The Cost of Relapsing-Remitting Multiple Sclerosis Patients Who Develop Neutralizing Antibodies during Interferon Beta Therapy.

BACKGROUND: Relapsing Remitting Multiple Sclerosis (RRMS) patients treated with interferon beta (IFN beta) can develop neutralizing antibodies (NAbs) that reduce treatment efficacy. Several clinical studies explored the association of NAb+ status with increased disease activity. OBJECTIVE: The aim of this study was to estimate the cost of RRMS patients who develop NAbs while treated with IFN beta by the Italian National Healthcare Service (NHS) and the Italian Society perspectives. METHODS: The clinical data derived from a published observational study on 567 RRMS Italian patients treated with IFN beta. The management cost data derived from the published literature. Cost data were inflated to Euro 2014. RESULTS: The annual direct cost to treat a patient was estimated in €15,428 in the NAb+ cohort and €14,317 in the NAb- cohort. The annual societal cost was estimated in €33,890 and €30,790 in NAb+ and NAb- patients, respectively. The cost increase related to the NAb+ status was €3,100 in the Italian societal perspective and €1,111 in the Italian NHS perspective. CONCLUSION: The results of this economic evaluation suggest the presence of an association between NAb+ status and increased costs for the management of RRMS in Italy. Further pharmacoeconomic research will be needed to confirm this first result.

Update on laser-evoked potential findings in fibromyalgia patients in light of clinical and skin biopsy features.

In fibromyalgia (FM), reduced habituation of laser-evoked potentials (LEPs) suggests a dysfunction of pain processing at a central level. In this study, we aimed to further examine the nociceptive pathways at the peripheral to the central level in a large group of FM patients by means of LEPs and skin biopsy, in light of healthy controls findings and main clinical features. One hundred and ninety-nine FM patients and 109 age- and sex-matched controls were submitted to LEPs by the dorsum of the right hand and the skin over the right chest and knee tender point stimulation. Skin biopsy was performed in 21 randomly selected FM patients and 60 age- and sex-matched controls. The mean N2-P2 amplitude was reduced in the whole FM group, with normal or even increased values in patients with migraine as comorbidity and reduced values in other patients including those presenting with distal sensory deficits. All patients had reduced N2-P2 habituation in respect to controls. In the FM group, LEPs habituation was correlated with pain at tender points and bad quality of life. Epidermal fiber density was significantly reduced in FM patients versus controls, and correlated with N2-P2 amplitude by the hand and chest tender-point stimulation. Dysfunction in the nociceptive system at both the central and peripheral levels may concur to explain phenotypical eterogeneity and clinical symptom complexity in fibromyalgia.

A case of unilateral burning mouth syndrome of neuropathic origin.

The neuropathic origin of a case of unilateral burning mouth syndrome, previously diagnosed as psychogenic, was ascertained by intra-oral mucosa biopsy, which showed a severe sensory fibers damage, probably caused by maxillary anesthetic block and dental surgery.

Molecular analysis in a family presenting with a mild form of late-onset autosomal dominant chronic progressive external ophthalmoplegia.

Nuclear genes affecting mitochondrial genome stability were screened in an Italian family presenting with autosomal dominant progressive external ophthalmoplegia (adPEO) associated with multiple mitochondrial DNA (mtDNA) deletions. We report on a heterozygous c.907C>T (p.R303W) mutation found in the N-terminal domain of the human mitochondrial DNA helicase, Twinkle protein, in six members of a family, in which two individuals manifested late-onset PEO and morphological and molecular signs of mitochondrial dysfunction along with two carriers who are presently free of disease manifestation. We also investigated if the p.R303W mutation in PEO1 gene affected the relative copy number of mitochondrial DNA genomes.

Pharmacodynamics of interferon beta in multiple sclerosis patients with or without serum neutralizing antibodies.

