Multiplehttp://msj.sagepub.com/ Sclerosis Journal
Effects of natalizumab on oligoclonal bands in the cerebrospinal fluid of multiple sclerosis patients: A longitudinal study R Mancuso, D Franciotta, M Rovaris, D Caputo, A Sala, A Hernis, S Agostini, MG Calvo and M Clerici Mult Scler published online 16 June 2014 DOI: 10.1177/1352458514538111 The online version of this article can be found at: http://msj.sagepub.com/content/early/2014/06/12/1352458514538111
Published by: http://www.sagepublications.com
On behalf of: European Committee for Treatment and Research in Multiple Sclerosis
Americas Committee for Treatment and Research in Multiple Sclerosis
Pan-Asian Committee for Treatment and Research in Multiple Sclerosis
Latin American Committee on Treatment and Research of Multiple Sclerosis
Additional services and information for Multiple Sclerosis Journal can be found at: Email Alerts: http://msj.sagepub.com/cgi/alerts Subscriptions: http://msj.sagepub.com/subscriptions Reprints: http://www.sagepub.com/journalsReprints.nav Permissions: http://www.sagepub.com/journalsPermissions.nav Downloaded from msj.sagepub.com at UNIVERSITE LAVAL on November 30, 2014
>> OnlineFirst Version of Record - Jun 16, 2014 What is This?
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538111
research-article2014
MSJ0010.1177/1352458514538111Multiple Sclerosis JournalR Mancuso, D Franciotta
MULTIPLE SCLEROSIS MSJ JOURNAL
Short Report
Effects of natalizumab on oligoclonal bands in the cerebrospinal fluid of multiple sclerosis patients: A longitudinal study
Multiple Sclerosis Journal 1–4 DOI: 10.1177/ 1352458514538111 © The Author(s), 2014. Reprints and permissions: http://www.sagepub.co.uk/ journalsPermissions.nav
R Mancuso, D Franciotta, M Rovaris, D Caputo, A Sala, A Hernis, S Agostini, MG Calvo and M Clerici
Abstract: Retrospective studies show that natalizumab modifies oligoclonal immunoglobulin (IgG) bands (OCBs) in the cerebrospinal fluid (CSF) of multiple sclerosis (MS) patients. In this study, we prospectively analyzed both serum and CSF samples from 24 MS patients, before and after 2 years of natalizumab-based therapy. Our results showed complete (55%) or partial (27%) disappearance of the OCBs in CSF samples that were taken after 2 years of therapy. Intrathecal IgG production, represented by the IgG index and IgGLoc , was also quantitatively reduced. Our data showed that natalizumab substantially modulates both intrathecal polyclonal and oligoclonal IgG production: This effect was much more potent than was previously reported. Keywords: Cerebrospinal fluid, multiple sclerosis, natalizumab, oligoclonal bands, intrathecal IgG Date received: 26 February 2014; revised: 9 May 2014; accepted: 10 May 2014
Introduction Natalizumab, a humanized antibody directed toward the very late activation antigen-4 (VLA-4) adhesion molecule, has considerable efficacy in relapsing–remitting multiple sclerosis (RRMS).1 This drug also exerts a profound biological effect on B lymphocytes,1 which might partially account for the increased risk of natalizumab-associated progressive multifocal leukoencephalopathy (PML), a brain infection caused by the John Cunningham (JC) virus that occurs rarely in natalizumab-treated patients.2 Oligoclonal immunoglobulin G (IgG) bands (OCBs) in cerebrospinal fluid (CSF) are shown to be reduced or to have even disappeared in multiple sclerosis (MS) patients who are undergoing natalizumab treatment.3,4 This observation is of great interest, because CSF OCBs are detected in more than 95% of MS patients5 and persist even after autologous hematopoietic cell transplantation6; however, these data derive from retrospective analyses and include baseline CSF samples obtained for diagnostic purposes in MS patients, well before the time of natalizumab treatment initiation.3,4
We present data from a prospective analysis of intrathecal IgG production and OCBs, in paired CSF and serum samples of RRMS patients, before and after 24 months of natalizumab therapy.
