Immune Response to Seasonal Influenza Vaccination in Multiple Sclerosis Patients Receiving Cladribine.

Cladribine has been approved for the treatment of multiple sclerosis (MS) and its administration results in a long-lasting depletion of lymphocytes. As lymphopenia is known to hamper immune responses to vaccination, we evaluated the immunogenicity of the influenza vaccine in patients undergoing cladribine treatment at different stages vs. controls. The antibody response in 90 cladribine-treated MS patients was prospectively compared with 10 control subjects receiving platform immunotherapy (NCT05019248). Serum samples were collected before and six months after vaccination. Response to vaccination was determined by the hemagglutination-inhibition test. Postvaccination seroprotection rates against influenza A were comparable in cladribine-treated patients and controls (H1N1: 94.4% vs. 100%; H3N2: 92.2% vs. 90.0%). Influenza B response was lower in the cladribine cohort (61.1% vs. 80%). The increase in geometric mean titers was lower in the cladribine group vs. controls (H1N1: +98.5 vs. +188.1; H3N2: +225.3 vs. +300.0; influenza B: +40.0 vs. +78.4); however, titers increased in both groups for all strains. Seroprotection was achieved irrespective of vaccination timing and lymphocyte subset counts at the time of vaccination in the cladribine cohort. To conclude, cladribine-treated MS patients can mount an adequate immune response to influenza independently of treatment duration and time interval to the last cladribine administration.

Effect of Previous Disease-Modifying Therapy on Treatment Effectiveness for Patients Treated With Ocrelizumab.

BACKGROUND AND OBJECTIVES: B cell-depleting antibodies were proven as effective strategy for the treatment of relapsing multiple sclerosis (RMS). The monoclonal antibody ocrelizumab was approved in 2017 in the United States and in 2018 in the European Union, but despite proven efficacy in randomized, controlled clinical trials, its effectiveness in the real-world setting remains to be fully elucidated. In particular, most study patients were treatment naive or switched from injectable therapies, whereas oral substances or monoclonal antibodies made up >1% of previous treatments. METHODS: We evaluated ocrelizumab-treated patients with RMS enrolled in the prospective cohorts at the University Hospitals Duesseldorf and Essen, Germany. Epidemiologic data at baseline were compared, and Cox proportional hazard models were applied to evaluate outcomes. RESULTS: Two hundred eighty patients were included (median age: 37 years, 35% male patients). Compared with using ocrelizumab as a first-line treatment, its use as a third-line therapy increased hazard ratios (HRs) for relapse and disability progression, whereas differences between first- vs second-line and second- vs third-line remained smaller. We stratified patients according to their last previous disease-modifying treatment and here identified fingolimod (FTY) (45 patients, median age 40 years, 33% male patients) as a relevant risk factor for ongoing relapse activity despite 2nd-line (HR: 3.417 [1.007-11.600]) or 3rd-line (HR: 5.903 [2.489-13.999]) ocrelizumab treatment, disability worsening (2nd line: HR: 3.571 [1.013-12.589]; 3rd line: HR: 4.502 [1.728-11.729]), and occurrence of new/enlarging MRI lesions (2nd line: HR: 1.939 [0.604-6.228]; 3rd line: HR: 4.627 [1.982-10.802]). Effects were persistent throughout the whole follow-up. Neither peripheral B-cell repopulation nor immunoglobulin G levels were associated with rekindling disease activity. DISCUSSION: Our prospectively collected observational data suggest suboptimal effectiveness of ocrelizumab in patients switching from FTY compared with those switching from other substances or having been treatment naive. These findings support previous studies indicating abated effectiveness of immune cell-depleting therapies following FTY treatment in patients with RMS. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that for patients with RMS, previous treatment with FTY compared with previous treatment with other immunomodulating therapies decreases the effectiveness of ocrelizumab.

Immunological consequences of cladribine treatment in multiple sclerosis: A real-world study.

