Lorena Lorefice

Overexpression of the Cytokine BAFF and Autoimmunity Risk

BACKGROUND Genomewide association studies of autoimmune diseases have mapped hundreds of susceptibility regions in the genome. However, only for a few association signals has the causal gene been identified, and for even fewer have the causal variant and underlying mechanism been defined. Coincident associations of DNA variants affecting both the risk of autoimmune disease and quantitative immune variables provide an informative route to explore disease mechanisms and drug‐targetable pathways. METHODS Using case–control samples from Sardinia, Italy, we performed a genomewide association study in multiple sclerosis followed by TNFSF13B locus–specific association testing in systemic lupus erythematosus (SLE). Extensive phenotyping of quantitative immune variables, sequence‐based fine mapping, cross‐population and cross‐phenotype analyses, and gene‐expression studies were used to identify the causal variant and elucidate its mechanism of action. Signatures of positive selection were also investigated. RESULTS A variant in TNFSF13B, encoding the cytokine and drug target B‐cell activating factor (BAFF), was associated with multiple sclerosis as well as SLE. The disease‐risk allele was also associated with up‐regulated humoral immunity through increased levels of soluble BAFF, B lymphocytes, and immunoglobulins. The causal variant was identified: an insertion–deletion variant, GCTGT→A (in which A is the risk allele), yielded a shorter transcript that escaped microRNA inhibition and increased production of soluble BAFF, which in turn up‐regulated humoral immunity. Population genetic signatures indicated that this autoimmunity variant has been evolutionarily advantageous, most likely by augmenting resistance to malaria. CONCLUSIONS A TNFSF13B variant was associated with multiple sclerosis and SLE, and its effects were clarified at the population, cellular, and molecular levels. (Funded by the Italian Foundation for Multiple Sclerosis and others.)

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.

The risk of Bipolar Disorders in Multiple Sclerosis

BACKGROUND The aim was to determine the risk of Mood Disorders (MD), particularly Bipolar Disorders (BD), in Multiple Sclerosis (MS) using standardized psychiatric diagnostic tools. METHODS Case-control study. CASES 201 consecutive-patients with MS. CONTROLS 804 sex- and age-matched subjects without MS, randomly selected from a database concurrently used for an epidemiological study on the MD prevalence in the community. Psychiatric diagnoses according to DSM-IV were determined by physicians using structured interview tools (ANTAS-SCID). RESULTS Compared to controls, MS patients had a higher lifetime prevalence of DSM-IV Major Depressive Disorders (MDD; P<0.0001), BD I (P=0.05), BD II (P<0.0001) and Cyclothymia (P=0.0001). As people with MS had a higher risk of depressive and bipolar spectrum disorders, ratio MDD/bipolar spectrum disorders was lower among cases (P<0.005) indicating a higher association with Bipolar Spectrum Disorders and MS. LIMITATIONS MS diagnosis was differently collected in cases and controls. Even if this might have produced false negatives in controls, it would have reinforced the null hypothesis of no increased risk for MD in MS; therefore, it does not invalidate the results of the study. CONCLUSIONS This study was the first to show an association between BD and MS using standardized diagnostic tools and a case-control design. The results suggest a risk of under-diagnosis of BD (particularly type II) in MS and caution in prescribing ADs to people with depressive episodes in MS without prior excluding BD. The association between auto-immune degenerative diseases (like MS) and BD may be an interesting field for the study of the pathogenic hypothesis.

Mitoxantrone treatment in patients with early relapsing-remitting multiple sclerosis

We investigated the clinical and MRI effects of mitoxantrone (MITOX) administered to 45 patients during the first five years of highly active relapsing-remitting multiple sclerosis. Differences occurring between the end of treatment and follow-up (clinical mean: 3.6 years; brain MR: 1.8 years) with respect to baseline variables (EDSS, annualized relapse rate, active T2 lesions, new T1 lesions and number of Gd-enhancing lesions) were analysed using parametric and non-parametric tests. One patient developed leukemia four months after the end of the treatment; no other serious adverse events occurred during treatment and the follow-up period. A clinically relevant reduction in the annualized relapse rate ( P < 0.0001 at end of treatment and P < 0.0001 at follow-up) and improvement in the EDSS (P < 0.0001 at end of treatment and P = 0.0005 at follow-up) was found. At the end of treatment, 53% of patients experienced no increase in active T2 lesions, while 73% showed no increase in the number of new T1 lesions. At follow-up, 41 out of 45 (91%) patients showed a stable MRI pattern and were active-scan free. Despite potential serious adverse events, MITOX may be considered an option in selected patients with very active early MS. Multiple Sclerosis 2007; 13: 975—980. http://msj.sagepub.com

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.

