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Biomedical subjects

Sergio Paira

Publications and source records attributed to Sergio Paira.

9 recordsLinked to original sources

Argentine population genetic structure: large variance in Amerindian contribution.

Argentine population genetic structure was examined using a set of 78 ancestry informative markers (AIMs) to assess the contributions of European, Amerindian, and African ancestry in 94 individuals members of this population. Using the Bayesian clustering algorithm STRUCTURE, the mean European contribution was 78%, the Amerindian contribution was 19.4%, and the African contribution was 2.5%. Similar results were found using weighted least mean square method: European, 80.2%; Amerindian, 18.1%; and African, 1.7%. Consistent with previous studies the current results showed very few individuals (four of 94) with greater than 10% African admixture. Notably, when individual admixture was examined, the Amerindian and European admixture showed a very large variance and individual Amerindian contribution ranged from 1.5 to 84.5% in the 94 individual Argentine subjects. These results indicate that admixture must be considered when clinical epidemiology or case control genetic analyses are studied in this population. Moreover, the current study provides a set of informative SNPs that can be used to ascertain or control for this potentially hidden stratification. In addition, the large variance in admixture proportions in individual Argentine subjects shown by this study suggests that this population is appropriate for future admixture mapping studies.

Asian People↗

Pachydermodactyly: four additional cases.

Pachydermodactyly (PDD) is a rare, benign form of digital fibromatosis characterized by an asymptomatic soft tissue swelling affecting the skin of the lateral aspects of the proximal interphalangeal joints of the fingers, and it sometimes can be misdiagnosed with some rheumatic condition. Recognition on these features should lead to its more frequent diagnosis. The purpose of our study is to report four additional cases of PDD and discuss the differential diagnosis.

Adolescent↗

Analysis of IRF5 gene functional polymorphisms in rheumatoid arthritis.

OBJECTIVE: Recent findings suggest that interferon regulatory factor 5 (IRF-5) may play a crucial role in several cellular processes, including the transcription of genes for inflammatory cytokines. Two genetic variants of the IRF5 gene (rs2004640 in exon 1 and rs2280714 in the 3'-untranslated region) have been shown to exert functional modifications affecting IRF5 messenger RNA splicing and expression, and have been associated with genetic predisposition to systemic lupus erythematosus (SLE). The aim of this study was to analyze the possible contribution of the IRF5 gene to the predisposition to rheumatoid arthritis (RA). METHODS: Three case-control cohorts from Spain (724 RA patients and 542 healthy controls), Sweden (281 RA patients 474 healthy controls), and Argentina (284 RA patients and 286 healthy controls) were independently analyzed. Genotyping for IRF5 rs2004640 and rs2280714 was performed using a TaqMan 5' allele-discrimination assay. RESULTS: In the 3 cohorts studied, no statistically significant differences in allele or genotype frequencies of the rs2004640 and rs2280714 IRF5 polymorphisms were observed between RA patients and controls. Accordingly, haplotype analysis revealed that none of the IRF5 haplotypes was associated with genetic predisposition to RA. CONCLUSION: Our results suggest that the IRF5 functional polymorphisms analyzed do not seem to be implicated in genetic susceptibility to RA.

Argentina↗

Asymptomatic sensorineural hearing loss in patients with systemic lupus erythematosus.

OBJECTIVE: Hearing loss can accompany systemic lupus erythematosus (SLE). The purpose of this study was to evaluate the prevalence of asymptomatic sensorineural hearing loss (ASNHL) in patients with SLE. METHODS: Thirty-one unselected consecutive female patients with SLE (American College of Rheumatology criteria, 1982) were evaluated (in a prospective and descriptive study) for evidence of hearing abnormalities. Twenty-five healthy age-matched women served as controls. All patients and control groups underwent both a normal tympanoscopy and an audiometric testing as a prerequisite to be included in the study. RESULTS: Patients with SLE had a mean age of 35 years (range, 19-64 years) and the follow-up time (median) was 48 months (range, 4-180 months). One of 31 patients was excluded because of middle ear infectious disease. Of the remaining 30 patients, 21 (70%) had impaired hearing; 20 (66%) had sensorineural loss at high frequencies in a bilateral and symmetric way, and one had conductive alteration. Ten patients had normal audiometric studies. Four women in the control group had alterations of the audiometric tests: 3 patients had conductive alteration and the other one had bilateral ASNHL. No statistically significant correlation was found among the presence of ASNHL, the detection of antiphospholipid antibodies, and the treatment with hydroxychloroquine. Also, no correlation was observed between impaired hearing and SLE activity. CONCLUSION: If it can be established how often this ASNHL progresses to a clinical problem, it can be important that, as part of initial studies, patients with SLE undergo audiometric tests.

