Publications

Invariant natural killer T cells (iNKTs) are innate-like T cells that are highly concentrated in the liver and recognize lipids presented on the MHC-like molecule CD1d. Although capable of a myriad of responses, few essential functions have been described for iNKTs. Among the many cell types of the immune system implicated in metabolic control and disease, iNKTs seem ideally poised for such a role, yet little has been done to elucidate such a possible function. We hypothesized that lipid presentation by CD1d could report on metabolic status and engage iNKTs to regulate cellular lipid content through their various effector mechanisms. To test this hypothesis, we examined CD1d deficient mice in a variety of metabolically stressed paradigms including high fat feeding, choline-deficient feeding, fasting, and acute inflammation. CD1d deficiency led to a mild exacerbation of steatosis during high fat or choline-deficient feeding, accompanied by impaired hepatic glucose tolerance. Surprisingly, however, this phenotype was not observed in Jα18⁻/⁻ mice, which are deficient in iNKTs but express CD1d. Thus, CD1d appears to modulate some metabolic functions through an iNKT-independent mechanism.

BACKGROUND

Diffusion, dissemination, and implementation of scientific evidence into routine clinical practice is not well understood. The Adult AIDS Clinical Trials Group (ACTG) Protocol 5164 showed that early antiretroviral therapy (ART; ie, within 14 days) after diagnosis of an opportunistic infection improved clinical outcomes, compared with later initiation. Subsequently, the San Francisco General Hospital (SFGH) HIV/AIDS Service performed the SFGH 5164 Initiative to disseminate and implement the findings of ACTG 5164.

METHODS

We evaluated patients who received a diagnosis of Pneumocystis jirovecii pneumonia (PCP) from 1 January 2001 through 30 March 2011. Survival analyses were used to assess changes in the time to initiation of ART after PCP, and logistic regression was used to evaluate changes in the odds of early ART (ie, within 14 days) because of ACTG 5164 and SFGH 5164 Initiative.

RESULTS

Among 162 patients, the adjusted hazard of ART initiation increased by 3.05 (95% confidence interval [CI], 1.86-5.02) after ACTG 5164 and by 4.89 (95% CI, 2.76-8.67) after the SFGH Initiative, compared with before ACTG 5164. When compared with before ACTG 5164, the proportion of patients who received ART within the 14 days after PCP diagnosis increased from 7.4% to 50.0% (P < .001) after ACTG 5164 and from 50.0% to 83.0% (P = .02) after the SFGH 5164 Initiative.

CONCLUSIONS

Diffusion of findings from of a randomized trial changed practice at an academic medical center, but dissemination and implementation efforts were required to establish early ART at acceptable levels. Early ART initiation can be achieved in real-world patient populations.