Impact of CD34 Cell Dose and Conditioning Regimen on Outcomes after Haploidentical Donor Hematopoietic Stem Cell Transplantation with Post-Transplantation Cyclophosphamide for Relapsed/Refractory Severe Aplastic Anemia.

Severe aplastic anemia (SAA) is a life-threatening disease that can be cured with allogeneic cell transplantation (HCT). Haploidentical donor transplantation with post-transplantation cyclophosphamide (haplo-PTCy) is an option for patients lacking an HLA-matched donor. We analyzed 87 patients who underwent haplo-PTCy between 2010 and 2019. The median patient age was 14 years (range, 1 to 69 years), most were heavily transfused, and all received previous immunosuppression (25% without antithymocyte globulin). Almost two-thirds (63%) received standard fludarabine (Flu)/cyclophosphamide (Cy) 29/total body irradiation (TBI) 200 cGy conditioning, and the remaining patients received an augmented conditioning: Flu/Cy29/TBI 300-400 (16%), Flu/Cy50/TBI 200 (10%), or Flu/Cy50/TBI 400 (10%). All patients received PTCy-based graft-versus-host disease (GVHD) prophylaxis. Most grafts (93%) were bone marrow (BM). The median duration of follow-up was 2 years and 2 months. The median time to neutrophil recovery was 17 days. Primary graft failure occurred in 15% of the patients, and secondary or poor graft function occurred in 5%. The incidences of grade II-IV acute GVHD was 14%, and that of chronic GVHD was 9%. Two-year overall survival and event-free survival (EFS) were 79% and 70%, respectively. EFS was higher for patients who received augmented Flu/Cy/TBI (hazard ratio [HR], .28; P = .02), and those who received higher BM CD34 cell doses (>3.2 × 10E6/kg) (HR, .29; P = .004). The presence of donor-specific antibodies before HSCT was associated with lower EFS (HR, 3.92; P = .01). Graft failure (HR, 7.20; P < .0001) was associated with an elevated risk of death. Cytomegalovirus reactivation was frequent (62%). Haploidentical HCT for SAA is a feasible procedure; outcomes are improved with augmented conditioning regimens and BM grafts with higher CD34 cell doses.

Targeted-dose of busulfan: Higher risk of sinusoidal obstructive syndrome observed with systemic exposure dose above 5000 µMol⸱min. A historically controlled clinical trial.

Busulfan is given in the conditioning regimens preceding hematopoietic stem cell transplantation (HSCT), and plasma levels can be monitored. A targeted, individualized systemic exposure (SE) dose can be achieved by calculating the area under the plasma concentration versus time curve (AUC). The objective of this study was to determine a cutoff value for safety for the AUC for busulfan plasma levels in patients undergoing HSCT. A total of 149 consecutive HSCT patients were studied. After an oral test dose of busulfan, we set target doses of 4000, 5000, or 6000 µMol⸱min/day, and analyzed the AUC of oral or intravenous Bu. These patients were compared with 53 historical control subjects who had received myeloablative conditioning regimen without busulfan pharmacokinetic monitoring. Using a test dose and the administration route had no impact on the sinusoidal obstructive syndrome (SOS) incidence, transplant-related mortality or 1-year overall survival. However, patients receiving busulfan at doses set up at AUC > 5000 had an increased risk to develop SOS after HSCT (hazard ratio 3.39, p = 0.034, 95% CI 1.09-10.52). Adjusting the busulfan dose according to SE levels target dose during conditioning is associated with lower rates of oral severe mucositis and SOS. A cutoff of 5000 µMol⸱min is safe and does not impair survival.

Diagnosis by real-time polymerase chain reaction of pathogens and antimicrobial resistance genes in bone marrow transplant patients with bloodstream infections.

