[Second allogeneic hematopoietic stem cell transplantation with reduced-intensity conditioning and donor changes in relapsed hematological malignancies after the first allogeneic transplant]

Objective: The purpose of this study was to assess the safety and efficacy of a second allogeneic hematopoietic stem cell transplantation (allo-HSCT) with reduced-intensity conditioning (RIC) in patients with hematological malignancies who had relapsed after the first allo-HSCT. Methods: Between April 2018 and June 2021, 44 patients with hematological malignancies (B-ALL 23, T-ALL/T-LBL 4, AML15, and MDS 2) were enrolled and retrospectively examined. Unrelated donors (n=12) or haploidentical donors (n=32) were used. Donors were replaced in all patients for the second allo-HSCT. Hematological and immunological germline predisposition genes and hematopoietic and immune function tests were used to select the best-related donor. Total body irradiation (TBI) /fludarabine (FLU) -based (n=38), busulfan (BU) /FLU-based (n=4), total marrow irradiation (TMI) /FLU-based (n=1), and BU/cladribine-based (n=1) were the RIC regimens used. For graft versus host disease (GVHD) prevention, cyclosporine, mycophenolate mofetil, short-term methotrexate, and ATG were used. Eighteen (40.9%) of 44 patients with gene variations for which targeted medications are available underwent post-transplant maintenance therapy. Results: The median age was 25 years old (range: 7-55). The median interval between the first and second HSCT was 19.5 months (range: 6-77). Before the second allo-HSCT, 33 (75%) of the patients were in complete remission (CR), whereas 11 (25%) were not. All patients had long-term engraftment. The grade Ⅱ-Ⅳ GVHD and severe acute GVHD rates were 20.5% and 9.1%, respectively. Chronic GVHD was found in 20.5% of limited patterns and 22.7% of severe patterns. CMV and EBV reactivation rates were 29.5% and 6.8%, respectively. Hemorrhage cystitis occurred in 15.9% of cases, grade Ⅰ or Ⅱ. The 1-yr disease-free survival (DFS), overall survival (OS), and cumulative recurrence incidence (RI) rates of all patients were 72.5% (95% CI, 54.5%-84.3%), 80.6% (95% CI, 63.4%-90.3%), and 25.1% (95% CI, 13.7%-43.2%), respectively, with a median follow-up of 14 (2-39) months. There were eight deaths (seven relapses and one infection). The rate of non-relapse mortality (NRM) was only 2.3%. The CR patients' 1-yr RI rate was significantly lower than the NR patients (16.8% vs 48.1%, P=0.026). The DFS rate in CR patients was greater than in NR patients, although there was no statistical difference (79.9% vs 51.9%, P=0.072). Univariate analysis revealed that CR before the second allo-HSCT was an important prognostic factor. Conclusion: With our RIC regimens, donor change, and post-transplant maintenance therapy, the second allo-HSCT in relapsed hematological malignancies after the first allo-HSCT is a safe and effective treatment with high OS and DFS and low NRM and relapse rate. The most important factor influencing the prognosis of the second allo-HSCT is the patient's illness condition before the transplant.

[Comparative study of decompression of unilateral biportal endoscopic compared to laminectomy with fusion and internal fixation in the treatment of severe lumbar spinal stenosis]

