CD40LG and pneumocystosis: In conclusion, elevated 3-day average PM10 and NO2 ambient air concentrations immediately prior to hospital admission and 2 weeks prior to admission were associated with suppressed IgM antibody responses to recombinant Pneumocystis jirovecii major surface glycoprotein in HIV+ patients hospitalized with confirmed PCP, and active cigarette smoking appeared to augment the immunosuppressive effects of these pollutants.