Carla Evelyn Coimbra Nunez et al. Joaquim Barreto Oliveira Silvia de Barros-Mazon Vanessa H. S. Zago … Denise Beheregaray Kaplan Ruy T. Nakamura Magnus Ake Gidlund Erica I. L. Gomes Patricia Miralda Cazita Edna Nakandakare Helison R. Carmo Andrei C. Sposito Eliana Cotta de Faria
Abstract
Background
In the atherosclerotic plaque microenvironment, oxidized phospholipids expressed in the oxidized low-density lipoprotein (oxLDL) surface bind to scavenger receptors of macrophages eliciting foam cell formation and plaque progression. Auto-antibodies against oxLDL (oxLDL-Ab) interact with oxidative epitopes leading to the formation of immune complexes that are unable to interact with macrophage receptors, thus abrogating atherogenesis. Release of oxLDL-Ab by B cells involves interleukin 5 and Th2 response, which in turn are potentiated by HDL. Thereby, we hypothesized that individuals with higher levels of HDL-C may plausibly display elevated titers of oxLDL-Ab.
Objective
To evaluate the relationship between HDL-C and oxLDL-Ab levels.
Methods
Asymptomatic individuals (n = 193) were grouped according to their HDL-C concentration to one of three categories: low ( 80 mg/dL). P values < 0.05 were considered statistically significant.
Results
Our analysis included 193 individuals (mean age: 47 years; male: 26.3%). Compared to individuals in the lowest HDL-C tertile, those in the highest tertile were older (36 versus 53 years; p = 0.001) and less frequently male (42.6% versus 20.9%; p = 0.001). Mean values of oxLDL-Ab increased as the HDL-C group escalated (0.31, 0.33 and 0.43 units, respectively; p = 0.001 for trend). Simple linear regression found a significant, positive relationship between the independent variable, HDL-C, and the dependent variable, oxLDL-Ab (R = 0.293; p = 0.009). This relation remained significant (R = 0.30; p = 0.044), after adjustment by covariates. Apolipoprotein AI levels were also related to oxLDL-Ab in both simple and adjusted linear regression models.
Conclusion
HDL-C and oxLDL-Ab are independently related.