Luigina Musu

Epidemiology of multiple sclerosis in south-western Sardinia

Background: Sardinia is a known high-risk area for multiple sclerosis (MS), but no data for south-western Sardinia (SWS) are available. SWS has a genetically homogeneous population, apart from St Peter Island, and represents a peculiar environment related to the industrial, mineralogical and military economy. Objective: To estimate prevalence and incidence and to evaluate temporal trends and geographical distribution of MS in SWS. Methods: MS prevalence was evaluated on 31 December 2007 and crude mean annual incidence rate was defined between 2003 and 2007. Temporal trend in MS incidence was assessed using the Armitage test. To identify MS clusters, Standard Morbidity Ratio (SMR) was calculated for each village and geographical distribution prevalence by means of a Bayesian hierarchical model. Results: Total crude prevalence rate was 210.4 (95% CI 186.3–234.5): 280.3 (95% CI 241.4–319.3) for females, 138 (95% CI 110.1–165.8) for males. The crude mean annual incidence rate was 9.7/100,000 (95% CI 3.4–13.2): 4.7/100,000 (95% CI 2.4–17.0) and 14.6/100,000 (95% CI 11.8–34.8) for males and females respectively. MS incidence has increased over the last 50 years. Cluster analysis showed an SMR of 0.2 (95% CI 0.05–0.68, p = 0.002) on the island of San Pietro, and 2.0 (95% CI 1.35–2.95, p = 0.001) in Domusnovas. Spatial distribution of MS was confirmed by Bayesian geographical analysis. Conclusions: Our data confirm Sardinia as a high-risk area for MS and support the relevance of genetic factors in MS, as evidenced in St Peter Island. However, we found an unexpectedly high MS prevalence in one village, in particular in males, suggesting an environmental influence on MS occurrence.

Association between the ancestral haplotype HLA A30B18DR3 and multiple sclerosis in Central Sardinia

Association and linkage studies have established the importance of the major histocompatibility complex (MHC) in the susceptibility for multiple sclerosis (MS). We carried out a case‐control study to investigate the ancestral haplotype A30B18DR3 and MS in the Nuoro population of Sardinia, which is isolated and genetically distinct from other populations in the Mediterranean basin and characterized by genetic homogeneity, high level of inbreeding, low migration, high prevalence of MS, high frequency of the relevant haplotype, and high past malaria prevalence. Cases and controls were serologically typed for the currently recognized HLA‐A, B, and DR antigens. We used a log‐linear approach to fit a wide class of models. We tested our hypothesis comparing different models via a likelihood ratio test. We overcame the complication due to unknown gametic phase using expectation‐maximization (EM) algorithm as the estimation method. We estimated confidence intervals for odds ratio by using a profile likelihood approach. We found that: (1) the ancestral haplotype A30B18DR3 was associated to MS after allowing for a possible stratification in cases and controls; (2) DR3 allele was conditional independent on disease status, given A30B18 haplotype; (3) there was a tendency for ORs for the high‐risk haplotypes to be higher in the high malaria strata; however, this indication did not achieve statistical significance (P = 0.11). Genet. Epidemiol. 20:271–283, 2001.

Association between the ACCN1 gene and multiple sclerosis in central east sardinia

Multiple genome screens have been performed to identify regions in linkage or association with Multiple Sclerosis (MS, OMIM 126200), but little overlap has been found among them. This may be, in part, due to a low statistical power to detect small genetic effects and to genetic heterogeneity within and among the studied populations. Motivated by these considerations, we studied a very special population, namely that of Nuoro, Sardinia, Italy. This is an isolated, old, and genetically homogeneous population with high prevalence of MS. Our study sample includes both nuclear families and unrelated cases and controls. A multi-stage study design was adopted. In the first stage, microsatellites were typed in the 17q11.2 region, previously independently found to be in linkage with MS. One significant association was found at microsatellite D17S798. Next, a bioinformatic screening of the region surrounding this marker highlighted an interesting candidate MS susceptibility gene: the Amiloride-sensitive Cation Channel Neuronal 1 (ACCN1) gene. In the second stage of the study, we resequenced the exons and the 3′ untranslated (UTR) region of ACCN1, and investigated the MS association of Single Nucleotide Polymorphisms (SNPs) identified in that region. For this purpose, we developed a method of analysis where complete, phase-solved, posterior-weighted haplotype assignments are imputed for each study individual from incomplete, multi-locus, genotyping data. The imputed assignments provide an input to a number of proposed procedures for testing association at a microsatellite level or of a sequence of SNPs. These include a Mantel-Haenszel type test based on expected frequencies of pseudocase/pseudocontrol haplotypes, as well as permutation based tests, including a combination of permutation and weighted logistic regression analysis. Application of these methods allowed us to find a significant association between MS and the SNP rs28936 located in the 3′ UTR segment of ACCN1 with p = 0.0004 (p = 0.002, after adjusting for multiple testing). This result is in tune with several recent experimental findings which suggest that ACCN1 may play an important role in the pathogenesis of MS.

