Utility of oligoclonal IgG band detection for MS diagnosis in daily clinical practice.

An early and accurate diagnosis of multiple sclerosis (MS) is very important, since it allows early treatment initiation, which reduces the activity of the disease. Oligoclonal IgG band (OCGB) detection is a good ancillary tool for MS diagnosis. However, it was argued that its usefulness was limited by the high interlaboratory variability. In the last years, different techniques for OCGB detection have appeared. We performed a blinded aleatorized multicenter study in 19 Spanish hospitals to assess the accuracy and reproducibility of OCGB detection in this new scenario. We studied cerebrospinal fluid (CSF) and serum samples from 114 neurological patients. Every hospital contributed to the study with triplicated pairs of CSF and serum samples of six patients and analyzed 18 different samples. Global analysis rendered a sensitivity of 92.1%, a specificity of 95.1% and a Kappa value of 0.81. This shows that current techniques for OCGB detection have good accuracy and a high interlaboratory reproducibility and thus, represent a good tool for MS diagnosis. When we analyzed separately the different techniques used for OCGB detection, the highest concordance was observed in western blot with alkaline phosphatase detection (kappa=0.91). This indicates that high sensitivity techniques improve the reproducibility of this assay.

Polymorphisms in chromosome region 12q13 and their influence on age at onset of type 1 diabetes.

AIMS/HYPOTHESIS: A complex region covering numerous genes in 12q13 was first associated with type 1 diabetes in the Wellcome Trust Case-Control Consortium (WTCCC) study. Two studies performed in a white population have tested the association of polymorphisms within this region with age at onset of the disease, with seemingly contradictory results. We aimed at replicating three of the strongest signals in a group of patients with early and late disease onset. METHODS: Polymorphisms rs773107, rs2292239 and rs10876864 were genotyped in 444 type 1 diabetic Spanish participants (age at onset 0-65 years) and 861 controls. The influence of single nucleotide polymorphisms (SNPs) on age at onset was tested through stratified and continuous analyses. RESULTS: rs773107 and rs2292239 were significantly associated with the disease, while rs10876864 showed a trend towards statistical significance in the whole population analyses. Comparison of early-onset patients to controls was significant for the three polymorphisms (allelic p < 0.006). Late-onset patients and controls did not reveal statistical differences. Analysis of age at onset in both rs773107 and rs2292239 showed differences between genotypes (p ≤ 0.002), alleles (p ≤ 0.013) and homozygotes for the risk genotype (p ≤ 4 × 10(-4)). Polymorphism rs10876864 showed trends towards statistical significance in the allelic frequencies (p = 0.051) and homozygotes for the risk genotype (p = 0.056). Subjects with risk genotypes had a disease onset between 2 and 5 years earlier than carriers of protective alleles. CONCLUSIONS/INTERPRETATION: We replicate two of the previously studied associations in a Spanish population and find new evidence of the influence of the 12q13 region on age at onset of type 1 diabetes.

The R30Q DLG5 variant is not associated with celiac disease or inflammatory bowel disease in the Spanish population.

Alterations in intestinal epithelial permeability could underlie inflammatory bowel disease (IBD) and celiac disease (CeD) etiology, as supported by previous association studies. One related gene, DLG5 [discs, large homologue 5 (Drosophila)], has been associated with IBD in several populations and with CeD in the Dutch population. We tried to confirm the involvement of DLG5 in CeD performing a case-control study (725 CeD patients and 803 controls) by analysing the R30Q variant (rs1248696). Genetic frequencies did not significantly differ between groups (P > 0.80) and the meta-analysis with the Dutch data did not show any association. Additionally, we evaluated the effect of R30Q in IBD risk (858 patients), as discordant results were previously obtained. No association was detected. Our study does not support the effect of the R30Q DLG5 variant in CeD or IBD predisposition in the Spanish population.

Cartilaginous choristoma of the tongue.

Choristomas are lesions composed of normal cells or tissues occurring in an abnormal location. Cartilaginous choristomas of the oral mucosa are rare and occur preferentially on the tongue and less often in sites such as the soft palate and gingiva. Oral lesions are generally covered by integral mucosa and can occur at any age. The present study describes a case of a 73-year-old female presenting with an asymptomatic cartilaginous choristoma on the ventral surface of the tongue which had developed over a period of 3 years. The clinical presentation and management of the case are discussed and the literature is reviewed. This is the 28th reported case of a cartilaginous choristoma of the tongue and the third with a ventral localisation.

