Association of the CBLB gene with multiple sclerosis: new evidence from a replication study in an Italian population.

BACKGROUND: The T allele of rs9657904 within the CBLB gene was recently found to be significantly associated with multiple sclerosis (MS) in a genome-wide association study in Sardinia. OBJECTIVE: To replicate this association in an independent population with a different genetic background. METHODS: The rs9657904 variant was typed in a sample of 1435 cases and 1466 controls from the Italian mainland. RESULTS: It was found that in this sample also, the common allele T of rs9657904 is significantly positively associated (one-tailed p=7.35 × 10(-5)) and with a comparable effect size with MS (OR=1.31, 95% CI 1.14 to 1.52). CONCLUSION: These data provide further evidence of the association of MS disease with variation within CBLB.

Association of HLA class I markers with multiple sclerosis in the Italian and UK population: evidence of two independent protective effects.

BACKGROUND: The association of HLA A*02 with multiple sclerosis (MS) was recently confirmed by the authors, and it was observed that the combined presence of HLA Cw*05 significantly enhanced (threefold) the protective effect of HLA A*02. OBJECTIVES AND METHODS: Since A*02-Cw*05 is carried by two HLA extended haplotypes characterised by the B*4402 and B*1801 alleles, respectively, the association analysis was extended to HLA B*44 and B*18 in an Italian sample (1445 MS cases and 973 controls) and these associations were verified in a UK cohort (721 MS cases, 408 controls and 480 family trios). RESULTS: A strong protective effect, independent of DR15, of the A*02-Cw*05 combination carrying B*44 (OR 0.27, p=3.3×10(-5)) was seen in the Italian samples and confirmed in UK family trios (OR 0.33, p=5.5×10(-4)) and in a combined cohort of UK families and case-controls (OR 0.53, p=0.044). This protective effect was significantly stronger than that mediated by A*02 alone. Logistic regression showed that A*02-Cw*05 maintained a significant protection when adjusted for B alleles (Italy: OR 0.38, p=6.5×10(-7); UK: OR 0.60, p=0.0029), indicating that it was not secondary to linkage disequilibrium with B*44. Different from A*02, the other HLA class I tested markers individually showed no significant (Cw*05, B*18) or a modest (B*44) protection when adjusted for the remaining markers. CONCLUSIONS: This study identified at least two independent protective effects which are tagged by A*02-Cw*05 and A*02, respectively. Further studies are needed to elucidate whether this protective effect is due to the presence of an unanalysed factor characterising the HLA extended haplotype(s) carrying A*02 and Cw*05 or to a direct interaction between these alleles.

Prognostic values of soluble CD30 and CD30 gene polymorphisms in heart transplantation.

Pretransplant soluble CD30 (sCD30) is a predictor of kidney graft outcome. Its status as a predictor of heart transplant (HT) outcome has not been established. We have studied this question by assessing sCD30 levels and the number of (CCAT)n repeats of the microsatellite in the CD30 promoter region, which is able alone to repress gene transcription, in the sera of 83 HT patients and 77 of their donors. sCD30 was non-significantly increased in the patients, whereas there were no differences in the CD30 microsatellite allele frequencies. A negative correlation between the number of (CCAT)n and sCD30 levels was evident in the donors. Patients with pretransplant sCD30

HLA-DRB1 genotyping in Italian migraine patients.

We examined the distribution of HLA-DRB1 alleles in a cohort 255 Italian migraine patients and in a control group of 325 healthy subjects. 214 patients fulfilled the ICHD-II criteria for migraine without aura and 41 patients the criteria for migraine with aura. The frequency of DRB1*16 allele was found to be significantly increased in migraine without aura patients (p=0.02; OR 1.97, 95% CI: 1.10-3.54) than in healthy controls. The frequencies of HLA-DRB1 alleles were not significantly different between migraine with aura patients and controls. We did not detect any effect of DRB1 alleles on age at onset, duration of the disease, frequency and duration of migraine attacks. Our data suggest the presence of a genetic susceptibility factor for migraine without aura within the HLA region.

HLA Genotyping: Methods for the Identification of the HLA-DQ2,-DQ8 Heterodimers Implicated in Celiac Disease (CD) Susceptibility.