BACKGROUND: Early identification of pathogens and antimicrobial resistance in bloodstream infections (BSIs) decreases morbidity and mortality, particularly in immunocompromised patients. The aim of the present study was to compare real-time polymerase chain reaction (PCR) with commercial kits for detection of 17 pathogens from blood culture (BC) and 10 antimicrobial resistance genes. METHODS: A total of 160 BCs were taken from bone marrow transplant patients and screened with Gram-specific probes by multiplex real-time PCR and 17 genus-specific sequences using TaqMan probes and blaSHV, blaTEM, blaCTX, blaKPC, blaIMP, blaSPM, blaVIM, vanA, vanB, and mecA genes by SYBR Green. RESULTS: Twenty-three of 33 samples identified by phenotypic testing were concordantly positive by BC and real-time PCR. Pathogen identification was discordant in 13 cases. In 12 of 15 coagulase-negative staphylococci, the mecA gene was detected and four Enterococcus spp. were positive for vanA. Two blaCTX and three blaSHV genes were found by quantitative PCR. The blaKPC and metallo-ß-lactamase genes were not detected. Five fungal species were identified only by real-time PCR. CONCLUSIONS: Real-time PCR could be a valuable complementary tool in the management of BSI in bone marrow transplants patients, allowing identification of pathogens and antimicrobial resistance genes.

Brazilian Nutritional Consensus in Hematopoietic Stem Cell Transplantation: Graft- versus -host disease.

The Brazilian Consensus on Nutrition in Hematopoietic Stem Cell Transplantation: Graft- versus -host disease was approved by Sociedade Brasileira de Transplante de Medula Óssea , with the participation of 26 Brazilian hematopoietic stem cell transplantation centers. It describes the main nutritional protocols in cases of Graft- versus -host disease, the main complication of hematopoietic stem cell transplantation.

Plasma levels of FL and SDF-1 and expression of FLT-3 and CXCR4 on CD34+ cells assessed pre and post hematopoietic stem cell mobilization in patients with hematologic malignancies and in healthy donors.

Peripheral blood stem cells (PBSC) became the main source of cells for autologous transplantation. Alterations in the expression of adhesion molecules are essential in the CD34+ cells mobilization process. These molecules are involved in the interaction between hematopoietic and stromal cells and they have been disclosed as a considerable factor to the trafficking and homing of the CD34+ progenitor cells. This is a non-randomized PBSC mobilization study designed to evaluate the influence and behavior of FL and SDF-1 and their receptors in two different moments, prior and after HPCs mobilization, with the yield of CD34+ cells collected by apheresis. There was higher concentration of FL and lower of SDF-1 plasma level at post than pre PBSC mobilization (p=0.001 and p=0.012, respectively) regarding all individuals searched, but without any correlation with a good yield of CD34+ cells. However, CXCR4 expressions on the CD34+ cells from bone marrow aspirates (BMA), at pre and post mobilization showed a difference statistical significant for those individuals with good yield of CD34+ cells (p=0,036), but not achieved for poor yield (p=0,156). There was a higher expression of CXCR4 in steady-state for the successfully individuals than for those unsuccessfully (529.84+/-54.68 and 496.31+/-97.51, respectively). In conclusion, we confirmed the important role of CXCR4/SDF-1 axis in the process of PBSC mobilization.

Pharmacokinetics analysis results are similar for oral compared to intravenous busulfan in patients undergoing hematopoietic stem cell transplantation, except for the earlier onset of mucositis. A controlled clinical study.

Busulfan is used in myeloablative schemes for hematopoietic stem cell transplantation (HSCT), with monitoring of dosage through the area under the curve (AUC) of the drug plasma concentration (µMol min). In this study, we compared the complete pharmacokinetics of busulfan administered orally (Bu-Oral) and intravenously (Bu-IV). We evaluated 40 patients who underwent HSCT with different types of conditioning regimens. After one dose, in the Bu-Oral group (n = 21), the median AUC was 1174 µMol min (799-4000), reaching a median of 4440 µMol min (3428-7181.5) during conditioning in 24 h. In the Bu-IV group (n = 19), it was 1244.8 µMol min (1001.2-2021), reaching 5598.0 µMol min (3102-8818) during conditioning in 24 h. Measuring plasma concentration of Bu in patients undergoing HSCT is important, regardless of the formulation, and the inclusion of a pre-HSCT test can predict the optimal dose during conditioning. Pharmacokinetics of the oral administration of busulfan, as well as clearance, are extremely variable, and this can potentially compromise the clinical results of the treatment since it makes it difficult to predict clinical results.

