Santiago Rivero

T-cell subpopulations in the peripheral blood of patients with connective tissue diseases as determinated by flow cytometry using monoclonal antibodies

We studied by flow cytometry using monoclonal antibodies the T3, T4, and T8 subpopulations of T cells in the peripheral blood of 109 patients with various connective tissue diseases who were not receiving any treatment. Comparison of the results was made with those obtained with normal controls matched for age and sex with each connective tissue disease group. When compared as disease groups, patients with systemic lupus erythematosus (n = 41) had decreased T8 cells, but patients with active disease (n = 17) had all three T-cell subpopulations lower than their controls, whereas those with inactive disease (n = 24) showed no differences. Patients with rheumatoid arthritis (n = 23) had decreased T3 and T8 cells, whereas patients with scleroderma (n = 22) only had decreased T3 cells, and patients with primary Sjögrens syndrome (n = 15) had lower proportions of all three T-cell subpopulations than their matched controls. Patients with mixed connective tissue disease (n = 8) had proportions of all three T-cell subpopulations akin to those of their matched controls, but showed a tendency to have decreased T8 cells that reached statistical significance when compared to the entire control group. Although our findings tend to support the notion that the abnormalities in immunoregulatory T-cell circuits leading to autoimmunity are different in each connective tissue disease, the great variability found in both patients and controls seems to preclude the use of these determinations in individual patients for clinical purposes.

Clinical expression of rheumatoid arthritis in Chilean patients

In populations such as Northern Europeans in which the HLA-DR4 subtypes DW14 and Dw4 show strong association with rheumatoid arthritis (RA), these alleles and the double allelic dose of the shared epitope are considered severity markers. The clinical expression of RA varies in different populations, which may be determined by variation in the prevalence of these markers. In the present study we analyzed the expression of RA in 112 consecutive Chilean patients and its relation to the prevalence of genetic factors, prompted by our previous observation that DR4 is weakly associated to RA in this population. Mean age was 50 +/- 14 years; 90% were seropositive and 87% were female, with a disease duration of 10 +/- 8 years. Extra-articular manifestations were found in 38% of patients, rheumatoid nodules in 27%, vasculitis in 8%, and Sjogrens syndrome in 29%. Functional capacity (ACR, 1991) I or II: 82%.15% of patients stopped working. Hand radiographs scored according to Steinbrocker in 89 patients: I, 21%; II, 15%; III, 43%; IV, 21%. In this series, patients with less formal education seemed to have more benign arthritis. In 97 controls and in 65 (56%) RA patients the presence of DRB1 alleles corresponding to DR1 and DR4 serotypes, to DR4-Dw subtypes, and homozygocity, were determined by polymerase chain reaction followed by specific oligonucleotide hybridization. The shared epitope was present in 53% of RA patients and in 30% of controls (P = .0048, odds ratio [OR] = 2.64). A double allelic dose of the epitope was present in 15% of RA patients compared with 4% of controls (P = .026, OR = 4.23). In a subgroup of 31 erosive RA patients we did not find a significant association of disease severity with the shared epitope in a single or double allelic dose. None of the DR4 subtypes that associate with RA in other populations was found significantly more prevalent in our patients. The severity of RA in our study compared with published series was intermediate between British patients with severe RA and Greek patients with milder disease. This may be due to the high prevalence of Dwl3*0403 in our population.