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Objective: To reassess the prognostic value of minimal residual disease (MRD) and IKZF1 gene deletions in adults with B-cell acute lymphoblastic leukemia (B-ALL) who received pediatric-specific chemotherapy regimens during the Nanfang Hospital PDT-ALL-2016 trial. Methods: We retrospectively analyzed the prognosis of 149 adult patients with B-ALL who were admitted to Nanfang Hospital from January 2016 to September 2020. Prognostic factors were identified using Cox regression models. Results: The complete remission rate was 93.2% in 149 patients, with a 5-year overall survival (OS) rate of (54.3±5.0) % and a cumulative incidence of relapse (CIR) of (47.5±5.2) %. The Cox regression analysis revealed that MRD positivity at day 45 (MRD(3)) after induction therapy was independently associated with relapse risk ( HR =2.535, 95% CI 1.122-5.728, P =0.025). Deletion of IKZF1 gene was independently associated with mortality risk ( HR =1.869, 95% CI 1.034-3.379, P =0.039). Based on MRD(3) and IKZF1 gene status, we categorized adult patients with B-ALL into the low-risk (MRD(3)-negative and IKZF1 gene deletion-negative) and high-risk (MRD(3)-positive and/or IKZF1 gene wild type) groups. The 5-year OS and CIR rates were (45.5±6.0) % vs (69.4±8.6) % ( P <0.001) and (61.6±8.3) % vs (25.5±6.5) % ( P <0.001), respectively, in the high-risk and low-risk groups, respectively. The multivariate analysis showed that the high-risk group was an independent risk factor for OS ( HR =3.937, 95% CI 1.975-7.850, P <0.001) and CIR ( HR =4.037, 95% CI 2.095-7.778, P <0.001) . Conclusion: The combined use of MRD and IKZF1 gene in prognostic stratification can improve clinical outcome prediction in adult patients with B-ALL, helping to guide their treatment.

Objectives: To investigate the value of metagenomic next-generation sequencing (mNGS) in the diagnosis of Pneumocystis jirovecii pneumonia (PJP) in patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) . Methods: The data of 98 patients with suspected pulmonary infection after allo-HSCT who underwent pathogen detection from bronchoalveolar lavage fluid between June 2016 and August 2023 at Nanfang Hospital were analyzed. The diagnostic performance of mNGS, conventional methods, and real-time quantitative polymerase chain reaction (qPCR) for PJP were compared. Results: A total of 12 patients were diagnosed with PJP, including 11 with a proven diagnosis and 1 with a probable diagnosis. Among the patients with a proven diagnosis, 1 was positive by both conventional methods and qPCR, and 10 were positive by qPCR only. Pneumocystis jirovecii was detected by mNGS in all 12 patients. The diagnostic sensitivity of mNGS for PJP was 100%, which was greater than that of conventional methods (8.3%, P =0.001) and similar to that of qPCR (91.6%, P =1.000) . A total of 75% of the patients developed mixed pulmonary infections, and cytomegalovirus and Epstein-Barr virus were the most common pathogens. Mixed infection was detected in eight patients by mNGS and in five patients by qPCR, but not by conventional methods ( P =0.008) . Conclusions: mNGS had good sensitivity for diagnosing PJP after allo-HSCT and was advantageous for detecting mixed infectious pathogens; therefore, mNGS might be an effective supplement to regular detection methods and qPCR.

