephalopathy. About 80% of patients harbor antibodies directed against the water channel aquaporin-4 (AQP4-IgG), expressed on astrocytes, which was found to be both a biomarker and a pathogenic cause of NMOSD. More recently, antibodies against myelin oligodendrocyte glycoprotein (MOG-IgG), have been found to be a biomarker of a different entity, termed MOG antibody-associated disease (MOGAD), which has overlapping, but different pathogenesis, clinical features, treatment response, and prognosis when compared to AQP4-IgG-positive NMOSD. Despite important refinements in the accuracy of AQP4-IgG and MOG-IgG testing assays, a small proportion of patients with NMOSD still remain negative for both antibodies and are called “seronegative” NMOSD. Whilst major advances have been made in the diagnosis and treatment of these conditions, biomarkers that could help predict the risk of relapses, disease activity, and prognosis are still lacking. In this context, a number of serum and/or cerebrospinal fluid biomarkers are emerging as potentially useful in clinical practice for diagnostic and treatment purposes. These include antibody titers, cytokine profiles, complement factors, and markers of neuronal (e.g., neurofilament light chain) or astroglial (e.g., glial fibrillary acidic protein) damage. The aim of this review is to summarize current evidence regarding the role of emerging diagnostic and prognostic biomarkers in patients with NMOSD and MOGAD.
Collapse
Affiliation(s)
- Alessandro Dinoto
- Neurology Unit, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Elia Sechi
- Department of Medical, Surgical and Experimental Sciences, University of Sassari, Sassari, Italy
| | - Eoin P. Flanagan
- Department of Neurology, Mayo Clinic College of Medicine and Science, Rochester, MN, United States
- Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine and Science, Rochester, MN, United States
| | - Sergio Ferrari
- Neurology Unit, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Paolo Solla
- Department of Medical, Surgical and Experimental Sciences, University of Sassari, Sassari, Italy
| | - Sara Mariotto
- Neurology Unit, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
- *Correspondence: Sara Mariotto
| | - John J. Chen
- Departments of Ophthalmology and Neurology, Mayo Clinic College of Medicine and Science, Rochester, MN, United States
| |
Collapse
|
4
|
Arévalo B, Blázquez M, Serafín V, Montero-Calle A, Calero M, Valverde A, Barderas R, Campuzano S, Yáñez-Sedeño P, Pingarrón JM. Unraveling autoimmune and neurodegenerative diseases by amperometric serological detection of antibodies against aquaporin-4. Bioelectrochemistry 2021; 144:108041. [PMID: 34929532 DOI: 10.1016/j.bioelechem.2021.108041] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 11/28/2021] [Accepted: 12/08/2021] [Indexed: 12/18/2022]
Abstract
This work reports the first electroanalytical bioplatform to date for the determination of antibodies against aquaporin-4 (AQP4-Abs), whose serum level is considered as relevant biomarker for certain autoimmune diseases. The bioplatform relies on the use of magnetic microparticles modified with the biotinylated protein for the capture of specific antibodies. The captured IgGs are enzymatically labelled with a secondary antibody conjugated to the horseradish peroxidase (HRP) enzyme. Amperometric transduction is performed using the H2O2/hydroquinone (HQ) system, which results in a cathodic current variation directly proportional to the concentration of the target antibodies. The evaluation of the analytical and operational characteristics of the developed bioplatform shows that it is competitive in terms of sensitivity with the only biosensor reported to date as well as with the commercially available ELISA kits. The achieved limit of detection value is 8.8 pg mL-1. In addition, compared to ELISA kits, the developed bioplatform is advantageous in terms of cost and point of care operation ability. The bioplatform was applied to the analysis of control serum samples with known AQP4-Abs contents as well as of sera from healthy individuals and patients diagnosed with Systemic Lupus Erythematosus (SLE) and Alzheimer (AD) diseases, providing results in agreement with the ELISA methodology.