BACKGROUND: Cladribine is a synthetic deoxyadenosine analogue approved for the treatment of highly active relapsing multiple sclerosis (RMS). Cladribine is considered to be a semi-selective immune-reconstitution therapy (IRT) that induces long-term remission following short course of treatment. Here, we evaluated the effect of cladribine on immune cell reduction and reconstitution during the first two years of treatment. METHODS: We analyzed our longitudinal, prospective, real-world cohort of 80 cladribine-treated RMS patients from two tertiary centers in Germany. Laboratory testing was conducted monthly and included evaluation of cellular as well as soluble parameters. Laboratory outcomes were correlated with infectious adverse events (AEs) and clinical or paraclinical disease activity. RESULTS: Selective alterations in immune cell populations occurred following cladribine treatment, with the most marked effects observed in year two of treatment. Specifically, a rapid reduction in CD56+ natural killer cells (nadir: month 1 (year 1) and 14 (year 2); -37 and -41% from baseline) was followed by a greater reduction in CD19+ B cells (nadir: month 2 and 14; -81 and -82%); a moderate effect on CD4+ (nadir: month 3 and 15; -48 and -61%) and CD8+ T cells (nadir: month 5 and 18; -40 and -48%). Despite the marked effect on B cells, immunoglobulin levels were unaffected. There was no or minimal effect on thrombocytes and innate immune cells. Clinical and paraclinical disease activity was unrelated to the observed immune alterations. Lymphopenia was the most commonly observed AE (86.3% of patients; grade III-IV lymphopenia: 38.8%). The cumulative incidence of infections was 55% with cladribine treatment, which were mostly mild or moderate. In total, 19 herpes infections developed in 8 (10%) cladribine-treated patients; all cases were dermatomal and 94.7% of the herpetic infections occurred during a period of lymphopenia. CONCLUSIONS: The immunophenotyping data obtained in our real-world setting are comparable to those demonstrated in pivotal clinical trials and provide further evidence that cladribine may represent a form of IRT. However, regarding the side-effect profile of cladribine, severe lymphopenia (exceeding grade II CTCAE) was more frequent, which may have prompted the development of herpes infections. Of note, lymphocyte dynamics did not correlate with clinical and paraclinical measures of disease activity in the two-year follow-up period.

Effectiveness and safety of cladribine in MS: Real-world experience from two tertiary centres.

BACKGROUND: Oral cladribine has been approved for the treatment of relapsing multiple sclerosis (MS) yet real-world evidence regarding its effectiveness and safety remains scarce. OBJECTIVE: To evaluate efficacy and safety outcomes of MS patients following induction of cladribine. METHODS: We evaluated our prospective cohort of cladribine-treated MS patients from two tertiary centres in Germany. Relapses, disability worsening and occurrence of new or enlarging T2-hyperintense magnetic resonance imaging (MRI) lesions were assessed as well as lymphocyte counts and herpes virus infections. RESULTS: Among 270 patients treated with cladribine, we observed a profound reduction of both relapses and new or enlarging MRI lesions. Treatment appeared more efficacious, especially in patients without previous therapy or following platform substances. Patients switching from natalizumab were prone to re-emerging disease activity. Among patients following dimethyl fumarate pre-treatment, severe lymphopenia was common and associated with increased rates of herpes virus manifestations. CONCLUSION: Overall, we observed an efficacy and safety profile of cladribine consistent with data from the phase 3 clinical trial. However, patients switching from natalizumab experienced suboptimal disease control beyond rebound activity following cessation of natalizumab. Furthermore, dimethyl fumarate pre-treatment was associated with a profound risk of developing severe lymphopenia and subsequent herpes virus infections.

Ocrelizumab Extended Interval Dosing in Multiple Sclerosis in Times of COVID-19.

OBJECTIVE: To evaluate the clinical consequences of extended interval dosing (EID) of ocrelizumab in relapsing-remitting multiple sclerosis (RRMS) during the coronavirus disease 2019 (COVID-19) pandemic. METHODS: In our retrospective, multicenter cohort study, we compared patients with RRMS on EID (defined as ≥4-week delay of dose interval) with a control group on standard interval dosing (SID) at the same period (January to December 2020). RESULTS: Three hundred eighteen patients with RRMS were longitudinally evaluated in 5 German centers. One hundred sixteen patients received ocrelizumab on EID (median delay [interquartile range 8.68 [5.09-13.07] weeks). Three months after the last ocrelizumab infusion, 182 (90.1%) patients following SID and 105 (90.5%) EID patients remained relapse free (p = 0.903). Three-month confirmed progression of disability was observed in 18 SID patients (8.9%) and 11 EID patients (9.5%, p = 0.433). MRI progression was documented in 9 SID patients (4.5%) and 8 EID patients (6.9%) at 3-month follow-up (p = 0.232). Multivariate logistic regression showed no association between treatment regimen and no evidence of disease activity status at follow-up (OR: 1.266 [95% CI: 0.695-2.305]; p = 0.441). Clinical stability was accompanied by persistent peripheral CD19+ B-cell depletion in both groups (SID vs EID: 82.6% vs 83.3%, p = 0.463). Disease activity in our cohort was not associated with CD19+ B-cell repopulation. CONCLUSION: Our data support EID of ocrelizumab as potential risk mitigation strategy in times of the COVID-19 pandemic. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that for patients with RRMS, an EID of at least 4 weeks does not diminish effectiveness of ocrelizumab.

Molecular treatment effects of alemtuzumab in skeletal muscles of patients with IBM.