Materials and methods Patients A total of 24 MS patients, who fulfilled the criteria of the Italian Medicine Agency for natalizumab treatment (www.agenziafarmaco.gov.it), entered our surveillance longitudinal 2-year study on JCV-specific immunity and viral DNA in biological fluids, at the Don C Gnocchi Foundation ONLUS in Milan, Italy. The local ethics committee approved our study. All patients signed informed consent forms. We collected paired CSF and serum samples 1 month before the first infusion of natalizumab and after at least 24 months of treatment (Table 1). Routine brain magnetic resonance imaging (MRI) was obtained at both baseline and after 1 or 2 years of treatment: Results were reviewed by local radiologists at different image acquisition centers.
Correspondence to: Roberta Mancuso Don C Gnocchi Foundation ONLUS, Piazza Morandi 3, 20100, Milano, Italy. [email protected] R Mancuso M Rovaris D Caputo A Sala A Hernis S Agostini MG Calvo Don C Gnocchi Foundation, ONLUS, Milan, Italy D Franciotta Laboratory of Neuroimmunology, IRCCS, C Mondino National Neurological Institute, Pavia, Italy M Clerici Don C Gnocchi Foundation, ONLUS, Milan, Italy/ University of Milan, Italy
http://msj.sagepub.com 1
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Multiple Sclerosis Journal Table 1. Demographic, clinical data and laboratory findings in 24 natalizumab-treated MS patients.
Clinical data Sex Age, years Age at onset, years Disease duration, years Treatment duration, months Number of infusions, n Pts with previous DMT (%) Pts with previous IST (%) EDSS Pts with MRI activity in Year 1 of treatment Pts with MRI activity in Year 2 of treatment Pts FDA during treatment period Laboratory findings Serum IgG (mg/dL) CSF IgG (mg/dL) Serum albumin (mg/dL) CSF albumin (mg/dL) QAlbx100 IgGLoc (mg/L) IgG index Pts with IgG index values > 0.70, n (%) Pts with positive CSF OCBs, n (%) Pts with decreased OCBs, n (%)a Pts with unchanged OCB patterns, n (%)a
Baseline
End of study period
4 M, 20 F 37.0 (29.5–44.5) 24.0 (18.0–29.0) 9.5 (7.0–15.5) 24 (24–26) 24.7 (24–25) 15 (62.5) 7 (29.2) 4.2 (3.0–5.3) – – –
– – – – – – – – 4.5 (3.0–5.5) 8 (33%) 2 (8%) 14 (58%)
901 (732–1004) 3.31 (2.25–5.74) 4000 (3600–4170) 21.2 (14.94–26.65) 0.48 (0.38–0.69) 0.52 (0.00–2.45) 0.88 (0.61–1.18) 16 (67) 22/24 (92) – –
845 (717–982) 2.13 (1.82–3.40) 4230 (3962–4545) 18.1 (15.47–25.45) 0.46 (0.33–0.62) 0.00 (0.00–0.35) 0.64 (0.56–0.82) 8 (33) 10/24 (42) 6 (27) 4 (18)
p valuesb – – – – – – – – 0.9090 – – – 0.1980 0.0001 0.2350 0.0630 0.1030 0.0003 0.0001 0.0078c 0.0005c – –
Data are expressed as medians, with IQR in parentheses. aOnly the 22 CSF OCB-positive patients were considered. bWilcoxon test. cMcNemar test. CSF: cerebrospinal fluid; DMT: disease modifying therapies, i.e. beta-interferons or glatiramer acetate; EDSS: Expanded Disability Status Scale; F: female; M: male; FDA: free from disease activity; IgGLoc: intrathecal IgG production calculated in accordance with Reiber’s formula10; IQR: interquartile range; IST: immunosuppressive therapies, i.e. azathioprine or mitoxantrone; MRI: magnetic resonance imaging; MS: multiple sclerosis; OCBs: oligoclonal IgG bands; Pts: patients; QAlb: albumin quotient
CSF and serum study IgG and albumin concentrations were measured by immunonephelometry (Immage; Beckman Coulter, Fullerton, CA, USA) on paired serum and CSF samples, which had been aliquoted within 1 hour of collection and stored at − 80°C until analysis. Equal amounts of CSF and serum IgG (0.2 µg) were loaded on the agarose gel, to detect OCBs with isoelectric focusing7 and immunofixation (Hydragel CSF-IEF system; Sebia, Norcross, GA, USA). The paired CSF and serum samples from both time points were analyzed in the same run, side-by-side. We also calculated albumin quotient (Q Alb), as a measure of blood-CSF barrier permeability, and IgG index and IgGLoc8, as quantitative measures of intrathecal IgG production.7 We based OCB detection and data
interpretation on consensus guidelines.7 When OCB disappearance was incomplete, patterns were categorized as ‘decreased OCB number’ if at least two bands had disappeared. Two experienced readers who were blinded to the pairing of samples and time points evaluated the OCB results.