In this chapter we will present the principal technical methods to genotype the HLA-DQA1* and -DQB1* alleles associated with celiac disease (CD), corresponding to the serological heterodimers HLA-DQ2 and -DQ8. We will present the methods specific for the genotyping of these heterodimers, which represents a common request from consultant doctors. Because these alleles are also common in healthy subjects, their presence is not diagnostic for CD. Conversely, their absence is more important because it excludes the disease, since CD patients negative for these heterodimers are very rare. Accordingly, HLA typing has been included as a useful test to exclude celiac disease in the ESPGHAN guidelines for diagnosis of celiac disease. The methods for HLA typing described in the present chapter are based on the following techniques: PCR-SSP (Polymerase Chain Reaction-Sequence Specific Primers): PCR with primers specific for HLA alleles encoding the CD risk heterodimers, whose presence is revealed through the electrophoresis of PCR products. Reverse PCR-SSOP (PCR-Sequence Specific Oligonucleotide Probes): PCR with primers specific for a single locus or a large group of alleles followed by hybridization with enzyme-conjugated probes specific for a single allele, immobilized on different supports (i.e., nitrocellulose strips), in which DNA-probes binding is revealed by the production of a colored precipitate derived from the enzymatic modification of a specific substrate. Real-Time PCR (RT-PCR): PCR with locus or allelic specific primers whose amplification is revealed by particular probes (i.e., Taqman probes) hybridizing the DNA template within the two PCR primers and emitting fluorescent while the PCR reaction occurs.

Tumor necrosis factor-alpha and interferon-gamma polymorphisms contribute to susceptibility to oral lichen planus.

Most lymphocytes in the lamina propria of oral lichen planus (OLP) lesions express and secrete interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha), whereas they do not secret interleukin-4 and -10 or transforming growth factor-beta. We analyzed whether the polymorphisms of several cytokines may influence the susceptibility to OLP. Cytokine typing was performed by a sequence-specific PCR assay. Thirteen cytokine genes with 22 single-nucleotide polymorphisms were studied. IFN-gamma UTR 5644 genotype frequencies showed a significant increase in number of T/T homozygotes in OLP patients compared with controls (40.9 vs. 22.9%; p=0.0022). Moreover, in OLP patients, the frequency of the -308A TNF-alpha allele was higher than in the controls (21.6 vs. 9.3%; p < 0.05) causing a significantly increased frequency of the genotype G/A in OLP (43.2 vs. 14.3%; p=0.0002). Because in patients with mucocutaneous lichen planus (LP), the frequency of the -308A TNF-alpha allele was more than double the values in the pure OLP patients (40.9 vs. 15.1%; p=0.003), the -308G/A TNF-alpha genotype showed a significantly higher frequency in patients with mucocutaneous LP than in patients with pure OLP (81.8 vs. 30.3%, p=0.003). In conclusion, we suggest that genetic polymorphism of the first intron of the promoter gene of IFN-gamma may be an important risk factor to develop oral lesions of LP, whereas an increase in the frequency of -308A TNF-alpha allele may best contribute to the development of additional skin involvement.

Cytokine gene polymorphisms in hepatitis C virus-related oral lichen planus.

Cytokine polymorphisms may influence both the risk of developing oral lichen planus (OLP) and the outcome of hepatitis C virus (HCV)-infected patients and OLP has been frequently associated with HCV infection. The aim of the present study was to analyse whether cytokine polymorphisms may influence the susceptibility to HCV-related OLP. Thirty-five patients with OLP and chronic HCV infection (OLP-HCV+ve) took part in the study. As controls, 44 patients with OLP but without HCV (OLP-HCV-ve) infection and 140 healthy donors were studied. Thirteen cytokine genes with 22 single nucleotide polymorphisms (SNP) were studied. IFN-gamma UTR 5644 genotype frequencies showed an increase in number of A/T heterozygote in OLP-HCV+ve patients compared with OLP-HCV-ve that approached the statistical significance [P = 0.03, P-corrected (PC) = 0.66]. Contrarily, in OLP-HCV+ve patients, the frequency of genotype -308 G/A of the TNF-alpha was decreased, whereas the genotype -308 G/G was increased compared with OLP-HCV-ve (P = 0.0005, PC = 0.011 and P = 0.0016, PC = 0.0352, respectively). OLP patients with and without HCV infection showed a different genetic cytokine background suggesting distinct pathogenetic mechanisms.