Study of the association between the CAPSL-IL7R locus and type 1 diabetes.

AIMS/HYPOTHESIS: In the past few years, several genes outside the MHC region have been described as new susceptibility genetic factors to type 1 diabetes. An association between CAPSL-rs1445898 and type 1 diabetes was reported in a large white population and corroborated in a genome-wide analysis, which also found an association with IL7R, which is located adjacent to CAPSL. The aim of this study was to replicate the aforementioned associations in independent cohorts. METHODS: We analysed two CAPSL (rs1010601 and rs1445898) and three IL7R (rs6897932, rs987106 and rs3194051) polymorphisms. All these single nucleotide polymorphisms (SNPs) were genotyped using TaqMan minor groove binder chemistry in 301 unrelated Spanish type 1 diabetes patients and 646 healthy controls. Additionally, the associated CAPSL SNP rs1445898 was genotyped in a Dutch cohort consisting of 429 type 1 diabetes patients and 720 healthy controls. RESULTS: The homozygous mutant genotype of the CAPSL SNP rs1445898 showed a trend towards a protective effect in the overall Spanish cohort (OR [95% CI] 0.70 [0.44-1.09]; p = 0.09) and in the Dutch cohort (OR [95% CI] 0.74 [0.51-1.05]; p = 0.09). Pooling of both cohorts was performed, yielding a statistically significant difference (Mantel-Haenszel OR 0.71; p = 0.005). This protective effect was significantly different in early-onset vs late-onset Spanish patients (OR [95% CI] 0.26 [0.10-0.65]; p = 0.001). Similarly, in the early-onset subgroup, the homozygous mutant genotype of the IL7R SNP rs6897932 showed a similar protective effect (OR [95% CI] 0.18 [0.02-0.94]; p = 0.02). CONCLUSIONS/INTERPRETATION: In summary, we describe an independent replication of the association between the CAPSL-IL7R locus and type 1 diabetes, especially for early-onset type 1 diabetes patients.

NFkappaB1 gene does not affect type 1 diabetes predisposition in a Spanish population.

The chromosomal location of the NFkappaB1 gene on 4q, a region linked to type 1 diabetes (T1D), together with the observed resistance to T1D of NFkappaB1-deficient mice, suggests its potential role as candidate gene increasing diabetes predisposition. Previous association studies in diverse populations yielded inconclusive results. Two polymorphisms in the promoter region of the NFkappaB1 gene have been studied: a functional -94ins/delATTG regulating the gene expression and a very informative CA-repeat microsatellite. A strong association with the latter was reported in British population but could not be replicated in Danish families. No evidence of association was detected for those genetic markers in 270 Spanish T1D patients and 484 healthy ethnically matched controls. Therefore, it seems that this gene plays no major role in T1D predisposition.

Triplet repeat polymorphism in the transmembrane region of the MICA gene in celiac disease.

Celiac disease (CD) is characterized by a striking expansion of gamma delta T cells in the intestine. These cells interact with MICA, a cell surface protein encoded by a major histocompatibility complex gene. We investigated whether MICA gene polymorphism could contribute to susceptibility to CD. DNA typing for HLA-DR, DQA1, DQB1, TNF-308, TNFa, TNFb and a triplet repeat polymorphism in the transmembrane region of the MICA gene were carried out. We performed case-control stratified association studies and transmission disequilibrium tests. Our results indicate that although there is no primary association between MICA polymorphism and CD, there is, in addition to HLA-DQ, a second susceptibility locus on the 8.1 ancestral haplotype in strong linkage disequilibrium with MICA A5.1 allele.

Celiac disease and TNF promoter polymorphisms.