Multiple sclerosis and bipolar disorders: the burden of comorbidity and its consequences on quality of life.

BACKGROUND The purpose is to measure the worsening of the Quality of Life (QoL) in people with Multiple Sclerosis (MS) and the concomitant role of co-morbid Major Depressive Disorder (MDD) and Bipolar Disorder (BD), the latter not yet studied even though it was found strictly associated with MS. METHODS CASES 201 consecutive-MS-patients. CONTROLS 804 sex-and-age-matched subjects without MS, randomly selected from an epidemiological database study. Psychiatric diagnoses according to DSM-IV were determined by physicians using structured interview tools (ANTAS-SCID). Bipolar Spectrum Disorders were identified by Mood Disorders Questionnaire (MDQ). QoL was measured by SF-12. RESULTS MS was the strongest determinant in worsening the QoL in the overall sample. Both MDD and BD type-II lifetime diagnoses were significantly associated with a poorer quality of life in the total sample as in cases of MS. In MS the impairment of the QoL attributable to BD type-II was even greater than that in MDD. LIMITATIONS The MS diagnosis was made differently in cases and controls. Although this may have produced false negatives in controls, it would have reinforced the null hypothesis (no role of MS in worsening the QoL); therefore, it does not invalidate the study. CONCLUSIONS MDD as well BD type-II are co-determinants in worsening QoL in MS. Clinicians should consider depressive symptoms as well as the hypomanic and mixed components in MS. Additional research is required to confirm our results and further clarify the manner in which BD and the mixed symptoms of BD type-II may affect awareness of both the underlying disease and psychiatric component and finally to what extent they impact treatment adherence with the available therapies for MS.

Mycobacterium avium subsp. Paratuberculosis and multiple sclerosis in Sardinian patients: Epidemiology and clinical features

Background: Mycobacterium avium subspecies paratuberculosis (MAP) is an infectious factor recently found in association with multiple sclerosis (MS) in Sardinia. Objectives: The objectives of this study were to confirm this association and evaluate its role in clinical features. Methods: A total of 436 patients and 264 healthy controls (HCs) were included. We examined the blood of each individual for MAPDNA and MAP2694 antibodies using IS900-specific PCR and ELISA, respectively. Differences in MAP presence between the MS group and HCs were evaluated. In MS patients, we considered: gender, age, age at onset, duration of disease, course, EDSS, therapy, relapse/steroids at study time, and oligoclonal bands (OBs). Results: MAPDNA and MAP2694 antibodies were detected in 68 MS and six HCs (p = 1.14 × 10−11), and 123 MS and 10 HCs (p = 2.59 × 10−23), respectively. OBs were found with reduced frequency in MAP-positive patients (OR = 0.52; p = 0.02). MAP2694 antibodies were detected more in patients receiving MS treatments (OR = 2.26; p = 0.01), and MAPDNA in subjects on steroids (OR = 2.65; p = 0.02). Conclusion: Our study confirmed the association of MAP and MS in Sardinia. The low OB frequency in MAP patients suggests a peripheral role as a trigger in autoimmunity. MAP positivity might be influenced by steroids and MS therapy. Studies in other populations are needed to confirm the role of MAP in MS.

What do multiple sclerosis patients and their caregivers perceive as unmet needs

BackgroundMultiple sclerosis (MS) has a major impact on the physical, psychological and social life of patients and their families. The aim of this study was to evaluate the different perceptions of patients and caregivers about management of MS, particularly about the same items, to gather information to ameliorate the care of patients.MethodsWe evaluated what MS patients and caregivers perceive as unmet needs and compared patients’ opinions with caregivers’ opinions using a multidimensional questionnaire. The questionnaire was specifically designed for the study, taking into account different aspects of the global care perceived by patients and care givers, such as information about MS, medical treatment and rehabilitation, patients’ relationships with medical staff and their psychological and social life.ResultsWe administered the questionnaire to 497 patients and 206 caregivers. Results showed that the majority of participants were satisfied with medical staff but expressed a desire that staff be more forthcoming with information about MS. As for medical treatment concerns, more patients found there to be useful a multidisciplinary approach than caregivers did. Both required psychological support for patients but patients felt a greater need for it at the time of diagnosis, whereas caregivers felt it was required post-diagnosis. Both reported significant strains on patient relationships at work but no effect on other social interactions.ConclusionsA better understanding of MS patient needs, starting from the point of view of patients and caregivers, could have a great impact on quality of life and on management of the disease.