Guidelines on the clinical use for the detection of neutralizing antibodies (NAbs) to IFN beta in multiple sclerosis therapy: report from the Italian Multiple Sclerosis Study group

Interferon beta (IFNβ) was the first specific disease-modifying treatment licensed for relapsing-remitting multiple sclerosis, and is still one of the most commonly prescribed treatments. A strong body of evidence supports the effectiveness of IFNβ preparations in reducing the annual relapse rate, magnetic resonance (MRI) disease activity and disease progression. However, the development of binding/neutralizing antibodies (BAbs/NAbs) during treatment negatively affects clinical and MRI outcomes. Therefore, guidelines for the clinical use for the detection of NAbs in MS may result in better treatment of these patients. In October 2012, a panel of Italian neurologists from 17 MS clinics convened in Milan to review and discuss data on NAbs and their clinical relevance in the treatment of MS. In this paper, we report the panel’s recommendations for the use of IFNβ Nabs detection in the early identification of IFNβ non-responsiveness and the management of patients on IFNβ treatment in Italy, according to a model of therapeutically appropriate care.

Influence of treatments in multiple sclerosis disability: A cohort study

Background and objective: A critical aspect of multiple sclerosis (MS) treatments is understanding the effect of disease-modifying drugs (DMDs) on the long-term risk of disability and whether the effect is related to disability at start of treatment. Methods: We performed an observational study on 3060 MS patients. The effect of therapy on progression to Expanded Disability Status Scale (EDSS) 3.0 and 6.0 from onset was analysed in treated vs untreated (UTP) patients using Cox regression analysis adjusted for propensity score and immortal time bias. Results: Compared to UTP, the risks of EDSS 3.0 were 94% and 73% lower in immunomodulant (IMTP-) and immunosuppressant (ISTP-) treated patients, respectively, while the risk of EDSS 6.0 was 86% lower in IMTP. The risk of EDSS 6.0 was, respectively, 91% and 75% lower in 1275 IMTP before and 114 after EDSS 3.0 than in 539 UTP; the risk was higher in IMTP starting therapy after EDSS 3.0 than before (HR = 4.42). Conclusions: DMDs delayed long-term disability in MS patients treated either in the early or, to a lesser extent, in the later phase of the disease. Thus, the window of therapeutic opportunity is relatively extended, assuming that early is better than late treatment, but late is better than never.

An ecologic study of geographical variation in multiple sclerosis risk in Central Sardinia, Italy

We carried out an ecological study in the most archaic area of Sardinia to obtain a reliable estimate of the prevalence of multiple sclerosis (MS) and to investigate the geographical variation in the prevalence across the 100 administrative communes. To estimate the area-specific prevalence rate, we adopted a Bayesian approach that makes it possible to filter out the random variation from the estimates and to obtain a map that reflects the true geographical variation in MS prevalence. 428 resident cases were identified by the case register, including 69 multiplex families. The overall prevalence was 157 per 100,000 inhabitants. The Bayesian area-specific prevalence ranged from 143 to 262/100,000. The high prevalence and its moderate geographical variation in a genetically homogeneous population, as well as the high number of multiplex families observed in the communes with the highest prevalence, could be interpreted as representing a high susceptibility of the population to MS.