Collapse
Affiliation(s)
- Beatriz Arévalo
- Department of Analytical Chemistry, Faculty of Chemistry, Complutense University of Madrid, 28014-Madrid, Spain
| | - Marina Blázquez
- Department of Analytical Chemistry, Faculty of Chemistry, Complutense University of Madrid, 28014-Madrid, Spain
| | - Verónica Serafín
- Department of Analytical Chemistry, Faculty of Chemistry, Complutense University of Madrid, 28014-Madrid, Spain
| | - Ana Montero-Calle
- Chronic Disease Programme, UFIEC, Institute of Health Carlos III, Majadahonda, 28220-Madrid, Spain
| | - Miguel Calero
- Chronic Disease Programme, UFIEC, Institute of Health Carlos III, Majadahonda, 28220-Madrid, Spain; Alzheimer's Center Reina Sofía Foundation -CIEN Foundation and CIBERNED, Institute of Health Carlos III, Majadahonda, 28220-Madrid, Spain
| | - Alejandro Valverde
- Department of Analytical Chemistry, Faculty of Chemistry, Complutense University of Madrid, 28014-Madrid, Spain
| | - Rodrigo Barderas
- Chronic Disease Programme, UFIEC, Institute of Health Carlos III, Majadahonda, 28220-Madrid, Spain
| | - Susana Campuzano
- Department of Analytical Chemistry, Faculty of Chemistry, Complutense University of Madrid, 28014-Madrid, Spain.
| | - Paloma Yáñez-Sedeño
- Department of Analytical Chemistry, Faculty of Chemistry, Complutense University of Madrid, 28014-Madrid, Spain.
| | - José M Pingarrón
- Department of Analytical Chemistry, Faculty of Chemistry, Complutense University of Madrid, 28014-Madrid, Spain
| |
Collapse
|
5
|
Liu J, Tan G, Li B, Zhang J, Gao Y, Cao Y, Jia Z, Sugimoto K. Serum Aquaporin 4-Immunoglobulin G Titer and Neuromyelitis Optica Spectrum Disorder Activity and Severity: A Systematic Review and Meta-Analysis. Front Neurol 2021; 12:746959. [PMID: 34744983 PMCID: PMC8565925 DOI: 10.3389/fneur.2021.746959] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Accepted: 09/15/2021] [Indexed: 12/29/2022] Open
Abstract
Background: Aquaporin 4-immunoglobulin G (AQP4-IgG) plays a major role in the pathogenesis of neuromyelitis optica spectrum disorder (NMOSD). Seropositive status for this antibody has become one of the required indicators for NMOSD diagnosis. Objective: Our goal was to systematically review and perform a meta-analysis of the current works of literature evaluating the clinical relevance of serum AQP4-IgG titer in patients with NMOSD. We sought to determine whether AQP4-IgG could indicate disease activity or severity, in addition to its diagnostic value in NMOSD. Methods: Electronic databases were searched for published literature, yielding 4,402 hits. Of the 124 full articles screened, 17 were included in the qualitative analysis and 14 in the meta-analysis. Results: There were no significant differences in serum AQP4-IgG titers between the relapse and remission phases in patients with NMOSD [standard mean difference (SMD): 0.32, 95% CI (-0.10, 0.74), p = 0.14]. Subgroup meta-analysis of AQP4-IgG detected by cell-based assays (CBA), an AQP4-IgG testing method recommended by the 2015 international consensus diagnostic criteria for NMOSD, confirmed the aforementioned result [SMD: 0.27, 95% CI (-0.01, 0.55), p = 0.06]. Moreover, the serum AQP4-IgG titer was positively correlated with the number of involved spinal cord segments [correlation coefficient (COR): 0.70, 95% CI (0.28-0.89), p = 0.003] and the Expanded Disability Status Scale (EDSS) score [COR: 0.54, 95% CI (0.06-0.82), p = 0.03] in the attack phase in patients with NMOSD. Conclusions: The present study systematically assessed the association between serum AQP4-IgG titer and NMOSD activity and severity. The results demonstrated that the serum AQP4-IgG titer was not associated with disease activity but indicated the disease severity in the attack phase in patients with NMOSD. A further meta-analysis with a larger number of studies that employed standardized AQP4-IgG assays and detected attack-remission paired samples from the same patients with detailed medication information will be required to confirm our findings and shed more light on optimizing clinical AQP4-IgG monitoring. Systematic Review Registration: [www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=208209], PROSPERO, identifier [CRD42020208209].