Vitamin D Responsive Elements within the HLA-DRB1 Promoter Region in Sardinian Multiple Sclerosis Associated Alleles

Vitamin D response elements (VDREs) have been found in the promoter region of the MS-associated allele HLA-DRB1*15∶01, suggesting that with low vitamin D availability VDREs are incapable of inducing *15∶01 expression allowing in early life autoreactive T-cells to escape central thymic deletion. The Italian island of Sardinia exhibits a very high frequency of MS and high solar radiation exposure. We test the contribution of VDREs analysing the promoter region of the MS-associated DRB1 *04∶05, *03∶01, *13∶01 and *15∶01 and non-MS-associated *16∶01, *01, *11, *07∶01 alleles in a cohort of Sardinians (44 MS patients and 112 healthy subjects). Sequencing of the DRB1 promoter region revealed a homozygous canonical VDRE in all *15∶01, *16∶01, *11 and in 45/73 *03∶01 and in heterozygous state in 28/73 *03∶01 and all *01 alleles. A new mutated homozygous VDRE was found in all *13∶03, *04∶05 and *07∶01 alleles. Functionality of mutated and canonical VDREs was assessed for its potential to modulate levels of DRB1 gene expression using an in vitro transactivation assay after stimulation with active vitamin D metabolite. Vitamin D failed to increase promoter activity of the *04∶05 and *03∶01 alleles carrying the new mutated VDRE, while the *16∶01 and *03∶01 alleles carrying the canonical VDRE sequence showed significantly increased transcriptional activity. The ability of VDR to bind the mutant VDRE in the DRB1 promoter was evaluated by EMSA. Efficient binding of VDR to the VDRE sequence found in the *16∶01 and in the *15∶01 allele reduced electrophoretic mobility when either an anti-VDR or an anti-RXR monoclonal antibody was added. Conversely, the Sardinian mutated VDRE sample showed very low affinity for the RXR/VDR heterodimer. These data seem to exclude a role of VDREs in the promoter region of the DRB1 gene in susceptibility to MS carried by DRB1* alleles in Sardinian patients.

Interaction between HLA-DRB1-DQB1 Haplotypes in Sardinian Multiple Sclerosis Population

We performed a case-control study in 2,555 multiple sclerosis (MS) Sardinian patients and 1,365 healthy ethnically matched controls, analyzing the interactions between HLA-DRB1-DQB1 haplotypes and defining a rank of genotypes conferring a variable degree of risk to the disease. Four haplotypes were found to confer susceptibility (*13∶03-*03∶01 OR = 3.3, Pc 5.1×10−5, *04∶05-*03∶01 OR = 2.1, Pc 9.7×10−8, *15∶01-*06∶02 OR = 2.0, Pc = 9.1×10−3, *03∶01-*02∶01 OR = 1.7 Pc = 7.9×10−22) and protection (*11, OR = 0.8, Pc = 2.7×10−2, *16∶01-*05∶02 OR = 0.6, Pc = 4.8×10−16, *14∶01-4-*05∶031 = OR = 0.5, Pc = 9.8×10−4 and *15∶02-*06∶01 OR = 0.4, Pc = 5.1×10−4). The relative predispositional effect method confirms all the positively associated haplotypes and showed that also *08 and *04 haplotypes confers susceptibility, while the *11 was excluded as protective haplotype. Genotypic ORs highlighted two typologies of interaction between haplotypes: i) a neutral interaction, in which the global risk is coherent with the sum of the single haplotype risks; ii) a negative interaction, in which the genotypic OR observed is lower than the sum of the OR of the two haplotypes. The phylogenic tree of the MS-associated DRB1 alleles found in Sardinian patients revealed a cluster represented by *14∶01, *04∶05, *13∶03, *08∶01 and *03∶01 alleles. Sequence alignment analysis showed that amino acids near pocket P4 and pocket P9 differentiated protective from predisposing alleles under investigation. Furthermore, molecular dynamics simulation performed on alleles revealed that position 70 is crucial in binding of MBP 85–99 peptide. All together, these data suggest that propensity to MS observed in Sardinian population carried by the various HLA-DRB1-DQB1 molecules can be due to functional peculiarity in the antigen presentation mechanisms.