Objective:To investigate the distribution and clinical characteristics of pathogenic bacteria following hematopoietic stem cell transplantation (HSCT), as well as to provide a preliminary research foundation for key microbial monitoring, and clinical diagnosis and treatment of infections after HSCT in hematological patients.Methods:We retrospectively analyzed the clinical data of 190 patients who tested positive for microbial testing [G-bacteria blood culture and/or carbapenem-resistant organism (CRO) screening of perianal swabs] at our center from January 2018 to December 2022. Patients were divided into blood culture positive, perianal swab positive, and double positive groups based on the testing results. The three patient groups underwent statistical analysis and comparison.Results:The top four pathogenic bacteria isolated from sixty-three patients with G-bacteria bloodstream infection (BSI) were Escherichia coli (28 strains, 43.75% ), Klebsiella pneumonia (26 strains, 40.63% ), Pseudomonas aeruginosa (3 strains, 4.69% ), and Enterobacter cloacae (3 strains, 4.69% ). The top three pathogenic bacteria isolated from 147 patients with CRO perianal colonization were carbapenem-resistant Klebsiella pneumoniae (58 strains, 32.58% ), carbapenem-resistant Escherichia coli (49 strains, 27.53% ), and carbapenem-resistant Enterobacter cloacae (20 strains, 11.24% ). The 3-year disease-free survival (DFS ) and overall survival (OS) of double positive group patients were significantly lower compared to those in the blood culture and perianal swab positive groups (DFS: 35.6% vs 53.7% vs 68.6%, P=0.001; OS: 44.4% vs 62.4% vs 76.9%, P<0.001), while non-relapse mortality (NRM) was significantly higher (50.0% vs 34.9% vs 10.6%, P<0.001). Failed engraftment of platelets and BSI are independent risk factors for NRM ( P<0.001). Using polymyxin and/or ceftazidime-avibactam for more than 7 days is an independent protective factor for NRM ( P=0.035) . Conclusion:This study suggests that the occurrence of BSI significantly increases the NRM after HSCT in patients with hematological diseases; CRO colonization into the bloodstream has a significant impact on the DFS and OS of HSCT patients.

Objective:This study aimed to analyze the homology between carbapenem-resistant organisms (CRO) intestinal colonization strains and bloodstream infection (BSI) strains in patients undergoing hematopoietic stem cell transplantation (HSCT), confirming the clinical use of the real-time rectal swab Xpert Carba-R assay, and investigate its feasibility in early warning of BSI.Methods:Drug-resistant strains obtained from rectal swabs and blood culture samples of patients undergoing the same HSCT from January 2021 to December 2021 were collected and analyzed. The homology of the CRO intestinal colonization and BSI strains was confirmed using strain identification, antimicrobial resistance phenotyping, whole genome sequencing (WGS), multilocus sequence typing (MLST), and carbapenemase type identification. Rectal swab cultures and the real-time rectal swab Xpert Carba-R assay were conducted concurrently on patients with HSCT from August 2021 to August 2022. The accuracy of the real-time rectal swab Xpert Carba-R assay was confirmed with the sequencing results of polymerase chain reaction amplification products of the carbapenemase gene from purified colonies as a reference standard.Results:This study included 24 CRO strains from 10 patients undergoing HSCT, including 14 intestinal colonizers and 10 CRO-BSI strains. The results revealed that the CRO intestinal colonization strains and CRO-BSI strains from the same patient and their carbapenemase genes were almost identical. Additionally, WGS revealed that CRO intestinal colonization and CRO-BSI strains from the same patient were more closely related than strains from different patients. Additionally, this study included 488 rectal swab specimens from 184 patients undergoing HSCT, with CRO detection rates of 16.4% for rectal swab culture and 18.4% for the real-time rectal swab Xpert Carba-R assay. The overall sensitivity, specificity, and positive and negative predictive values of the real-time rectal swab Xpert Carba-R assay were 96.6%, 72.8%, 90.6%, and 88.9%, respectively.Conclusions:A high degree of homology was found between the CRO intestinal colonization strains and the CRO-BSI strains in patients undergoing HSCT. The real-time rectal swab Xpert Carba-R assay is a reliable and convenient method for detecting common carbapenemase genes, serving as an alternative to rectal swab culture for early warning of CRO-BSI.