Objective: To study the incidence of bloodstream infections, pathogen distribution, and antibiotic resistance profile in patients with hematological malignancies. Methods: From January 2018 to December 2021, we retrospectively analyzed the clinical characteristics, pathogen distribution, and antibiotic resistance profiles of patients with malignant hematological diseases and bloodstream infections in the Department of Hematology, Nanfang Hospital, Southern Medical University. Results: A total of 582 incidences of bloodstream infections occurred in 22,717 inpatients. From 2018 to 2021, the incidence rates of bloodstream infections were 2.79%, 2.99%, 2.79%, and 2.02%, respectively. Five hundred ninety-nine types of bacteria were recovered from blood cultures, with 487 (81.3%) gram-negative bacteria, such as Klebsiella pneumonia, Escherichia coli, and Pseudomonas aeruginosa. Eighty-one (13.5%) were gram-positive bacteria, primarily Staphylococcus aureus, Staphylococcus epidermidis, and Enterococcus faecium, whereas the remaining 31 (5.2%) were fungi. Enterobacteriaceae resistance to carbapenems, piperacillin/tazobactam, cefoperazone sodium/sulbactam, and tigecycline were 11.0%, 15.3%, 15.4%, and 3.3%, with a descending trend year on year. Non-fermenters tolerated piperacillin/tazobactam, cefoperazone sodium/sulbactam, and quinolones at 29.6%, 13.3%, and 21.7%, respectively. However, only two gram-positive bacteria isolates were shown to be resistant to glycopeptide antibiotics. Conclusions: Bloodstream pathogens in hematological malignancies were broadly dispersed, most of which were gram-negative bacteria. Antibiotic resistance rates vary greatly between species. Our research serves as a valuable resource for the selection of empirical antibiotics.

Objective: To examine the efficacy and safety of third-party bone marrow-derived mesenchymal stem cells (MSCs) in the treatment of refractory delayed hemorrhagic cystitis (LOHC) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) . Methods: Twenty patients with refractory LOHC received conventional therapy combined with MSCs obtained from third-party donors' bone marrow (BM) . MSCs were given intravenously at a dose of 1 × 10(6) cells/kg once weekly until either the symptoms improved or no changes in LOHC were seen after continuous infusion four times. BK viruria (BKV) -DNA, JC viruria (JCV) -DNA, and CMV-DNA were detected by real-time quantitative PCR before and 8 weeks after the MSCs infusion. Results: ① Of the 20 patients with refractory LOHC, 15 were males, and 5 were females, and the median age was 35 (15-56) years. There were 5 cases of acute lymphoblastic leukemia (ALL) , 9 cases of acute myeloid leukemia (AML) , 5 cases of myelodysplastic syndrome (MDS) , and 1 case of maternal plasma cell like dendritic cell tumor (BPDCN) . There were 4 cases of HLA identical transplantation and 16 cases of HLA incomplete transplantation. ②The median number of MSC infusions for each patient was 3 (range: 2-8) . Seventeen patients achieved complete response, and one had a partial response after treatment. The overall response rate was 90%. Over a median follow-up period of 397.5 days (range 39-937 days) post-transplantations, 13 patients survived, and 7 died. The causes of death included aGVHD (1 case) , infections (5 cases) , and TMA (1 case) . ③The copy numbers of BKV-DNA and CMV-DNA in urine in the 8th week after MSCs infusion were significantly lower than those observed before treatment (11342.1×10(8) copies/L vs 5.2×10(8) copies/L, P =0.016; 3170.0×10(4) copies/L vs 0.2×10(4) copies/L, P =0.006, respectively) , while JCV-DNA did not significantly differ when compared to before treatment ( P =0.106) . ④ No adverse reactions related to MSC infusion occurred in any of the 20 patients. Conclusion: Third-party bone marrow-derived MSC has significant efficacy and good safety in the treatment of refractory LOHC after allogeneic HSCT.