Objective: To compare the clinical efficacy of unilateral biportal endoscopy unilateral laminotomy for bilateral decompression (UBE-ULBD) to posterior lumbar interbody fusion (PLIF) in the treatment of severe lumbar spinal stenosis (SLSS). Methods: The clinical data of 64 patients with SLSS treated with PLIF and UBE-ULBD in Dalian Central Hospital Affiliated to Dalian Medical University from April 2018 to April 2021 were collected and divided into UBE group and PLIF group according to the different surgical procedures. There were 30 cases in the UBE group, including 12 males and 18 females, aged (69.8±6.8) years. There were 34 patients in the PLIF group, including 15 males and 19 females, aged (69.3±6.3) years. The operation time, intraoperative blood loss, surgical complications, the volume of drainage, transfusion, post-operative bed rest time, postoperative hospital stay, surgical costs of both groups were recorded and analyzed. The visual analogue scales (VAS) of back/leg pain (pre-operation and 1 d, 1 month, 6 month, 12 month post-operation) and Oswestry disability index (ODI) (pre-operation and 1 month, 6 month, 12 month post-operation) were used to determine the outcome. And the dural sac cross-sectional area (DSCA) and Schizas grade of both groups preoperatively and 6 month postoperatively were recorded. Results: The operation time in the UBE group was (69.2±8.0) min, it was lower than that in the PLIF group (139.0±15.3) min (P<0.05). The intraoperative blood loss and drainage in the UBE group were (19.5±5.6) ml and (15.0±10.8) ml, which were both lower than those in the PILF group [(212.4±34.1) ml and (169.6±43.8) ml] (both P<0.05). The postoperative bed rest time and hospital stay in the UBE group were (1.8±0.7) days and (3.0±0.9) days, which were both shorter than those in the PLIF group [(4.5±1.4) days and (7.1±1.7) days] (both P<0.05). The surgical cost was also lower in the UBE group than that in the PLIF group [RMB,(18.4±1.0) thousands yuan vs (33.9±2.4) thousands yuan, P<0.05]. In addition, no patient received blood transfusion in the UBE group. Dural sac tear occurred in 2 cases in the UBE group and in 3 cases in PLIF group; nerve root injury and infection occurred in one case in the PLIF group, respectively. In the PLIF group, the VAS of back pain was not significantly improved 1 day after operation when compared with that before the operation, but it significantly improved 1 month, 6 months and 1 year after operation (all P<0.05). The VAS for back pain at 1 day after operation and ODI at 1 month after operation in the UBE group were significantly superior to those in the PLIF group (both P<0.05), while there was no significant difference between the two groups in the VAS for back pain at 1 month, 6 months and 1 year after operation and ODI at 6 months and 1 year after operation. Both groups got significant canal expansion after the surgery and the PLIF group showed larger canal expansion extent (all P<0.05). Both groups improved significantly after surgery in the Schizas grade, there were 25 cases in UBE group improved to grade A, 5 cases to grade B while 30 cases in PLIF group improved to grade A, 4 cases to grade B, but there was no significant difference between the two groups (P>0.05). Conclusion: ULBD-UBE could achieve full decompression of the whole spinal canal with limited structures damage in treating SLSS. Compared with PLIF, UBE-ULBD could get complete decompression as well as less iatrogenic damage, it may be an ideal alternative surgical technique for SLSS with less invasion.

Determination of IL-2 and cytotoxicity of killer cells in MTT colorimetry

The activity of interleukin 2 (IL-2) in culture supernatants of lymphokine-activated killer (LAK) cells and tumor infiltrating lymphocytes (TIL) as well as cytotoxicity of LAK cells on cultured leukemic cells were determined by MTT colorimetry. The results showed that higher activity of IL-2 in culture supernatant of LAK and TIL cells was found; it could be used to support the culture of IL-2 dependent cell lines. The significant cytotoxicity of LAK cells on leukemic cell lines could be found in vitro, and it was consistent with the ratio of effector cells to target cells. The number of living leukemic cells is consistently related with the concentration of formazan metabolite of MTT. It suggested that the numbers of living cells and cytotoxicity of LAK cells could be estimated by determination of formazan metabolite OD value.

Safety and immunogenicity of live attenuated hepatitis A virus vaccine (H2 strain) in humans

A study was made in Neijiang City, Sichuan Province to observe the safety and immunogenicity of a live attenuated hepatitis A virus (HAV) vaccine (H2 strain). 3,031 children, aged 6 to 9 years, were injected subcutaneously with 10(6.0) TCID50, 10(5.5) TCID50, and 10(5.0) TCID50 of HAV vaccine; the seroconversion rate and antibody GMT were 97.52%-90.68%, GMT = 1:5.19 +/- 1.90-1:3.36 +/- 1.94; 84.75%-76.27%, GMT = 1:4.29 +/- 1.96-1:2.0 +/- 2.67; 53.23%-51.61%, GMT = 1:2.57 +/- 1.89-1:1.68 +/- 1.41 respectively after 4 weeks to 12 months of inoculation. Forty-eight children in the control group were anti-HAV negative at 4, 8, and 12 weeks; 21 children in the oral group were not antibody positive 4 and 8 weeks after oral administration of the vaccine. The stool specimens of 3 of the 14 vaccinated children were HAA positive. The results suggest that the live attenuated HAV vaccine (H2 strain) is of good immunogenicity and safety.

