Total nucleated cell dose in graft is a better prognostic factor for survival in pediatric patients transplanted with bone marrow compared to CD34+, CD3+, or total mononuclear cell count.

BACKGROUND: Most studies investigating the impact of graft composition on transplant-related outcomes have focused on the effect of CD34+ cell dose and reported equivocal results. The aim of this study is to investigate the impact of doses of total nucleated cells (TNCs), total mononuclear cells (TMCs), CD3+, and CD34+ cells on the outcome of children receiving allogeneic hematopoietic stem cell transplantation (HSCT). METHODS: Children and adolescents who underwent allogeneic HSCT for malignant hemato-oncological diseases or nonmalignant diseases in Cukurova University Faculty of Medicine, Pediatric Bone Marrow Transplantation Center between 2010 and 2020 were enrolled in the study. RESULTS: A total of 212 patients receiving allogeneic HSCT (154 bone marrow transplantation; 58 peripheral blood stem cell transplantation) from matched related or unrelated donors were included in the study. Higher TNC doses associated with a superior 5-year event-free survival (EFS; 67.7% vs 44.7%) in the whole group (log-rank P = .027). Overall survival (OS) and EFS of bone marrow-transplanted patients differed significantly according to TNC doses (log-rank P = .041 and .027, respectively). Multivariant analysis for OS revealed a P value of .038 for TNC, Exp(B) = 1.939 (95% CI: [1.038, 3.621]). That for EFS revealed a P value of .025 for TNC, Exp(B) = 1.992 (95% CI: [1.088, 3.647]). There was no relationship between doses of CD34+ cells, CD3+ cells, TMC, TNC, and neutrophil or platelet engraftment. CONCLUSION: Our data suggest that TNC dose is a better prognostic factor for pediatric allogeneic HSCT outcomes than doses of CD34+ cells, CD3+ cells, or TMC in patients transplanted with bone marrow. Future studies analyzing cell subsets and other components in TNC could elaborate the factor(s) accompanying this observed survival advantage.

Microfluidic transfection of mRNA into human primary lymphocytes and hematopoietic stem and progenitor cells using ultra-fast physical deformations.

Messenger RNA (mRNA) delivery provides gene therapy with the potential to achieve transient therapeutic efficacy without risk of insertional mutagenesis. Amongst other applications, mRNA can be employed as a platform to deliver gene editing molecules, to achieve protein expression as an alternative to enzyme replacement therapies, and to express chimeric antigen receptors (CARs) on immune cells for the treatment of cancer. We designed a novel microfluidic device that allows for efficient mRNA delivery via volume exchange for convective transfection (VECT). In the device, cells flow through a ridged channel that enforces a series of ultra-fast and large intensity deformations able to transiently open pores and induce convective transport of mRNA into the cell. Here, we describe efficient delivery of mRNA into T cells, natural killer (NK) cells and hematopoietic stem and progenitor cells (HSPCs), three human primary cell types widely used for ex vivo gene therapy applications. Results demonstrate that the device can operate at a wide range of cell and payload concentrations and that ultra-fast compressions do not have a negative impact on T cell function, making this a novel and competitive platform for the development of ex vivo mRNA-based gene therapies and other cell products engineered with mRNA.

Hypoxic Culture Maintains Cell Growth of the Primary Human Valve Interstitial Cells with Stemness.

The characterization of aortic valve interstitial cells (VICs) cultured under optimal conditions is essential for understanding the molecular mechanisms underlying aortic valve stenosis. Here, we propose 2% hypoxia as an optimum VIC culture condition. Leaflets harvested from patients with aortic valve regurgitation were digested using collagenase and VICs were cultured under the 2% hypoxic condition. A significant increase in VIC growth was observed in 2% hypoxia (hypo-VICs), compared to normoxia (normo-VICs). RNA-sequencing revealed that downregulation of oxidative stress-marker genes (such as superoxide dismutase) and upregulation of cell cycle accelerators (such as cyclins) occurred in hypo-VICs. Accumulation of reactive oxygen species was observed in normo-VICs, indicating that low oxygen tension can avoid oxidative stress with cell-cycle arrest. Further mRNA quantifications revealed significant upregulation of several mesenchymal and hematopoietic progenitor markers, including CD34, in hypo-VICs. The stemness of hypo-VICs was confirmed using osteoblast differentiation assays, indicating that hypoxic culture is beneficial for maintaining growth and stemness, as well as for avoiding senescence via oxidative stress. The availability of hypoxic culture was also demonstrated in the molecular screening using proteomics. Therefore, hypoxic culture can be helpful for the identification of therapeutic targets and the evaluation of VIC molecular functions in vitro.

Selective elimination of CML stem/progenitor cells by picropodophyllin in vitro and in vivo is associated with p53 activation.