Objective: This study aimed to investigate the prognostic significance of IKZF1 gene deletion in patients with acute B lymphoblastic leukemia (B-ALL) . Methods: The clinical data of 142 patients with B-ALL diagnosed in Nanfang Hospital between March 2016 and September 2019 were analyzed. Results: IKZF1 deletion was found in 36.0% of the 142 patients with B-ALL, whereas exon 4-7 deletion was found in 44.0% . White blood cell counts were higher in patients with the IKZF1 deletion (52.0% and 28.3% , P =0.005) ; these patients also experienced worse effects of mid-term induction therapy (40.0% and 70.7% , P <0.001) and had a higher proportion of Philadelphia chromosome-positive (52.0% and 21.7% , respectively, P <0.001) . Univariate analysis revealed that the 3-year overall survival rate (OS) and event-free survival rate (EFS) in the IKZF1 deletion group were significantly lower than the IKZF1 wild-type group [ (37.1±7.3) % vs (54.7±5.4) % , (51.8±7.9) % vs (73.9±4.7) % ; P =0.025, 0.013, respectively]. Multivariable analysis showed that harboring IKZF1 deletion was an adverse factor of EFS and OS ( HR =1.744, 2.036; P =0.022, 0.020, respectively) . Furthermore, the IKZF1 deletion/chemotherapy group had significantly lower 3-year OS, EFS, and disease-free survival rates than other subgroups. In the IKZF1 deletion cohort, allo-hematopoietic stem cell transplantation (HSCT) significantly improved OS and EFS compared to non-allo-HSCT[ (67.9±10.4) % vs (31.9±11.0) % , (46.6±10.5) % vs (26.7±9.7) % ; P =0.005, 0.026, respectively]. Conclusion: Pediatric-inspired chemotherapy was unable to completely reverse the negative effect of IKZF1 deletion on prognosis. Pediatric-inspired regimen therapy combined with allo-HSCT, in contrast, significantly improved the overall prognosis of IKZF1 deletion B-ALL.

Objective: To analyze the efficacy of sinonasal adenoid cystic carcinoma (ACC) with perineural invasion (PNI), and explore the prognostic value of PNI on sinonasal adenoid cystic carcinoma. Methods: The clinical data of 105 patients with sinonasal ACC admitted to Cancer Hospital, Chinese Academy of Medical Sciences from January 2000 to December 2016 were retrospectively reviewed. All patients were restaged according to American Joint Committee on Cancer 8th edition. Follow-up visits were conducted to obtain information of treatment failure and survival outcome. The Log rank test was used for univariate analysis of prognostic factors, and Cox regression model was used for multivariate prognostic analysis. Results: The maxillary sinus ( n =59) was the most common primary site, followed by the nasal cavity ( n =38). There were 93 patients with stage Ⅲ-Ⅳ. The treatment modalities included surgery alone ( n =14), radiotherapy alone ( n =13), preoperative radiotherapy plus surgery ( n =10), and surgery plus postoperative radiotherapy ( n =68). The median follow-up time was 91.8 months, the 5-year local control (LC), distant metastasis-free survival (DMFS), progression-free survival (PFS), and overall survival (OS) rates were 72.6%, 73.0%, 52.9% and 78.0%, respectively. There were 33 patients (31.4%) with PNI-positive. The 5-year DMFS, PFS, and OS rates of PNI-positive group were 53.7%, 29.4% and 56.5%, respectively, which were significantly inferior to those of PNI-negative group (80.8%, 63.0% and 86.8%, respectively, P <0.05), while there was no significant difference in the 5-year LC rate between both groups (64.5% vs 76.5%, P =0.273). The multivariate Cox regression analysis showed PNI was one of the poor prognostic factors of DMFS ( HR =3.514, 95% CI: 1.557-7.932), PFS ( HR =2.562, 95% CI: 1.349-4.866) and OS ( HR =2.605, 95% CI: 1.169-5.806). Among patients with PNI-positive, the 5-year LC, PFS and OS rates of patients received surgery combined with radiotherapy were 84.9%, 41.3% and 72.7%, respectively, which were significantly higher than 23.3%, 10.0% and 26.7% of patients receiving surgery or radiotherapy alone ( P <0.05). Conclusion: The presence of PNI increases the risk of distant metastasis in patients with sinonasal ACC. Compared with patients with PNI-negative, the prognosis of patients with PNI-positive is relatively poor, and surgery combined with radiotherapy for PNI-positive sinonasal ACC results in good clinical outcomes.

