ABSTRACT
PURPOSE: To determine whether pediatric SLE patients without European ancestry are at higher risk for development of severe lupus nephritis (ISN/RPS class III, IV or V). METHODS: Ninety-eight of 101 patients with pediatric SLE (age <18 years at diagnosis) were enrolled. Race/ethnicity of four grandparents, socioeconomic status (SES) and language proficiency were collected. The primary outcome was time to development of severe lupus nephritis. RESULTS: Based on patient report of four grandparent ancestry, 29% had at least one grandparent of European ancestry (14% had all four grandparents of European ancestry). Patients without European ancestry were 46% Hispanic, 47% Asian, and 3% African American. In the entire 98 patient cohort, 12% had ≥3 different ancestries. Patients without European ancestry had significantly lower SES levels and English proficiency. There was no significant difference between patients with or without European ancestry in duration of SLE, age of onset, and lag time between symptoms and diagnosis. Patients with at least one grandparent of European ancestry had a decreased risk of developing severe lupus nephritis, which remained significant after controlling for age, gender, SES and English proficiency (hazard ratio 0.4, 95% confidence interval 0.2-0.9). CONCLUSION: This study demonstrates that presence of at least one grandparent of European ancestry decreases the risk of severe lupus nephritis, a finding that is not explained by measurable socioeconomic differences and language barriers.
Subject(s)
Lupus Erythematosus, Systemic/ethnology , Lupus Nephritis/ethnology , White People/statistics & numerical data , Adolescent , Age of Onset , California/epidemiology , Chi-Square Distribution , Child , Communication Barriers , Disease Progression , Disease-Free Survival , Female , Humans , Kaplan-Meier Estimate , Language , Lupus Erythematosus, Systemic/diagnosis , Lupus Erythematosus, Systemic/therapy , Lupus Nephritis/diagnosis , Lupus Nephritis/prevention & control , Male , Prognosis , Proportional Hazards Models , Risk Assessment , Risk Factors , Severity of Illness Index , Socioeconomic Factors , Time FactorsABSTRACT
1. The contractile and electrical responses to acetylcholine (ACh) in isolated segments of guinea-pig and rabbit coronary arteries were compared to those of the putative adenosine 5'-triphosphate (ATP)-dependent K+ channel opener, BRL 38227. 2. Both ACh and BRL 38227 produced concentration-dependent relaxation of vessel segments contracted with the H1-receptor agonist, 2-(2-aminoethyl)pyridine. 3. An IC90 of either vasodilator also produced 17-20 mV of hyperpolarization of the guinea-pig coronary artery. 4. Glibenclamide (1-35 microM) depolarized the guinea-pig coronary artery by 8-12 mV and antagonized BRL 38227- but not ACh-induced relaxation and hyperpolarization. 5. In the guinea-pig coronary artery, the K+ channel blockers phencyclidine (PCP, 100 microM), tetraethylammonium (TEA, 10 mM) and scorpion venom (8.7 micrograms ml-1) all significantly reduced ACh-induced relaxation and hyperpolarization whereas only PCP was an effective antagonist of both relaxation and hyperpolarization with BRL 38227. 6. Similar effects of glibenclamide and scorpion venom on ACh- and BRL 38227-induced relaxation were observed in the rabbit coronary artery. 7. Apamin (3.5 microM) was without effect on either the ACh- or BRL 38227-induced relaxation in the guinea-pig coronary artery. 8. In conclusion, the actions of BRL 38227 in coronary artery are compatible with its proposed effects on ATP-dependent K+ channels. In contrast, the results with ACh suggest that some step between the initial binding of ACh to endothelial muscarinic receptors and the final relaxation of the smooth muscle depends upon the opening of Ca(2+)-activated K+ channels.
