Association between Protective and Deleterious HLA Alleles with Multiple Sclerosis in Central East Sardinia

The human leukocyte antigen (HLA) complex on chromosome 6p21 has been unambiguously associated with multiple sclerosis (MS). The complex features of the HLA region, especially its high genic content, extreme polymorphism, and extensive linkage disequilibrium, has prevented to resolve the nature of HLA association in MS. We performed a family based association study on the isolated population of the Nuoro province (Sardinia) to clarify the role of HLA genes in MS. The main stage of our study involved an analysis of the ancestral haplotypes A2Cw7B58DR2DQ1 and A30Cw5B18DR3DQ2. On the basis of a multiplicative model, the effect of the first haplotype is protective with an odds ratio (OR) = 0.27 (95% confidence interval CI 0.13–0.57), while that of the second is deleterious, OR 1.78 (95% CI 1.26–2.50). We found both class I (A, Cw, B) and class II (DR, DQ) loci to have an effect on MS susceptibility, but we saw that they act independently from each other. We also performed an exploratory analysis on a set of 796 SNPs in the same HLA region. Our study supports the claim that Class I and Class II loci act independently on MS susceptibility and this has a biological explanation. Also, the analysis of SNPs suggests that there are other HLA genes involved in MS, but replication is needed. This opens up new perspective on the study of MS

Two distinctive HLA haplotypes harbor the B27 alleles negatively or positively associated with ankylosing spondylitis in Sardinia : Implications for disease pathogensis

Objective. To compare haplotype distribution in HILA-B27-positive patients with ankylosing spondylitis (AS) and healthy control subjects possessing either AS-associated HLA-B27 alleles or the non-AS-associated HLA-B*2709 allele. Methods. DNA samples from 47 HLA-B27-positive patients with AS and 76 HLA-B27-positive healthy controls (19 positive and 57 negative for B*2709) living in different areas of Sardinia were collected and typed for HLA class I and class 11 alleles. The third exon of the B27 gene was analyzed for the presence of Asp 116 or His(116), which differentiates B*2709 from the other two B27 subtypes (B*2705 and B*2702) that are mostly found in Sardinia. The parents of 6 subjects positive for B*2709 were also typed for HLA class I and class 11 alleles. Statistical analysis was performed by Fisher's exact test. Results. In Sardinia, the B27 alleles conferring susceptibility to AS appear to be more frequently carried by a haplotype (A2;B27;Cw2;DR16) that reaches its highest frequency in patients with AS (A2 80.8%, B27 100%, Cw2 and DR16 74.5%). Conversely, the non-AS-associated B*2709 allele is more frequently found together with other HLA alleles whose frequencies are inversely correlated with the disease (A32 or A30, Cw1 and DR12). Familial analysis of 6 subjects positive for HLA-B*2709 confirmed the existence of a "Sardinian" haplotype that is not associated with AS (A32;B*2709;Cw1;DR12). Conclusion. In Sardinia, 2 distinct haplotypes harbor the non-AS-associated HLA-B*2709 allele or the AS-associated B27 alleles. Our findings are compatible with the hypothesis that other genes within the HLA region besides HLA-B27 may play some role in conferring susceptibility to AS

MICA Gene Triplet Repeat Polymorphism in Patients with HLA-B27 positive and negative Ankylosing Spondylitis from Sardinia

We investigated the distribution of MICA triplet repeat polymorphism in a random population and in patients with seronegative spondyloarthritis from Sardinia compared to continental Italy. METHODS: We analyzed the distribution of MICA triplet repeat polymorphism in HLA-B*2709 [not associated with ankylosing spondylitis (AS)] and B*2705 (associated with AS) haplotypes, to verify whether the strong association of MICA-A4 with HLA-B27 reported in other populations is maintained in Sardinia, and compared the distribution of MICA-A alleles in HLA-B27 negative versus HLA-B27+ patients with AS. RESULTS: We found that the frequency of MICA-A4 triplet repeat allele in a random Sardinia population is higher (53.2%) than in other Caucasian populations (around 20%); this allele is strongly associated with both HLA-B*2709 and B*2705. No significant difference between HLA-B27+ patients with AS and healthy controls was found: the MICA-A4 allele was present in more than 90% of subjects. MICA-A4 was found in 16 out of 20 HLA-B27 negative Sardinian patients with AS, with a frequency (80%) more similar to that of the HLA-B27+ group of patients than that of controls. CONCLUSION: The high frequency of MICA-A4 allele in HLA-B27 negative patients with AS from Sardinia, suggests the presence within the HLA region of a susceptibility factor other and certainly weaker than B27. This factor is likely to be more easily found by analyzing genetically homogeneous populations like the Sardinian, characterized by a small number of very frequent haplotypes

Susceptibility to ankylosing spondylitis but not disease outcome is influenced by the level of HLA-B27 expression, which shows moderate variability over time