Statistics We analyzed the pre- versus post-treatment variables with the Wilcoxon test (between-median differences), McNemar test (categorical data) and Spearman rank-order test (monotonic relationships). Linear regression was used for between-variable relationships; a p value < 0.05 was considered statistically significant.
2 http://msj.sagepub.com
Downloaded from msj.sagepub.com at UNIVERSITE LAVAL on November 30, 2014
R Mancuso, D Franciotta et al. (immunomodulating versus immunomodulating and immunosuppressive) parameters were compared in MS patients in whom OCBs were or were not modified by therapy. Discussion Data herein confirmed that natalizumab can reduce intrathecal OCBs in MS patients and indicated that this effect is more pronounced than what had been previously believed.3,4 Thus, a complete (55%) or partial (27%) disappearance of CSF OCBs was observed in the majority of patients in whom they were present at baseline.
Figure 1. Representative samples of CSF oligoclonal IgG bands (arrows). Complete (a) or incomplete (b) disappearance of OCBs in paired CSF and serum samples of multiple sclerosis patients, before and after the 24-month therapy with natalizumab are shown. CSF: cerebrospinal fluid; OCBs: oligoclonal IgG bands; pre: before therapy; post: after therapy; ser: serum
Results During the study period, no patients discontinued therapy and none developed PML; a single event of clinical disease relapse was observed in 6 cases (25%) and the Expanded Disability Status Scale (EDSS) was stable in all individuals. The comparison between pre- versus post-natalizumab parameters showed that median IgG concentrations were greatly decreased in the CSF (mean degree of reduction, 40%; p < 0.0001) and in serum (mean degree of reduction, 12%). Intrathecal IgG synthesis decreased significantly (p < 0.0005) as well (Table 1), whereas the Q Alb values were unchanged (≤ 0.70). Finally, CSF OCBs that were detected in 22/24 patients at baseline disappeared in 12/22 (55%), were reduced in 6/22 (27%) and remained unmodified in 4/22 patients (18%; p < 0.0001) (Table 1; Figure 1). Regarding MS subgroups with or without OCB changes, or intrathecal IgG synthesis decreases, no differences emerged when their clinical (sex, age and EDSS at study entry, age at disease onset, disease duration, clinical or MRI relapses) or previous treatment
The ability of natalizumab to affect OCBs is observed in 16% of patients in the largest published series4; whereas a previous study found results similar to ours, but in that case only six individuals were available.3 Nevertheless, these retrospective analyses suffer from a selection bias because CSF sampling was performed to rule out PML, patients were heterogeneous in terms of treatment duration and different methods were used for OCB detection. Consistent with previous results,3,4 we found that natalizumab therapy had no influence on the blood-CSF barrier permeability; this is not surprising, given the central nervous system (CNS)-specific anti-inflammatory activity of the drug. Long-lived plasma cells, which are likely the major source of OCBs in MS,9 sustain persistent antibody production in autoimmune diseases and are highly resistant to immunosuppression.10 Indeed, OCBs persisted even in advanced MS patients who underwent autologous hematopoietic cell transplantation.6 In the MS brain, parenchymal plaques and subpial ectopic B-cell follicles represent the niches where the microenvironment allows the survival of long-lived plasma cells.9 The mechanisms by which natalizumab interferes with the survival of these cells in such niches can be only hypothesized and probably involves the dysregulation of pro-survival factors comprising cytokines, receptors and adhesion molecules, including the VLA-4 antigen.10 Notably, this hypothesis seems to be supported by the observation that OCBs reappear in natalizumab-treated MS patients whom discontinue therapy because of PML.3,4 Moreover, the hypothesis is neutral towards theories favoring or opposing a possible viral pathogenesis for MS, as the shortage of the factors able to induce immunoglobulin production could affect long-lived plasma cells independently from the causes underlying their CNS settlement.10