Proliferating cell nuclear antigen (PCNA), p53 and MDM2 expression in Hodgkins disease.

CONTEXT AND OBJECTIVE: Tumor cells in Hodgkins disease (HD) express cell proliferation markers that are evaluated according to the oncogenes involved or the expression of their proteins. Correlations between the protein expression grade and clinical data are now important for disease prognosis. DESIGN AND SETTING: This was a retrospective analysis on proliferating cell nuclear antigen (PCNA), p53 and MDM2 (murine double minute-2) expression using immunohistochemistry, on formalin-fixed, paraffin-embedded tissues from diagnostic biopsies on 51 patients with HD. The study was conducted at the Division of Hematology and Transfusion Medicine, Hospital São Paulo, Universidade Federal de São Paulo. METHODS: Antigen expression was evaluated as the proportions of positive Hodgkin and Reed-Sternberg (HRS) cells and reactive lymphocytes (L), which were compared using Spearman correlation coefficients. The Friedman test was used for comparisons between the markers. The Pearson test was used to investigate associations between marker expression and clinical and laboratory parameters, marrow involvement, complete remission (CR) and overall survival (OS) rates. RESULTS: There was overexpression of antigen proteins in HRS, in relation to L (p < 0.001). In HRS, MDM2 was higher than p53 and PCNA (p < 0.003), while the latter two were equivalent. In L, p53 was lower than MDM2 and PCNA (p < 0.001), while the latter two were equivalent. There was no relationship between protein expression and clinical and laboratory variables or outcome. CONCLUSIONS: PCNA, p53 and MDM2 are tumor markers for HD, but showed no clinical or prognostic significance in our analysis.

Allogeneic hematopoietic stem cell transplantation in patients with advanced indolent lymphoproliferative disorders.

BACKGROUND: The role of allogeneic hematopoietic stem cell transplantation for advanced indolent lymphoproliferative disorders remains to be established. OBJECTIVE: This paper aims to describe the results of allogeneic hematopoietic stem cell transplantation in patients with advanced indolent lymphoproliferative disorders. METHODS: This article reports on 29 adult patients submitted to allogeneic transplantations from 1997 to 2010. RESULTS: Most had follicular non-Hodgkin lymphoma (n=14) or chronic lymphocytic leukemia (n=12). The median age was 44 years (range: 24-53 years) and 65% of patients were male. Only 21% had had access to rituximab and 45% to fludarabine. All had advanced disease (stage IV) with partial response or stable disease. Most underwent myeloablative conditioning n=17-59%). In this scenario, refractory disease was observed in seven (24%) patients, the 100-day mortality rate was 17% (n=5) and relapse occurred in four patients (18%). The main cause of death throughout the follow up was refractory disease in six of the 12 patients who died. Moderate and severe chronic graft-versus-host disease was frequent; about 41% of 24 patients analyzed. The overall survival rates and disease free survival at 42 months were 56.7% and 45.4%, respectively. According to Kaplan-Meyer analysis, the median time from diagnosis to transplant predicted the overall survival; however age, gender and conditioning regimen did not predict the prognosis. It was impossible to reach other conclusions because of the small sample size in this study. CONCLUSIONS: The role of allogeneic transplantations should be re-evaluated in the era of targeted therapy.

Switching to nilotinib versus imatinib dose escalation in patients with chronic myeloid leukaemia in chronic phase with suboptimal response to imatinib (LASOR): a randomised, open-label trial.