Objective: To establish a screening system of adult Philadelphia chromosome-like acute lymphoblastic leukemia (Ph-like ALL) by fluorescence in situ hybridization (FISH) . Method: Based on the genetic characteristics of Ph-like ALL, FISH probes were designed for ABL1, ABL2, JAK2, EPOR, CRLF2, CSF1R, PDGFRB, and P2RY8 gene breakpoints, which were used to screen Ph-like ALL in B-ALL patients without BCR-ABL1, ETV6-RUNX1, MLL, and E2A gene arrangement. Furthermore, it was analyzed in combination with flow immunophenotype, next-generation sequencing for targeted gene mutations, and RNA sequencing (RNA-seq) . Results: A total of 189 adult B-ALL patients diagnosed in Nanfang Hospital from January 2016 to April 2019 were enrolled in this study. Using FISH and/or PCR, BCR-ABL1, ETV6-RUNX1, MLL, or E2A arrangement was detected in 83 of them, and Ph-like ALL was detected by FISH in the other 106, resulting in the presence of typical gene arrangements of Ph-like ALL in 12 patients (11.3% , 12/106) . Validated by RNA-seq, the sensitivity and specificity of FISH for Ph-like ALL were 71.4% and 95.8% , respectively. After further analysis with immunophenotype, targeted gene mutations, and RNA-seq, 14 (13.2% , 14/106) were diagnosed with Ph-like ALL. Conclusion: This data shows high specificity of FISH for identification of Ph-like ALL and combining immunophenotype and sequencing technology can improve the diagnostic system.

Objective: To investigate the clinical implications of p16 gene deletion in adult Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph(+) ALL) . Methods: Retrospective analysis of clinical, immunophenotypic, cytogenetics, molecular characteristics and prognosis of 80 newly diagnosed Ph(+) ALL patients with p16 deletion. Results: Of 80 adult Ph(+) ALL, the prevalence of p16 gene deletion was 31.3%. p16 gene deletion carriers frequently accompanied with high WBC counts (WBC≥30×10(9)/L) and CD20 expression. The incidence of complex chromosome abnormality in p16 gene deletion group was higher than that in non-deletion group, with alternations in chromosome 7, 8, 19 and der (22) more frequently observed. There was no difference occurred between patients with or without p16 gene deletion in complete remission (CR) rate following induction chemotherapy combined with tyrosine kinase inhibitors (TKIs) . However, after three cycles of chemotherapy, the MMR and CMR rate in the p16 gene deletion group was lower than patients with wild-type p16 gene ( P =0.034, P =0.036) . The p16 gene deletion patients showed no significant differences in MMR, CMR and relapse rate between Imatinib or Dasatinib plus chemotherapy ( P >0.05) . Deletion of p16 gene was significantly associated with poor outcomes including worse overall survival (OS) (37.1% vs 54.1%, P =0.037) , lower disease free-survival (DFS) (12.4% vs 45.9%, P =0.026) , and increased cumulative incidence of relapse ( P =0.033) . Among the 25 patients with p16 deletion, 14 underwent allo-HSCT and the median survival was 21 months, better than that of patients received chemotherapy alone (12 months) ( P =0.030) . Conclusion: This study indicated that deletion of p16 was associated with poor prognosis in adult Ph(+) ALL, and the utility of second-generation TKI (Dasatinib) does not necessarily have an edge on efficacy over Imatinib, but allo-HSCT has the potential of elongating life expectancy. It is an important significance to define the status of p16 in Ph(+) ALL for predicting prognosis and guiding therapy decision-making.

