Effects of natalizumab therapy on intrathecal antiviral antibody responses in MS

Effects of natalizumab on oligoclonal bands in the cerebrospinal fluid of patients with multiple sclerosis: a systematic review and meta-analysis

INTRODUCTION

Oligoclonal bands (OCBs) in cerebrospinal fluid (CSF) are utilized for diagnosing multiple sclerosis (MS), as they are found in 95% of patients. Additionally, OCBs are linked to disease prognosis. The primary contributors to OCB production are long-lived plasma cells. This study aims to quantify the impact of natalizumab (NTZ) on OCB levels in the CSF of MS patients.

METHODS

A systematic search on MEDLINE, SCOPUS and Web of Science for English-written and peer-reviewed longitudinal studies on adults was performed. Methodological quality was assessed with the Newcastle-Ottawa Scale. Proportional meta-analysis was performed in R using a generalized linear mixed-effects model. We investigated heterogeneity with influence diagnostics, sensitivity analysis and meta-regression.

RESULTS

Eight eligible studies of adequate quality with a total sample of 326 relapsing-remitting MS patients were included. A summary rate of 14.07% [95% CI, 4.48%-36.36%] for complete loss of OCBs and 42.02% [95% CI, 15.23%-74.51%] for reduction in OCB number or intensity was observed, both with considerable heterogeneity. Pooled estimates dropped (11% [95% CI, 0.04%-0.29%] and 34% [95% CI, 0.11%-0.68%] respectively) after the identification of an influential study. Multivariable meta-regression identified IgG index as a factor contributing to heterogeneity (adj. p = 0.0279), regarding reduction of OCB number or intensity.

DISCUSSION

In conclusion, our systematic review and meta-analysis showed that NTZ can lead to reduction of intrathecal OCBs in MS patients, indicating a possible effect of NTZ on memory plasma cells, which are the main source of OCBs in MS.

HLA Associations of Intrathecal IgG Production against Specific Viruses in Multiple Sclerosis

OBJECTIVE

Specific human leucocyte antigen (HLA) alleles are not only associated with higher risk to develop multiple sclerosis (MS) and other autoimmune diseases, but also with the severity of various viral and bacterial infections. Here, we analyzed the most specific biomarker for MS, that is, the polyspecific intrathecal IgG antibody production against measles, rubella, and varicella zoster virus (MRZ reaction), for possible HLA associations in MS.

METHODS

We assessed MRZ reaction from 184 Swiss patients with MS and clinically isolated syndrome (CIS) and 89 Swiss non-MS/non-CIS control patients, and performed HLA sequence-based typing, to check for associations of positive MRZ reaction with the most prevalent HLA alleles. We used a cohort of 176 Swedish MS/CIS patients to replicate significant findings.

RESULTS

Whereas positive MRZ reaction showed a prevalence of 38.0% in MS/CIS patients, it was highly specific (97.7%) for MS/CIS. We identified HLA-DRB1*15:01 and other tightly linked alleles of the HLA-DR15 haplotype as the strongest HLA-encoded risk factors for a positive MRZ reaction in Swiss MS/CIS (odds ratio [OR], 3.90, 95% confidence interval [CI] 2.05-7.46, padjusted = 0.0004) and replicated these findings in Swedish MS/CIS patients (OR 2.18, 95%-CI 1.16-4.02, padjusted = 0.028). In addition, female MS/CIS patients had a significantly higher probability for a positive MRZ reaction than male patients in both cohorts combined (padjusted <0.005).

INTERPRETATION

HLA-DRB1*15:01, the strongest genetic risk factor for MS, and female sex, 1 of the most prominent demographic risk factors for developing MS, predispose in MS/CIS patients for a positive MRZ reaction, the most specific CSF biomarker for MS. ANN NEUROL 2024;95:1112-1126.

Natalizumab promotes anti-inflammatory and repair effects in multiple sclerosis

BACKGROUND

Multiple sclerosis is an inflammatory and degenerative disease of the central nervous system leading to demyelination and axonal loss. Relapsing-remitting multiple sclerosis (RRMS) is commonly treated by anti-inflammatory drugs, where one of the most effective drugs to date is the monoclonal antibody natalizumab.

