Combination Of CD34 Research Articles

Dipeptide Nitrile CD34 with Curcumin: A New Improved Combination Strategy to Synergistically Inhibit Rhodesain of Trypanosoma brucei rhodesiense.

Rhodesain is the main cysteine protease of Trypanosoma brucei rhodesiense, the parasite causing the acute lethal form of Human African Trypanosomiasis. Starting from the dipeptide nitrile CD24, the further introduction of a fluorine atom in the meta position of the phenyl ring spanning in the P3 site and the switch of the P2 leucine with a phenylalanine led to CD34, a synthetic inhibitor that shows a nanomolar binding affinity towards rhodesain (Ki = 27 nM) and an improved target selectivity with respect to the parent dipeptide nitrile CD24. In the present work, following the Chou and Talalay method, we carried out a combination study of CD34 with curcumin, a nutraceutical obtained from Curcuma longa L. Starting from an affected fraction (fa) of rhodesain inhibition of 0.5 (i.e., the IC50), we observed an initial moderate synergistic action, which became a synergism for fa values ranging from 0.6 to 0.7 (i.e., 60-70% inhibition of the trypanosomal protease). Interestingly, at 80-90% inhibition of rhodesain proteolytic activity, we observed a strong synergism, resulting in 100% enzyme inhibition. Overall, in addition to the improved target selectivity of CD34 with respect to CD24, the combination of CD34 + curcumin resulted in an increased synergistic action with respect to CD24 + curcumin, thus suggesting that it is desirable to use CD34 and curcumin in combination.

Peripheral Blood CD34 Donor Chimerism has Greater Clinical Utility Than CD3 for Detecting Relapse after Allogeneic Stem Cell Transplantation for Acute Myeloid Leukemia or Myelodysplastic Syndrome

Monitoring of donor chimerism (DC) may detect early relapse following allogeneic hematopoietic stem cell transplantation (allo-SCT) for acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS). Most centers use unfractionated peripheral blood or T-cells to monitor DC, although CD34+ DC may be more predictive. The limited adoption of CD34+ DC may be due to the lack of detailed, comparative studies. To address this knowledge gap, we compared peripheral blood CD34+ and CD3+ DC in 134 patients who underwent allo-SCT for AML or MDS. In July 2011, the Alfred Hospital Bone Marrow Transplantation Service adopted routine monitoring of DC in the lineage-specific CD34+ and CD3+ cell subsets from peripheral blood at 1, 2, 3, 4, 6, 9, and 12 months post-transplantation for AML or MDS. Immunologic interventions, including rapid withdrawal of immunosuppression, azacitidine, and donor lymphocyte infusion, were prespecified for CD34+ DC ≤80%. Overall, CD34+ DC ≤80% detected 32 of 40 relapses (positive predictive value [PPV], 68%; negative predictive value [NPV], 91%), compared with 13 of 40 relapses for CD3+ DC ≤80% (PPV, 52%; NPV, 75%). Receiver operating characteristic analysis showed the superiority of CD34+ DC, with the greatest value at day 120 post-transplantation. CD3+ DC provided additional value in only 3 cases, preceding CD34+ DC ≤80% by 1 month. We further show that the CD34+ DC sample can be used to detect NPM1mut, with the combination of CD34+ DC ≤80% and NPM1mut identifying the highest risk of relapse. Among the 24 patients in morphologic remission at the time of CD34+ DC ≤80%, 15 (62.5%) responded to immunologic interventions (rapid withdrawal of immunosuppression, azacitidine, or donor lymphocyte infusion) with recovery of CD34+ DC >80%, and 11 of these patients remained in complete remission for a median of 34 months (range, 28 to 97 months). In contrast, the other 9 patients did not respond to the clinical intervention and relapsed within a median of 59 days after detecting CD34+ DC ≤80%. The CD34+ DC was significantly higher in responders than in nonresponders (median, 72% versus 56%; P=.015, Mann-Whitney U test). Overall, monitoring of CD34+ DC was considered clinically useful (early diagnosis of relapse enabling preemptive therapy or predicting low risk of relapse) in 107 of 125 evaluable patients (86%). Our findings show that peripheral blood CD34+ DC is feasible and superior to CD3+ DC for predicting relapse. It also provides a source of DNA for measurable residual disease testing, which may further stratify the risk of relapse. If validated by an independent cohort, our results suggest that CD34+ should be used in preference to CD3+ DC for detecting early relapse and guiding immunologic interventions following allo-SCT for AML or MDS.

