Clinical and Economic Impact of CMV Infection in Allogeneic Hematopoietic Stem Cell Transplantation: Perspectives from a Middle-Income Nation.

BACKGROUND: Cytomegalovirus infection (CMV) is a common complication after allogeneic hematopoietic stem cell transplantation (AHSCT). CMV infection increases transplantation costs; however, the extent of the financial burden may vary in different countries. This study aims to determine the clinical and economic impact of CMV infection in patients undergoing AHSCT in a middle-income country. METHODS: A total of 150 adult and pediatric patients post-AHSCT were included for analysis. In addition to incidence of CMV infections, data on graft versus host disease (GVHD) were also collected. Standard hospital charges for AHSCT and any additional transplantation-related expenditure within 12 months were also retrieved in 104 patients. RESULTS: CMV infection, acute GVHD and chronic GVHD occurred in 38.7%, 60.7%, and 22.0% of patients, respectively. Patients with CMV infections had higher readmission rates compared to those who did not (67.2% vs. 47.8%; p = 0.020). Additional expenditure was seen in HLA-haploidentical AHSCT and CMV infection (MYR11 712.25/USD2 504.49; p < 0.0001 and MYR5 807.24/USD1 241.79; p = 0.036), respectively. CONCLUSION: This single-center study demonstrated that patients who underwent HLA-haploidentical AHSCT and subsequently developed CMV infection had higher transplantation expenditures compared to those who had matched-related transplantation. Further studies should be conducted to evaluate if primary prophylaxis against CMV is cost-effective, especially in patients who undergo HLA-haploidentical AHSCT.

A review on the epidemiology of invasive fungal infections in Asian patients with haematological malignancies (2011-2021).

The incidences of invasive fungal infection (IFI) are increasing especially in patients diagnosed with haematological malignancies due to their immunocompromised nature. Risk factors include advanced age, exposure to immunosuppressants, neutropenia and catheter usage. Some of the most common organisms reported are Candida and Aspergillus species while other fungal species including Scedosporium, Ttrichosporon, Cryptococcus and Fusarium have also increasingly been reported in the past years. However, the epidemiological data on IFI amongst patients with haematological malignancies in Asian countries are lacking and therefore, we aim to investigate published epidemiological data on such cases in the last 10 years (2011-2021) and to discuss the challenges faced in the diagnosis and management of IFI.

CMV Infection Post Allogeneic Hematopoietic Stem Cell Transplantation in a Resource Limited Country.

Cytomegalovirus (CMV) infection is one of the common complications which can lead to significant morbidity and mortality in patients after allogeneic hematopoietic stem cell transplantation (HSCT). As the seroprevalence of CMV infection in Malaysia is high, this study aims to determine the prevalence of CMV infection in patients post HSCT and to evaluate the associated risk factors. Patients who underwent allogeneic HSCT in adult ward from 2008 to 2020 at a tertiary teaching hospital in Kuala Lumpur, Malaysia were studied retrospectively. They were followed up for a minimum of 100 days post-HSCT to determine the incidence of CMV infection. CMV infection was defined according to CMV Drug Development Forum 2014. Risk factors such as type of transplant, serostatus of donor and patients, age, gender, race, presence of graft versus host disease (GVHD) and underlying disease were included for analysis. A total of 112 patients were included. Forty (35.7%) patients had CMV infection with median of onset recorded as 40 days (range 13-95 days). Only haplo-identical HSCT and presence of GVHD were identified as significant risk factors. Patients who had CMV infection had a lower median survival time although this was not statistically significant. The CMV infection rate was comparable with previous reports in Asia and as expected, higher than the western countries. Therefore, vigilant monitoring of CMV infection should be implemented especially in patients who had haplo-identical HSCT and acute GVHD.

Presence of Polyketide Synthase (PKS) Gene and Counterpart Virulence Determinants in Klebsiella pneumoniae Strains Enhances Colorectal Cancer Progression In-Vitro.

Klebsiella pneumoniae (K. pneumoniae) colonizes the human gut and is a causative factor of pyogenic liver abscess (PLA). Retrospective studies conducted on K. pneumoniae PLA patients revealed subsequent CRC development in later years of their life with increasing prevalence of these strains harbouring polyketide synthase (PKS) genes. To our knowledge there are no known studies directly implicating K. pneumoniae with CRC to date. Our aims are to characterize K. pneumoniae isolates from CRC patients and investigate its effects on cell proliferation in vitro. K. pneumoniae isolates were characterized by screening virulence genes including polyketide synthase (PKS), biofilm assay, antibiotic susceptibility, and string test to determine hypervirulent (hvKp) strains. Solubilised antigens of selected K. pneumoniae isolates were co-cultured with primary colon cell lines and CRC cell lines (Stage I-IV) for 48 h. The enhancement of proliferation was measured through MTT and ECIS assay. Twenty-five percent of K. pneumoniae isolates were PKS-positive out of which 50% were hvKp strains. The majority of the isolates were from the more virulent serotype of K1 (30%) and K2 (50%). PKS-positive K. pneumoniae isolates did not possess genes to confer carbapenem resistance but instead were more highly associated with siderophore genes (aerobactin, enterobactin, and yersiniabactin) and allantoin metabolism genes (allS, allS2). Cell proliferation in primary colon, SW1116 (Stage I), and SW480 (Stage II) CRC cell lines were enhanced when co-cultured with PKS-positive K. pneumoniae antigens. ECIS revealed enhanced cell proliferation upon recurrent antigen exposure. This demonstrates the possible role that PKS-positive K. pneumoniae has in exacerbating CRC progression.