Objective:This study aimed to analyze the homology between carbapenem-resistant organisms (CRO) intestinal colonization strains and bloodstream infection (BSI) strains in patients undergoing hematopoietic stem cell transplantation (HSCT), confirming the clinical use of the real-time rectal swab Xpert Carba-R assay, and investigate its feasibility in early warning of BSI.Methods:Drug-resistant strains obtained from rectal swabs and blood culture samples of patients undergoing the same HSCT from January 2021 to December 2021 were collected and analyzed. The homology of the CRO intestinal colonization and BSI strains was confirmed using strain identification, antimicrobial resistance phenotyping, whole genome sequencing (WGS), multilocus sequence typing (MLST), and carbapenemase type identification. Rectal swab cultures and the real-time rectal swab Xpert Carba-R assay were conducted concurrently on patients with HSCT from August 2021 to August 2022. The accuracy of the real-time rectal swab Xpert Carba-R assay was confirmed with the sequencing results of polymerase chain reaction amplification products of the carbapenemase gene from purified colonies as a reference standard.Results:This study included 24 CRO strains from 10 patients undergoing HSCT, including 14 intestinal colonizers and 10 CRO-BSI strains. The results revealed that the CRO intestinal colonization strains and CRO-BSI strains from the same patient and their carbapenemase genes were almost identical. Additionally, WGS revealed that CRO intestinal colonization and CRO-BSI strains from the same patient were more closely related than strains from different patients. Additionally, this study included 488 rectal swab specimens from 184 patients undergoing HSCT, with CRO detection rates of 16.4% for rectal swab culture and 18.4% for the real-time rectal swab Xpert Carba-R assay. The overall sensitivity, specificity, and positive and negative predictive values of the real-time rectal swab Xpert Carba-R assay were 96.6%, 72.8%, 90.6%, and 88.9%, respectively.Conclusions:A high degree of homology was found between the CRO intestinal colonization strains and the CRO-BSI strains in patients undergoing HSCT. The real-time rectal swab Xpert Carba-R assay is a reliable and convenient method for detecting common carbapenemase genes, serving as an alternative to rectal swab culture for early warning of CRO-BSI.

Multiple myeloma (MM) is an incurable plasma cell malignancy with a typical course characterized by response to initial treatment and eventual resistance. Despite major advances in the clinical treatment of multiple myeloma driven by the introduction of new drugs (e.g., proteasome inhibitors and immunomodulators), MM remains incurable. Nevertheless, subsequent cycles of remission and relapse continue as long as new treatments are available to patients. With the development of many new treatments, the approval of 12 new drugs over the past 15 years, and the promising trend of clinical trials, the treatment landscape has dramatically changed and patient survival has improved. This article reviews the progress of new treatments for MM.