Collapse
Affiliation(s)
- Jia Liu
- Department of Neurology, Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, China.,Institute for Brain Disorders, Beijing University of Chinese Medicine, Beijing, China
| | - Guojun Tan
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, China
| | - Bin Li
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, China
| | - Jingze Zhang
- Department of Neurology, Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, China
| | - Ying Gao
- Department of Neurology, Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, China.,Institute for Brain Disorders, Beijing University of Chinese Medicine, Beijing, China
| | - Yuanbo Cao
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, China
| | - Zhen Jia
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, China
| | - Kazuo Sugimoto
- Department of Neurology, Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, China.,Institute for Brain Disorders, Beijing University of Chinese Medicine, Beijing, China
| |
Collapse
|
6
|
Lambert J, Mejia S, Vojdani A. Plant and human aquaporins: pathogenesis from gut to brain. Immunol Res 2018; 67:12-20. [DOI: 10.1007/s12026-018-9046-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
|
7
|
Hubbard JA, Szu JI, Binder DK. The role of aquaporin-4 in synaptic plasticity, memory and disease. Brain Res Bull 2017; 136:118-129. [PMID: 28274814 DOI: 10.1016/j.brainresbull.2017.02.011] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 02/27/2017] [Accepted: 02/28/2017] [Indexed: 12/25/2022]
Abstract
Since the discovery of aquaporins, it has become clear that the various mammalian aquaporins play critical physiological roles in water and ion balance in multiple tissues. Aquaporin-4 (AQP4), the principal aquaporin expressed in the central nervous system (CNS, brain and spinal cord), has been shown to mediate CNS water homeostasis. In this review, we summarize new and exciting studies indicating that AQP4 also plays critical and unanticipated roles in synaptic plasticity and memory formation. Next, we consider the role of AQP4 in Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), Parkinson's disease (PD), multiple sclerosis (MS), neuromyelitis optica (NMO), epilepsy, traumatic brain injury (TBI), and stroke. Each of these conditions involves changes in AQP4 expression and/or distribution that may be functionally relevant to disease physiology. Insofar as AQP4 is exclusively expressed on astrocytes, these data provide new evidence of "astrocytopathy" in the etiology of diverse neurological diseases.
Collapse
Affiliation(s)
- Jacqueline A Hubbard
- Center for Glial-Neuronal Interactions, Division of Biomedical Sciences, School of Medicine, University of California, Riverside, United States
| | - Jenny I Szu
- Center for Glial-Neuronal Interactions, Division of Biomedical Sciences, School of Medicine, University of California, Riverside, United States
| | - Devin K Binder
- Center for Glial-Neuronal Interactions, Division of Biomedical Sciences, School of Medicine, University of California, Riverside, United States.
| |
Collapse
|
8
|
Abstract
Rituximab, a monoclonal antibody targeting the B cell marker CD20, was initially approved in 1997 by the United States Food and Drug Administration (FDA) for the treatment of non-Hodgkin lymphoma. Since that time, rituximab has been FDA-approved for rheumatoid arthritis and vasculitides, such as granulomatosis with polyangiitis and microscopic polyangiitis. Additionally, rituximab has been used off-label in the treatment of numerous other autoimmune diseases, with notable success in pemphigus, an autoantibody-mediated skin blistering disease. The efficacy of rituximab therapy in pemphigus has spurred interest in its potential to treat other autoantibody-mediated diseases. This review summarizes the efficacy of rituximab in pemphigus and examines its off-label use in other select autoantibody-mediated diseases.
