Cryptococcus neoformans Intracellular Proliferation and Capsule Size Determines Early Macrophage Control of Infection.

Cryptococcus neoformans is a significant fungal pathogen of immunocompromised patients. Many questions remain regarding the function of macrophages in normal clearance of cryptococcal infection and the defects present in uncontrolled cryptococcosis. Two current limitations are: 1) The difficulties in interpreting studies using isolated macrophages in the context of the progression of infection, and 2) The use of high resolution imaging in understanding immune cell behavior during animal infection. Here we describe a high-content imaging method in a zebrafish model of cryptococcosis that permits the detailed analysis of macrophage interactions with C. neoformans during infection. Using this approach we demonstrate that, while macrophages are critical for control of C. neoformans, a failure of macrophage response is not the limiting defect in fatal infections. We find phagocytosis is restrained very early in infection and that increases in cryptococcal number are driven by intracellular proliferation. We show that macrophages preferentially phagocytose cryptococci with smaller polysaccharide capsules and that capsule size is greatly increased over twenty-four hours of infection, a change that is sufficient to severely limit further phagocytosis. Thus, high-content imaging of cryptococcal infection in vivo demonstrates how very early interactions between macrophages and cryptococci are critical in the outcome of cryptococcosis.

One-year outcomes of women started on antiretroviral therapy during pregnancy before and after the implementation of Option B+ in Malawi: A retrospective chart review.

OBJECTIVE: To compare one-year outcomes of women started on antiretroviral therapy (ART) during pregnancy in the pre-Option B+ era to those in the Option B+ era. METHODS: A retrospective chart review was performed at three sites in Malawi. Women were included in the 'pre-Option B+' cohort if they started ART during pregnancy for a CD4 count < 350 cells/mm3 or WHO 3/4 condition and in the 'Option B+' cohort if they started ART during pregnancy regardless of CD4 count or clinical stage. One-year outcomes were compared using Fisher's exact and ANOVA F-tests. RESULTS: A higher proportion of women in the pre-Option B+ cohort started ART at WHO stage 3/4 (11.9% versus 1.1%, P < 0.001), switched ART regimens (5.9% versus 0%, P = 0.002), or died in the first year after starting treatment (3.9% versus .5%, P = 0.05). While more women in the Option B+ cohort had poor adherence or defaulted, these differences were not significant. CONCLUSIONS: At our study sites, the transition to Option B+ has been associated with ART initiation in women with less advanced HIV infection, improved medication tolerability, and lower mortality. Further research is needed to better understand outcomes of Option B+.