The effectiveness and safety of low dose trimethoprim-sulfamethoxazole for the treatment of pneumocystis pneumonia: A systematic review and meta-analysis.

BACKGROUND: Pneumocystis jirovecii pneumonia (PJP) is an opportunistic fungal infection causing significant morbidity and mortality in immunocompromised patients. The conventional treatment of PJP is sulfamethoxazole-trimethoprim (SMX-TMP) dosed at 15-20 mg/kg/day of the trimethoprim component. Several studies have suggested similar mortality outcomes and an improved adverse effect profile using a lower dose (<15 mg/kg/day) SMX-TMP regimen. Our objective of this meta-analysis was to evaluate the safety and efficacy of lower dose SMX-TMP for PJP pneumonia. METHODS: We conducted a systematic review and meta-analysis of the existing literature according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. MEDLINE and Embase databases were searched from inception to January 15, 2020, for studies in English evaluating low-dose SMX-TMP (<15 mg/kg/day) compared to conventional dosing for the treatment of PJP. Outcomes evaluated in our meta-analysis include survival and adverse reactions. RESULTS: After excluding studies that did not meet our inclusion criteria, four studies were analyzed for adverse reactions and three for mortality. Overall, there was no significant difference in mortality between low-dose and conventional-dose SMX-TMP groups (relative risk [RR]: 0.55, 95% confidence interval [CI], 0.18-1.70). There was a significant decrease in the rate of adverse reactions for the low-dose group compared with the conventional-dose group (RR: 0.70, 95% CI, 0.53-0.91). CONCLUSIONS: This meta-analysis shows a significant decrease in adverse reactions and similar mortality rates with lower-dose SMX-TMP compared to conventional dosing. A low-dose SMX-TMP regimen in the treatment of PJP should be considered a viable option as it could potentially decrease treatment discontinuation rates and reduce patient harm.

Generation, transcriptome profiling, and functional validation of cone-rich human retinal organoids.

Rod and cone photoreceptors are light-sensing cells in the human retina. Rods are dominant in the peripheral retina, whereas cones are enriched in the macula, which is responsible for central vision and visual acuity. Macular degenerations affect vision the most and are currently incurable. Here we report the generation, transcriptome profiling, and functional validation of cone-rich human retinal organoids differentiated from hESCs using an improved retinal differentiation system. Induced by extracellular matrix, aggregates of hESCs formed single-lumen cysts composed of epithelial cells with anterior neuroectodermal/ectodermal fates, including retinal cell fate. Then, the cysts were en bloc-passaged, attached to culture surface, and grew, forming colonies in which retinal progenitor cell patches were found. Following gentle cell detachment, retinal progenitor cells self-assembled into retinal epithelium-retinal organoid-that differentiated into stratified cone-rich retinal tissue in agitated cultures. Electron microscopy revealed differentiating outer segments of photoreceptor cells. Bulk RNA-sequencing profiling of time-course retinal organoids demonstrated that retinal differentiation in vitro recapitulated in vivo retinogenesis in temporal expression of cell differentiation markers and retinal disease genes, as well as in mRNA alternative splicing. Single-cell RNA-sequencing profiling of 8-mo retinal organoids identified cone and rod cell clusters and confirmed the cone enrichment initially revealed by quantitative microscopy. Notably, cones from retinal organoids and human macula had similar single-cell transcriptomes, and so did rods. Cones in retinal organoids exhibited electrophysiological functions. Collectively, we have established cone-rich retinal organoids and a reference of transcriptomes that are valuable resources for retinal studies.

The Utah Protocol for Postmortem Eye Phenotyping and Molecular Biochemical Analysis.

Purpose: Current understanding of local disease pathophysiology in AMD is limited. Analysis of the human disease-affected tissue is most informative, as gene expression, expressed quantitative trait loci, microenvironmental, and epigenetic changes can be tissue, cell type, and location specific. Development of a novel translational treatment and prevention strategies particularly for earlier forms of AMD are needed, although access to human ocular tissue analysis is challenging. We present a standardized protocol to study rapidly processed postmortem donor eyes for molecular biochemical and genomic studies. Methods: We partnered with the Utah Lions Eye Bank to obtain donor human eyes, blood, and vitreous, within 6 hours postmortem. Phenotypic analysis was performed using spectral-domain optical coherence tomography (SD-OCT) and color fundus photography. Macular and extramacular tissues were immediately isolated, and the neural retina and retinal pigment epithelium/choroid from each specimen were separated and preserved. Ocular disease phenotype was analyzed using clinically relevant grading criteria by a group of four ophthalmologists incorporating data from SD-OCT retinal images, fundus photographs, and medical records. Results: The use of multimodal imaging leads to greater resolution of retinal pathology, allowing greater phenotypic rigor for both interobserver phenotype and known clinical diagnoses. Further, our analysis resulted in excellent quality RNA, which demonstrated appropriate tissue segregation. Conclusions: The Utah protocol is a standardized methodology for analysis of disease mechanisms in AMD. It uniquely allows for simultaneous rigorous phenotypic, molecular biochemical, and genomic analysis of both systemic and local tissues. This better enables the development of disease biomarkers and therapeutic interventions.