[Study on Thalassemia in Han Population in Sanya of Hainan Province].

OBJECTIVE: To study the distribution characteristics of thalassemia genotype in Han Population in Sanya of Hainan Province. METHODS: Gap PCR and reverse dot hybridization were used to detect and analyze the thalassemia gene in 572 suspected thalassemia carriers of Han Population in Sanya. RESULTS: Among the 572 Han Population in Sanya, 271 cases of thalassemia gene abnormality were detected, among which 161 cases were founded to be carriers of α-thalassemia gene. A total of 9 genotypes were detected, in the following order of the detection rate was －－SEA/αα，－α3.7/αα，－α4.2/αα，－－SEA/－α3.7，－－SEA/－α4.2，－α4.2/－α4.2，－α3.7/－α4.2，－α3.7/－α3.7，－－SEA/－－SEA. Among them, the deletion type (－－SEA/αα) in southeast Asia was the most common, accounting for 66 cases. 99 cases of ß-thalassemia were detected, there were 7 genotypes, all of which were heterozygous. The order of the detection rate was CD41-42/ßN, IVS-II-654/ßN, CD17/ßN, CD71-72/ßN, -28/ßN, －29/ßN, CD27-28/ßN. Among them, CD41-42/ßN was the most common, accounting for 51 cases. In addition, 11 cases of combined α and ß thalassemia were detected. Five kinds of genotypes were checked out, the order of detection rate was －α3.7/αα composite CD41-42/ßN, －－SEA/αα composite IVS-II-654/ßN, －α4.2/－α4.2 composite CD41-42/ßN, －α4.2/αα composite －29/ßN , －－SEA/ －α4.2 composite CD41-42/ßN. CONCLUSION: Han Population in Sanya of Hainan Province is a high-risk population of thalassemia, the genotype characteristics are different from other areas with high incidence of thalassemia in China. The main type of α-thalassemia is the deficiency mutation of southeast Asia, while CD41-42 heterozygous mutation is the main type of ß-thalassemia.

[Single Center Analysis of Bloodstream Infection Clinical Characteristics and Prognosis in Patients with Hematological Malignancies in the Tropics].

OBJECTIVE: To analyze the characteristics, prognosis and risk factors of bloodstream infection in patients with hematological malignancies in the tropics, so as to provide evidence for the prevention and treatment of bloodstream infection. METHODS: The clinical features, blood culture results and prognosis of patients with bloodstream infection in patients with hematological malignancies admitted to Hainan Hospital of PLA General Hospital were retrospectively studied. RESULTS: The most common primary infection site of the 81 patients with hematological malignancies was lung (46.91%), followed by PICC (11.11%). The detection rate of Gram-positive bacteria and Gram-negative bacteria in the blood culture was 60.98% and 30.02%, respectively. Coagulase-negative staphylococci was the most common Gram-positive bacteria resulting in bloodstream infection in our study. Of the Gram-negatives, Klebsiella pneumoniae (34.38%) was predominant, followed by Escherichia coli (18.75%) and Pseudomonas aeruginosa (18.75%). Gram-positive bacteria was highly sensitive (100%) to vancomycin, linezolid and tigecycline. Study showed that Gram-negative bacteria had low sensitive to quinolones, in particular, the resistance rate of Escherichia coli to quinolones was as high as 83.33%. In terms of overall survival (OS), the 30-days OS of patients with Gram-negative and Gram-positive septicemia was 77.42% and 92.00%, respectively. There was no statistically significant difference between the two groups. Multivariate analysis revealed that septic shock (P=0.001, RR=269.27) was an independent risk factor for 30-day mortality, and remission status (P=0.027, RR=0.114) was an independent predictor of a favourable outcome of bloodstream infection in patients with hematological malignancies. CONCLUSION: Gram-positive bacteria are the main pathogens causing bloodstream infections in patients with hematological malignancies in the tropics. Improving the care of PICC is an important measure to reduce the incidence of bloodstream infection in patients with hematological malignancies in the tropics. A correct treatment relieving disease and effective prevention and treatment of septic shock can reduce mortality of patients with bloodstream infection in patients with hematological malignancies in the tropics.