Objective: To analyze the association of cytogenetic abnormalities with the prognosis of chronic myeloid leukemia (CML) patients in tyrosine kinase inhibitors (TKI) era. Methods: Karyotype analysis of chromosome G-banding was carried out in 387 newly diagnosed CML patients by short-term culture of bone marrow cells. The correlation of cytogenetic abnormalities and CML progression was explored in combination with ABL tyrosine point mutations. Result: Of 387 patients with positive BCR-ABL fusion gene assayed by fluorescence in situ hybridization (FISH) technique, 94.1% (364/387) patients were Ph positive and 5.9% (23/387) Ph negative; 320 patients (87.9%) had a translocation t (9;22) (q34;q11) and 5 (1.4%) a variant translocation t (v;22) . Additional cytogenetic aberrations (ACA) at diagnosis were found in 10.7% (39/387) Ph(+) patients, major route ACA in 22 (56.4%) cases and minor route ACA in 15 (38.5%) cases and 2 patients (5.1%) lacked the Y chromosome (-Y) ; 23.4% (71/303) patients occurred ACA during TKI treatment and the most frequent abnormalities were abnormal chromosome numbersd, which were likely associated with high proportion of disease progression ( χ (2)=168.21, P< 0.001) and ABL tyrosine point mutations ( χ (2)=29.04, P< 0.001) . Newly diagnosed CML-CP patients with t (9;22) (q34;q11) had a longer event-free survival (EFS) and disease-free survival (DFS) rates than that of patients with ACA ( P =0.037; P=0.003) , while the overall survival (OS) had no significant differences ( P =0.209) . As for CML-CP patients that occurred ACA during TKI therapy would have a marked low OS, EFS and DFS (all P <0.001) compared with no ACA occurred patients. Survival of advanced patients that occurred ACA were dramatically reduced. Conclusion: ACA often emerged during the disease progress in CML patients, regular and timely detection of chromosomes karyotype and ABL tyrosine point mutations during TKI treatment was important for therapeutic evaluation, progress and prognosis of CML.

Objective: To investigate the morbidity, treatment outcomes and prognosis of 35 therapy-related hematological neoplasms patients., Methods: A total of 35 cases of therapy-related hematological neoplasms were examined genetically and immunologically using flow cytometry, karyotype analysis and FISH, and their clinical data were retrospective analyzed and literatures were reviewed., Results: Among 35 patients, there were 20 cases of therapy-related acute myeloid leukemia (t-AML), 4 cases of therapy-related acute lymphoblastic leukemia (t-ALL), 1 case of acute mixed leukemia, therapy-related non-hodgkin' s lymphoma (t-NHL) in 8 cases and myelodysplastic syndrome (t-MDS) in 2 cases. The median onset of t-HN was 29(16-90) months, the median OS of t-HN was 14(1-60) months, and 3 years of OS was 17.1%. Among therapy-related acute leukemia (t-AL) patients, 40% (10/25) patients had combined complex karyotype, 36% (9/25) patients with MLL gene rearrangement, 12% (3/25) patients with combined AML/ETO fusion gene, 1 case with NPM1 point mutation and 1 case with P16 gene deletion., Conclusions: Therapy-related hematological neoplasms had a worse prognosis.

Objective: To explore the effect of mesenchymal stem cells (MSCs) on refractory acute graft-versus-host disease (GVHD) failed to second-line immunosuppressive therapy., Methods: Twenty-two patients with refractory aGVHD received the treatment of first- and/or second-line immunosuppressive agents in combination with MSCs. The MSCs from bone marrow (BM) of HLA-unrelated third-party donors, were used at the median time of 19 (11 - 49) days after aGVHD onset, at a dose of 1×10(6)/kg once with an interval of 14 days. If the symptoms of aGVHD did not improve after continuous infusion four times, MSCs would be discontinued. Meanwhile the proportion of CD3(+)CD4(+), CD3(+)CD8(+) and CD4(+)CD25(+) was detected by flow cytometry (FCM) before and 4 weeks after the MSCs infusion., Results: The median dose of MSC was 4.8 (2.5 - 6.3)×10(6) cell×kg(-1) with a median infusion of 2.5 (1 - 7) times per case. Twelve patients achieved complete response (CR), four partial response (PR) after treatment. The total effective rate was 72.7% (16/22). With a median follow-up of 246.5 (36 - 1116) days post-transplantation, 11 patients survived and 11 died. The causes of death included GVHD(n = 6), infections (n = 3), leukemia relapse (n = 1) and post-transplant lymphoproliferative diseases (n = 1), respectively. The proportion of CD3(+)CD4(+)/CD3(+)CD8(+) was significantly higher at 4th week after MSCs infusion compared to before infusion (1.58 ± 0.54 vs 0.49 ± 0.19, \%t\% = 0.628, P = 0.04). The number of CD4(+)CD25(+) Treg cells had not changed much compared to before infusion (P = 0.606)., Conclusion: MSCs derived from the BM of a third-party donor are effective to treat aGVHD failed to second-line immunosuppressive therapy after allo-HSCT. MSCs might play a role in aGVHD by regulating the rate of CD3(+)CD4(+)/CD3(+)CD8(+).

