Antonio de León

DQB1*0602 allele shows a strong association with multiple sclerosis in patients in Malaga, Spain

Abstract.Background:The human leukocyte antigen (HLA) class II DR2 haplotype (DRB1*1501, DQA1*0102, DQB1*0602) has been associated with multiple sclerosis (MS) in all ethnic groups and very strongly in Caucasians.Aim:To investigate the possible HLA class II (DRB1, DQA1 and DQB1) associations with MS in Malaga, southern Spain.Methods:We analysed the HLA class II sub-regions DRB1, DQA1 and DQB1 by polymerase chain reaction (PCR) and sequence-specific oligonucleotide probe hybridization (PCR/SSO) for DRB1 and DQB1 and with sequence-specific primers (PCR/SSP) for DRB1 subtypes and DQA1. Possible HLA class II associations with clinical MS characteristics were investigated in 149 subjects with and 160 without MS.Results:Associations were detected between MS and the HLA class II alleles DRB1*1501 (45.6 % vs. 21.3%, p = 0.001), DQA1*0102 (44% vs. 29.4%, p = 0.001) and DQB1*0602 (45% vs. 20.6%, p = 0.001). The DR2 haplotype (DRB1*1501, DQA1*0102, DQB1*0602) was associated with MS (43.6 % vs. 20%, p = 0.002). DQB1*0602 was the only allele that maintained an association with MS in a logistic regression model. No HLA class II alleles or genotypes were significantly associated with any clinical characteristics of MS.Conclusions:Our results confirm the positive association of the DR2 haplotype with MS, particularly the allele DQB1*0602, in the population studied. DR4 was not associated with the disease in Malaga. HLA class II alleles or haplotypes were not associated with clinical or demographic characteristics, or clinical form or severity of MS.

Study of binding and neutralising antibodies to interferon-β in two groups of relapsing-remitting multiple sclerosis patients

Abstract Interferon (IFN)-β is generally considered an effective treatment for multiple sclerosis (MS); however, some patients do not respond to this therapy, possibly due to the production of neutralising antibodies (NAB) which can prevent the biological effect of IFN-β. We compared the two types of IFN-β, the glycosylated IFN-β1a and the non-glycosylated IFN-β1b, as their chemical differences may entail differing immunogenic capacities. We studied 22 relapsing-remitting MS patients treated with IFN-β1a and 31 treated with IFN-β1b for 1 year, using the same assay and criteria, to compare the two types of IFN-β in their ability to induce binding and neutralising antibodies and examined the correlation of the findings with the clinical data. Binding antibodies to IFN-β1a and IFN-β1b were determined by enzyme-linked immunosorbent assay. A bioassay was used to detect and quantify the NABs to IFN-β, measuring the capacity of NABs to block the antiviral resistance induced by IFNs. Binding antibodies were found in 32 % of those treated with IFN-β1a and in 52 % of those treated with IFN-β1b; NABs were found in 14 % and 24 %, respectively. Both groups showed a significant decrease in relapse rate during the first year of treatment. These results demonstrate that the IFN-β1b molecule is more immunogenic than the IFN-β1a molecule. This may be due to the non-glycosylated, chemical structure of the former, which can produce aggregates and enhance antibody production. No association was found between the presence of NABs and the clinical status of the patients.

Kinetics and incidence of anti-natalizumab antibodies in multiple sclerosis patients on treatment for 18 months

Natalizumab is a monoclonal antibody shown to be highly effective in the treatment of relapsing–remitting multiple sclerosis (RRMS). Patients treated with natalizumab can develop antibodies directed against this agent that may affect the efficacy and safety of the drug. In this observational study, the kinetics of the appearance and the incidence of anti-natalizumab antibodies were followed prospectively for 18 months in a cohort of 64 consecutive patients treated with natalizumab for relapsing MS. Blood samples were drawn immediately before starting natalizumab therapy and each month afterwards. The presence of antibodies against natalizumab was assessed by enzyme-linked immunosorbent assay (ELISA) in all patients. Anti-natalizumab antibodies were detected in nine (14.1%) natalizumab-treated patients, three (4.68%) of whom were transiently positive while six (9.37%) were persistently positive (these patients discontinued natalizumab). All positive titres were observed during the first 4 months of treatment. One patient with a hypersensitivity reaction also had persistent antibodies. We conclude that antibodies against natalizumab develop early, within the first 6 months of therapy with natalizumab. Although no antibodies were detected after 4 months of therapy in this particular study, this does not rule out their development later on in exceptional cases.

Multiple sclerosis in Gypsies from southern Spain: prevalence, mitochondrial DNA haplogroups and HLA class II association

Occasional reports have mentioned the prevalence of multiple sclerosis (MS) among Gypsies, and no studies have examined to date the prevalence of MS or human leukocyte antigen (HLA) genetics associations in the Spanish Gypsy population. We decided to study the prevalence, mitochondrial DNA (mtDNA) haplogroups and HLA class II distribution among gypsies with MS in southern Spain. We searched for Gypsy MS patients and studied HLA class II alleles by polymerase chain reaction with sequence-specific oligonucleotide (PCR/SSO) probe hybridization or sequence-specific primers amplification. An additional study of the mtDNA haplogroups by sequencing of the hypervariable segments of the control region was also performed to provide details of their ethnic origin. Estimated prevalence of MS in the Gypsy population in Malaga was 52/100,000. No significant differences were found in mtDNA between Gypsy MS patients and Gypsy controls. DRB1*1501, DQB1*0602 and DQB1*0608 alleles were the only positive HLA association with MS. The Gypsies in our series have the same anthropological origin as other European gypsy groups, as shown by mtDNA haplogroups. Although interpreted with great caution because of the small sample size, we found that the prevalence of MS in Gypsies in Malaga is not as low as that in Central Europe, although it is significantly less than that found in Caucasians from Spain (75-79/100,000). DQB1*0602 was the strongest positive association found with Gypsy MS patients, and DRB1*1501-DQB1*0602 was the most frequent haplotype in this group.