http://msj.sagepub.com 3
Downloaded from msj.sagepub.com at UNIVERSITE LAVAL on November 30, 2014
Multiple Sclerosis Journal The CSF and serum IgG concentrations were also reduced in our patients: This effect of the drug had been recently described11; however, contrary to Villar et al.,12 we found no difference in intrathecal IgG synthesis, nor in the OCB changes when full responders were compared to patients with clinical relapses or MRI activity. The case series are nevertheless probably too small to draw definite conclusions. Our data demonstrated that natalizumab therapy has a substantial effect on both polyclonal and oligoclonal IgG production within the CNS, at a much higher degree than previously reported.3,4 They also provided additional evidence that this drug modulates B-cell activity, which might result in an impairment of humoral immunity-mediated defenses against infectious agents. An undesirable side-effect of this therapy could be the reactivation of pathogens within the CNS, a rare complication associated with the use of natalizumab. Conflict of interest None declared. Funding This work was supported by Biogen Idec and the Italian Ministry of Health (2012–2013 Ricerca Corrente).
References
Visit SAGE journals online http://msj.sagepub.com
SAGE journals
3. Von Glehn F, Farias AS, De Oliveira AC, et al. Disappearance of cerebrospinal fluid oligoclonal bands after natalizumab treatment of multiple sclerosis patients. Mult Scler 2012; 18: 1038–1041. 4. Harrer A, Tumani H, Niendorf S, et al. Cerebrospinal fluid parameters of B-cell related activity in patients with active disease during natalizumab therapy. Mult Scler 2013; 19: 1209–1212. 5. Tumani H, Deisenhammer F, Giovannoni G, et al. Revised McDonald criteria: The persisting importance of cerebrospinal fluid analysis. Ann Neurol 2011; 70: 520. 6. Bowen JD, Kraft GH, Wundes A, et al. Autologous hematopoietic cell transplantation following highdose immunosuppressive therapy for advanced multiple sclerosis: Long-term results. Bone Marrow Transpl 2012; 47: 946–951. 7. Andersson M, Alvarez-Cermeno J, Bernardi G, et al. Cerebrospinal fluid in the diagnosis of multiple sclerosis: A consensus report. J Neurol Neurosurg Psychiatry 1994; 57: 897–902. 8. Reiber H. Cerebrospinal fluid: Physiology, analysis and interpretation of protein patterns for diagnosis of neurological diseases. Mult Scler 1998; 4: 99–107. 9. Franciotta D, Salvetti M, Lolli F, et al. B cells and multiple sclerosis. Lancet Neurol 2008; 7: 852–858. 10. Hiepe F, Dorner T, Hauser AE, et al. Longlived autoreactive plasma cells drive persistent autoimmune inflammation. Nat Rev Rheumatol 2011; 7: 170–178.
1. Polman CH, O’Connor PW, Havrdova E, et al. A randomized, placebo-controlled trial of natalizumab for relapsing multiple sclerosis. N Engl J Med 2006; 354: 899–910.
11. Selter RC, Biberacher V, Grummel V, et al. Natalizumab treatment decreases serum IgM and IgG levels in multiple sclerosis patients. Mult Scler 2013; 19: 1454–1461.
2. Warnke C, Menge T, Hartung HP, et al. Natalizumab and progressive multifocal leukoencephalopathy: What are the causal factors and can it be avoided? Arch Neurol 2010; 67: 923–930.
12. Villar LM, Garcia-Sanchez MI, Costa-Frossard L, et al. Immunological markers of optimal response to natalizumab in multiple sclerosis. Arch Neurol 2012; 69: 191–197.
