Marco Capobianco

Persistent neutralizing antibodies abolish the interferon β bioavailability in MS patients

Background: MxA is an antiviral protein exclusively induced by type I interferons (IFN) and some viruses, and MxA gene expression is one of the most appropriate markers for measuring the biologic activity of exogenous IFNβ. Methods: A new quantitative-competitive PCR method was used to quantify MxA mRNA in peripheral blood mononuclear cells of 99 treatment-naïve and 92 IFNβ-treated patients with MS (22 Avonex, 17 Betaferon, and 53 Rebif-22). Every 3 months, IFNβ-induced neutralizing antibodies (NAb) were evaluated in sera using a cytopathic effect assay. Three categories of patients were identified: NAb negative (NAb−), persistent NAb positive (NAb+, ≥2 consecutive positive samples), and isolated NAb+ (one positive sample). Results: Treatment-naïve patients expressed detectable MxA mRNA levels (mean = 36 ± 32 fg MxA/pg glyceraldehyde-3-phosphate dehydrogenase (GAPDH); range 1 to 160) and an upper normal threshold was established (mean + 3 SD = 132 fg MxA/pg GAPDH). IFNβ-treated patients exhibited more than 11-fold higher levels (mean = 412 ± 282 fg MxA/pg GAPDH; range 16 to 1,172). However, 17 patients did not exhibit an increase in MxA mRNA level; 15 of these 17 patients showed a concurrent Nab+ titer. Moreover, 13 were persistent NAb+. Isolated NAb+ patients did not show a decrease in bioavailability of IFNβ (n = 9; mean = 567 ± 366 fg MxA/pg GAPDH; range 83 to 1,120). In NAb− patients, bioavailability was comparable among the three different IFNβ preparations 12 hours after injection. Conclusion: During IFNβ therapy, the presence of NAb reduced or abolished bioavailability in a relevant percentage of patients. These data could be important for the early detection of patients with MS who are not responsive to IFNβ therapy.

Neutralizing antibodies reduce the efficacy of βIFN during treatment of multiple sclerosis

Objective: To analyze the impact of neutralizing antibodies (NAbs) on the clinical efficacy of IFNβ. Methods: This was an open-label study involving 78 patients with multiple sclerosis treated with Betaferon 8 million IU (MIU) subcutaneously (SC) every other day (n = 20), Rebif 22 μg SC 3 times weekly (n = 25), or Avonex 30 μg IM once weekly (n = 33). Every 3 months, blood samples were collected and sera were analyzed for NAbs using an antiviral cytopathic effect assay. Patients were categorized according to their NAb status: NAb negative (NAb−); isolated NAb positive (NAb+), patients with ≥1 positive sample (titer ≥ 20); and persistent NAb+, patients with ≥2 consecutive positive samples (titer ≥ 20). Patients who were NAb− and persistent NAb+ were compared for relapse rate, time between first and second relapse, percentage of relapse-free patients, and percentage of patients who had a sustained progression of ≥1 point on the Expanded Disability Status Scale (EDSS). Results: The incidence of persistent NAb+ patients was 35% for Betaferon, 20% for Rebif, and 3% for Avonex. During IFNβ treatment, both NAb+ and NAb− patients showed a reduction in relapse rate; this reduction (25%) was not significant in NAb+ patients but was significant (67%; p < 0.0001) in NAb− patients. In addition, the mean relapse rate was higher (p = 0.039), mean time between first and second relapse was shorter (13 vs 21 months; p = 0.0064), and there was a trend suggesting that NAbs affected the probability of remaining relapse free (p = 0.08). A higher percentage of NAb+ patients versus NAb− patients had worsening of EDSS scores during follow-up (p = 0.013). Conclusion: Persistent NAbs significantly reduce the clinical efficacy of IFNβ.