Objective: Previous reports have highlighted the relevance of HLA-B27 expression in the pathogenesis of ankylosing spondylitis (AS). The aim of the current study was to estimate the level of HLA-B27 expression on the cell surface of ex vivo monocytes and lymphocytes by a quantitative method and to correlate this with AS disease susceptibility, disease clinical indexes, and the occurrence of acute anterior uveitis (AAU). Method: We recruited 32 B27-positive patients with AS and 32 B27-positive healthy normal controls (NCs) for evaluation at different time points. The expression of HLA-B27 molecules was quantified by flow cytometry on ex vivo peripheral blood mononuclear cells (PBMCs). Patients were also evaluated by scores on the Bath AS disease activity (BASDAI), functional (BASFI), and metrology (BASMI) indexes. Results: The expression of HLA-B27 molecules was significantly higher in patients with AS than in B27-matched controls in the case of both monocytes [219K (IQR 174K308K) vs. 137K (IQR 96K170K), p < 0.0001] and lymphocytes [82K (IQR 58K118K) vs. 54K (IQR 44K-61K), p < 0.0001]; AS only vs. AS with AAU: p 0.744 in monocytes and p 0.701 in lymphocytes. Comparisons with metrology and functional indexes were also not significant (BASMI: r 0.05, p 0.77; BASFI: r -0.09, p 0.67). The overexpression of HLA-B27 molecules was stable after 1 week of follow-up. At 3 years follow-up, the variability was moderate and did not correlate with variations in disease activity (BASDAI: r -0.01, p 0.92 ns). Conclusions: The level of HLA-B27 expression in PBMCs correlates with the susceptibility to AS but not with the disease outcome, nor with the occurrence of extra-articular manifestations such as AAU

Changing patterns of thalassaemia in Italy: a WebThal perspective.

Background - Migration has impacted the spread of thalassaemia which is gradually becoming a global health problem. Italy, with an approximate estimation of 7,000 patients, does not have an accurate national record for haemoglobinopathies. This cross-sectional evaluation includes data for approximately 50% of beta-thalassaemia patients in Italy to provide an overview of the burden of thalassaemia syndromes. Materials and methods - The analysis included data on epidemiology, transfusions and clinical parameters from 3,986 thalassaemia patients treated at 36 centres in Italy who were alive on 31st December 2017. The study used WebThal, a computerised clinical record that is completely free-of-charge and that does not have any mandatory fields to be filled. Results - For patients with thalassaemia major, 68% were aged ≥35 years and 11% were aged ≤18 years. Patients with thalassaemia intermedia were slightly older. Transfusion data, reported in a subgroup of 1,162 patients, showed 9% had pre-transfusion haemoglobin &lt;9 g/dL, 63% had levels between ≥9 and &lt;10 g/dL, and 28% had levels ≥10 g/dL. These 1,162 patients underwent 22,272 transfusion days during 2017, with a mean of 19 transfusion days/year/patient (range 1-54 days). Severity of iron overload was reported in 756 patients; many had moderate or mild liver iron load (74% had liver iron &lt;7.5 mg/g dry weight). In the same cohort, 85% of patients had no signs of cardiac iron load (MRT2* &gt;20 ms), and only 3% showed signs of high-risk heart condition (T2* &lt;10 ms). Most patients had normal alanine amino transferase levels due to treatment with the new anti-hepatitis C virus (HCV) drugs. Discussion - This study provides an overview of the current health status of patients with thalassaemia in Italy. Moreover, these data support the need for a national comprehensive thalassaemia registry

Feasibility, reproducibility, and reliability for the T2* iron evaluation at 3 T in comparison with 1.5 T

This study aimed to determine the feasibility, reproducibility, and reliability of the multiecho T*(2) Magnetic resonance imaging technique at 3 T for myocardial and liver iron burden quantification and the relationship between T*(2) values at 3 and 1.5 T. Thirty-eight transfusion-dependent patients and 20 healthy subjects were studied. Cardiac segmental and global T*(2) values were calculated after developing a correction map to compensate the artifactual T*(2) variations. The hepatic T*(2) value was determined over a region of interest. The intraoperator and interoperator reproducibility for T*(2) measurements at 3 T was good. A linear relationship was found between patients' R\u2009*2 (1000/T*(2) ) values at 3 and 1.5 T. Segmental correction factors were significantly higher at 3 T. A conversion formula returning T*(2) values at 1.5 T from values at 3 T was proposed. A good diagnostic reliability for T*(2) assessment at 3 T was demonstrated. Lower limits of normal for 3 T T*(2) values were 23.3 ms, 21.1 ms, and 11.7 ms, for the global heart, mid-ventricular septum, and liver, respectively. In conclusion, T*(2) quantification of iron burden in the mid-ventricular septum, global heart, and no heavy-moderate livers resulted to be feasible, reproducible, and reliable at 3 T. Segmental heart T*(2) analysis at 3 T may be challenging due to significantly higher susceptibility artifacts