4 http://msj.sagepub.com
Effects of natalizumab on oligoclonal bands in the cerebrospinal fluid of multiple sclerosis patients: A longitudinal study R Mancuso, D Franciotta, M Rovaris, D Caputo, A Sala, A Hernis, S Agostini, MG Calvo and M Clerici Mult Scler published online 16 June 2014 DOI: 10.1177/1352458514538111 The online version of this article can be found at: http://msj.sagepub.com/content/early/2014/06/12/1352458514538111
Published by: http://www.sagepublications.com
On behalf of: European Committee for Treatment and Research in Multiple Sclerosis
Americas Committee for Treatment and Research in Multiple Sclerosis
Pan-Asian Committee for Treatment and Research in Multiple Sclerosis
Latin American Committee on Treatment and Research of Multiple Sclerosis
Additional services and information for Multiple Sclerosis Journal can be found at: Email Alerts: http://msj.sagepub.com/cgi/alerts Subscriptions: http://msj.sagepub.com/subscriptions Reprints: http://www.sagepub.com/journalsReprints.nav Permissions: http://www.sagepub.com/journalsPermissions.nav Downloaded from msj.sagepub.com at UNIVERSITE LAVAL on November 30, 2014
>> OnlineFirst Version of Record - Jun 16, 2014 What is This?
Downloaded from msj.sagepub.com at UNIVERSITE LAVAL on November 30, 2014
538111
research-article2014
MSJ0010.1177/1352458514538111Multiple Sclerosis JournalR Mancuso, D Franciotta
MULTIPLE SCLEROSIS MSJ JOURNAL
Short Report
Effects of natalizumab on oligoclonal bands in the cerebrospinal fluid of multiple sclerosis patients: A longitudinal study
Multiple Sclerosis Journal 1–4 DOI: 10.1177/ 1352458514538111 © The Author(s), 2014. Reprints and permissions: http://www.sagepub.co.uk/ journalsPermissions.nav
R Mancuso, D Franciotta, M Rovaris, D Caputo, A Sala, A Hernis, S Agostini, MG Calvo and M Clerici
Abstract: Retrospective studies show that natalizumab modifies oligoclonal immunoglobulin (IgG) bands (OCBs) in the cerebrospinal fluid (CSF) of multiple sclerosis (MS) patients. In this study, we prospectively analyzed both serum and CSF samples from 24 MS patients, before and after 2 years of natalizumab-based therapy. Our results showed complete (55%) or partial (27%) disappearance of the OCBs in CSF samples that were taken after 2 years of therapy. Intrathecal IgG production, represented by the IgG index and IgGLoc , was also quantitatively reduced. Our data showed that natalizumab substantially modulates both intrathecal polyclonal and oligoclonal IgG production: This effect was much more potent than was previously reported. Keywords: Cerebrospinal fluid, multiple sclerosis, natalizumab, oligoclonal bands, intrathecal IgG Date received: 26 February 2014; revised: 9 May 2014; accepted: 10 May 2014
Introduction Natalizumab, a humanized antibody directed toward the very late activation antigen-4 (VLA-4) adhesion molecule, has considerable efficacy in relapsing–remitting multiple sclerosis (RRMS).1 This drug also exerts a profound biological effect on B lymphocytes,1 which might partially account for the increased risk of natalizumab-associated progressive multifocal leukoencephalopathy (PML), a brain infection caused by the John Cunningham (JC) virus that occurs rarely in natalizumab-treated patients.2 Oligoclonal immunoglobulin G (IgG) bands (OCBs) in cerebrospinal fluid (CSF) are shown to be reduced or to have even disappeared in multiple sclerosis (MS) patients who are undergoing natalizumab treatment.3,4 This observation is of great interest, because CSF OCBs are detected in more than 95% of MS patients5 and persist even after autologous hematopoietic cell transplantation6; however, these data derive from retrospective analyses and include baseline CSF samples obtained for diagnostic purposes in MS patients, well before the time of natalizumab treatment initiation.3,4
We present data from a prospective analysis of intrathecal IgG production and OCBs, in paired CSF and serum samples of RRMS patients, before and after 24 months of natalizumab therapy.