To analyze the in vivo biological effect of anti-interferon beta (IFN-beta) neutralizing antibodies (NABs), blood concentrations of neopterin, beta2microglobulin (Beta2-MG), mRNA-dependent myxovirusresistant protein A (MxA) and dsRNA-dependent protein kinase (PKR) were measured before (predose) and 24 hours after (postdose) IFN-beta administration in 49 patients with multiple sclerosis (MS) with (n = 25) and without (n = 24) NABs. The results indicated that predose levels of MxA-mRNA and PKR-mRNA were highly variable [coefficient of variation (CV) > 100%] among patients. A lower inter-individual variability was observed for pre-dose levels of Beta2-MG and neopterin (CVs of 29% and 44%, respectively). Significantly lower pre- and post-dose blood levels of IFN induced markers, except for postdose PKR-mRNA (p = 0.09), were seen in NAB+ compared with NAB-patients and between patients with high (> 200 t(1/10)) and low ( pound 200 t(1/10)) NAB titers. A significant inverse correlation between NAB titer and pre-dose levels of the above IFN-induced markers was found. In summary, our findings confirm that NABs affect absolute concentrations of IFN-beta induced markers and suggest that such an effect occurs in a titer-dependent manner.

A case of vacuolar myopathy during the course of chronic hepatitis C.

Several cases of inflammatory myopathy have been reported during the chronic course of hepatitis C (HC) in recent years. It has been suggested that this muscular inflammatory involvement in HC is related to an immune-mediated mechanism caused by the hepatitis C virus (HCV), as HCV RNA has been detected in the muscle of patients with concomitant inflammatory myopathy and chronic HC. Herein, we report on a patient with a history of chronic HC, who developed a slowly progressive proximal muscle weakness; muscle biospy revealed a vacuolar myopathy. Histological, immunohistochemical and biochemical study did not disclose any known cause of vacuolar myopathy. To our knowledge, this is the first report of a vacuolar myopathy during the course of HC. We suggest that it may be opportune to include HC among the possible aetiologies of vacuolar myopathy, should other reports confirm this association.

Serial immunoprecipitation assays for interferon--(IFN)-beta antibodies in multiple sclerosis patients.

We devised a sensitive, radioimmunoprecipitation assay (RIPA) for anti-interferon (IFN)-beta-binding antibody (BAB) detection. Our RIPA showed good agreement with a reference RIPA (mean difference, -3.2 +/- 10.6 AU), and detected BAB to both IFN-beta-1a and IFN-beta-1b. Neutralizing antibodies to IFN-b (NAB) were also determined with a standard method. BAB and NAB were measured in 393 serum samples from 77 multiple sclerosis (MS) patients treated with IFN-beta-1a or -1b, who were studied over two years, and subsequently classified as responders and non-responders. BAB were found at higher concentrations, and more frequently detected, in IFN-beta-1b- than in IFN-beta-1a-treated patients, and, at highest titres, preferentially in patients who were positive for NAB. However, in our series of MS patients, both titres and frequency of detection of BAB or NAB did not differ between IFN-b responders and non-responders.

Neutralizing and binding antibodies to IFN-beta: relative frequency in relapsing-remitting multiple sclerosis patients treated with different IFN-beta preparations.

The frequencies of anti-interferon-beta (IFN-beta) antibody development reported to date in patients treated with different IFN-beta preparations are not readily comparable mainly because of differences in underlying diseases and assay methods. Thus, the frequency of neutralizing antibody (NAb) and binding antibody (BAb) development was analyzed in a sample of sera derived from a homogeneous group of relapsing-remitting multiple sclerosis (RRMS) patients treated with different IFN-beta preparations. The frequency of developing NAb and BAb to IFN-beta varied according to the IFN-beta given. Specifically, the NAb seroconversion frequency was significantly higher in patients treated with Betaferon, Schering AG, Berlin, Germany (31.3%) than in patients treated with both preparations of recombinant IFN-beta 1a (Rebif, Serono, Geneva, Switzerland [7.4%] or Avonex, Biogen, Cambridge, MA [6.3%]). Analysis of BAb seroconversion frequency in the same patients revealed that different IFN-beta preparations may also have different capability to induce BAb development and that BAb are produced during IFN-beta therapy at a significantly higher rate than NAb. Our main conclusion is that different human IFN-beta preparations may possess different immunogenicities, leading to varying frequency of development of antibody to IFN-beta in RRMS.