Objective: To evaluate the efficacy and safety of bone marrow-derived mesenchymal stem cells (MSC) from a third party donor for secondary poor graft function (PGF) following allogeneic hematopoietic stem cell transplantation(allo-HSCT)., Methods: Five patients with secondary PGF were treated with MSC at a dose of 1 x 10(6)/kg body weight at a median of 47 days (35 to 61) after secondary PGF. MSC were derived from bone marrow (BM) of HLA-disparate third party donors, cultured in vitro and infused without HSC. If absolute neutrophil cell (ANC) and platelet counts (PLT) did not reach the standardization of > 1.5 x 10(9)/L and > 50.0 x 10(9)/L, respectively, within 28-30 days after the first MSC treatment, a second MSC treatment was required., Results: MSC were infused once in one patient and twice in four patients with an interval of 28 to 30 days. All patients obtained ANC and PLT recovery at a median of 34 (25 to 49) days and 47 (26 to 54) days, respectively, without toxic side effects within follow-up periods of median 761 (204-1491) days. Three patients developed Epstein-Barr virus (EBV) reactivation at 42, 48, 108 days after MSC infusion, respectively and two of the three coverted to posttransplant lymphoproliferative disorders (PTLD)., Conclusion: MSC from a third party donor are effective to patients with secondary PGF following allo-HSCT, whether it might increase the risk of EBV reactivation and EBV-associated PTLD need further observation.

Objective: To analyze the incidence and the risk factors of late-onset non-infectious pulmonary complications (LONIPC) after allogeneic hematopoietic stem cell transplantation (allo-HSCT)., Methods: Clinical data from 144 patients who underwent allo-HSCT and survived more than 3 months at our institution between January 2003 and August 2006 were collected, and the incidence and its risk factors of LONIPC were reviewed retrospectively., Results: With a median follow-up time of 1149 (103 - 2151) d, 24 patients (16.7%) fulfilled the diagnostic criteria for LONIPC. The median time to diagnosis of LONIPC was 235 days after transplantation (range, 116 - 950 days). Three variables were associated with LONIPC on univariate analysis: CMV antigenaemia (P = 0.000), grade II-IV aGVHD (P = 0.026) and cGVHD (P = 0.002). By using a Binary Logistic regression model for multivariate analysis, cGVHD (OR = 18.804, P = 0.004) and CMV antigenaemia (OR = 14.376, P = 0.000) were the risk factors of LONIPC., Conclusion: LONIPC is one of the major complications after allo-HSCT and cGVHD and CMV antigenaemia are the risk factors for developing LONIPC.