Materials and methods Patients A total of 24 MS patients, who fulfilled the criteria of the Italian Medicine Agency for natalizumab treatment (www.agenziafarmaco.gov.it), entered our surveillance longitudinal 2-year study on JCV-specific immunity and viral DNA in biological fluids, at the Don C Gnocchi Foundation ONLUS in Milan, Italy. The local ethics committee approved our study. All patients signed informed consent forms. We collected paired CSF and serum samples 1 month before the first infusion of natalizumab and after at least 24 months of treatment (Table 1). Routine brain magnetic resonance imaging (MRI) was obtained at both baseline and after 1 or 2 years of treatment: Results were reviewed by local radiologists at different image acquisition centers.
Correspondence to: Roberta Mancuso Don C Gnocchi Foundation ONLUS, Piazza Morandi 3, 20100, Milano, Italy. [email protected] R Mancuso M Rovaris D Caputo A Sala A Hernis S Agostini MG Calvo Don C Gnocchi Foundation, ONLUS, Milan, Italy D Franciotta Laboratory of Neuroimmunology, IRCCS, C Mondino National Neurological Institute, Pavia, Italy M Clerici Don C Gnocchi Foundation, ONLUS, Milan, Italy/ University of Milan, Italy
http://msj.sagepub.com 1
Downloaded from msj.sagepub.com at UNIVERSITE LAVAL on November 30, 2014
Multiple Sclerosis Journal Table 1. Demographic, clinical data and laboratory findings in 24 natalizumab-treated MS patients.
Clinical data Sex Age, years Age at onset, years Disease duration, years Treatment duration, months Number of infusions, n Pts with previous DMT (%) Pts with previous IST (%) EDSS Pts with MRI activity in Year 1 of treatment Pts with MRI activity in Year 2 of treatment Pts FDA during treatment period Laboratory findings Serum IgG (mg/dL) CSF IgG (mg/dL) Serum albumin (mg/dL) CSF albumin (mg/dL) QAlbx100 IgGLoc (mg/L) IgG index Pts with IgG index values > 0.70, n (%) Pts with positive CSF OCBs, n (%) Pts with decreased OCBs, n (%)a Pts with unchanged OCB patterns, n (%)a
Baseline
End of study period
4 M, 20 F 37.0 (29.5–44.5) 24.0 (18.0–29.0) 9.5 (7.0–15.5) 24 (24–26) 24.7 (24–25) 15 (62.5) 7 (29.2) 4.2 (3.0–5.3) – – –
– – – – – – – – 4.5 (3.0–5.5) 8 (33%) 2 (8%) 14 (58%)
901 (732–1004) 3.31 (2.25–5.74) 4000 (3600–4170) 21.2 (14.94–26.65) 0.48 (0.38–0.69) 0.52 (0.00–2.45) 0.88 (0.61–1.18) 16 (67) 22/24 (92) – –
845 (717–982) 2.13 (1.82–3.40) 4230 (3962–4545) 18.1 (15.47–25.45) 0.46 (0.33–0.62) 0.00 (0.00–0.35) 0.64 (0.56–0.82) 8 (33) 10/24 (42) 6 (27) 4 (18)
p valuesb – – – – – – – – 0.9090 – – – 0.1980 0.0001 0.2350 0.0630 0.1030 0.0003 0.0001 0.0078c 0.0005c – –
Data are expressed as medians, with IQR in parentheses. aOnly the 22 CSF OCB-positive patients were considered. bWilcoxon test. cMcNemar test. CSF: cerebrospinal fluid; DMT: disease modifying therapies, i.e. beta-interferons or glatiramer acetate; EDSS: Expanded Disability Status Scale; F: female; M: male; FDA: free from disease activity; IgGLoc: intrathecal IgG production calculated in accordance with Reiber’s formula10; IQR: interquartile range; IST: immunosuppressive therapies, i.e. azathioprine or mitoxantrone; MRI: magnetic resonance imaging; MS: multiple sclerosis; OCBs: oligoclonal IgG bands; Pts: patients; QAlb: albumin quotient
CSF and serum study IgG and albumin concentrations were measured by immunonephelometry (Immage; Beckman Coulter, Fullerton, CA, USA) on paired serum and CSF samples, which had been aliquoted within 1 hour of collection and stored at − 80°C until analysis. Equal amounts of CSF and serum IgG (0.2 µg) were loaded on the agarose gel, to detect OCBs with isoelectric focusing7 and immunofixation (Hydragel CSF-IEF system; Sebia, Norcross, GA, USA). The paired CSF and serum samples from both time points were analyzed in the same run, side-by-side. We also calculated albumin quotient (Q Alb), as a measure of blood-CSF barrier permeability, and IgG index and IgGLoc8, as quantitative measures of intrathecal IgG production.7 We based OCB detection and data
interpretation on consensus guidelines.7 When OCB disappearance was incomplete, patterns were categorized as ‘decreased OCB number’ if at least two bands had disappeared. Two experienced readers who were blinded to the pairing of samples and time points evaluated the OCB results.