BACKGROUND: Optimal management of patients with chronic myeloid leukaemia in chronic phase with suboptimal cytogenetic response remains undetermined. This study aimed to investigate the safety and efficacy of switching to nilotinib vs imatinib dose escalation for patients with suboptimal cytogenetic response on imatinib. METHODS: We did a phase 3, open-label, randomised trial in patients with chronic myeloid leukaemia in chronic phase with suboptimal cytogenetic response to imatinib according to the 2009 European LeukemiaNet criteria, in Latin America, Europe, and Asia (59 hospitals and care centres in 12 countries). Eligible patients were aged 18 years or older with Philadelphia chromosome-positive chronic myeloid leukaemia in chronic phase and Eastern Cooperative Oncology Group performance status of 0-2. Before enrolment, all patients had received 3-18 months of imatinib 400 mg once daily and had a suboptimal cytogenetic response according to 2009 ELN recommendations, established through bone marrow cytogenetics. By use of an interactive response technology using fixed blocks, we randomly assigned patients (1:1) to switch to nilotinib 400 mg twice per day or an escalation of imatinib dose to 600 mg once per day (block size of 4). Investigators and participants were not blinded to study treatment. Crossover was allowed for loss of response or intolerance at any time, or for patients with no complete cytogenetic response at 6 months. The primary endpoint was complete cytogenetic response at 6 months in the intention-to-treat population. Efficacy endpoints were based on the intention-to-treat population, with all patients assessed according to the treatment group to which they were randomised (regardless of crossover); the effect of crossover was assessed in post-hoc analyses, in which responses achieved after crossover were excluded. We present the final results at 24 months' follow-up. This study is registered with ClinicalTrials.gov (NCT00802841). FINDINGS: Between July 7, 2009, and Aug 29, 2012, we enrolled 191 patients. 96 patients were randomly assigned to nilotinib and 95 patients were randomly assigned to imatinib. Complete cytogenetic response at 6 months was achieved by 48 of 96 patients in the nilotinib group (50%, 95·18% CI 40-61) and 40 of 95 in the imatinib group (42%, 32-53%; difference 7·9% in favour of nilotinib; 95% CI -6·2 to 22·0, p=0·31). Excluding responses achieved after crossover, 48 (50%) of 96 patients in the nilotinib group and 34 (36%) of 95 patients in the imatinib group achieved complete cytogenic response at 6 months (nominal p=0·058). Grade 3-4 non-haematological adverse events occurring in more than one patient were headache (nilotinib group, n=2 [2%, including 1 after crossover to imatinib]; imatinib group, n=1 [1%]), blast cell crisis (nilotinib group, n=1 [1%]; imatinib group, n=1 [1%]), and QT prolongation (nilotinib group, n=1 [1%]; imatinib group, n=1 [1%, after crossover to nilotinib]). Serious adverse events on assigned treatment were reported in 11 (11%) of 96 patients in the nilotinib group and nine (10%) of 93 patients in the imatinib group. Seven (7%) of 96 patients died in the nilotinib group and five (5%) of 93 patients died in the imatinib group; no deaths were treatment-related. INTERPRETATION: While longer-term analyses are needed to establish whether the clinical benefits observed with switching to nilotinib are associated with improved long-term survival outcomes, our results suggest that patients with suboptimal cytogenetic response are more likely to achieve improved cytogenetic and molecular responses with switching to nilotinib than with imatinib dose escalation, although the difference was not statistically significant when responses achieved after crossover were included. FUNDING: Novartis Pharmaceuticals.

Brazilian Nutritional Consensus in Hematopoietic Stem Cell Transplantation: Graft- versus -host disease / Consenso Brasileiro de Nutrição no Transplante de Células Tronco Hematopoiéticas: doença do enxerto contra o hospedeiro

ABSTRACT The Brazilian Consensus on Nutrition in Hematopoietic Stem Cell Transplantation: Graft- versus -host disease was approved by Sociedade Brasileira de Transplante de Medula Óssea , with the participation of 26 Brazilian hematopoietic stem cell transplantation centers. It describes the main nutritional protocols in cases of Graft- versus -host disease, the main complication of hematopoietic stem cell transplantation.