Interferon β neutralizing antibodies in multiple sclerosis : neutralizing activity and cross-reactivity with three different preparations

The presence and titer of neutralizing antibodies (NABs) was evaluated by an antiviral biological assay in 387 samples of 111 multiple sclerosis (MS) patients treated with one of the three commercial preparations of interferon beta (IFNbeta). Fifty NAB positive samples were found in 19 patients: 11 treated with IFNbeta-1b (Betaferon(R)) and eight with IFNbeta-1a (five with Avonex(R) and three with Rebif(R)). All the 38 NABs+ samples of patients treated with IFNbeta-1b cross-reacted with IFNbeta-1a of both commercial types. The median level of neutralizing units (NUs) of the sera was higher when tested against IFNbeta-1a than against IFNbeta-1b (p=0.000 vs. Avonexr(R) and p=0.003 vs. Rebif(R)). In line with these data, the NABs+ sera of patients treated with IFNbeta-1a cross-reacted with IFNbeta-1b and the level of NUs were lower when tested against IFNbeta-1b than against IFNbeta-1a (p=0.003). The different amount of NUs against IFNbeta types 1a and 1b could be due to the presence of aggregates in the IFNbeta-1b preparation. The different levels of cross-reactivity of NABs could reduce the bioavailability and therapeutic efficacy of IFNbeta in NABs+ patients switching from IFNbeta-1b to IFNbeta-1a.

Biological markers of interferon-beta therapy: comparison among interferon-stimulated genes MxA, TRAIL and XAF-1.

Biological activity of interferon-beta (IFNβ) can be assessed by measuring IFN-stimulated genes (ISGs). Among them, myxovirus resistance protein A (MxA) appears to have the highest specificity, but it has no role in the pathogenesis of multiple sclerosis (MS). To investigate the reliability of MxA as a biomarker, we compared its expression to that of two other ISGs: TNF-related apoptosis-inducing ligand (TRAIL) and X-linked inhibitor of apoptosis factor-1 (XAF-1). Both were shown to be involved in immunoregulatory mechanisms and might play a role in MS. Quantitative-PCR measurements were performed in peripheral blood mononuclear cells from 73 MS patients after short-term and long-term treatment with IFNβ. A time-dependent response for multiple ISGs was observed in all patients after short-term treatment. In contrast, long-term treatment induced concurrent inhibition of ISGs in 12.3% (9/73) of patients, in whom neutralizing antibodies (NAbs) were detectable. Besides, 22% (16/73) of chronically treated patients showed a non-NAbs-related abrogation of TRAIL expression. In summary, 1) MxA expression was significantly higher than both TRAIL and XAF-1, and 2) MxA was the most sensitive gene to detect decreased bioavailability due to NAbs. These findings identify MxA as an appropriate biomarker for IFNβ, although there is no evidence for a functional role of it in MS.

Predictive markers for response to interferon therapy in patients with multiple sclerosis.

Background: Prolonged therapy with interferon β (IFNβ) often leads to the development of anti-IFNβ binding antibodies (BAbs). A subset of the BAbs is of a neutralizing nature (neutralizing antibodies, NAbs) and is associated with reduced clinical efficacy of therapy. Myxovirus-resistance-protein A (MxA) has proven to be a reliable biomarker of IFNβ bioactivity. We analyzed the prognostic value of MxA mRNA, NAbs, and BAbs on the risk of having a new relapse in IFNβ-treated patients. Methods: A 3-year study was conducted in 137 IFNβ-treated patients. Blood samples for BAbs, NAbs, and MxA mRNA measurements were taken after 12 ± 3 months of therapy. Analysis of relapse-free survival (RFS) was performed for all measures by using known thresholds, generating “positive” and “negative” groups. Also, time between sampling and following relapse and risk of new relapses were calculated. Results: The MxA-negative group showed poorer RFS rates than the MxA-positive group [p < 0.0001, hazard ratio (HR) = 2.87]. Likewise, the NAb-positive group showed poorer RFS rates than the NAb-negative group (p =0.0013; HR = 2.49). On the contrary, BAb measurement did not show a clear clinical significance. Conclusions: Findings indicate that measurements of both myxovirus-resistance-protein A (MxA) and neutralizing antibodies (NAbs) predict the risk of new relapses; however, the slightly stronger prognostic significance of MxA mRNA and the easier method for it measurement make MxA mRNA the preferred biomarker for monitoring interferon β (IFNβ)-treated patients. This information can be used to better tailor treatment to the individual patient with MS. GLOSSARY: BAb = binding antibody; CPE = cytopathic effect; EDSS = Expanded Disability Status Scale; GAPDH = glyceraldehyde phosphate dehydrogenase; HR = hazard ratio; IFN = interferon; MxA = myxovirus-resistance-protein A; NAb = neutralizing antibody; RFS = relapse-free survival; ROC = receiver operating characteristic; TRU = 10-fold reduction units.

