ABSTRACT
Autoantibodies specific for double stranded DNA (anti-dsDNA Abs) are a serological biomarker of systemic lupus erythematosus (SLE) and constitute useful tools for monitoring many SLE patients. A new automated immunofluorescence and quantitative assay (EliA dsDNA) has recently become available. Its performance has been demonstrated to be equivalent to the Farr and Crithidia luciliae fluorescence (CLIFT) tests. The aim of the present work was to assess the utility of this new assay to monitor clinical activity in a large cohort of SLE patients. To this end, 1020 sera from 181 SLE patients were evaluated by the two methods. Results showed a higher frequency of positive results of anti-dsDNA Abs during lupus flares measured by EliA dsDNA than by CLIFT. Likewise, titers of those Abs were significantly increased in active SLE in comparison with inactive SLE when measured by EliA dsDNA but not by CLIFT. Serum titers of anti-dsDNA Abs by both assays showed a significant negative association with concentrations of C3 and C4. In summary, this retrospective study on a large cohort of patients demonstrated that EliA dsDNA was at least as useful as CLIFT as monitoring tool in the follow-up of SLE patients, but with the advantages of being automated, quick and quantitative.
Subject(s)
Antibodies, Antinuclear/blood , DNA/immunology , Fluorescent Antibody Technique/methods , Lupus Erythematosus, Systemic/blood , Adolescent , Adult , Aged , Aged, 80 and over , Cohort Studies , Complement C3/metabolism , Complement C4/metabolism , Female , Humans , Male , Middle Aged , Predictive Value of Tests , Reproducibility of Results , Retrospective Studies , Severity of Illness IndexABSTRACT
BACKGROUND: Drug-metabolizing capacity is generally reduced in the elderly. The purpose of this investigation was to study antipyrine clearance and metabolite excretion in old subjects of both sexes. METHODS: Saliva clearance of antipyrine and the production clearances of antipyrine metabolites were studied in young and elderly volunteers of both sexes. Seventy-six elderly subjects (mean age 81 years) were compared with a group of 24 young subjects (mean age 29 years). RESULTS: After oral administration, salivary antipyrine clearance declined with age in both males and females, whether or not this variable was corrected for weight, and antipyrine half-life was significantly prolonged in elderly groups of either sex. The percentage urinary excretion of the antipyrine metabolites (hydroxymethylantipyrine, HMA; norantipyrine, NORA; and 4-hydroxyantipyrine, OHA) was reduced at 48 h in the elderly compared to young subjects by 23%, 31%, and 10%, respectively, in males, and by 41%, 41%, and 24%, respectively, in females. The formation clearance of HMA was reduced by 47% in males and by 52% in females. NORA clearance declined by 42 and 56%, respectively, in males and females. A decrease of 30% in males and 44% in females was observed in OHA clearance. CONCLUSIONS: The findings suggest that aging leads to altered disposition of antipyrine in both males and females and that the main metabolic pathways of the compound are not different in the elderly.
Subject(s)
Aging/metabolism , Anti-Inflammatory Agents, Non-Steroidal/metabolism , Antipyrine/metabolism , Sex Characteristics , Administration, Oral , Adult , Aged , Aged, 80 and over , Aging/urine , Anti-Inflammatory Agents, Non-Steroidal/administration & dosage , Anti-Inflammatory Agents, Non-Steroidal/urine , Antipyrine/administration & dosage , Antipyrine/analogs & derivatives , Antipyrine/urine , Body Weight , Edaravone , Female , Free Radical Scavengers/metabolism , Free Radical Scavengers/urine , Half-Life , Humans , Kidney/metabolism , Male , Metabolic Clearance Rate , Saliva/metabolismABSTRACT
The purpose of this study was to identify variables that can account for the decline of antipyrine clearance (CLAP) in elderly adults and that may help predict a reduction in metabolizing capacity. For comparison, ClAP was determined in 177 elderly (mean age 82 years) and 25 young (mean age 29 years) volunteers. Antipyrine (1 g) was administered orally and ClAP was determined by the one-sample saliva method. Mean ClAP was reduced by 38% and antipyrine half-life increased by 64% in old subjects. Multiple regression analysis of ClAP revealed an independent value for age, serum aspartate transaminase (AST), and height in the elderly. The independent variables collectively accounted for 27% of the variance explained. Age, high serum AST, use of diuretics, and no consumption of drugs known to stimulate oxidative metabolism were selected by multivariate analysis (logistic model) as independent predictors of a low metabolizing capacity. The findings indicate that factors other than age may contribute to impaired hepatic oxidative metabolism in the elderly.