Adult↗

Cytidine deaminase in polymyalgia rheumatica and elderly onset rheumatoid arthritis.

Serum cytidine deaminase (CD) as a marker of inflammatory disease was assessed in 44 patients and 47 controls to differentiate polymyalgia rheumatica (PMR) from elderly onset rheumatoid arthritis (EORA). The patients were divided into four groups: PMR with and without synovitis and seropositive and seronegative EORA. No statistically significant differences were found when serum CD levels of seropositive EORA patients were compared with serum CD of PMR patients without synovitis, neither when serum CD levels of all PMR patients were compared with a seronegative EORA group, nor when serum CD levels of PMR patients with synovitis were compared with those with EORA. Nevertheless, statistically significant differences were detected between EORA's serum CD levels and the control group (p=0.023). This difference was 10% when comparing CD levels of PMR patients with the control group (p=0.070). We did not demonstrate that serum CD levels could be a useful tool to differentiate PMR from EORA, but these findings could nevertheless reflect the presence of an inflammatory disease.

Aged↗

Erythromelalgia with subsequent digital necrosis, glomerulonephritis, and antiphospholipid antibodies.

Erythromelalgia is a condition of extremities characterized by redness, increased temperature, and burning pain. We describe the first reported case of erythromelalgia in a young woman with digital necrosis and mesangial nephritis associated with antiphospholipid antibodies. The symptoms and necrosis completely resolved with treatment with corticosteroids. We discuss the differential diagnosis of this entity and highlight the importance of a follow up of these patients, because erythromelalgia may precede a myeloproliferative disorder or systemic lupus erythematosus by months or years.

Adolescent↗

Chromosome 17p12-q11 harbors susceptibility loci for systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the presence of autoantibodies against intracellular components, the formation of immune complexes, and inflammation in various organs, typically the skin and kidney glomeruli. The etiology of the disease is not well understood but is most likely the result of the interaction between genetic and environmental factors. In order to identify susceptibility loci for SLE, we have performed genome scans with microsatellite markers covering the whole genome in families from Argentina, Italy, and Europe. The results reveal a heterogeneous disease with different susceptibility loci in different family sets. We have found significant linkage to chromosome 17p12-q11 in the Argentine set of families. The maximum LOD score was given by marker D17S1294 in combination with D17S1293, when assuming a dominant inheritance model (Z = 3.88). We also analyzed a repeat in the promoter region of the NOS2A gene, a strong candidate gene in the region, but no association was found. The locus on chromosome 17 has previously been identified in genetic studies of multiple sclerosis families. Several other interesting regions were found at 1p35, 1q31, 3q26, 5p15, 11q23 and 19q13, confirming previously identified loci for SLE or other autoimmune diseases.

Adult↗

Widespread cutaneous necrosis associated with antiphospholipid antibodies: report of four cases.

We describe four patients with widespread cutaneous necrosis as a manifestation of the antiphospholipid antibody syndrome. In three of the patients, the lesions were the first manifestation of the syndrome, and they were located in upper and lower extremities. Vascular thrombosis was present in the skin biopsy in all of the patients. Patients were effectively treated with anticoagulants, and healing occurred within 60 days. Such widespread cutaneous necrosis is a rare manifestation of the syndrome, and it must be regarded as major thrombotic event. Long-term treatment with anticoagulants must be considered. The recognition of these lesions is important, because they may be the onset of the syndrome, allowing its early diagnosis and treatment.

Journal Article↗