Prevalence and association of pks+ Escherichia coli with colorectal cancer in patients at the University Malaya Medical Centre, Malaysia.

Escherichia coli (E. coli) from the B2 phylogenetic group is implicated in colorectal cancer (CRC) as it possesses a genomic island, termed polyketide synthetase (pks), which codes for the synthesis of colibactin, a genotoxin that induces DNA damage, cell cycle arrest, mutations and chromosomal instability in eukaryotic cells. The aim of this study was to detect and compare the prevalence of E. coli expressing pks (pks+ E. coli) in CRC patients and healthy controls followed by investigating the virulence triggered by pks+ E. coli using an in-vitro model. Mucosal colon tissues were collected and processed to determine the presence of pks+ E. coli. Thereafter, primary colon epithelial (PCE) and colorectal carcinoma (HCT116) cell lines were used to detect cytopathic response to the isolated pks+ E. coli strains. Our results showed 16.7% and 4.3% of CRC and healthy controls, respectively were pks+ E. coli. Further, PCE displayed syncytia and cell swelling and HCT116 cells, megalocytosis, in response to treatment with the isolated pks+ E. coli strains. In conclusion, pks+ E. coli was more often isolated from tissue of CRC patients compared to healthy individuals, and our in-vitro assays suggest these isolated strains may be involved in the initiation and development of CRC.

Erratum: Author Correction: High-resolution bacterial 16S rRNA gene profile meta-analysis and biofilm status reveal common colorectal cancer consortia.

[This corrects the article DOI: 10.1038/s41522-017-0040-3.].

High-resolution bacterial 16S rRNA gene profile meta-analysis and biofilm status reveal common colorectal cancer consortia.

Colorectal cancer (CRC) remains the third most common cancer worldwide, with a growing incidence among young adults. Multiple studies have presented associations between the gut microbiome and CRC, suggesting a link with cancer risk. Although CRC microbiome studies continue to profile larger patient cohorts with increasingly economical and rapid DNA sequencing platforms, few common associations with CRC have been identified, in part due to limitations in taxonomic resolution and differences in analysis methodologies. Complementing these taxonomic studies is the newly recognized phenomenon that bacterial organization into biofilm structures in the mucus layer of the gut is a consistent feature of right-sided (proximal), but not left-sided (distal) colorectal cancer. In the present study, we performed 16S rRNA gene amplicon sequencing and biofilm quantification in a new cohort of patients from Malaysia, followed by a meta-analysis of eleven additional publicly available data sets on stool and tissue-based CRC microbiota using Resphera Insight, a high-resolution analytical tool for species-level characterization. Results from the Malaysian cohort and the expanded meta-analysis confirm that CRC tissues are enriched for invasive biofilms (particularly on right-sided tumors), a symbiont with capacity for tumorigenesis (Bacteroides fragilis), and oral pathogens including Fusobacterium nucleatum, Parvimonas micra, and Peptostreptococcus stomatis. Considered in aggregate, species from the Human Oral Microbiome Database are highly enriched in CRC. Although no detected microbial feature was universally present, their substantial overlap and combined prevalence supports a role for the gut microbiota in a significant percentage (>80%) of CRC cases.

Redundant Innate and Adaptive Sources of IL17 Production Drive Colon Tumorigenesis.

IL17-producing Th17 cells, generated through a STAT3-dependent mechanism, have been shown to promote carcinogenesis in many systems, including microbe-driven colon cancer. Additional sources of IL17, such as γδ T cells, become available under inflammatory conditions, but their contributions to cancer development are unclear. In this study, we modeled Th17-driven colon tumorigenesis by colonizing Min(Ap) (c+/-) mice with the human gut bacterium, enterotoxigenic Bacteroides fragilis (ETBF), to investigate the link between inflammation and colorectal cancer. We found that ablating Th17 cells by knocking out Stat3 in CD4(+) T cells delayed tumorigenesis, but failed to suppress the eventual formation of colonic tumors. However, IL17 blockade significantly attenuated tumor formation, indicating a critical requirement for IL17 in tumorigenesis, but from a source other than Th17 cells. Notably, genetic ablation of γδ T cells in ETBF-colonized Th17-deficient Min mice prevented the late emergence of colonic tumors. Taken together, these findings support a redundant role for adaptive Th17 cell- and innate γδT17 cell-derived IL17 in bacteria-induced colon carcinogenesis, stressing the importance of therapeutically targeting the cytokine itself rather than its cellular sources. Cancer Res; 76(8); 2115-24. ©2016 AACR.