Infections after T-replete haploidentical transplantation and high-dose cyclophosphamide as graft-versus-host disease prophylaxis.

BACKGROUND: Recently, a platform of T-cell replete haploidentical hematopoietic stem cell transplantation (haplo-HSCT) using post-transplant cyclophosphamide (Cy) has shown high reproducibility and acceptable safety profile. METHOD: This prospective cohort analysis allowed us to collect data on infections among 70 consecutive recipients of haplo-HSCT affected by various hematologic malignancies. RESULTS: After a median follow-up of 23 months, cumulative incidence of viral infections was 70% (95% confidence interval [CI] 59-81) at 100 days and 77% (95% CI 67-87) at 1 year; 35 of 65 patients at risk had CMV reactivation (54%) and the rate of polyomavirus-virus-associated cystitis was 19% (13/70). Cumulative incidence of bacterial and fungal infections at 1 year were 63% (95% CI 51-75) and 12% (95% CI 4-19), respectively. Of note, only 1 invasive fungal infection occurred beyond 1 year after transplant (day +739). CONCLUSION: In conclusion, despite a high rate of viral infections in the early period, present data suggest a satisfactory infectious profile after T-cell replete haplo-HSCT using post-transplant Cy. These results may help clinicians to improve both prophylactic and therapeutic antimicrobial strategies in this emerging haploidentical setting.

Genomics approach to the analysis of bacterial communities dynamics in Hirschsprung's disease-associated enterocolitis: a pilot study.

INTRODUCTION: The most invalidating and life-threatening complication in Hirschsprung's disease patients (HSCR) is Hirschsprung's disease-associated enterocolitis (HAEC). The mechanisms underlying enterocolitis have not been identified. The limited knowledge of the role of intestinal microflora is in part due to the complexity of the intestinal microbiome and to the limitation of cultivation-based technologies, given that less than 25% of the intestinal bacterial species can be cultured. MATERIALS AND METHODS: We used amplified ribosomal DNA restriction analysis (ARDRA) with four different restriction enzymes to study variations of microflora composition of the stools of a selected HSCR patient in different clinical conditions (acute phase vs. remission). RESULTS: We assessed a total of 15 stool specimens belonging to the same 3-year-old male patient suffering from HSCR, which were harvested during 4 HAEC episodes and remission phases. Restriction analysis showed that HAEC episodes seem to cluster together at ARDRA analysis, thus suggesting a sort of predisposing bacterial community for HAEC development and the need for a microflora equilibrium to maintain wellness. CONCLUSIONS: This approach proved to be effective, useful and powerful in assessing microflora dynamics and indicated that the differences in microflora associated with acute HAEC or remission are likely to result from a combination of disease activity and different antibiotic therapies. ARDRA proved to be useful in discriminating disease versus remission. Our findings indicated that HAEC results from a change in the equilibrium between bacterial species or from altered discrimination of harmless from harmful microorganisms, challenging the definition of pathogenic and non-pathogenic species. Based on these results, we propose ARDRA as a rapid inexpensive tool to assess microflora dynamics during HAEC episodes.

Identification, molecular cloning and functional characterization of NKp46 and NKp30 natural cytotoxicity receptors in Macaca fascicularis NK cells.

Natural killer (NK) cell recognition and function in humans is regulated by multiple cell surface receptors. The "on" signal leading to NK cell triggering is primarily mediated by natural cytotoxicity receptors (NCR). Analysis of NK cells in primate animal models is of particular relevance because NK cells may play an essential role in host defenses against infections. We analyzed Macaca fascicularis PBMC and in vitro-derived NK cell populations and clones by cytofluorometry, using a wide panel of mAb, and by cytolytic activity assays. In addition, RT-PCR strategy and transient transfections were used to isolate M. fascicularis NCR. NCR-specific mAb reactivity (anti-NKp46 and anti-NKp30) was present on M. fascicularis PBMC and on NK cell cultures. Macaque NCR were functional in both redirected killing and in mAb-mediated masking assays. Cloning of macNKp46 and macNKp30 NCR homologous genes showed a high sequence similarity (86 % and 88 %, respectively) with their human counterparts. Attempts at identifying NKp44 surface reactivity and at cloning the macaque homologue were unsuccessful. NKp46 and NKp30 NCRs, but not NKp44, are highly conserved in M. fascicularis NK cells. This suggests the possibility of a staged appearance of the NCR during phylogenesis and provides a useful tool for the study of natural immunity correlates of protection in primate SIV/SHIV infection models.