Risk for Relatives of Patients with Multiple Sclerosis in Central Sardinia, Italy

Multiple sclerosis (MS) is a chronic, inflammatory, disabling disease of the central nervous system, known for its complex interplay between genetic and environmental factors. We used life table techniques to calculate age-adjusted recurrence risks for different categories of relatives of MS patients from Central Sardinia (Italy), a genetically homogeneous, stable population with a high degree of consanguinity. We included 313 probands and a total of 12,717 relatives in the analysis. The overall age-adjusted recurrence risk for relatives of MS probands is 1.90% [95% confidence interval (CI): 1.57–2.30]. The age-adjusted recurrence risk in parents was 1.26% (95% CI 0.60–2.63), in children 2.33% (95% CI 0.09–5.56), in sibs 4.76% (95% CI 3.57–6.32), in second-degree relatives 0.72% (95% CI 0.42–1.22), and in third-degree relatives 1.79% (95% CI 1.27–2.51). The sex of the probands (male) and of the relatives (female), and the number of affected relatives in the family significantly increase the risk of MS in relatives.

Erratum: Guidelines on the clinical use for the detection of neutralizing antibodies (NAbs) to IFN beta in multiple sclerosis therapy: Report from the Italian Multiple Sclerosis Study group (Neurological Sciences (2014))

Antonio Bertolotto • Marco Capobianco • Maria Pia Amato • Elisabetta Capello • Ruggero Capra • Diego Centonze • Maria Di Ioia • Antonio Gallo • Luigi Grimaldi • Luisa Imberti • Alessandra Lugaresi • Chiara Mancinelli • Maria Giovanna Marrosu • Lucia Moiola • Enrico Montanari • Silvia Romano • Luigina Musu • Damiano Paolicelli • Francesco Patti • Carlo Pozzilli • Silvia Rossi • Marco Salvetti • Gioachino Tedeschi • Maria Rosaria Tola • Maria Trojano • Mauro Zaffaroni • Simona Malucchi

No evidence of disease activity (NEDA-3) and disability improvement after alemtuzumab treatment for multiple sclerosis: a 36-month real-world study

In this retrospective, multicenter, real-world study we collected clinical and magnetic resonance imaging (MRI) data of all patients (n = 40) with relapsing-remitting multiple sclerosis (RRMS) treated with alemtuzumab according to a “free-of-charge” protocol available before the drug marketing approval in Italy. Almost all (39/40) started alemtuzumab after discontinuing multiple disease-modifying treatments (DMTs) because of either lack of response or safety concerns. We considered the proportion of alemtuzumab-treated patients who had no evidence of disease activity (NEDA-3) and disability improvement over a 36-month follow-up period. NEDA-3 was defined as absence of relapses, disability worsening, and MRI activity. Disability improvement was defined as a sustained reduction of ≥ 1-point in Expanded Disability Status Scale (EDSS) score. At follow-up, 18 (45%) patients achieved NEDA-3, 30 (75%) were relapse-free, 33 (82.5%) were EDSS worsening-free, and 25 (62.5%) were MRI activity-free. Eleven (27.5%) patients had a sustained disability improvement. We found no predictor for the NEDA-3 status, while the interaction of higher EDSS score by higher number of pre-alemtuzumab relapses was associated with a greater chance of disability improvement (odds ratio 1.10, p = 0.049). Our study provides real-world evidence that alemtuzumab can promote clinical and MRI disease remission, as well as disability improvement, in a significant proportion of patients with RRMS despite prior multiple DMT failures. The drug safety profile was consistent with data available from clinical trials.

Autoimmune comorbidities in multiple sclerosis: what is the influence on brain volumes? A case–control MRI study

BackgroundSeveral studies indicated that multiple sclerosis (MS) is frequently associated with other autoimmune diseases. However, it is little known if the coexistence of these conditions may influence the radiologic features of MS, and in particular the brain volumes.ObjectivesTo evaluate the effect of autoimmune comorbidities on brain atrophy in a large case–control MS population.MethodsA group of MS patients affected by a second autoimmune disorder, and a control MS group without any comorbidity, were recruited. Patients underwent a brain MRI and volumes of whole brain (WB), white matter (WM), and gray matter (GM) with cortical GM were estimated by SIENAX.ResultsThe sample included 286 MS patients, of which 30 (10.5%) subjects with type 1 diabetes (T1D), 53 (18.5%) with autoimmune thyroiditis (AT) and 4 (0.1%) with celiac disease. Multiple regression analysis found an association between T1D and lower GM (p = 0.038) and cortical GM (p = 0.036) volumes, independent from MS clinical features and related to T1D duration (p < 0.01), while no association was observed with AT and celiac disease.ConclusionsOur data support the importance of considering T1D as possible factors influencing the brain atrophy in MS. Further studies are needed to confirm our data and to clarify the underlying mechanisms.