BACKGROUND: Mechanisms of inflammation and protein accumulation are crucial in inclusion body myositis (IBM). Recent evidence demonstrated that intravenous immunoglobulin failed to suppress cell-stress mediators in IBM. Here we studied the molecular changes in skeletal muscle biopsies from patients with IBM before and after treatment with alemtuzumab. METHODS: Relevant inflammatory and degeneration-associated markers were assessed by quantitative-PCR and immunohistochemistry in repeated muscle biopsy specimens from patients with IBM, which had been treated in a previously published uncontrolled proof-of-concept trial with alemtuzumab. RESULTS: There were no significant changes of the mRNA expression levels of the pro-inflammatory chemokines CXCL-9, CCL-4, and the cytokines IFN-γ, TGF-ß, TNF-α, and IL-1ß. Similarly, the degeneration-associated molecules ubiquitin, APP and αB-crystallin did not substantially change. Although no overall beneficial treatment effect was noted except for a 6-month stabilization, some patients experienced a transient improvement in muscle strength. In such responders, a trend towards reduced expression of inflammatory markers was noted. In contrast, the expression remained unchanged in the others who did not experience any change. The expression levels of IL-1ß and MHC-I correlated with the positive clinical effect. By immunohistochemistry, some inflammatory mediators like CD8, CXCL-9, and MHC-I were downmodulated. However, no consistent changes were noted for ubiquitin, nitrotyrosin and ß-amyloid. CONCLUSIONS: Alemtuzumab showed a trend towards downregulation of the expression of some inflammatory molecules in skeletal muscle of IBM patients but has no effect on several crucial markers of cell stress and degeneration. The data are helpful to explain the molecular treatment effects of future lymphocyte-targeted immunotherapies in IBM.

HMGB1 and RAGE in skeletal muscle inflammation: Implications for protein accumulation in inclusion body myositis.

Inflammation is associated with protein accumulation in IBM, but precise mechanisms are elusive. The "alarmin" HMGB1 is upregulated in muscle inflammation. Its receptor RAGE is crucial for ß-amyloid-associated neurodegeneration. Relevant signaling via HMGB1/RAGE is expected in IBM pathology. By real-time-PCR, mRNA-expression levels of HMGB1 and RAGE were upregulated in muscle biopsies of patients with IBM and PM, but not in muscular dystrophy or non-myopathic controls. By immunohistochemistry, both molecules displayed the highest signal in IBM, where they distinctly co-localized to intra-fiber accumulations of ß-amyloid and neurofilament/tau. In these fibers, identification of phosphorylated Erk suggested that relevant downstream activation is present upon HMGB1 signaling via RAGE. Protein expressions of HMGB1, RAGE, Erk and phosphorylated Erk were confirmed by Western blot. In a well established cell-culture model for pro-inflammatory cell-stress, exposure of human muscle-cells to IL-1ß+IFN-γ induced cytoplasmic translocation of HMGB1 and subsequent release as evidenced by ELISA. Upregulation of RAGE on the cell surface was demonstrated by immunocytochemistry and flow-cytometry. Recombinant HMGB1 was equally potent as IL-1ß+IFN-γ in causing amyloid-accumulation and cell-death, and both were abrogated by the HMGB1-blocker BoxA. The findings strengthen the concept of unique interactions between degenerative and inflammatory mechanisms and suggest that HMGB1/RAGE signaling is a critical pathway in IBM pathology.

Cell stress molecules in the skeletal muscle of GNE myopathy.

BACKGROUND: Mutations of the UDP-N-acetylglucosamine-2-epimerase/N-acetylmannosamine-kinase (GNE)-gene are causally related to GNE myopathy. Yet, underlying pathomechanisms of muscle fibre damage have remained elusive. In sporadic inclusion body myositis (sIBM), the pro-inflammatory cell-stress mediators αB-crystallin and inducible nitric oxide synthase (iNOS) are crucial markers of the disease pathology. METHODS: 10 muscle biopsies from GNE myopathy patients were analyzed for mRNA-expression of markers of cell-stress, inflammation and ß-amyloid and compared to non-myopathic controls. Using double-labeling immunohistochemistry, serial sections of skeletal muscle biopsies were stained for amyloid precursor protein (APP), major histocompatibility complex (MHC)-I, αB-crystallin, neural cell adhesion molecule (NCAM), interleukin (IL)-1ß, ß-amyloid, iNOS, and phosphorylated neurofilament (P-neurofilament) as well as hematoxylin/eosin histochemistry. Corresponding areas of all biopsies with a total of 2,817 muscle fibres were quantitatively assessed for all markers. RESULTS: mRNA-expression of APP, NCAM, iNOS, TNF-α and TGF-ß was higher in GNE myopathy compared to controls, yet this was not statistically significant. The mRNA-expression of APP and αB-crystallin significantly correlated with the expression of several pro-inflammatory and cell-stress-associated markers as NCAM, IL-1ß, TGF-ß, CCL-3, and CCL4. By immunohistochemistry, αB-crystallin and iNOS were co-upregulated and the number of fibres positive for αB-crystallin, NCAM, MHC-I and iNOS significantly correlated with each other. A large fraction of fibres positive for αB-crystallin were double positive for iNOS and vice-versa. Moreover, several fibres with structural abnormalities were positive for αB-crystallin and iNOS. Notably, particularly normal appearing fibres displayed an overexpression of these molecules. CONCLUSIONS: The cell-stress molecules αB-crystallin and iNOS are overexpressed in GNE myopathy muscle and may identify early disease mechanisms. The data help to better understand the pathology of GNE myopathy.