Publications
Department of Medicine faculty members published more than 3,600 peer-reviewed articles in 2024.
2013
2013
BACKGROUND
Ambient air pollution (AAP) may be associated with increased risk for Pneumocystis pneumonia (PCP). The mechanisms underlying this association remain uncertain.
OBJECTIVES
To determine if real-life exposures to AAP are associated with suppressed IgM antibody responses to P. jirovecii in HIV-infected (HIV+) patients with active PCP, and to determine if AAP, mediated by suppressed serologic responses to Pneumocystis, is associated with adverse clinical outcomes.
METHODS
We conducted a prospective cohort study in HIV+ patients residing in San Francisco and admitted to San Francisco General Hospital with microscopically confirmed PCP. Our AAP predictors were ambient air concentrations of particulate matter of < 10 µm in diameter (PM10) and < 2.5 µm in diameter (PM2.5), nitrogen dioxide (NO2), ozone (O3), and sulfur dioxide (SO2) measured immediately prior to hospital admission and 2 weeks prior to admission. Our primary outcomes were the IgM serologic responses to four recombinant P. jirovecii major surface glycoprotein (Msg) constructs: MsgC1, MsgC3, MsgC8, and MsgC9.
RESULTS
Elevated PM10 and NO2 exposures immediately prior to and two weeks prior to hospital admission were associated with decreased IgM antibody responses to P. jirovecii Msg. For exposures immediately prior to admission, every 10 µg/m(3) increase in PM10 was associated with a 25 to 35% decrease in IgM responses to Msg (statistically significant for all the Msg constructs), and every 10 ppb increase in NO2 was associated with a 19-45% decrease in IgM responses to Msg (statistically significant for MsgC8 and MsgC9). Similar findings were seen with exposures two weeks prior to admission, but for fewer of the Msg constructs.
CONCLUSIONS
Real life exposures to PM10 and NO2 were associated with suppressed IgM responses to P. jirovecii Msg in HIV+ patients admitted with PCP, suggesting a mechanism of immunotoxicity by which AAP increases host susceptibility to pulmonary infection.
View on PubMed2013
OBJECTIVE
HIV controllers demonstrate high rates of spontaneous clearance of hepatitis C virus (HCV) infection. The objective of this study was to evaluate the role of human leukocyte antigen (HLA) B*57 and other genetic polymorphisms on HCV clearance in HIV controllers.
DESIGN
This is a prospective cohort study.
METHODS
Patients in the Study of the Consequences of Protease Inhibitor Era (SCOPE) were tested for anti-HCV using enzyme immunoassay (EIA3) and HCV RNA using discriminatory HCV transcription-mediated amplification assay (Norvatis). We compared the proportion of HIV controllers and noncontrollers demonstrating HCV clearance and fitted multivariable Poisson regression models with robust standard errors to estimate adjusted prevalence ratios (APRs) and assessed genetic and immunologic predictors of HCV clearance.
RESULTS
Of 279 HIV/HCV seropositive individuals, 48 were HIV controllers. HIV controllers compared to HIV noncontrollers, were significantly more likely to have HLA B*57 (33 vs. 10%, P < 0.01). In multivariate analyses, adjusting for HLAB57, IL28B genotype, age, sex and race/ethnicity, HCV clearance was significantly more likely in HIV controllers than HIV noncontrollers [APR 1.78; 95% confidence interval (CI) 1.06-3.0; P = 0.03]. HLA B*57 did not explain the increased proportion of HCV clearance in HIV controllers, but IL28B CC genotype was independently associated with spontaneous HCV clearance (APR 2.76; 95% CI 1.85-4.11; P < 0.001).
CONCLUSION
Although enriched in HIV controllers, HLA B*57 does not explain the increased HCV clearance. Further identification of host immunologic or genetic factors that contribute to control of HIV and HCV may support the development of novel treatments for and effective vaccines against both viruses.
View on PubMed2013
2013
2013
2013