The possibility that genetic susceptibility to celiac disease (CD) might be influenced by tumor necrosis factor (TNF) genes polymorphism has repeatedly been put forward. To date, this has only been investigated in case-control studies and results have been contradictory. In order to avoid any possible ethnic mismatching between patients and controls, we have approached this problem studying 71 celiac families, establishing the parental haplotypes and comparing CD versus control haplotypes (the so-called AFBAC or affected family-based controls). We used DNA-based methods to screen for HLA-DRB1, -DQA1, and -DQB1 alleles, TNFalpha promoter polymorphims and TNFa and b microsatellites. The guanine-to-adenine polymorphism at position -308 of the TNFalpha gene promoter region was found associated with CD as the TNF-308A allele appeared significantly increased in frequency in CD haplotypes, and this was shown to be independent of the association between CD and the DRB1*0301,DQA1*0501,DQB1*0201 alleles. Our results indicate that at least another gene, in addition to the known association of CD with HLA class II, has a susceptibility role in this disease. This should be either TNFalpha or another polymorphic gene in the telomeric end of the HLA class III region.

Influenza virus immunization effectivity in kidney transplant patients subjected to two different triple-drug therapy immunosuppression protocols: mycophenolate versus azathioprine.

BACKGROUND: Due to possible complications and treatment limitations, the prevention of influenza in renal transplant (RT) patients is highly indicated. METHODS: Forty-nine patients with a 1-year functioning RT subjected to two different immunosuppressive regimens and 37 healthy relatives (HR) were administered the anti-influenza vaccine as recommended for 1996 to 1997. Anti-influenza antibody, creatinine, and immunological markers were estimated at 1 and 3 months after vaccination. RESULTS: Three months after vaccination, 46.2% of the RT patients and 69% of the HR (P=0.06) showed protective antibody titers to influenza A (relative risk [RR]; 0.67; 95% confidence interval: 0.44-1.02). A total of 20.5% of the RT patients and 44.8% of the HR showed antibodies to influenza B (P=0.03). Despite these differences, the incidence of illness was similar. The immunosuppressive regimen had no effect on the antibody response. CONCLUSIONS: Although the RT patients showed a reduced antibody response, no negative effects on graft outcome were observed.

Primary association of a TNF gene polymorphism with susceptibility to multiple sclerosis.

The associations of three promoter polymorphisms in the tumor necrosis factor (TNFA) gene have been studied in 238 patients and 324 control subjects. A significant correlation was found between MS susceptibility and the TNFA-376 polymorphism. This association was independent of the human leukocyte antigen (HLA) class II association and the combined inheritance of HLA-DRB1*1501 and the TNFA-376A allele more than additively increased susceptibility to MS.

Pancolitis and genetic markers in the Spanish population.

BACKGROUND: although the etiology of ulcerative colitis disease remains an enigma, the importance of the major histocompatibility complex genes has been described, as in many other autoimmune diseases. AIM: we investigated the contribution of HLA-DRB1, DQA1 and DQB1 genes (HLA region) in patients with pancolitis. METHODS: we studied a total of 89 patients diagnosed as having ulcerative colitis (34 pancolitis and 55 left colitis) and 275 healthy control subjects. Complete information on sex, age, family history, age of onset, localization, complications, surgery and treatment was obtained from all patients. DNA was extracted from peripheral blood leukocytes and all individuals were HLA-DRB1 genotyped. RESULTS AND CONCLUSIONS: there was an association between pancolitis and the presence of DR4-Val86 (p = 0.009; OR = 3.3) and DRB1*0103 (p = 0.02; OR = 5.1) alleles. In patients with left colitis an association with DRB1*1501 (p = 0.03; OR = 1.9) and DRB1*0103 alleles (p = 0.03; OR = 3.8) was observed. We conclude that a strong association between DR4-Val86 and pancolitis exists.

Contribution of HLA class II genes to susceptibility in achalasia.

Achalasia is a motor disorder of the esophagus resulting in functional obstruction. The cause of the lesion is unknown although genetic and immunologic factors have been suggested. An association with serological HLA epitopes has been previously reported. In this study, we have further examined this HLA class II association with susceptibility to achalasia by DNA based methods. Achalasia patients (n=40) and healthy controls (n=275), all Caucasians and unrelated, were included in the analysis. The strongest associations were with HLA-DQA1*0101 and two HLA-DQ alphabeta heterodimers having their alpha chain encoded by this allele. Moreover, relative risk was significantly higher in DQA1*0101 homozygotes as compared to heterozygotes and results suggested that DQB1*02 may have a protective role.

HLA-DR2 gene and Spanish patients with ulcerative colitis.