Statistics We analyzed the pre- versus post-treatment variables with the Wilcoxon test (between-median differences), McNemar test (categorical data) and Spearman rank-order test (monotonic relationships). Linear regression was used for between-variable relationships; a p value < 0.05 was considered statistically significant.
2 http://msj.sagepub.com
Downloaded from msj.sagepub.com at UNIVERSITE LAVAL on November 30, 2014
R Mancuso, D Franciotta et al. (immunomodulating versus immunomodulating and immunosuppressive) parameters were compared in MS patients in whom OCBs were or were not modified by therapy. Discussion Data herein confirmed that natalizumab can reduce intrathecal OCBs in MS patients and indicated that this effect is more pronounced than what had been previously believed.3,4 Thus, a complete (55%) or partial (27%) disappearance of CSF OCBs was observed in the majority of patients in whom they were present at baseline.
Figure 1. Representative samples of CSF oligoclonal IgG bands (arrows). Complete (a) or incomplete (b) disappearance of OCBs in paired CSF and serum samples of multiple sclerosis patients, before and after the 24-month therapy with natalizumab are shown. CSF: cerebrospinal fluid; OCBs: oligoclonal IgG bands; pre: before therapy; post: after therapy; ser: serum
Results During the study period, no patients discontinued therapy and none developed PML; a single event of clinical disease relapse was observed in 6 cases (25%) and the Expanded Disability Status Scale (EDSS) was stable in all individuals. The comparison between pre- versus post-natalizumab parameters showed that median IgG concentrations were greatly decreased in the CSF (mean degree of reduction, 40%; p < 0.0001) and in serum (mean degree of reduction, 12%). Intrathecal IgG synthesis decreased significantly (p < 0.0005) as well (Table 1), whereas the Q Alb values were unchanged (≤ 0.70). Finally, CSF OCBs that were detected in 22/24 patients at baseline disappeared in 12/22 (55%), were reduced in 6/22 (27%) and remained unmodified in 4/22 patients (18%; p < 0.0001) (Table 1; Figure 1). Regarding MS subgroups with or without OCB changes, or intrathecal IgG synthesis decreases, no differences emerged when their clinical (sex, age and EDSS at study entry, age at disease onset, disease duration, clinical or MRI relapses) or previous treatment
The ability of natalizumab to affect OCBs is observed in 16% of patients in the largest published series4; whereas a previous study found results similar to ours, but in that case only six individuals were available.3 Nevertheless, these retrospective analyses suffer from a selection bias because CSF sampling was performed to rule out PML, patients were heterogeneous in terms of treatment duration and different methods were used for OCB detection. Consistent with previous results,3,4 we found that natalizumab therapy had no influence on the blood-CSF barrier permeability; this is not surprising, given the central nervous system (CNS)-specific anti-inflammatory activity of the drug. Long-lived plasma cells, which are likely the major source of OCBs in MS,9 sustain persistent antibody production in autoimmune diseases and are highly resistant to immunosuppression.10 Indeed, OCBs persisted even in advanced MS patients who underwent autologous hematopoietic cell transplantation.6 In the MS brain, parenchymal plaques and subpial ectopic B-cell follicles represent the niches where the microenvironment allows the survival of long-lived plasma cells.9 The mechanisms by which natalizumab interferes with the survival of these cells in such niches can be only hypothesized and probably involves the dysregulation of pro-survival factors comprising cytokines, receptors and adhesion molecules, including the VLA-4 antigen.10 Notably, this hypothesis seems to be supported by the observation that OCBs reappear in natalizumab-treated MS patients whom discontinue therapy because of PML.3,4 Moreover, the hypothesis is neutral towards theories favoring or opposing a possible viral pathogenesis for MS, as the shortage of the factors able to induce immunoglobulin production could affect long-lived plasma cells independently from the causes underlying their CNS settlement.10