METHODS

The cerebrospinal fluid (CSF) proteome was analyzed in 56 patients with RRMS before and after natalizumab treatment, using label-free mass spectrometry and a subset of the changed proteins were verified by parallel reaction monitoring in a new cohort of 20 patients, confirming the majority of observed changes.

RESULTS

A total of 287 differentially abundant proteins were detected including (i) the decrease of proteins with roles in immunity, such as immunoglobulin heavy constant mu, chitinase-3-like protein 1 and chitotriosidase, (ii) an increase of proteins involved in metabolism, such as lactate dehydrogenase A and B and malate-dehydrogenase cytoplasmic, and (iii) an increase of proteins associated with the central nervous system, including lactadherin and amyloid precursor protein. Comparison with the CSF-PR database provided evidence that natalizumab counters protein changes commonly observed in RRMS. Furthermore, vitamin-D binding protein and apolipoprotein 1 and 2 were unchanged during treatment with natalizumab, implying that these may be involved in disease activity unaffected by natalizumab.

CONCLUSIONS

Our study revealed that some of the previously suggested biomarkers for MS were affected by the natalizumab treatment while others were not. Proteins not previously suggested as biomarkers were also found affected by the treatment. In sum, the results provide new information on how the natalizumab treatment impacts the CSF proteome of MS patients, and points towards processes affected by the treatment. These findings ought to be explored further to disclose potential novel disease mechanisms and predict treatment responses.

A comparison of measles-rubella-zoster reaction, oligoclonal IgG bands, oligoclonal kappa free light chains and kappa index in multiple sclerosis

BACKGROUND AND OBJECTIVES

To evaluate the diagnostic performance of the measles-rubella-zoster reaction (MRZR) in a large real-world multiple sclerosis (MS) cohort. Second, to compare MRZR with the determination of oligoclonal IgG bands (OCB), oligoclonal kappa free light chain bands (oKFLC), and the KFLC index.

METHODS

A single-center retrospective study was conducted at the University Hospital Ostrava (Czech Republic). Patients were eligible if aged ≥18 years with a determined clinical diagnosis. IgG antibodies against measles (M), rubella (R), and varicella zoster (Z) viruses were determined in paired CSF and serum using ELISA and MRZR indicated as positive if at least two components had an antibody index >1.4. OCB and oKFLC were detected by means of isoelectric focusing, and KFLC CSF and serum concentrations for calculation of the KFLC index were determined immunochemically.

RESULTS

A total of 1,751 patients were included in the analyzed data set, which comprised 379 MS patients and 1,372 non-MS controls. The frequency of positive MRZR was higher in MS than in non-MS cases (MS 32.2 % vs non-MS 2.8 %; p < 0.001). This corresponded to a specificity of 97.2 % (95 % CI 96.1-98.0) and sensitivity of 32.2 % (95 % CI 27.5-37.2) and overall accuracy of 83.1 % (95 % CI 81.3-84.8). In comparison, the highest sensitivity of 95.6% (95 % CI 93.0-97.5) was for OCB with specificity of 86.9 % (95 % CI 84.9-88.7), followed by oKFLC with sensitivity and specificity of 94.7 % (95 % CI 91.5-96.9) and 78.4% (95 % CI 75.7-80.8), respectively, and the KFLC index with sensitivity of 92.5 % (95 % CI 86.6-96.3) and specificity of 93.5 % (95 % CI 90.5-95.9).

DISCUSSION

MRZR remains a very specific test for the diagnosis of MS but has low sensitivity, which disallows its independent use. In contrast, OCB showed the highest sensitivity and thus remains the gold standard for the diagnosis of MS.

Serum IgG levels to Epstein-Barr and measles viruses in patients with multiple sclerosis during natalizumab and interferon beta treatment

Background

Patients with multiple sclerosis (MS) demonstrate higher seroprevalence of Epstein-Barr virus (EBV) and increased anti-EBV IgG levels in serum compared with healthy controls. Intrathecal antibody production to measles virus (MeV) is a common finding in patients with MS.

