Abstract
Pneumocystis jirovecii dihydropteroate synthase (DHPS) gene mutations are well-reported. Although sulfa prophylaxis generally is associated with DHPS mutant infection, whether mutant infection is associated with poorer clinical outcomes is less clear. The differing definitions of sulfa prophylaxis and the different mortality endpoints used in these studies may be one explanation for the conflicting study results. Applying different definitions of prophylaxis, mortality endpoints and DHPS mutant to 301 HIV-infected patients with Pneumocystis pneumonia, we demonstrate that prophylaxis, irrespective of definition, increased the risk of infection with pure mutant (any prophylaxis: AOR 4.00, 95% CI: 1.83–8.76, P < 0.001) but not mixed genotypes (any prophylaxis: AOR 0.78, 95% CI: 0.26–2.36, P = 0.65). However, infection with mutant DHPS, irrespective of definition, was not associated with increased mortality (all-cause or PCP death) at the three time-intervals examined (all P > 0.05). Future studies should standardize key variables associated with DHPS mutant infection as well as examine DHPS mutant subtypes (pure mutant vs. mixed infections) – perhaps even individual DHPS mutant genotypes – so that data can be pooled to better address this issue.
Acknowledgments
The authors would like to thank the patients, staff, and administration of San Francisco General Hospital's Ward 86 HIV/AIDS Clinic, in particular Daniel Wlodarczyk, M.D.
Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and the writing of the paper.
This work was supported by the National Heart, Lung and Blood Institutes at the National Institutes of Health, [K24 HL097713, R01 HL 090335, R01 HL090335-02S109 all three to LH] and [T32 HL007185 to CY].