Collapse
Affiliation(s)
- Nina A Ran
- Department of Dermatology, University of Pennsylvania, 1009 Biomedical Research Building, 421 Curie Boulevard, PA, USA
| | - Aimee S Payne
- Department of Dermatology, University of Pennsylvania, 1009 Biomedical Research Building, 421 Curie Boulevard, PA, USA
| |
Collapse
|
9
|
Weinfurtner K, Graves J, Ness J, Krupp L, Milazzo M, Waubant E. Prolonged Remission in Neuromyelitis Optica Following Cessation of Rituximab Treatment. J Child Neurol 2015; 30:1366-70. [PMID: 25387545 DOI: 10.1177/0883073814553974] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2014] [Accepted: 09/11/2014] [Indexed: 11/17/2022]
Abstract
Neuromyelitis optica is an autoimmune disease characterized by acute episodes of transverse myelitis and optic neuritis. Several small, open-label studies suggest rituximab, a monoclonal antibody against CD20, prevents relapses in neuromyelitis optica; however, there is little consensus on timing or duration of treatment. Here we report four patients with severe relapsing neuromyelitis optica who were stabilized on rituximab and, after discontinuing treatment, continued to experience prolonged remission of their disease. Remission ranged from 4.5 to 10.5 years total, including 3 to 9 years off all therapies. The patients had sustained clinical responses despite normal B-lymphocyte levels and, in at least 2 patients, continued seropositivity for aquaporin-4 antibodies. These cases suggest that rituximab may induce prolonged remission in certain neuromyelitis optica patients, and they highlight the need for further elucidation of rituximab's mechanism in neuromyelitis optica.
Collapse
Affiliation(s)
| | - Jennifer Graves
- Department of Neurology, University of California, San Francisco, CA, USA
| | - Jayne Ness
- Department of Neurology, University of Alabama, AL, USA
| | - Lauren Krupp
- Lourie Center for Pediatric Multiple Sclerosis, Stony Brook University, NY, USA
| | - Maria Milazzo
- Lourie Center for Pediatric Multiple Sclerosis, Stony Brook University, NY, USA School of Nursing, State University of New York, Stony Brook, NY, USA
| | - Emmanuelle Waubant
- Department of Neurology, University of California, San Francisco, CA, USA Department of Pediatrics, University of California, San Francisco, CA, USA
| |
Collapse
|
10
|
Kitley J, Woodhall M, Leite MI, Palace J, Vincent A, Waters P. Aquaporin-4 antibody isoform binding specificities do not explain clinical variations in NMO. NEUROLOGY-NEUROIMMUNOLOGY & NEUROINFLAMMATION 2015; 2:e121. [PMID: 26140280 PMCID: PMC4476052 DOI: 10.1212/nxi.0000000000000121] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2015] [Accepted: 04/20/2015] [Indexed: 11/15/2022]
Abstract
Objective: To assess the clinical relevance of the differential binding of antibodies against the 2 main aquaporin-4 (AQP4) isoforms in neuromyelitis optica (NMO) patient sera using stably transfected human embryonic kidney cells. Methods: Flow cytometry of human embryonic kidney cells stably transfected with either M23 or M1 AQP4 was used to measure antibody endpoint titers in 52 remission samples and 26 relapse samples from 34 patients with clinically well-characterized AQP4 antibody–positive NMO/NMO spectrum disorder. Results: The AQP4 M23 (40–61,440) and AQP4 M1 (<20–20,480) titers varied widely between patients, as did the M23:M1 antibody ratio (1–192). In 76 of 78 samples, binding to M23 was higher than binding to M1, including during relapses and remissions (p < 0.0001), and the M23:M1 ratio was relatively constant within an individual patient. Titers usually fell after immunosuppression, but the titers at which relapses occurred varied markedly; no threshold level for relapses could be identified, and relapses could occur without a rise in titers. Relapse severity did not correlate with M23 or M1 antibody titers, although there was a correlation between the earliest M23 titers and annualized relapse rates. The M23:M1 ratio and absolute M23 and M1 titers did not relate to age at disease onset, ethnicity, disease severity, phenotype, or relapses at different anatomical sites. Conclusion: Relative AQP4 antibody binding to M23 and M1 isoforms differs between patients but there is no consistent association between these differences and clinical characteristics of disease. Nevertheless, the M23 isoform provided a slightly more sensitive substrate for AQP4-antibody assays, particularly for follow-up studies.
Collapse
Affiliation(s)
- Joanna Kitley
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - Mark Woodhall
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - M Isabel Leite
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - Jackie Palace
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - Angela Vincent
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - Patrick Waters
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, UK
| |
Collapse
|