RESUMO O Consenso Brasileiro de Nutrição no Transplante de Células Tronco Hematopoiéticas: doença do enxerto contra o hospedeiro foi aprovado pela Sociedade Brasileira de Transplante de Medula Óssea, com a participação de 26 centros brasileiros de transplante de células-tronco hematopoiéticas. O Consenso descreve as principais condutas nutricionais em casos de doença do enxerto contra o hospedeiro, a principal complicação do transplante de células-tronco hematopoiéticas.

Pericardial effusion and cardiac tamponade: clinical manifestation of chronic graft-versus-host disease after allogeneic hematopoietic stem cell transplantation.

The authors report a case with pericardial effusion and cardiac tamponade as a rare clinical manifestation of chronic graft-versus-host disease in a young man with acute myelogenous leukemia submitted to an allogeneic hematopoietic stem cell transplantation from a related donor.

Evaluation of 16 SNPs allele-specific to quantify post hSCT chimerism by SYBR green-based qRT-PCR.

The importance of monitoring post haematopoietic stem cell transplantation (hSCT) chimerism has been defined in numerous publications. Single-nucleotide polymorphisms (SNPs) are molecular markers that vary significantly among different populations. Allied to a very sensible technique, SNP assays seem to be very sensitive (0.001%) when post hSCT chimerism is measured. However, well known SNP frequencies are limited to certain populations, mainly in countries where there is a high level of diversity in its population, therefore restricting their use worldwide. Amplification by SYBR green based quantitative real time PCR of eight pairs of allele-specific SNPs (MLH-1, PECAM-1, ICAM-1, SUR-1, HA-1, rs715405, rs713503, rs2296600) was conducted in 88 patient/donor pairs, who underwent allogeneic myeloablative or non-myeloablative hSCT. One informative allele was detected in at least 42% (n=37) of the samples; 20% (n=18) had at least two informative alleles; 10% (n=9) had at least three informative alleles; 9% (n=8) had more than three informative alleles and 18% (n=16) showed no informative allele at all. Overall, the frequency of informative alleles for these SNPs in the Brazilian population was very low. Consequently, the amount of information attained reached 9% of those expected, being able to discriminate only eight pairs of donor/recipient samples with more than three informative alleles, making them useless for the quantification of chimerism in our routine.

Transplante de células-tronco hematopoéticas alogênico com regime de condicionamento de intensidade reduzida em linfoma folicular refratário ou recaído: uma alternativa promissora / Allogeneic hematopoietic stem cell transplantation with reduced-intensity conditioning regimen in refractory or relapsed follicular lymphoma: a promising alternative

O linfoma folicular é um tipo de linfoma não Hodgkin de células B indolente. Apenas 30% dos pacientes apresentam doença em fase inicial ao diagnóstico. Os pacientes com estadiamento III-IV estão entre a maioria dos diagnósticos da doença e apresentam altas taxas de recaída ou refratariedade ao tratamento. O linfoma folicular recaído ou refratário permanece um desafio para a prática clínica. O transplante de células-tronco hematopoéticas autólogo vem sendo utilizado há muito tempo nesse perfil de pacientes, com altos índices de complicações como segunda neoplasia e curto período de remissão. O transplante de células-tronco hematopoéticas alogênico com regime de condicionamento mieloablativo apresenta resultados pouco aceitáveis, devido ao aumento da mortalidade relacionada ao tratamento sem benefícios em sobrevida global, da sobrevida livre de doença ou da taxa de recaída que sustentem tal indicação O transplante de células-tronco hematopoéticas alogênico com regime de condicionamento com intensidade reduzida parece ser uma alternativa promissora, inclusive como primeiro transplante. Alguns estudos comparando os resultados dos três tipos de transplantes em pacientes com linfoma folicular recaído ou refratário, com enfoque principal no transplante de células-tronco hematopoéticas alogênico de condicionamento com intensidade reduzida, são descritos neste artigo de revisão.(AU)