[Clinical Characteristics and Prognosis of Patients with Relapsed or Refractory Diffuse Large B-Cell Lymphoma].

OBJECTIVE: To investigate the clinical characteristics of relapsed or refractory (R/R) diffuse large B-cell lymphoma (DLBCL) and the factors affecting overall survival (OS) time. METHODS: The clinical data of 14 R/R DLBCL patients admitted to the Hainan Hospital of Chinese PLA General Hospital from April 2012 to March 2019 were analyzed retrospectively and the overall response rate (ORR) after the end of different treatments was estimated. Kaplan-Meier method was used to describe the survival curve, and Log-rank test was used to compare whether different survival curves showed statistically different. RESULTS: There were 8 males and 6 females with a median age of 51 (26-75) years old and the median course of treatment before R/R was 7 (4-13). Finally, 11 patients achieved remission, 6 patients of which showed complete remission, and 5 patients showed partial remission, with the median ORR duration at 2.5 (0-51) months. All patients in the group of ibrutinib combined with second-line chemotherapy achieved remission (4/4), it was equivalent to the high-dose chemotherapy followed by autologous hematopoietic stem cell transplantation (HDC-AHSCT) group (4/4), which was significantly higher than that of the other second-line group (3/6). The median OS time of patients was 17 (6-76) months. The survival of patients receiving ibrutinib combined with second-line chemotherapy and HDC-AHSCT was significantly better than that of patients not receiving ibrutinib combined with second-line chemotherapy and HDC-AHSCT. Normal lactate dehydrogenase, IPI score＜3 at diagnosis, and CR/PR after treatment could improve the survival time of patients. CONCLUSION: The duration of remission for R/R DLBCL patients is short and the prognosis is very poor. The survival time of patients with high level of lactate dehydrogenase, IPI score≥3 at diagnosis and SD/PD after treatment is significantly shortened. Ibrutinib combined second-line chemotherapy and HDC-AHSCT can improve the efficacy and survival of R/R DLBCL patients.

[Clinical Analysis of Allogeneic Hematopoietic Stem Cell Transplantation for Treatment of 12 Patients with Acute Leukemia in Tropical Area].

OBJECTIVE: To analyze the efficacy of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for treatment of acute leukemia in the tropical area. METHODS: Twelve acute leukemia patients who were underwent allo-HSCT from April 2013 to November 2018 in Hainan Hospital of Chinese PLA General Hospital were selected, including 5 cases of acute lymphoblastic leukemia (ALL) and 7 case of acute myeloid leukemia (AML). Three cases received HLA matched sibling hematopoietic stem cell transplantation, 8 cases received haploidentical hematopoietic stem cell transplantation, 1 cases received partially mismatched unrelated hematopoietic stem cell transplantation. Pretreatment regimen: 9 cases received modified BU/CY+ATG pretreatment regimen, 3 cases received BU/CY pretreatment regimen. Graft-versus-host disease (GVHD) prevention regimen: all patients received cyclosporine A, mycophenolate mofetil combined with short-term methotrexate regimen. The clinical efficacy of allo-HSCT in treatment of acute leukemia in the tropical area was analyzed by detecting hematopoietic reconstitution, GVHD, infection, relapse and survival after transplantation. RESULTS: All the 12 patients achieved granulocyte reconstruction and megakaryocyte reconstruction. The median time of granulocyte reconstruction was 11.5 (6-14) days, and the median time of megakaryocytic reconstruction was 12.5 (10-22) days. Within 100 days after transplantation, the acute GVHD occurved in 8 cases, including 6 cases of Ⅱ-Ⅳ degree acute GVHD and 2 cases of Ⅲ-Ⅳ degree acute GVHD, 11 cases survived more than 100 days after transplantation, and the chronic GVHD occurred in 1 case, which was mildly limited. Pulmonary infection occurred in 7 cases, cytomegaloviremia occurred in 6 cases, EB viremia occurred in 6 cases, and hemorrhagic cystitis occurred in 5 cases. 2 cases relapsed and eventually died, and the remaining 10 patients survived without disease until the date of follow-up. The median follow-up time was 4 (1-68) months, 83.3% (10/12) survived without disease, and 16.7% (2/12) relapsed. CONCLUSION: Allo-HSCT is an effective method for the treatment of acute leukemia in adults. Leukemia patients should be transplanted as soon as possible after remission. The incidence of pulmonary fungal infection in transplanted patients in tropics is high, therefore the prevention and treatment of fungal infection should be strengthened.