Objective

To measure serum IgG reactivity to EBV glycoprotein 350 (gp350) and MeV nucleocapsid protein (N_CORE) in patients with MS and healthy controls and to determine if reactivity changed in patients during interferon beta (IFNβ) and/or natalizumab (NAT) treatment. A secondary aim was to determine the seroprevalence of EBV in patients and controls.

Methods

Patients with MS (n=728) were included from the Swedish pharmacovigilance study for NAT. Paired serum samples from 714 patients drawn before and during NAT treatment and paired samples from 170 patients during prior IFNβ treatment were analysed. In total, 156 patients were included in both groups. Samples from 144 matched blood donors served as controls. Indirect ELISA was applied using recombinant EBVgp350 and MeV N_CORE as antigens. EBVgp350 IgG seronegative samples were also analysed using EBV nuclear antigen 1 and viral capsid antigen (VCA).

Results

Patients with MS showed higher serum levels of anti-EBVgp350 and anti-MeV N_CORE IgG compared with controls. During NAT treatment, the levels of anti-EBVgp350 and anti-MeV N_CORE IgG declined, compared with the relatively stable levels noted during prior IFNβ treatment. Ten patients failed to demonstrate anti-EBVgp350 IgG but did show detectable anti-VCA IgG, indicating EBV seropositivity. In contrast, 10/144 controls were EBV seronegative.

Conclusions

Treatment with NAT, which is considered a selective immunosuppressive agent with a compartmentalised effect on the central nervous system, appeared to be associated with a moderate decrease in circulating IgG levels to EBVgp350 and MeV N_CORE. All patients with MS were EBV IgG seropositive, supporting the potential role of EBV in the pathogenesis of MS.

Decreased Intrathecal Concentrations of Free Light Chains Kappa in Multiple Sclerosis Patients Taking Very High Effective Disease-Modifying Treatment

Free light chains kappa (FLCκ) in cerebrospinal fluid (CSF) are a part of the intrathecal immune response. This observational study was conducted to investigate the effects of different disease-modifying therapies (DMT) on the humoral intrathecal immune response in the CSF of patients with multiple sclerosis (MS). FLCκ were analyzed in CSF and serum samples from MS patients taking DMT (n = 60) and those in a control cohort of treatment-naïve MS patients (n = 90). DMT was classified as moderately effective (including INFß-1a, INFß-1b, glatiramer acetate, dimethyl fumarate, teriflunomide, triamcinolone); highly effective (including fingolimod, daclizumab) and very highly effective (alemtuzumab, natalizumab, rituximab/ocrelizumab, mitoxantrone). FLCκ were measured using a nephelometric FLCκ kit. Intrathecal FLCκ and IgG concentrations were assessed in relation to the hyperbolic reference range in quotient diagrams. Intrathecal FLCκ concentrations and IgG concentrations were significantly lower in samples from the cohort of MS patients taking very highly effective DMT than in samples from the cohort of MS patients taking highly effective DMT and in the treatment-naïve cohort (FLCκ: p = 0.004, p < 0.0001 respectively/IgG: p = 0.013; p = 0.021). The reduction in FLCκ could contribute to an anti-inflammatory effect in the CNS through this mechanism. There was no difference in the appearance of CSF-specific oligoclonal bands (p = 0.830). Longitudinal analyses are required to confirm these results.

Natalizumab Induces Changes of Cerebrospinal Fluid Measures in Multiple Sclerosis

