TRAF1/C5 but not PTPRC variants are potential predictors of rheumatoid arthritis response to anti-tumor necrosis factor therapy.

BACKGROUND: The aim of our work was to replicate, in a Southern European population, the association reported in Northern populations between PTPRC locus and response to anti-tumor necrosis factor (anti-TNF) treatment in rheumatoid arthritis (RA). We also looked at associations between five RA risk alleles and treatment response. METHODS: We evaluated associations between anti-TNF treatment responses assessed by DAS28 change and by EULAR response at six months in 383 Portuguese patients. Univariate and multivariate linear and logistic regression analyses were performed. In a second step to confirm our findings, we pooled our population with 265 Spanish patients. RESULTS: No association was found between PTPRC rs10919563 allele and anti-TNF treatment response, neither in Portuguese modeling for several clinical variables nor in the overall population combining Portuguese and Spanish patients. The minor allele for RA susceptibility, rs3761847 SNP in TRAF1/C5 region, was associated with a poor response in linear and logistic univariate and multivariate regression analyses. No association was observed with the other allellic variants. Results were confirmed in the pooled analysis. CONCLUSION: This study did not replicate the association between PTPRC and the response to anti-TNF treatment in our Southern European population. We found that TRAF1/C5 risk RA variants potentially influence anti-TNF treatment response.

Effectiveness and safety of infliximab in two cases of severe chondrocalcinosis: nine years of follow-up.

Objectives. To investigate the efficacy of infliximab in the treatment of severe calcium pyrophosphate deposition diseases (CPPD). Methods. Two patients with severe CPPD and diffuse idiopathic skeletal hyperostosis- (DISH-) like phenotype are described. Both patients were resistant to therapy with nonsteroidal anti-inflammatory drugs (NSAIDs). Both patients were treated with infliximab, a TNF-α receptor antagonist, for nine years. Results. Treatment with infliximab resulted in major clinical and laboratory improvements without relevant side effects. Conclusions. These results suggest that infliximab may be an effective treatment of severe CPDD.

Fine mapping of a major histocompatibility complex in ankylosing spondylitis: association of the HLA-DPA1 and HLA-DPB1 regions.

OBJECTIVE: To investigate the potential association of major histocompatibility complex (MHC) markers other than HLA-B27 with ankylosing spondylitis (AS). METHODS: A total of 603 patients with AS and 542 healthy control subjects, all of whom were HLA-B27 positive, were selected for this study based on clinical criteria. First, high-density genotyping across the MHC region (2,360 single-nucleotide polymorphisms [SNPs]) was performed in a cohort of 191 patients and 241 control subjects. After a fine-mapping study, 5 SNPs from the HLA-DPA1/DPB1 region were validated in a second cohort of 412 patients with AS and 301 healthy control subjects. RESULTS: Seventeen SNPs located within or near the HLA-DPA1 and HLA-DPB1 loci showed association with AS (P = 1.38 × 10⁻5 to 0.05). In addition, multimarker tests, both linkage disequilibrium and sliding windows, showed association of some groups of adjacent SNPs within the HLA-DPA1/DPB1 region with AS (P = 1.0 × 10⁻4 to 3.96 × 10⁻7). We validated the association by genotyping 5 SNPs from the DPA1/DPB1 region in an additional cohort and obtained P values from 6.42 × 10⁻5 to 0.01 in the analysis of the combined cohorts. Subtyping analysis of HLA-DPA1 and HLA-DPB1 showed that HLA-DPA1*01:03, A1*02:01, and B1*13:01 were the subtypes most susceptible to AS. CONCLUSION: HLA markers and linkage disequilibrium blocks near HLA-DPA1 and HLA-DPB1 are statistically associated with AS. We identified a region located around the HLA-DPA1 and HLA-DPB1 loci associated with AS, another region within the MHC that is different from HLA-B27.

The effects of vitrification on gene expression in mature mouse oocytes by nested quantitative PCR.

PURPOSE: this study was conducted on the effects of vitrification cryotop method on gene expression of mature oocytes in Mus musculus. METHODS: transcript analyses of three mouse genes, namely Mater, Hook1 and Sod1, were performed upon non-vitrified and vitrified oocytes with different concentrations of dimethyl sulfoxide (DMSO) and ethylene glycol (EG),15%: 7.5% DMSO + 7.5% EG, and 30%: 15% DMSO + 15% EG, using cryotop following normalization of transcripts with Hprt1 by nested quantitative PCR. RESULTS: vitrification caused down-regulation of Mater and Hook1 and up-regulation of Sod1 when lower concentrations of cryoprotectants were used as opposed to the control group. The relative expression of Sod1 in vit(2) (30% v/v) was significantly higher than vit(1) (15% v/v)(.) Quantitative transcript analysis of Mater and Hook1 for the vit(2) condition failed to produce any data. Survival rates were the same for both vitrification treatments and significantly lower than control group. CONCLUSIONS: although vit(1) treatment had lower survival rate compared to control group, it demonstrated better stability comparing to vit(2) based on the transcript analysis.

Evaluation of two methods for computational HLA haplotypes inference using a real dataset.

BACKGROUND: HLA haplotype analysis has been used in population genetics and in the investigation of disease-susceptibility locus, due to its high polymorphism. Several methods for inferring haplotype genotypic data have been proposed, but it is unclear how accurate each of the methods is or which method is superior. The accuracy of two of the leading methods of computational haplotype inference--Expectation-Maximization algorithm based (implemented in Arlequin V3.0) and Bayesian algorithm based (implemented in PHASE V2.1.1)--was compared using a set of 122 HLA haplotypes (A-B-Cw-DQB1-DRB1) determined through direct counting. The accuracy was measured with the Mean Squared Error (MSE), Similarity Index (IF) and Haplotype Identification Index (IH). RESULTS: None of the methods inferred all of the known haplotypes and some differences were observed in the accuracy of the two methods in terms of both haplotype determination and haplotype frequencies estimation. Working with haplotypes composed by low polymorphic sites, present in more than one individual, increased the confidence in the assignment of haplotypes and in the estimation of the haplotype frequencies generated by both programs. CONCLUSION: The PHASE v2.1.1 implemented method had the best overall performance both in haplotype construction and frequency calculation, although the differences between the two methods were insubstantial. To our knowledge this was the first work aiming to test statistical methods using real haplotypic data from the HLA region.