Objective: To evaluate the impact of luteinizing hormone-releasing hormone (LHRH) on the protection of thymic function after allogenic hematopoietic stem cell transplantation (allo-HSCT)., Methods: Murine model of MHC mismatched allogeneic HSCT (C57BL/6-->BALB/c) was established. The severity of acute graft-versus-host-disease (GVHD) was assessed according to a clinical scoring system. The intra-cellular levels of IFN gamma, TNFalpha and IL-1 beta in thymocyte were analyzed by protein array and thymic function by quantification of signal-joint TCR rearrangement excision circles (sjTRECs)., Results: All recipients in group A (allogeneic mice), B (allogeneic LHRH castrated-mice) and C (syngenic mice) achieved hematopoietic reconstitution. White blood cell (WBC) over 1.0 x 10(9)/L in groups A, B and C were on day (11.2 +/- 1.4), day (9.8 +/- 0.6) and day (9.7 +/- 0.7), respectively (P = 0.003, 0.002). The onset of acute GVHD in group B was (14.1 +/- 0.7) d and in group A was (11.4 +/- 1.2) d (P = 0.000). All mice in groups A and B developed acute GVHD. No mice occurred aGVHD in group C. The average scores of acute GVHD in groups A and B were (9.1 +/- 0.7) and (5.1 +/- 1.0), respectively (P = 0.000). The levels of IFN gamma, TNFalpha and IL-1 beta in control group were (2.3 +/- 2.5) ng/ml, (1.7 +/- 1.1) pg/ml and (1.8 +/- 1.2) pg/ml, respectively. The IFN gamma levels in groups A, B and C were (10.5 +/- 2.1) ng/ml, (6.7 +/- 2.1) ng/ml and (5.2 +/- 3.3) ng/ml, TNFalpha levels were (7.0 +/- 2.6) pg/ml, (4.3 +/- 0.8) pg/ml and (3.0 +/- 1.8) pg/ml, and IL-1 beta levels were (24.9 +/- 9.0) pg/ml, (17.4 +/- 3.9) pg/ml and (10.8 +/- 3.1) pg/ml, respectively. There were significant differences in the levels of cytokines between group A and the control group (P = 0.000, 0.000, 0.000). The levels of cytokines in group B were significantly higher than those in control group (P = 0.000, 0.003, 0.000). The levels of IFN gamma and IL-beta in group C were significantly higher than those of in control group (P = 0.015, 0.013), and so did in group A than in group B (P = 0.002, 0.002, 0.004), and in group A than in group C (P = 0.000, 0.000, 0.000). The analysis of linear regression showed that the average levels of IFN gamma and TNFalpha paralleled with aGVHD scores (r(2) = 0.359, P = 0.045; r(2) = 0.228, P = 0.019). The average sjTRECs copies/1000 PBMNCs were (39.4 +/- 44.7) in the control group and (12.3 +/- 13.0), (58.0 +/- 71.8) and (19.6 +/- 14.6) in groups A, B and C, respectively. There was no significant difference in the multiple comparisons of peripheral blood levels of sjTRECs among these four groups (P = 0.468)., Conclusion: IFN gamma, TNFalpha and IL-1 beta might be involved in the damage to the thymus by acute GVHD. Sex steroid inhibitor can not only reduce the severity of thymic damage after allo-HSCT, but also reduce the severity of aGVHD and the mechanism might be associated with the reduction of intra-cellular levels of IFN gamma in thymocyte.

Objective: To compare the hemopoietic reconstitution, immune reconstitution, infection, incidence of graft-versus-host disease (GVHD) and clinical outcome between unrelated donor peripheral blood stem cell (PBSC) transplantation and bone marrow (BM) transplantation for leukemias., Methods: The clinical results of 21 leukemia patients receiving G-CSF mobilized PBSC graft from unrelated donors were compared with that of 32 patients receiving unrelated BM transplants., Results: Compared with BM grafts, the PBSC graft contained significantly more nucleated cells (P = 0.000), and resulted in a significantly shorter time-to-neutrophil (12.43 +/- 3.67 vs 16.16 + 2.99 days) and platelet engraftment (14.67 +/- 6.19 vs 21.23 +/- 8.25 days), (P = 0.000 and 0.003, respectively). T cell reconstitution between the two groups differed little after transplantation. The incidences of early-stage infection (42.86% vs 53.13%), the probabilities of acute graft-versus-host disease (aGVHD) (61.90% vs 71.88%), the grades III to IV aGVHD (23.81% vs 15.63%), the chronic GVHD (47.06% vs 43.48%) and the probabilities of relapse (6.90% vs 12.50%) between PBSC and BM groups all has no statistical significance (NS). The 2-year disease free survival (DFS) rates of the two groups were (50.14 +/- 12.00) % and (59.81 +/- 8.99)%, respectively also have no NS., Conclusion: G-CSF-mobilized unrelated donor PBSCs engraft more rapidly in the recipients as compared with conventional BM grafts. The T cell reconstitution, the incidence of infection, the incidence and severity of aGVHD and cGVHD, and the 2-year DFS rates between the two groups all have no significant differences.