BACKGROUND: An association with class II MHC genes has been described in ulcerative colitis, as in other diseases with immunological pathogenesis. Heterogeneous results have been reported, depending on the studied population. OBJECTIVE: To study the importance of these genes in our population, mainly the alleles of group HLA DR2 (gene HLA-DRB1). PATIENTS AND METHODS: We studied a total of 107 patients diagnosed of ulcerative colitis and 200 unaffected controls. Complete information about sex, age, family antecedent, age of onset, localization, complications, surgery and treatment was obtained from these patients. DNA was extracted from peripheral blood leukocytes and all the individuals were HLA-DRB1 genotyping. RESULTS AND CONCLUSIONS: We conclude that a positive association exists between DR15 and ulcerative colitis (p < 0.05). This positive association was characterized and various clinical parameters were analyzed, being concluded that DR1501 is more frequent in this disease (p < 0.05) and in benign manifestations; the frequency of the allele DR1502 was also found to be elevated in severe manifestations.

Polymorphism within the HLA-DQB1*02 promoter associated with susceptibility to coeliac disease.

Susceptibility to coeliac disease is associated with a particular HLA-DQ alpha beta heterodimer encoded by the DQA1*0501 and DQB1*02 genes. A single base polymorphism in the DQB1*02 promoter region in DR7, DQA1*0201, DQB1*02 haplotypes was observed, associated with an increased susceptibility to the disease. This finding suggests a novel mechanism of susceptibility to immune-mediated diseases.

Positive and negative associations of distinct HLA-DR2 subtypes with ulcerative colitis (UC).

In UC, as in many other diseases with a suspected autoimmune etiology or pathogenesis, an association with certain HLA class II specificities has been investigated. In the Japanese, several studies have shown a positive association with DR2, but in Caucasian populations the results are conflicting. Therefore we undertook a study of HLA class II gene association with UC in a large group of white Madrid patients and ethnically matched controls, using molecular biology techniques to investigate whether any allelic subspecificity within the HLA-DR2 group is associated with susceptibility to or protection against UC. Patients with ulcerative colitis (n = 107) and 200 controls were typed using molecular, DNA-based techniques for HLA-DRB1, DQA1 and DQB1 alleles. Those HLA-DR2+ were then specifically typed for the individual alleles within the HLA-DR2 group. We observed a positive association with HLA-DR15 (P=0.021) and its subtype DRB1*1501 (P=0.018). HLA-DRB1*1502 was also increased, although its frequency both in patients and controls was very low. When the HLA-DR2+ population was studied, HLA-DRB1*1601 was significantly decreased in patients (P=0.026). Both HLA-DR3 (P=0.002) and HLA-DQB1*02 (P=0.001) were also negatively associated with the disease, the latter especially with pancolitis. Therefore, HLA class II association with UC is complex, and separate alleles confer either susceptibility or resistance. Conflicting results with HLA-DR2 appear to be due to the presence in this group of both positively associated (HLA-DRB1*1501 and DRB1*1502) and negatively associated (HLA-DRB1*1601) subspecificities. Moreover, HLA-DR3 and HLA-DQB1*02 are associated negatively.

HLA-linked genes acting as additive susceptibility factors in celiac disease.

Susceptibility to developing CD is widely accepted to be primarily associated with a particular HLA-DQ alpha beta heterodimer encoded by the DQA1*0501 and DQB1*0201 alleles in cis position on the DR3,DQ2 haplotype or in trans position by DR5,DQ7/DR7,DQ2 heterozygotes. We performed genomic HLA-DR and -DQ typing of 100 unrelated Spanish celiac children and 180 ethnically matched controls. As expected, most (92 out of 100) celiac patients carried the HLA-DQ alpha beta heterodimer, and we selected these individuals for further studies. The results corroborate that although the DQA1*0501 and DQB1*0201 genes in single dosage appear sufficient for conferring disease susceptibility, individuals homozygotes for DQB1*0201 show an increased risk. Furthermore, our data also show that those carrying the genotype DR5,DQ7/DR7,DQ2 have a significantly increased risk of developing CD as compared to those that are non-DR7 positive, also carrying the CD-associated HLA-DQ alpha beta heterodimer. This strongly suggests that there is an MHC linked non-HLA-DQ gene primarily associated with CD present on DR7,DQ2 haplotype, which should either be DR7 or in strong linkage disequilibrium with it. Our data also indicate that, as has already been suggested, another HLA-associated CD susceptibility gene may be present on some DR4-carrying haplotypes.