Solitary Fibrous Tumours/Hemangiopericytomas of the Maters(Meninx):A Clinicopathologic Analysis

To study the clinicopathologic characteristics,immunohistochemical features,differential diagnosis,and prognosis of solitary fibrous tumours(SFT)/hemangiopericytomas(HPC)in the maters(meninx). Methods A series of 7 cases previously diagnosed as SFT/HPC at the Department of Pathology,Peking Union Medical College Hospital,during the period from 2008 to 2018 were analyzed for clinical data,histopathology,and immunohistochemical findings.The patients were followed up and the relevant literatures were reviewed. Results These seven patients included two males and 5 females aged 22 to 77 years(mean,49 years).Headache was the most common symptom.The magnetic resonance imaging of SFT/HPC showed irregularly contoured masses and dural tail sign was observed at the periphery of the lesion in 4 cases.The major axis of the tumor ranged from 1.8 cm to 10 cm(mean,4 cm).The tumors were located in the mater in 6 cases and in the spinal meninx in 1 case.The tumors were surgically removed in all cases.Under light microscope,the tumors were formed by long round,oval or spindle cells,with rich branching vascular pattern and varying quantity of collagenous fibers bands in both sparse areas and dense areas.According the WHO classification,2 cases were in WHO grade Ⅰ,2 cases in WHO grade Ⅱ,and 3 cases in WHO grade Ⅲ.Immunohistochemistry of the paraffin-embedded tissues in all cases showed positive immunoreativity for CD34 and vimentin in all seven cases,along with positive signal transducer and activator of transcription 6 in 4 cases,negative epithelial membrane antigen and S-100 in 7 cases,and negative progestational hormone and somatostatin receptor 2 in 6 cases.The Ki-67 index ranged from 1% to 15%.Five patients with follow-up data(including 1 current case)were alive,while 2 patients were lost to follow-up. Conclusions The SFT/HPC are rare in the maters(meninx)and is clinically difficult to be differentiated from other meningioma.The combination of CD34 and signal transducer and activator of transcription 6 helps to diagnose this disease.

An Immature Immunophenotype (CD34pos, CD38dim, nTdTdim) on Malignant B-Cell Precursor Blasts at Diagnosis Predicts High Minimal Residual Disease in BCP-ALL

Abstract Background Flow cytometry is widely used for B-cell precursor acute lymphoblastic leukemia (BCP-ALL) diagnosis, and the detection of Minimal Residual Disease (MRD) by flow cytometry is an established stratification tool after induction therapy. Early risk stratification in BCP-ALL allows for individualized treatment strategies, improving prognosis and lowering treatment related toxicity. The Leukemia-Associated ImmunoPhenotype (LAIP) at time of diagnosis might comprise an early and easily accessible risk stratification tool. However, immunophenotypically distinct subpopulations are common in BCP-ALL (Øbro et al, Leukemia, 2011), yet current scoring methods do not account for this heterogeneity. This could make classification less accurate and hereby underestimate the prognostic value of the LAIP, urging the need for detailed LAIP characterization. Aim To systematically characterize the LAIP including immunophenotypic subpopulations at time of diagnosis in order to assess the prognostic potential of the LAIP in patients with BCP-ALL Methods We retrospectively evaluated flow cytometry data from time of diagnosis in 200 patients diagnosed with BCP-ALL between October 2009 and June 2015 and treated according to the NOPHO ALL 2008 protocol. Age, white blood cell count (WBC), cytogenetics and day 0 treatment stratification were registered. The expression of intracellular and surface B-lineage markers (CD19, CD20, CD22, nTdT, cyCD79a, and cyCD22), non-lineage (CD45, CD34, CD38, CD10, and nTdT) and cross-lineage expressed markers (CD123, CD66c, CD133, CD13, CD33, and CD15) was scored as negative or positive (dim/normal/bright), and broad or bimodal expression was registered. For bimodal expression the overall score was assigned according to that of the dominant subpopulation. For reference intervals, five non-ALL bone marrow samples with unaffected B-lymphopoiesis were used. The CD34, CD38, nTdT and CD45 median fluorescence intensity was assessed (data will be presented). All samples were run on a FACS Canto and analyzed in DIVA 6.0 software. End-of-induction (day 29) MRD by flow cytometry was used as primary outcome. The best combination of markers was found using a forward selection procedure in a multiple regression analysis. Gene chip analyses were performed in 171 of the 200 patients (human gene 1.0 ST array, Affymetrix) (data will be presented) Results Immunophenotypically distinct subpopulations were common at time of diagnosis (54%) with 19 patients (9.5%) having three or more subpopulations. CD34 was the most commonly bimodal marker (bimodal in 32.7%). We examined the association of the LAIP with MRD, accounting for the frequent bimodal marker expressions in LAIP scoring. Of all markers, CD34 expression had the strongest association with MRD (p<0.0001, linear regression. p=0.0034 adjusting for age, cytogenetic group, treatment arm and WBC). A combination of CD34 (p=0.0005), CD38 (p=0.0288) and nTdT (p=0.0093) (multiple regression) predicted MRD best with a CD34pos/bright, CD38 neg/dim, nTdT neg/dim phenotype associating with higher MRD. In order to exclude marker expression differences related to cytogenetic groups, we further examined patients with no cytogenetic aberrations (n=73). The association of the three markers with MRD was confirmed in this group. We examined whether high CD34 expression was enriched among patients who later relapsed (n=7), and this was the case: CD34 was brightly expressed in 42% vs. 5% in non-relapse patients, further suggesting an association between CD34 expression and prognosis. Discussion By applying a detailed LAIP characterization accounting for subpopulations, we showed that malignant BCP blasts expressing an immature phenotype (CD34pos, CD38dim, nTdTdim), resembling the pre-pro B cell-like phenotype (Sanz et al, PNAS, 2010), seem to be associated with poor treatment response in BCP-ALL. The LAIP might be a useful tool for early treatment stratification in the future. Disclosures No relevant conflicts of interest to declare.