Background: There is a lack of knowledge about the evolution of cerebrospinal fluid (CSF) markers in multiple sclerosis (MS) patients undergoing natalizumab treatment. Aim: We aimed to evaluate the effect of natalizumab on basic inflammatory CSF and MRI measures. Methods: Together, 411 patients were screened for eligibility and 93 subjects with ≥2 CSF examinations ≤6 months before and ≥12 months after natalizumab initiation were recruited. The effect of natalizumab on CSF as well as clinical and paraclinical measures was analyzed using adjusted mixed models. Results: Natalizumab induced a decrease in CSF leukocytes (p < 1 × 10⁻¹⁵), CSF protein (p = 0.00007), the albumin quotient (p = 0.007), the IgG quotient (p = 6 × 10⁻¹⁵), the IgM quotient (p = 0.0002), the IgG index (p = 0.0004), the IgM index (p = 0.003) and the number of CSF-restricted oligoclonal bands (OCBs) (p = 0.0005). CSF-restricted OCBs positivity dropped from 94.6% to 86% but 26 patients (28%) had an increased number of OCBs at the follow-up. The baseline to follow-up EDSS and T2-LV were stable; a decrease in the relapse rate was consistent with a decrease in the CSF inflammatory markers and previous knowledge about the effectiveness of natalizumab. The average annualized brain volume loss during the follow-up was −0.50% (IQR = −0.96, −0.16) and was predicted by the baseline IgM index (B = −0.37; p = 0.003). Conclusions: Natalizumab is associated with a reduction of basic CSF inflammatory measures supporting its strong anti-inflammatory properties. The IgM index at the baseline predicted future brain volume loss during the course of natalizumab treatment.

Secondary Immunodeficiency and Risk of Infection Following Immune Therapies in Neurology

Secondary immunodeficiencies (SIDs) are acquired conditions that may occur as sequelae of immune therapy. In recent years a number of disease-modifying therapies (DMTs) has been approved for multiple sclerosis and related disorders such as neuromyelitis optica spectrum disorders, some of which are frequently also used in- or off-label to treat conditions such as chronic inflammatory demyelinating polyneuropathy (CIDP), myasthenia gravis, myositis, and encephalitis. In this review, we focus on currently available immune therapeutics in neurology to explore their specific modes of action that might contribute to SID, with particular emphasis on their potential to induce secondary antibody deficiency. Considering evidence from clinical trials as well as long-term observational studies related to the patients' immune status and risks of severe infections, we delineate long-term anti-CD20 therapy, with the greatest data availability for rituximab, as a major risk factor for the development of SID, particularly through secondary antibody deficiency. Alemtuzumab and cladribine have relevant effects on circulating B-cell counts; however, evidence for SID mediated by antibody deficiency appears limited and urgently warrants further systematic evaluation. To date, there has been no evidence suggesting that treatment with fingolimod, dimethyl fumarate, or natalizumab leads to antibody deficiency. Risk factors predisposing to development of SID include duration of therapy, increasing age, and pre-existing low immunoglobulin (Ig) levels. Prevention strategies of SID comprise awareness of risk factors, individualized treatment protocols, and vaccination concepts. Immune supplementation employing Ig replacement therapy might reduce morbidity and mortality associated with SIDs in neurological conditions. In light of the broad range of existing and emerging therapies, the potential for SID warrants urgent consideration among neurologists and other healthcare professionals.

Effects of Natalizumab Therapy on Intrathecal Immunoglobulin G Production Indicate Targeting of Plasmablasts

OBJECTIVES

To evaluate the long-term effects of natalizumab (NTZ) on different features of intrathecal immunoglobulin (Ig) synthesis in patients with multiple sclerosis (MS) and to quantify the expression of α4-integrin in stages of B-cell maturation.

METHODS

We combined a cross-sectional (49 NTZ-treated MS patients, mean treatment duration 5.1 years, and 47 untreated MS patients) and a longitudinal study (33 patients with MS before and during NTZ, mean treatment duration: 4.8 years), analyzing paired serum and CSF samples for IgG, IgA, and IgM levels, reactivity against selected viruses (measles virus, rubella virus, and varicella zoster virus [MRZ] reaction), and oligoclonal bands (OCBs). Banding patterns before and after therapy were directly compared by isoelectric focusing in 1 patient. In addition, we determined the expression of α4-integrin by FACS analysis on blood-derived B-cell subsets (plasmablasts, memory B cells, and naive B cells) of healthy controls.

