The presence of the HLA-DRB1 shared epitope correlates with erosive disease in Chilean patients with rheumatoid arthritis.

Objective: To assess the contribution of the HLA-DRB1 shared epitope (SE) to the radiological outcome of rheumatoid arthritis (RA) after 6 yr of follow-up in a reported series of 129 Chilean patients with established disease.

Methods: A prospective study was conducted between 1992 and 1998 using hand radiographs to assess disease outcome in a published series of patients in whom two doses of the SE were present in 20%, one dose was present in 34% and the SE was absent in 46%. At study entry, 29 of the 92 patients with hand radiographs were at Steinbrocker stages I or II (non-erosive), with a median disease duration of 2.

Influence of the HLA-DR beta shared epitope on susceptibility to and clinical expression of rheumatoid arthritis in Chilean patients.

Objective: To analyse the influence of shared epitope positive HLA-DRB1 alleles (QKRAA or QRRAA)) on rheumatoid arthritis (RA) susceptibility and severity in Chileans, a population that exhibits a weak association with HLA-DR4.

Methods: Prevalence of alleles DRB1*01 and DRB1*04 alleles was determined by polymerase chain reaction amplification and sequence specific oligonucleotide hybridisation in 129 RA patients with defined clinical features and in 97 healthy controls.

Results: The shared epitope was found in 70 (54%) of the RA patients and in 29 (30%) of controls (odds ratio (OR) = 3; 95% confidence intervals (CI) = 1.

[Seronegative arthritis: reexamination of the initial diagnosis and prognosis after 10 years].

Seronegative arthritides are a heterogeneous group of diseases that includes rheumatoid arthritis with negative rheumatoid factor. Between 1980 and 1984 we studied 38 patients with seronegative arthritis. Thirty of these patients were reassessed in 1994 after 9 to 20 years of evolution.

[Frequency of lumbar spine osteopenia in an asymptomatic postmenopausal Chilean population].

The aim of this study was to assess lumbar spine bone density in a group of chilean postmenopausal females and to estimate the frequency of vertebral osteopenia in the national urban female population. A clinical assessment and lumbar spine bone density measurement were performed to 171 healthy women over 40 years of age and not receiving medications that modify bone turnover. Calcium ingestion was recalled in 77 of these.

[Computed tomography guided fine needle aspiration biopsies].

Computed tomography (CT) allows the performance of fine needle aspiration biopsies in situations in which ultrasound or conventional X rays do not correctly visualize the lesion or the needle tract. One hundred four patients with a clinical suspicion of neoplasia were subjected to CT guided percutaneous aspiration biopsies in a lapse of 6 years. The most frequently biopsied organs were the lung (39.