The Enhancement of Short-Term Engraftment in NOD/Scid Mice after Double Cord Blood Transplantation Is Mediated by CD34+ Cells

Introduction: Cord blood (CB) is an attractive source of hematopoietic stem cells, however, the low number of cells available hampers its use in adult patients. Transplantation of two unrelated CB units seems to overcome the cell dose limitations for adult patients with at least similar engraftment levels compared to single CB transplantation with sufficient cell numbers. Pre-clinical studies show an important role for total cell numbers in the graft, but also CD34+ stem cells or CD34− cells, including NK cells and/or Lin+, CD3+ T cells may play a facilitating role, possibly via a graft-versus-graft effect. In this study we explored the role of the CD34+ and CD34− cells in facilitating engraftment in NOD/Scid mice after double CB transplantation.Methods: Cohorts (ch.) of irradiated (3.5Gy) NOD/Scid mice (n=9–18 mice per cohort; 3 independent experiments) were transplanted with a combination of 1.105 CD34+ cells (MACS purified; >94% pure) and 1.107 CD34- cells derived from one CB unit. In addition, mice received a combination of CD34+ and CD34− cells, or CD34+, or CD34− cells only, derived from a second CB unit (Table 1). BM engraftment was assessed by the percentage of human CD45+ cells at 6 weeks after transplantation. In addition, the percentage of human lymphoid (CD19/CD3) and myeloid (CD33) cells in the BM were evaluated at 6 weeks. Human platelet (hPLT) and human CD45+ cell recovery in blood was measured from 3 to 6 weeks after transplantation.Results: At 6 weeks, 67% of the mice in the single CB cohort (ch.1), 75% in the cohort co-transplanted with CD34− cells (ch.4), 83% in the cohort co-transplanted with CD34+ cells (ch.3) and 89% in the cohort co-transplanted with the combination of CD34+ and CD34− cells of the second donor, showed engraftment (>10% human CD45+ cells) in the BM. Mice that were co-transplanted with CD34+ cells only (ch.3) had a significantly higher level of engraftment in the BM than mice receiving no second CB unit (ch.1) (54% vs. 22%; p=0.011). A similar engraftment enhancing effect was observed in mice co-transplanted with a combination of CD34+ and CD34− cells (ch.2) (50% p=0.016 vs. ch.1). In contrast, no significant enhancing effect was observed after co-transplantation of CD34− cells only (ch.4) (36%). The distribution between human lymphoid and myeloid cells in BM was similar between al cohorts. All engrafted mice had sustained mixed chimerism in the BM without pre-dominance of a single CB unit during the time of evaluation. hPLT recovery was significantly increased in mice co-transplanted with CD34+ cells, either alone (ch.3; 607plt/μl) or in combination with CD34− cells (ch.2; 1076 plt/μl) compared to mice receiving no second CB (ch.1; 183 plt/μl) (p=0.04 and p<0.001 resp.). The observed mean hPTL concentration in cohort-2 and -3 was greater than expected by the sum of the single CBs (305 plt/μl), indicating a synergistic effect. In mice that were cotransplantated with CD34− cells from a second donor (ch.4) no significant effect on hPLT recovery (253 plt/μl) was observed. Similar results were obtained for hCD45 recovery in peripheral blood.Conclusion: These results show that the engraftment facilitating effect of co-transplantation of CD34+ cells only are similar compared to co-stransplantation of both CD34+ and CD34− cells. Therefore, it is suggested that enhancement of short-term engraftment in NOD/Scid mice by double cord blood transplantation is mainly mediated by the CD34+ cells in the second CB.Table 1: Composition of the transplants per cohort.Cohort-1 received a single CB transplantation of donor-1 or donor-2. Cohort-2 received a normal double CB transplantation.CohortTransplanted cells of donor-1Co-transplanted cells of donor 21CD34+ + CD34−ORCD34+ + CD34−2CD34+ + CD34−ANDCD34+ + CD34−3CD34+ + CD34−ANDCD34+4CD34+ + CD34−ANDCD34−