Objective: To investigate the pathogenic causes of community-acquired pneumonia (CAP) in adult patients in China, the relation of previous antibiotic use and the Pneumonia Patient Outcome Research Team (PORT) classification to microbial etiology, and the prevalence of drug resistance of common CAP bacteria., Methods: A prospective study was performed on 665 consecutive adult patients with CAP at 12 centers in 7 Chinese cities during one year. The etiology of pneumonia was considered if one of the following criteria was met: (1) valid sputum sample yielding one or more predominant strains; (2) blood cultures yielding a bacterial pathogen; (3) seroconversion, a > or = 4-fold increase or decrease titers of antibodies to Mycoplasma pneumoniae, Chlamydia pneumoniae and Legionella pneumophila. Minimum inhibitory concentration (MIC) of respiratory tract isolates was determined using the agar dilution method., Results: Pathogens were identified in 324/610 patients (53.1%) with valid serum samples and sputum cultures as follows: Mycoplasma pneumoniae (126, 20.7%), Streptococcus pneumoniae (63, 10.3%), Haemophilus influenzae (56, 9.2%), Chlamydia pneumoniae (40, 6.6%), Klebsiella pneumoniae (37, 6.1%), Legionella pneumophila (31, 5.1%), Staphylococcus aureus (23, 3.8%), Escherichia coli (10, 1.6%), Moraxella catarrhalis (8, 1.3%), Pseudomonas aeruginosa (6, 1.0%). Of 195 patients with a bacterial pathogen, an atypical pathogen was identified in 62 (10.2%) cases. The non-susceptibility rate of Streptococcus pneumoniae to penicillin, azithromycin, and moxifloxacin was 20.3%, 75.4% and 4.3% respectively., Conclusions: Atypical pathogens have important role in CAP, with Mycoplasma pneumoniae being the most common pathogen, and mixed infection of atypical pathogens with bacteria was found in 10.2% of the cases. Streptococcus pneumoniae and Haemophilus influenzae remain the most important bacteria for CAP. More than 75.0% of Streptococcus pneumoniae was resistant to macrolides and 20.3% was resistant to penicillin.

Objective: To study the pathogens in community-acquired pneumonia (CAP), especially the prevalence of atypical pathogens., Methods: A prospective study was performed on 103 consecutive adult patients with CAP between November 2001 and June 2002. Antibodies of the paired serum samples to Mycoplasma pneumoniae, Legionella pneumophilia, and Chlamydia pneumoniae were detected. The P1 adhesion gene of Mycoplasma pneumoniae and the 16S ribosome gene specific for Chlamydia pneumoniae were detected with polymerase chain reaction (PCR). Legionella antigen in urine was detected using enzyme immunoassay (EIA) method. Sputum samples were collected for culture, and bacteria were isolated and identified using conventional methods., Results: The etiology of CAP was identified in 50 (48.5%) patients. The distribution of causal agents was as follows: Mycoplasma pneumoniae in 23 (22.3%) cases, Legionella pneumophilia 3 (2.9%), Chlamydia pneumoniae 2 (1.9%), streptococcus pneumoniae 12 (11.7%), Haemophilus influenzae 9 (8.7%), and Klebsiella pneumoniae 7(6.8%). In 6 patients (5.8%) more than one causal agent were found, among them Mycoplasma pneumoniae was found in 5 cases with mixed infections., Conclusions: Atypical pathogens especially Mycoplasma pneumoniae have an important role in CAP. Streptococcus pneumoniae and Haemophilus influenzae remain the most common bacteria, and mixed infection should not be ignored.