The efficacy of natalizumab in patients with multiple sclerosis according to level of disability: results of an observational study

Background: Little is known about how the level of disability at the start of treatment with natalizumab affects its efficacy. Objectives: The aim of this study was to investigate the effect of natalizumab on relapses in patients with different levels of baseline disability associated with MS. Methods: This single-centre observational study collected demographic data for patients followed prospectively and who were scheduled to start natalizumab therapy due to the presence of disease activity. The annualized relapse rate (ARR) and Kurtzke Expanded Disability Status Scale scores were analysed for the previous year, on starting treatment (baseline) and 1 year after starting therapy. Results: Seventy-seven patients (mean age: 39.0 years, mean disease duration: 12.4 years) were included. The difference between ARR before and after starting treatment was 0.92 for baseline Expanded Disability Status Scale ≤3.5 (p < 0.0005), 0.70 for Expanded Disability Status Scale 4.0–6.0 (p < 0.007) and 0.57 for Expanded Disability Status Scale ≥6 (p = 0.386). Expanded Disability Status Scale did not vary during the study. One patient discontinued treatment due to an adverse event and nine patients discontinued due to positive anti-natalizumab antibodies. Conclusions: The findings support the efficacy of natalizumab in reducing ARR in the year after starting treatment in patients with baseline Expanded Disability Status Scale ≤6.

Validation of the spanish version of the multiple sclerosis international quality of life (musiqol) questionnaire

BackgroundThe Multiple Sclerosis International Quality Of Life (MusiQoL) questionnaire, a 31-item, multidimensional, self-administrated questionnaire that is available in 14 languages including Spanish, has been validated using a large international sample. We investigated the validity and reliability of the Spanish version of MusiQoL in Spain.MethodsConsecutive patients with different types and severities of multiple sclerosis (MS) were recruited from 22 centres across Spain. All patients completed the MusiQoL questionnaire, the 36-Item Short Form (SF-36) health survey, and a symptoms checklist at baseline and 21 days later. External validity, internal consistency, reliability and reproducibility were tested.ResultsA total of 224 Spanish patients were evaluated. Dimensions of MusiQoL generally demonstrated a high internal consistency (Cronbachs alpha: 0.70-0.92 for all but two MusiQoL domain scores). External validity testing revealed that the MusiQoL index score correlated significantly with all SF-36 dimension scores (Pearsons correlation: 0.46-0.76), reproducibility was satisfactory (intraclass correlation coefficient: 0.60-0.91), acceptability was high, and the time taken to complete the 31-item questionnaire was reasonable (mean [standard deviation]: 9.8 [11.8] minutes).ConclusionsThe Spanish version of the MusiQoL questionnaire appears to be a valid and reliable instrument for measuring quality of life in patients with MS in Spain and constitutes a useful instrument to measure health-related quality of life in the clinical setting.

Study of new metallomacrocyclic Pd(II) complexes based on hybrid pyrazole sulfoxide/sulfone ligands and their contribution to supramolecular networks

Treatment of the pyrazole sulfoxide, 1,1′-(2,2′-sulfoneinylbis(ethanediyl))bis(3,5-dimethyl-1-pyrazole) (L1), and pyrazole sulfone, 1,1′-(2,2′-sulfoneonylbis(ethanediyl))bis(3,5-dimethyl-1-pyrazole) (L2) ligands, with [PdCl2(CH3CN)2] in a 1 : 1 M : L ratio, yields two kinds of complexes, monomer or dimer, depending on the solvent of the reaction. Monomeric complexes [PdCl2(L)] (L = L1 (1) or L2 (3)) are obtained when the solvent is acetonitrile, whereas when the reaction takes place in tetrahydrofuran, dimeric complexes [PdCl2(L)]2 (L = L1 (2) or L2 (4)) are obtained. Diffusion NMR studies have been performed to characterize a mixture of the monomeric/dimeric species in CD3CN solution. The solid-state structures of 3 and 4 have been determined by single-crystal X-ray diffraction methods. The extended structures allowed the study of the effects of the structure of the ligands on the topology and interpenetration form (two-dimensional layer polymers and three-dimensional networks). Finally, it has been observed that dimers are converted into the corresponding monomers under continuous acetonitrile reflux conditions, thus indicating that the latter are thermodynamically more stable than dimers.

Environmentally benign and selective synthesis of hybrid pyrazole sulfoxide and sulfone ligands

Organic compounds containing sulfoxide or sulfone moieties are important as commodity chemicals and as pharmaceuticals. This has led to multiple research regarding new methodologies for their preparation. In this manuscript, we report the development of efficient chemical methodologies for the selective oxidation of a pyrazole–alkylthioether ligand to sulfoxide or sulfone ligands. Electrochemical green routes have also been explored not only for rationalizing the selectivity of the chemical oxidation methodology but also to selectively obtain the sulfoxide and sulfone ligands in good yields.