Follicular Lymphoma is a type of indolent B-cell non-Hodgkin´s lymphoma. Only 30% of the patients present with an early phase of the disease at diagnosis. Patients with stage III-IV are among the majority of the diagnoses of the disease, and these have high rates of relapse or refractoriness to treatment. Relapsed or refractory follicular lymphoma remains a challenge for clinical practice. Autologous hematopoietic stem cell transplantation has been used for a long time in this profile of patients, with high rates of complications, such as second neoplasia and short remission period. The allogenic hematopoietic stem cell transplantation with myeloablative conditioning regimen presents poorly acceptable results due to increased treatment-related mortality with no overall survival benefits, disease-free survival, or relapse rate to warrant it. Allogeneic hematopoietic stem cell transplantation with reduced-intensity conditioning regimen seems to be a promising alternative, even as the first transplant. Some studies comparing the results of the three types of transplants in patients with relapsed or refractory follicular lymphoma , with a main focus on hematopoietic stem cell transplantation allogenic with reduced-intensity conditioning regimen, will be described in this review article.(AU)

Allogeneic hematopoietic stem cell transplantation in patients with advanced indolent lymphoproliferative disorders

BACKGROUND: The role of allogeneic hematopoietic stem cell transplantation for advanced indolent lymphoproliferative disorders remains to be established. OBJECTIVE: This paper aims to describe the results of allogeneic hematopoietic stem cell transplantation in patients with advanced indolent lymphoproliferative disorders. METHODS: This article reports on 29 adult patients submitted to allogeneic transplantations from 1997 to 2010. RESULTS: Most had follicular non-Hodgkin lymphoma (n = 14) or chronic lymphocytic leukemia (n = 12). The median age was 44 years (range: 24-53 years) and 65% of patients were male. Only 21% had had access to rituximab and 45% to fludarabine. All had advanced disease (stage IV) with partial response or stable disease. Most underwent myeloablative conditioning n = 17 - 59%). In this scenario, refractory disease was observed in seven (24%) patients, the 100-day mortality rate was 17% (n = 5) and relapse occurred in four patients (18%). The main cause of death throughout the follow up was refractory disease in six of the 12 patients who died. Moderate and severe chronic graft-versus-host disease was frequent; about 41% of 24 patients analyzed. The overall survival rates and disease free survival at 42 months were 56.7% and 45.4%, respectively. According to Kaplan-Meyer analysis, the median time from diagnosis to transplant predicted the overall survival; however age, gender and conditioning regimen did not predict the prognosis. It was impossible to reach other conclusions because of the small sample size in this study. CONCLUSIONS: The role of allogeneic transplantations should be re-evaluated in the era of targeted therapy.

Prevalence of chimerism after non-myeloablative hematopoietic stem cell transplantation.

CONTEXT AND OBJECTIVE: Non-myeloablative hematopoietic stem cell transplantation (NMA-HSCT) is performed in onco-hematological patients who cannot tolerate ablative conditioning because of older age or comorbidities. This approach does not completely eliminate host cells and initially results in mixed chimerism. Long-term persistence of mixed chimerism results in graft rejection and relapse. Involvement of graft-versus-host disease is concomitant with complete chimerism and graft-versus-tumor effect. The aim of this study was to evaluate the prevalence of chimerism in onco-hematological patients who underwent NMA-HSCT. DESIGN AND SETTING: Observational clinical study on chimerism status after human leukocyte antigen-identical NMA-HSCT at the Discipline of Hematology and Hemotherapy of Universidade Federal de São Paulo. METHODS: We sequentially analyzed the amplification of APO-B, D1S80, DxS52, FVW, 33.6, YNZ-2 and H-ras primers using variable number of tandem repeats (VNTR) on 17 pairs and fluorescent in situ hybridization (FISH) with the XY probe and SRY primer on 13 sex-unmatched pairs. RESULTS: The informativeness of the primers using VNTR was 60% for APO-B, 75% D1S80, 36% DxS52, 14% FVW, 40% YNZ-22 and 16% H-ras. The SRY primer was informative in female receptors with male donors. The XY-FISH method was informative in 100% of the sex-unmatched pairs. CONCLUSION: These methods were sensitive and informative. In VNTR, the association of APO-B with D1S80 showed 88% informativeness. The quantitative FISH method was more sensitive, but had the disadvantage of only being used for sex-unmatched pairs.

