ABSTRACT
BACKGROUND AND OBJECTIVES: Streptococcus pneumoniae continues to cause serious infections in HIV-positive individuals in the era of highly active anti-retroviral therapy. This led to the recommendation to revaccinate HIV-positive individuals with PPV23 five years after primary vaccination. The benefits of revaccination and the impact of long term highly active anti-retroviral therapy (HAART) on antigen-specific B cell reconstitution have remained unclear thus far and were investigated. DESIGN AND METHODS: We assessed antibody levels, opsonophagocytic activity and phenotype of pneumococcal polysaccharide (PPS) specific-B cells post-revaccination in long term HAART cohorts stratified according to CD4 count as group A (CD4>200) and group B (CD4<200). Anti-PPS IgG, IgM and functional antibody response against vaccine serotypes 14 and 23F were measured by ELISA and opsonophagocytic assay followed by phenotypic analysis of PPS14 and 23F-specific B cells using fluorescently labeled PPS. RESULTS: Significant increases in total and functional antibody titers were noted in groups A and B post-vaccination concomitant with significant rise in PPS-specific IgM memory B cells, a critical B cell subset required for protection against PPS although the overall response remained significantly diminished compared to HIV-negative volunteers. CONCLUSION: Comparable increases in opsonophagocytic titers between study groups A and B concomitant with a comparable rise in PPS-specific IgM memory B cells indicate revaccination to be beneficial regardless of the degree of CD4 T cell reconstitution. These findings emphasize the importance of defining effective vaccination practices amongst high-risk individuals.
ABSTRACT
OBJECTIVE: Clostridium difficle-associated infection (CDI) is usually treated with antibiotics; nevertheless, the infection has a high relapse rate. Case series and case reports using fecal microbiota transplant (FMT) for CDI show promising results. However, there are no large studies to provide evidence for the efficacy of this therapy. The aim of this pooled patient data meta-analysis was to determine the efficacy of FMT in CDI. METHODS: We performed a literature search for FMT for CDI or pseudomembranous colitis. Individual patient data were obtained from each study. The primary endpoint was to assess the rate of diarrhea resolution. Secondary endpoints were to identify variables associated with treatment failure and side effects of therapy. RESULTS: A total of 289 patients from 25 published articles who received FMT for CDI were included in the pooled data analysis. FMT had an overall success rate of 91.2%. On univariate analysis, shorter duration of symptoms before FMT (< 60 days) and gastroduodenal route of fecal instillation were associated with treatment failure. On multivariate regression analysis, shorter duration of symptoms (< 60 days) before the FMT (OR= 11.08; p = 0.0009) was associated with treatment failure. Reported adverse events following FMT were irritable bowel syndrome (n = 1), symptoms of mild enteritis (n = 3), and suspected peritonitis following the procedure (n = 1). CONCLUSION: FMT is a safe and effective treatment option for CDI. Shorter duration of symptoms (< 60 days) before administering FMT is associated with treatment failure.