[Clinical Characteristics and Prognosis of U2AF1 Mutation in Patients with Acute Myeloid Leukemia].

OBJECTIVE: To investigate the incidence, clinical features of U2AF1 gene mutation in patients with acute myeloid leukemia(AML) and its effect of prognosis. METHODS: A total of 161 patients with AML were enrolled. The second-generation sequencing method was used to detect U2AF1 gene mutation, and the relationship between U2AF1 mutation and clinical features, prognosis was analyzed. RESULTS: The mutation rate of U2AF1 gene in 161 AML patients was 3.73%. The counts of peripheral blood leukocytes and platelets in the U2AF1 gene mutation group were lower than those in the wild type group. The complete response rate of U2AF1 gene mutation group was 66.67%, while that in wild type group was 55.48%, which shows no significant difference between the two groups (P=0.70). The median EFS of wild type group and the mutant group was not reached and reached to 133 days, respectively (P=0.03), while the medium OS in two groups was not reached and reached to 210 days (P=0.01). CONCLUSION: The AML patients with U2AF1 mutation positive have a poor prognosis as compared with the wild type group, which may be a poor prognostic factor for acute myeloid leukemia.

[Single Center Analysis of Pathogenic Characteristics of Lung Candida Infection and Other Pathogenic Bacteria Infection in the Patients with Hemotological Maliglancies in the Tropical Region of Hainan].

OBJECTIVE: To analyze the infection characteristics of sputum and venous blood pathogen in the patients with hematological malignancies and respiratory symptom in the Hematology Department in tropical region and to investigate its drug-resistance so as to provide etiological evidence for clinical treatment. METHODS: The pathogens and their drug-resistance of 2466 samples in the patients with hematological malignancies and respiratory symptom in the Department were analyzed retrospectively from January 2013 to November 2017. The samples were collected from sputum and venous blood. RESULTS: The sputum sample culture in patients with hematologic diseases showed that 224 strains were isolated, out of them 98 strains (43.75%) were fungi mainly candida albicans (41 strains); and then 88 Gram-negative strains (39.28%), among them the main pathogenic bacteria were Escherichia coli(22 strains) and klebsiella Klebsiella pneumoniae(12 strains); and then 38 Gram-positive strains (16.96%), among them the main pathogeni-bacteria were Enteroccocus (14 strains) and Gram-positive bacilli (14 strains). The blood samples culture of patients with hematologic diseases showed that 61 strains were isolated, out of them the isolated rate of Gram-positive bactetia was higherst, which accounted for 55.74%(34/61), mainly including staphylococcus lominis (19 strains); and the isolated rate of Gram-negative bacteria was 44.26% (27/61), among them main pathogenic bacteria was Klebsiella pneumoniae (12 strains). The resistance test of pathogenic bacteria to drugs showed that the resistant rate of Gram-negative bacteria to tigecycline, imipenem and atl-962 duenner was lowest, while the Gram-positive pathogenic bacteria such as Enterococcus, Gram-positive bacilli and Staphylococcus aureus were sensitive to vancomycin, tigecycline and linezolid was high. CONCLUSION: the patients in hematology department are infected easily in the hospital in tropical region. The main pathogens are fungal strains in the respiratory tract of patients with hematological malignancy according to the sputum culture results. The clinician in tropical regions should choose suitable antibiotics for anti-infective therapy, which is different from the situation in North China or other northern areas.