Intensive Immunosuppression Plus T-Cell Depleted Autologous Peripheral Blood Stem Cell Transplantation for Systemic Sclerosis.

Autologous peripheral blood stem cell transplantation (PBSCT) may be therapeutic in patients (pts) with severe autoimmune disorders. A pre-PBSCT regimen that optimizes immunosuppression without excessive myelotoxicity would potentially have favorable safety and efficacy profiles in these pts. To test this hypothesis we are conducting a phase I trial of cyclophosphamide (CY) dose escalation (initial CY dose 200 mg/m2/day x 5, days −7 to −3) plus fludarabine (25 mg/m2/day x 5, days −7 to −3) and rabbit anti-thymocyte globulin (ATG; 2.5 mg/kg/day x 3, days −5 to −3) followed by T-cell depleted (TCD) autologous PBSCT in adults with systemic sclerosis (SSc). To date, 5 pts (2 male, 3 female; median age, 44 yr; range, 39–59 yr) have undergone TCD PBSCT. Each pt had satisfactory PBSC collection with one 4-hr large-volume leukapheresis (LVL) after mobilization with CY (2.0 g/m2) plus G-CSF. Mean yields of CD34+ and CD3+ cells by LVL were 18.8 (range, 10.5–33.0) x 106/kg and 1.23 (range, 0.37–2.45) x 108/kg, respectively. To deplete T cells in the PBSC product we used a combination of CD34+ selection (Isolex 300i v 2.5; Baxter Oncology) and ex vivo incubation with anti-CD3 antibody (OKT3; Ortho Biotech), which resulted in a mean 5.2-log reduction of T cells (range, 4.7–6.3 log). The final PBSC products contained a mean of 9.94 (range, 4.8–13.0) x 106 CD34+ cells/kg and 1.34 (range, 0.06–4.54) x 103 CD3+ cells/kg. The daily dose of CY was 200 mg/m2 in the first 3 pts and 400 mg/m2 in the next 2 pts. Using rare-event flow cytometry, we found that the mean half-life (t 1/2) of CD3+ cells in these pts was biphasic; t 1/2 was 0.8 days from day −7 to −5 and 0.2 days from −5 to −3 days, correlating with ATG administration. In contrast, the mean t1/2 of CD3+ cells was 2.5 days in pts with hematologic malignancies receiving a myeloablative preparative regimen of CY, busulfan and etoposide. After PBSCT, the median nadir of WBC, neutrophil and platelet levels were 1.2 (range, 0.4–2.0), 0.9 (range, 0.1–1.7) and 135 (range, 114–185) x 109/L, respectively. One pt at the second CY dose level developed pericardial effusion and tamponade at day +5 and required surgical intervention. No pts developed opportunistic infections. All pts are alive at a median of 6.5+ months (range, 4.9+–15.5+ months) after PBSCT. Compared with pre-PBSCT levels, Rodnan total skin score (TSS) decreased by 10, 11 and 15 points, respectively, in 3 pts and increased by 5 and 8 points in 2 pts. One pt with worsening TSS at 12 months after PBSCT developed SSc renal crisis and requires hemodialysis. Of 3 pts with improved TSS, 1 has worsening polymyositis and 1 has recurrence of palpable tendon friction rubs. Even at the lowest CY dose, this immunosuppressive regimen provides significantly greater and more rapid T-cell kill than a conventional myeloablative regimen. The efficacy of this regimen and TCD-PBSCT in SSc is encouraging but requires longer followup and experience with a larger number of pts.