Disease-modifying drugs in childhood-juvenile multiple sclerosis: results of an Italian co-operative study.

Objective: Immunomodulatory drugs (IDs) (interferon beta (IFNβ) and glatiramer acetate (GA)) reduce relapse rate and disease progression in relapsing-remitting multiple sclerosis (RRMS) but extensive data are not available on the effectiveness and tolerability of these drugs in childhood or adolescence. The aim of this study was to evaluate the impact of IFNβ and GA in MS patients treated before 16 years of age. Methods: A research group (Immunomodulatory Treatment of Early onset MS (ITEMS)) was promoted in Italy to collect a large series of patients affected by clinically definite and RRMS and treated with IDs before 16 years of age. Fifteen centres recognized subjects suitable for inclusion: 76 patients (52 females) were collected with a mean age at onset of 12.4 (SD 2.5) years, a mean disease duration of 18.6 (SD 14.7) and a relapse rate of 3.1 (SD 2.9). Results: Results were evaluated in 65 (45 females) subjects with a pretreatment and a treatment duration >3 months: 38 were treated with IFNβ-1a once weekly (Avonex), 18 with IFNβ three times weekly (16 with Rebif, 2 with Betaferon) and nine with GA (Copaxone). The mean pretreatment period was respectively 20, 18 and 9.2 months. The treatment duration lasted respectively 23.3, 40.7 and 33.3 months. The mean annualized relapse rate decreased dramatically during the treatment: from 2.4 to 0.4 in the Avonex group, from 3.2 to 0.8 in the Rebif-Betaferon group and from 2.8 to 0.25 in the GA group. The mean final EDSS scores were respectively (in brackets the initial scores): 1.3 (1.4), 1.6 (1.8) and 0.6 (1.1). In the whole group, the final score was unchanged or reduced in all subjects except eight. Clinical side effects were recorded in 41/65 subjects (mainly in subjects treated with IFNβ), abnormal laboratory findings were observed in 13/65 subjects: they were transient in most cases. IFNβ was stopped in six cases: in four because of inefficacy and in two cases because of side effects. Conclusions: Sixty-five clinically definite MS subjects were treated during childhood or adolescence with IDs. The treatment reduced the relapse rate and the progression of the disease in most cases. Side effects were common in subjects treated with IFNβ, but were well tolerated in most cases.

Acute myeloid leukemia in Italian patients with multiple sclerosis treated with mitoxantrone.

Objectives: To evaluate the incidence and dose-dependency of mitoxantrone (MTX)-associated acute myelocytic leukemia (AML) in the network of Italian multiple sclerosis (MS) clinics. Methods: We performed a multicenter retrospective cohort study of patients treated with MTX in MS centers under the Italian national health care system between 1998 and 2008. Demographic, disease, treatment, and follow-up information were collected using hospital records. Results: Data were available for 3,220 patients (63% women) from 40 Italian centers. Follow-up (mean ± SD) was 49 ± 29 months (range 12–140 months). We observed 30 cases of AML (incidence 0.93% [95% confidence interval 0.60%–1.26%]). The mean cumulative dose was higher in patients with AML (78 vs 65 mg/m2, p = 0.028). The median interval from the start of therapy to AML diagnosis was longer than expected at 33 months (range 13–84 months); 8 patients (27%) developed AML 4 years or more after the first MTX infusion. The rate of mortality associated with AML was 37%. Conclusions: This higher than expected risk of AML and related mortality requires that treatment decisions must be made jointly between clinicians and patients who understand their prognosis, treatment options, and treatment-related risks. The now large exposed MS population must be monitored for hematologic abnormalities for at least 6 years from the end of therapy, to ensure the rapid actions needed for early diagnosis and treatment of AML.

