Brief Report: Adiponectin Levels Linked to Subclinical Myocardial Fibrosis in HIV
JAIDS-JOURNAL OF ACQUIRED IMMUNE DEFICIENCY SYNDROMES
Authors: Balmaceda, Julia B.; Abd-Elmoniem, Khaled Z.; Liu, Chia Ying; Purdy, Julia B.; Ouwerkerk, Ronald; Matta, Jatin R.; Schenck, Jessica K.; Gharib, Ahmed M.; Hadigan, Colleen
Abstract
Background: Persons living with HIV (PLWH) are at an increased risk of myocardial dysfunction and metabolic disturbances represent one of several potential contributing factors. Adiponectin is an adipokine that enhances insulin sensitivity with potential cardioprotective effects. We therefore investigated the relationship between myocardial fibrosis, adiponectin, and related metabolic parameters to better understand the pathophysiologic mechanisms of myocardial injury in PLWH. Methods: This is a prospective, cross-sectional study of PLWH without known cardiovascular disease (n = 87) and 28 healthy matched controls. Diffuse myocardial fibrosis and epicardial adipose tissue (EAT) were evaluated using cardiac magnetic resonance imaging and cardiac computed tomography. Results: Myocardial fibrosis was increased in PLWH and was correlated with adiponectin (r = 0.26, P = 0.004) and EAT (r = -0.42, P < 0.0001). Myocardial fibrosis was not associated with smoking pack years or CD4/CD8 ratio. In multivariate analysis that included body mass index, HIV status (P = 0.04), female sex (P < 0.0001), higher adiponectin (P = 0.046) and lower EAT (P = 0.01) were independently associated with myocardial fibrosis. Conclusion: We describe a novel association between serum adiponectin and subclinical intramyocardial fibrosis, as well as a significant inverse relationship between intramyocardial fibrosis and EAT. Adiponectin may represent a target for preventing myocardial injury in the future; however, our findings reflect the complexity of the metabolic interactions of adiponectin and epicardial adipose as factors associated with the myocardial architecture.
Characterization of Clozapine-Responsive Human T Cells
JOURNAL OF IMMUNOLOGY
Authors: Ogese, Monday O.; Lister, Adam; Jenkins, Rosalind E.; Meng, Xiaoli; Alfirevic, Ana; Douglas, Lisa; Mcloughlin, Rachel; Silva, Edward; Park, B. Kevin; Pirmohamed, Munir; Naisbitt, Dean J.
Abstract
Use of the atypical antipsychotic clozapine is associated with life-threatening agranulocytosis. The delayed onset and the association with HLA variants are characteristic of an immunological mechanism. The objective of this study was to generate clozapinespecific T cell clones (TCC) and characterize pathways of T cell activation and cross-reactivity with clozapine metabolites and olanzapine. TCC were established and characterized by culturing PBMCs from healthy donors and patients with a history of clozapine-induced agranulocytosis. Modeling was used to explore the drug-HLA binding interaction. Global TCC protein changes were profiled by mass spectrometry. Six well-growing clozapine-responsive CD4(+) and CD8(+) TCC were used for experiments; activation of TCC required APC, with clozapine interacting directly at therapeutic concentrations with several HLA-DR molecules. TCC were also activated with N-desmethylclozapine and olanzapine at supratherapeutic concentrations. Marked changes in TCC protein expression profiles were observed when clozapine treatment was compared with olanzapine and the medium control. Docking of the compounds into the HLA-DRB1*15:01 and HLA-DRB1*04:01 binding clefts revealed that clozapine and olanzapine bind in a similar conformation to the P4-P6 peptide binding pockets, whereas clozapine N-oxide, which did not activate the TCC, bound in a different conformation. TCC secreted Th1, Th2, and Th22 cytokines and effector molecules and expressed TCR v beta 5.1, 16, 20, and 22 as well as chemokine receptors CXCR3, CCR6, CCR4, and CCR9. Collectively, these data show that clozapine interacts at therapeutic concentrations with HLA-DR molecules and activates human CD4(+) T cells. Olanzapine only activates TCC at supratherapeutic concentrations.