RESULTS

In serum, NTZ decreased IgM and IgG, but not IgA, levels. IgM hypogammaglobulinemia occurred in 28% of NTZ-treated patients. In CSF, NTZ treatment resulted in a strong reduction of intrathecally produced IgG and, to a lesser extent, IgA, whereas IgM indices [(Ig CSF/Serum)/(Albumin CSF/Serum)] remained largely unchanged. Reduction of the IgG index correlated with NTZ treatment duration, as did serum IgM and IgA levels. MRZ reaction was unchanged and OCB persisted. Direct comparison of OCB pattern before and after NTZ revealed the persistence of individual bands. α4-Integrin expression was highest on plasmablasts (CD19⁺CD38⁺CD27⁺).

CONCLUSION

Our data indicate that NTZ reduces short-lived plasmablasts in the CNS compartment but has little effect on locally persisting long-lived plasma cells.

Natalizumab differentially affects plasmablasts and B cells in multiple sclerosis

BACKGROUND

Natalizumab treatment increases the frequencies of B cells in blood but reduces IgG in blood and CSF. Plasmablasts are important in the production of IgG, and the development of plasmablasts is CD49d dependent.

OBJECTIVE

We hypothesized that natalizumab treatment affects the development of plasmablasts.

METHODS

We retrospectively analyzed frequencies and absolute counts of B cell subsets by flow cytometry from a longitudinal cohort of 9 progressive multiple sclerosis (MS) patients treated with natalizumab for 60 weeks, and a cross-sectional relapsing-remitting MS (RRMS) cohort with 17 untreated and 37 treated with natalizumab (17 stable and 20 unstable patients with relapse activity). Additionally, CD49d expression on B cell subsets was examined in 10 healthy controls, and blood and cerebrospinal fluid (CSF) frequencies of B cell subsets were quantified in untreated and natalizumab treated RRMS patients.

RESULTS

In progressive MS, levels of IgG decreased in plasma (p<0.001) from baseline to 60 weeks follow-up. In the progressive MS and RRMS cohorts we observed that natalizumab treatment significantly increased the frequency of B cells (p=0.004; p<0.0001) and several B cell subsets, most pronounced for memory B cell subsets (p=0.0001; p<0.0001), while there was a decrease in plasmablast frequency (p=0.008; p=0.008). In both progressive MS and RRMS the absolute cell counts of B cells increased (p=0.004; p<0.001), which was explained by a significant increase in all subsets, except for plasmablasts. Furthermore, we found decreased memory B cell counts in unstable compared to stable natalizumab-treated patients (p=0.02). The expression of CD49d was higher on plasmablasts compared to other B cell subsets (p<0.0001). In CSF, plasmablasts could not be detected in patients treated with natalizumab, in contrast to an increased frequency in untreated RRMS patients.

CONCLUSION

We confirm previous studies showing that natalizumab increases circulating number of B cells, particularly memory cells, concomitant with a decrease in plasma IgG concentrations. Moreover, we demonstrate in two separate cohorts that natalizumab treatment markedly decreases frequencies of plasmablasts while the absolute number is stable. Additionally, plasmablasts have high expression of CD49d, and plasmablasts could not be detected in the CSF of natalizumab-treated patients. Finally, memory B cells were found to be reduced in unstable natalizumab-treated patients, which could possibly indicate increased recruitment to the CNS.

High rates of JCV seroconversion in a large international cohort of natalizumab-treated patients

Aims:

To retrospectively assess factors associated with John Cunningham virus (JCV) seroconversion in natalizumab-treated patients.

Background:

Natalizumab is highly effective for the treatment of relapsing–remitting multiple sclerosis (RRMS), but its use is complicated by opportunistic JCV infection. This virus can result in progressive multifocal leukoencephalopathy (PML). Serial assessment of JCV serostatus is mandated during natalizumab treatment.

Methods:

Patients treated with natalizumab for RRMS at six tertiary hospitals in Melbourne, Australia (n = 865) and 11 MS treatment centres in Brazil (n = 136) were assessed for change in JCV serostatus, duration of exposure to natalizumab and prior immunosuppression. Sensitivity analyses examined whether sex, age, tertiary centre, prior immunosuppression or number of JCV tests affected time to seroconversion.

