Sulfa or Sulfone Prophylaxis and Geographic Region Predict Mutations in the<i>Pneumocystis carinii</i>Dihydropteroate Synthase Gene

TLDR

The study aimed to identify factors linked to DHPS gene mutations in HIV‑infected patients with Pneumocystis carinii pneumonia across Atlanta, Seattle, and San Francisco. Clinical data were collected via interviews and chart reviews, and DHPS genotypes were identified by DNA sequencing. Mutant DHPS genotypes were present in 68.5% of patients, especially in San Francisco, and were independently associated with sulfa/sulfone prophylaxis and study site; notably, over half of newly diagnosed HIV patients who had never received prophylaxis carried mutant genotypes, suggesting possible person‑to‑person or environmental transmission.

Abstract

To determine factors associated with mutations in the Pneumocystis carinii dihydropteroate synthase (DHPS) gene, a prospective study of human immunodeficiency virus (HIV)—infected patients with confirmed P. carinii pneumonia was conducted in Atlanta, Seattle, and San Francisco. Clinical information was obtained from patient interview and chart abstraction. DHPS genotype was determined from DNA sequencing. Overall, 76 (68.5%) of 111 patients had a mutant DHPS genotype, including 22 (81.5%) of 27 patients from San Francisco. In multivariate analysis, sulfa or sulfone prophylaxis and study site were independent predictors of a mutant genotype. Fourteen (53.8%) of 26 patients who were newly diagnosed with HIV infection and had never taken prophylaxis had a mutant genotype. The significance of geographic location as a risk factor for mutant genotype and the high proportion of mutant genotypes among persons never prescribed prophylaxis, including those newly diagnosed with HIV infection, provide indirect evidence that these mutations are transmitted from person to person either directly or through a common environmental source.