An analysis of antigenic polypeptides of dengue viruses and their specificity with western blotting

Dengue virus (DV) samples which harvested after having been either propagated in C6/36 cells or passaged by murine intracerebral inoculation were investigated by Western blotting. Two different denaturing methods with the same solution were selected before electrophoresis, one at 60 degrees C for 20 min; the other at 100 degrees C for 5 min. After the samples were heated at 60 degrees C for 20 min, 3 bands of sizes 46 ku, 70 ku and 98 ku were positively recognized by rabbit immunized sera. The peptide of 98 ku was DV group specific; While that of 46 ku could also react with the sera against both heterologous DV serotype and Japanese B encephalitis virus (JEV). After the samples were heated at 100 degrees C for 5 min, 3 peptides in size of 20 ku, 46 ku and 57 ku were recognized by the rabbit sera against both homologous and heterologous DV serotypes, while the peptide of 57 ku could also be recognized by anti-JEV serum. There was no significant difference in the results of Western blot between the DV antigens harvested from cellular culture and those from intra-cerebral inoculation.

Studies on monoclonal anti-isotypic and anti-idiotypic antibodies against leukemia and myeloma: V. The effects of monoclonal antibodies and interferon on the levels of cyclic nucleotides in leukemic cell lines

After the leukemic cell lines were treated with monoclonal antibodies (McAbs) and interferon (IFN-alpha), the changes of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) levels in the corresponding leukemic cell lines were measured by radioimmunoassay. The results showed that when the ratio of antigen to antibody was 80 to 1, the cAMP levels in the leukemic cell lines were obviously higher than those in the controls while the cGMP levels were obviously lower after being treated with the corresponding McAbs for 16-24 h (P < 0.001). The average level of intracellular cAMP was remarkably increased and that of cGMP underwent no significant changes in the leukemic cell lines after treatment with IFN-alpha.

Purification and immunoreactivity of monoclonal antibodies against myeloma-lambda chain

In this study, two murine IgM-monoclonal antibodies (IgM-McAbs) against lambda chain of myeloma protein from hybridoma ascites were purified by Sephadex G200 chromatography. The eluate of the first peak on absorption at 280 nm formed one precipitation band with rabbit anti-mouse IgM or anti-mouse immunoglobulin in agar gel double diffusion test; it also formed a detectable precipitation line in the IgM reaction area in immunoelectrophoresis. These findings showed that the eluate of the first peak on absorption at 280 nm contained purified IgM-McAbs. It was found in indirect ELISA that the immunoreactivity of the eluate of the first peak was four to five fold higher than that of the original ascites with equimolar protein concentration. Double antibody sandwich ELISA analyses of the immunoreactivity of HRP-conjugated IgM-monoclonal antibodies with lambda chain denoted that the purified IgM-McAb-HRP-conjugate might be of practical value in quantitative as well as qualitative assay of lambda chains.

Studies on monoclonal anti-isotypic and anti-idiotypic antibodies against leukemia and myeloma: II. Preparation and characteristics of monoclonal anti-isotypic antibodies to IgM from B chronic lymphocytic leukemia

Five hybridomas producing McAbs against human serum IgM-isotype were obtained by fusing the myeloma NS-1 cell and the BALB/C murine spleen cell which had been immunized by serum IgM of patient with B chronic lymphocytic leukemia (B-CLL). These McAbs only reacted with human IgM, not with other immunoglobulins in ELISA and immune double diffusion test. An approximate positive rate of peripheral blood lymphocyte (PBL) was got when these McAbs and the McAbs against B cell were tested by indirect immunofluorescent assay. The positive rate was similar to that obtained by direct immunofluorescent test. Immunoblotting showed that the molecular weight of the antigen to these McAbs was 70-90 Kd, indicating that the antigen was IgM. The practical value of the McAbs against human IgM was also discussed.