Objective:To summarize the clinical characteristics, common images, pathogens, and gene mutation types of chronic granulomatosis disease (CGD) in 19 children.Methods:The clinical manifestations, laboratory findings, treatment, and prognosis of 19 patients diagnosed with CGD in Hong Kong University-Shenzhen Hospital from December 2012 to December 2018 were analyzed.Results:The 19 patients were all males and confirmed as CGD by the dihydrorhodamine test and gene sequencing.The age of the first infection was mostly 1 month after birth(13 cases), and the age of clinical diagnosis ranged from 2 months to 10 years.Sixteen mothers were carriers.The patients presented with pulmonary fungal infection (19/19 cases), Bacillus Calmette Guerin (BCG)-osis (14/19 cases), lymphadenitis (14/19 cases), perianal abscess (9/19 cases), skin abscess (5/19 cases) and ulcerative colitis (2/19 cases). There were 59 positive cultures.Pathogens included fungi (9 cases), Klebsiella pneumonia (8 cases), mycobacteria (7 cases), Streptococcus Viridans (5 cases), Escherichia coli (3 cases), gram-positive bacteria (3 cases), Staphylococcus aureus (3 cases), and Burkholderia cenocepacia (2 cases). Gene mutations were found in all 19 patients, including 17 cases of CYBB, 1 case of CYBA and 1 case of NCF2.The type of mutations included nonsense mutations (6 cases), deletion mutations (5 cases, including 2 large fragment deletions), splice mutations (3 cases) and missense mutations (5 cases). Five mutations were novel.Splice mutations in 3 cases often led to skin abscess, perianal abscess and lymphadenitis.Two patients with large deletion mutations had more serious infection than other patients. Conclusions:In China, CGD is characterized with pulmonary infection and disseminated BCG-osis.Mycobacteria are common pathogens of CGD, and fungi are dominant pathogens of CGD.The most common infection is respiratory infection. Klebsiella pneumonia and Escherichia coli often lead to perianal abscess.The relationship between gene mutation types and clinical phenotypes requires further verification by big data.

OBJECTIVETo enrich our national database with data of rare diseases by analyzing molecular diagnosis and hematopoietic stem cell transplantation (HSCT) in children with inherited bone marrow failure syndromes (IBMFS).

METHODNext-generation sequencing (NGS)-based genetic diagnosis panel was applied for the clinical diagnosis and management of IBMFS. Retrospective analysis was performed on clinical and genetic data of 17 consecutive children who received HSCT over a long time interval (November. 2005-June 2015).

RESULTThree patients were diagnosed only by clinical manifestation before 2012. After that NGS-based genetic diagnosis panel was used to identify IBMFS-related genes in 12/14.IBMFS patients (except two Diamond-Blackfan anemia (DBA) patients). Two Fanconi anemia (FA) patients were confirmed to be new variations through family-genotype-analysis and 3 families accepted prenatal diagnosis to avoid birth of affected fetuses. Seventeen IBMFS patients (10 FA,5 DBA and 2 dyskeratosis congenital (DKC)) were treated with HSCT from matched sibling donors (n=2), matched unrelated donors (n=8) or mismatched unrelated donors (n=7). The source of stem cells for transplantation included peripheral blood (n=12) and cord blood (n=5). With regard to the conditioning regimens, FA and DKC patients received fludarabine-based reduced intensity conditioning, while DBA patients received classical busulfan-based myeloablative conditioning. Median age at the time of HSCT was 36 months (7-156 months). The number of infused mononuclear cells and CD34⁺ cells was (10.6 ± 6.7) × 10⁸ and (5.9 ± 7.0) × 10⁶ per kilogram of recipient body weight, respectively. The median number of days to neutrophil recovery was 13 days after HSCT (range: 10-19 days). Platelet recovery was faster in the PBSCT group than in the CBT group ((16.3 ± 6.0) days vs. (30.0 ± 17.1) days,t=-2.487,P=0.026). During a median follow-up of 17 months (range: 2-114 months), except one FA patient who was transplanted with HLA-matched unrelated cord blood (CB) died from pneumonia and heart failure because of engraftment failure, other 16 children are alive after the successful HSCT. The failure-free survival rate of the patients three years after HSCT was 94%.

CONCLUSIONNGS-based molecular diagnosis technology and effective HSCT have significantly facilitated the treatment of children with IBMFS in our country, and our national database about this rare disease is to be further exploited.

Anemia, Aplastic ; Anemia, Diamond-Blackfan ; therapy ; Bone Marrow Diseases ; Child ; Dyskeratosis Congenita ; therapy ; Fanconi Anemia ; therapy ; Fetal Blood ; Hematopoietic Stem Cell Transplantation ; Hemoglobinuria, Paroxysmal ; diagnosis ; genetics ; therapy ; Humans ; Retrospective Studies ; Siblings ; Survival Rate ; Transplantation Conditioning ; Unrelated Donors ; Vidarabine ; analogs & derivatives ; therapeutic use