http://msj.sagepub.com 3
Downloaded from msj.sagepub.com at UNIVERSITE LAVAL on November 30, 2014
Multiple Sclerosis Journal The CSF and serum IgG concentrations were also reduced in our patients: This effect of the drug had been recently described11; however, contrary to Villar et al.,12 we found no difference in intrathecal IgG synthesis, nor in the OCB changes when full responders were compared to patients with clinical relapses or MRI activity. The case series are nevertheless probably too small to draw definite conclusions. Our data demonstrated that natalizumab therapy has a substantial effect on both polyclonal and oligoclonal IgG production within the CNS, at a much higher degree than previously reported.3,4 They also provided additional evidence that this drug modulates B-cell activity, which might result in an impairment of humoral immunity-mediated defenses against infectious agents. An undesirable side-effect of this therapy could be the reactivation of pathogens within the CNS, a rare complication associated with the use of natalizumab. Conflict of interest None declared. Funding This work was supported by Biogen Idec and the Italian Ministry of Health (2012–2013 Ricerca Corrente).
References
Visit SAGE journals online http://msj.sagepub.com
SAGE journals
3. Von Glehn F, Farias AS, De Oliveira AC, et al. Disappearance of cerebrospinal fluid oligoclonal bands after natalizumab treatment of multiple sclerosis patients. Mult Scler 2012; 18: 1038–1041. 4. Harrer A, Tumani H, Niendorf S, et al. Cerebrospinal fluid parameters of B-cell related activity in patients with active disease during natalizumab therapy. Mult Scler 2013; 19: 1209–1212. 5. Tumani H, Deisenhammer F, Giovannoni G, et al. Revised McDonald criteria: The persisting importance of cerebrospinal fluid analysis. Ann Neurol 2011; 70: 520. 6. Bowen JD, Kraft GH, Wundes A, et al. Autologous hematopoietic cell transplantation following highdose immunosuppressive therapy for advanced multiple sclerosis: Long-term results. Bone Marrow Transpl 2012; 47: 946–951. 7. Andersson M, Alvarez-Cermeno J, Bernardi G, et al. Cerebrospinal fluid in the diagnosis of multiple sclerosis: A consensus report. J Neurol Neurosurg Psychiatry 1994; 57: 897–902. 8. Reiber H. Cerebrospinal fluid: Physiology, analysis and interpretation of protein patterns for diagnosis of neurological diseases. Mult Scler 1998; 4: 99–107. 9. Franciotta D, Salvetti M, Lolli F, et al. B cells and multiple sclerosis. Lancet Neurol 2008; 7: 852–858. 10. Hiepe F, Dorner T, Hauser AE, et al. Longlived autoreactive plasma cells drive persistent autoimmune inflammation. Nat Rev Rheumatol 2011; 7: 170–178.
1. Polman CH, O’Connor PW, Havrdova E, et al. A randomized, placebo-controlled trial of natalizumab for relapsing multiple sclerosis. N Engl J Med 2006; 354: 899–910.
11. Selter RC, Biberacher V, Grummel V, et al. Natalizumab treatment decreases serum IgM and IgG levels in multiple sclerosis patients. Mult Scler 2013; 19: 1454–1461.
2. Warnke C, Menge T, Hartung HP, et al. Natalizumab and progressive multifocal leukoencephalopathy: What are the causal factors and can it be avoided? Arch Neurol 2010; 67: 923–930.
12. Villar LM, Garcia-Sanchez MI, Costa-Frossard L, et al. Immunological markers of optimal response to natalizumab in multiple sclerosis. Arch Neurol 2012; 69: 191–197.
4 http://msj.sagepub.com