Results:

From a cohort of 1001 natalizumab-treated patients, durable positive seroconversion was observed in 83 of 345 initially JCV negative patients (24.1%; 7.3% per year). Conversely, 16 of 165 initially JCV positive patients experienced durable negative seroconversion (9.7%; 3.8% per year). Forty patients (3.9%) had fluctuating serostatus. Time-to-event analysis did not identify a relationship between JCV seroconversion and duration of natalizumab exposure. Prior exposure to immunosuppression was not associated with an increased hazard of positive JCV seroconversion. Male sex was associated with increased JCV seroconversion risk [adjusted hazard ratio 2.09 (95% confidence interval 1.17–3.71) p = 0.012].

Conclusion:

In this large international cohort of natalizumab-treated patients we observed an annual durable positive seroconversion rate of 7.3%. This rate exceeds that noted in registration and post-marketing studies for natalizumab. This rate also greatly exceeds that predicted by epidemiological studies of JCV seroconversion in healthy populations. Taken together, our findings support emerging evidence that natalizumab causes off-target immune changes that may be trophic for JCV seroconversion. In addition, male sex may be associated with increased positive JCV seroconversion.

Biological Significance of Anti-SARS-CoV-2 Antibodies: Lessons Learned From Progressive Multifocal Leukoencephalopathy

OBJECTIVE

To discuss the pathogenic and diagnostic relevance of cellular and humoral immune responses against severe acute respiratory syndrome novel coronavirus (SARS-COV-2) and pertinent observations made in progressive multifocal leukoencephalopathy (PML).

METHODS

Review of pertinent literature. RESULTS: There is at least 1 precedent for an antibody response against a viral pathogen that fails to provide host protection in the absence of immune-competent CD4+ T cells. PML is an infection of the CNS caused by JC virus (JCV), which commonly occurs during treatment with the therapeutic monoclonal antibody natalizumab. In this context, the humoral immune response fails to prevent JCV reactivation, and elevated anti-JCV serum indices are associated with a higher PML incidence. The more relevant immune-competent cells in host defense against JCV appear to be T cells. T cell-mediated responses are also detectable in convalescing patients with SARS-COV-2 irrespective of the humoral immune response.

CONCLUSION

Based on pathogenic lessons learned from PML under natalizumab therapy, we suggest the incorporation of functional assays that determine neutralizing properties of SARS-CoV-2-specific antibodies. In addition, we outline the potential role of T-cell detection assays in determining herd immunity in a given population or in studying therapeutic responses to vaccines.

High anti-JCPyV serum titers coincide with high CSF cell counts in RRMS patients

Background:

Progressive multifocal leukoencephalopathy (PML) can in rare cases occur in natalizumab-treated patients with high serum anti-JCPyV antibodies, hypothetically due to excessive blockade of immune cell migration.

Objective:

Immune cell recruitment to the central nervous system (CNS) was assessed in relapsing-remitting multiple sclerosis (RRMS) patients stratified by low versus high anti-JCPyV antibody titers as indicator for PML risk.

Methods:

Cerebrospinal fluid (CSF) cell counts of 145 RRMS patients were quantified by flow cytometry. Generalized linear models were employed to assess influence of age, sex, disease duration, Expanded Disability Status Scale (EDSS), clinical/radiological activity, current steroid or natalizumab treatment, as well as anti-JCPyV serology on CSF cell subset counts.

Results:

While clinical/radiological activity was associated with increased CD4, natural killer (NK), B and plasma cell counts, natalizumab therapy reduced all subpopulations except monocytes. With and without natalizumab therapy, patients with high anti-JCPyV serum titers presented with increased CSF T-cell counts compared to patients with low anti-JCPyV serum titers. In contrast, PML patients assessed before (n = 2) or at diagnosis (n = 5) presented with comparably low CD8 and B-cell counts, which increased after plasma exchange (n = 4).

Conclusion:

High anti-JCPyV indices, which could be indicative of increased viral activity, are associated with elevated immune cell recruitment to the CNS. Its excessive impairment in conjunction with viral activity could predispose for PML development.