Learning from nature: pregnancy changes the expression of inflammation-related genes in patients with multiple sclerosis.

Background Pregnancy is associated with reduced activity of multiple sclerosis (MS). However, the biological mechanisms underlying this pregnancy-related decrease in disease activity are poorly understood. Methodology We conducted a genome-wide transcription analysis in peripheral blood mononuclear cells (PBMCs) from 12 women (7 MS patients and 5 healthy controls) followed during their pregnancy. Samples were obtained before, during (i.e. at the third, sixth, and ninth month of gestation) and after pregnancy. A validation of the expression profiles has been conducted by using the same samples and an independent group of 25 MS patients and 11 healthy controls. Finally, considering the total group of 32 MS patients, we compared expression profiles of patients relapsing during pregnancy (n = 6) with those of relapse-free patients (n = 26). Principal Findings Results showed an altered expression of 347 transcripts in non-pregnant MS patients with respect to non-pregnant healthy controls. Complementary changes in expression, occurring during pregnancy, reverted the previous imbalance particularly for seven inflammation-related transcripts, i.e. SOCS2, TNFAIP3, NR4A2, CXCR4, POLR2J, FAM49B, and STAG3L1. Longitudinal analysis showed that the overall deregulation of gene expression reverted to “normal” already within the third month of gestation, while in the post-partum gene expressions rebounded to pre-pregnancy levels. Six (18.7%) of the 32 MS patients had a relapse during pregnancy, mostly in the first trimester. The latter showed delayed expression profiles when compared to relapse-free patients: in these patients expression imbalance was reverted later in the pregnancy, i.e. at sixth month. Conclusions Specific changes in expression during pregnancy were associated with a decrease in disease activity assessed by occurrence of relapses during pregnancy. Findings might help in understanding the pathogenesis of MS and may provide basis for the development of novel therapeutic strategies.

Biological responsiveness to first injections of interferon-beta in patients with multiple sclerosis

This study is the first to evaluate biological response to first injections of interferon-beta (IFNbeta) in patients with multiple sclerosis. MxA mRNA was measured in 96 patients receiving IFNbeta-1a (Avonex, n=32), IFNbeta-1b (Betaferon, n=19), IFNbeta-1a (Rebif) 22 microg (n=30), or IFNbeta-1a 44 microg (n=15). Patients were analysed before, 3 and 24 h after the first injection, and 12 h after the second administration. Results showed that up-regulation was evident within 3 h of IFNbeta injection, peaked 12 h after injection, and progressively declined 24 h after administration. The cumulative responses were similar after a single administration, regardless of product/dose. Moreover, data indicate that the abolition of the biological activity detected during IFNbeta therapy is due to underlying phenomena (e.g., neutralizing antibodies), because all patients were constitutively responders to IFNbeta at treatment initiation.

Variable responses to rituximab treatment in neuromyelitis optica (Devic's disease).

We have described two cases of Devic’s disease patients treated with rituximab with different outcomes. The results indicate that there may be early unresponsiveness in very aggressive cases. Well designed clinical trials are needed to assess treatment effects in such a rare disease.SommarioAbbiamo descritto due casi di Malattia di Devic trattati con Rituximab con differente risposta terapeutica. I risultati indicano la possibilità di una non risposta precoce nei casi molto aggressivi. Sono necessari trial clinici ben strutturati per la valutazione dell’efficacia dei trattamenti in questa rara malattia.