CD34-positive cells and their subpopulations characterized by flow cytometry analyses on the bone marrow of healthy allogenic donors.

CONTEXT AND OBJECTIVE: Counting and separating hematopoietic stem cells from different sources has importance for research and clinical assays. Our aims here were to characterize and quantify hematopoietic cell populations in marrow donors and to evaluate CD34 expression and relate this to engraftment. DESIGN AND SETTING: Cross-sectional study on hematopoietic stem cell assays, using flow cytometry on donor bone marrow samples, for allogenic transplantation patients at two hospitals in São Paulo. METHODS: Immunophenotyping of marrow cells was performed in accordance with positive findings of CD34FITC, CD117PE, CD38PE, CD7FITC, CD33PE, CD10FITC, CD19PE, CD14FITC, CD13PE, CD11cPE, CD15FITIC, CD22PE, CD61FITC and CD56PE monoclonal antibodies in CD45PerCP+ cells, searching for differentiation and maturation regions. CD34+ sorting cells were analyzed for CD38 and CD117. Rh-123 retention was done before and after sorting. Antigen expression and CD34+ cells were correlated with engraftment. RESULTS: In region R1, 0.1% to 2.8% of cells were CD34+/CD45+ and 1.1%, CD34+/CD45-. The main coexpressions of CD45+ cells were CD38, CD22, CD19 and CD56 in R2 and CD33, CD11c, CD14, CD15 and CD61 in R3 and R4. After sorting, 2.2x10(6) CD34+ cells were equivalent to 4.9% of total cells. Coexpression of CD34+/CD38+ and CD34+/CD117+ occurred in 94.9% and 82% of events, respectively. There was a positive relationship between CD34+ cells and engraftment. More than 80% of marrow cells expressed high Rh-123. CD34+ cell sorting showed that cells in regions of more differentiated lineages retained Rh-123 more intensively than in primitive lineage regions. CONCLUSION: We advocate that true stem cells are CD34+/CD45-/CD38-/low-Rh-123 accumulations.

Pericardial effusion and cardiac tamponade: clinical manifestation of chronic graft-versus-host disease after allogeneic hematopoietic stem cell transplantation

The authors report a case with pericardial effusion and cardiac tamponade as a rare clinical manifestation of chronic graft-versus-host disease in a young man with acute myelogenous leukemia submitted to an allogeneic hematopoietic stem cell transplantation from a related donor.

Does mobilization for autologous stem cell transplantation damage stromal layer formation?

Autologous hematopoietic stem cell transplantation (HSCT) has proved efficient to treat hematological malignancies. However, some patients fail to mobilize HSCs. It is known that the microenvironment may undergo damage after allogeneic HSCT. However little is known about how chemotherapy and growth factors contribute to this damage. We studied the stromal layer formation (SLF) and velocity before and after HSC mobilization, through long-term bone marrow culture from 22 patients and 10 healthy donors. Patients' SLF was similar at pre- (12/22) and post-mobilization (9/20), however for controls this occurred more at pre-mobilization (9/10; p=0.03). SLF velocity was higher at pre than post-mobilization in both groups. Leukemias and multiple myeloma showed faster growth of SLF than lymphomas at post-mobilization, the latter being similar to controls. These findings could be explained by less uncommitted HSC in controls than patients at post-mobilization. Control HSCs may migrate more in response to mobilization, resulting in a reduced population by those cells.