Chronic myeloid leukemia (CML) is a hematologic malignancy originating from BCR-ABL oncogene-transformed hematopoietic stem cells (HSCs) known as leukemia stem cells (LSCs). Therefore, targeting LSCs is of primary importance to eradicate CML. The present study demonstrates that picropodophyllin (PPP) effectively induces apoptosis and inhibits colony formation in CML stem/progenitor cells as well as quiescent CML progenitors resistant to imatinib therapy, while sparing normal hematopoietic cells in vitro. Administration of PPP in vivo markedly diminishes CML stem/progenitor cells in a transgenic mouse model of CML by inhibition of cell proliferation and enhancement of apoptosis in LSK cells, and significantly improves survival of CML mice. Furthermore, PPP treatment preferentially leads to transcriptional activation of p53 in CML but not normal CD34+ cells, upregulation of p53 protein in LSCs-enriched Sca-1+ cells from CML mice, and increased phosphorylation of p53 and upregulation of Bax protein in Ku812 cells. These results suggest that the inhibitory effects of PPP on CML stem/progenitor cells are associated with selective activation of p53 pathway and propose that PPP is a potent agent that selectively targets CML LSCs, and may be of value in the CML therapy.

An innovation in stem cell harvesting: Heparin use.

BACKGROUND AND OBJECTIVES: Stem cell transplantation is a growing treatment strategy for most malignant and non- malignant hematological diseases. Plerixafor and granulocyte colony stimulating factor (G-CSF) are usually used in mobilization regimens to increase the CD34+ cell count in the harvest. Heparin is a sulphated glycosaminoglycated polymer with 12-15 kDa mass. Heparin inhibits the CXCR4/SDF1 axis, as does plerixafor. In this study, our aim was to investigate the effect of using heparin on stem cell mobilization and harvesting. MATERIALS AND METHODS: We administered 5000 units of unfractioned heparin intravenously in 150 mL (mL) of isotonic sodium chloride solution, 15 min before the stem cell harvesting procedure to 141 patients who underwent bone marrow transplantation between the years of 2018 and 2019 at our Stem Cell Transplantation Unit. Thirty patients were included as a control group, and they were not given heparin. The study population included patients with multiple myeloma and lymphoma equally in each group. RESULTS: In all patients hematopoeitic stem cells were successfully harvested in a single cycle of apheresis. In multiple myeloma patients who received heparin, the mean collected CD34+ cell number was 8 × 106/kg, and the mean CD34+ cell number yield was 12,555/µl. In the control group, the mean collected CD34+ cell number was 4,2 × 106/kg, and mean CD34+ cell number in yield was 492/µl. In lymphoma patients who received heparin, the mean collected CD34+ cell number was 6,8 × 106/kg, and the mean CD34+ cell number was 1421/µl. In the control group the mean collected CD34+ cell number was 4,3 × 106/kg, and the mean CD34+ cell number was 358/µl. The effect of heparin on the collected stem cell number in both myeloma and lymphoma patients was statistically significant (p < 0.01). CONCLUSIONS: Our results have shown that heparin increases harvested stem cell numbers significantly. Heparin may be a promising agent for stem cell harvesting.

Prognostic value of CD34 expression status in patients with myxofibrosarcomas and undifferentiated pleomorphic sarcomas.

It is controversial whether patients with myxofibrosarcomas (MFSs) have better prognoses than those with undifferentiated pleomorphic sarcomas (UPSs). No useful prognostic factors have been established to date. We therefore aimed to evaluate the prognostic value of CD34 expression status in 192 patients with MFSs and UPSs. Using the log-rank test, we showed that patients with MFSs had a significantly better overall survival than did those with UPSs when defining the former as having a > 10% myxoid component (p = 0.03), but not when defining it as having a > 50% myxoid component (p = 0.1). Under the definition of MFSs as > 10% myxoid component, the log-rank test revealed that the diagnosis of the UPS and the CD34 loss (p < 0.001) were significant adverse predictors of overall survival. As per the Cox model, the CD34 loss remained an independent prognostic factor (hazard ratio = 3.327; 95% confidence interval 1.334-8.295), while the diagnosis of the UPS was a nonsignificant confounding factor (hazard ratio = 1.084; 95% confidence interval 0.679-1.727). In conclusion, CD34 expression status is a useful prognostic factor in patients with MFS and UPS, and it should be incorporated into grading systems that are used to predict outcomes.

In vitro expansion of fetal liver hematopoietic stem cells.

Fetal liver hematopoietic stem and progenitor cells (HSPCs) have been considered appropriate for the management of aplastic anemia owing to their proliferative potential. Bone marrow recovery was possible in some cases; the engraftment potential of these cells, however was unsatisfactory, possibly due to the availability of a smaller number of these cells from a single fetus. The present study explores how we can expand fetal liver hematopoietic stem cells under in vitro conditions. We isolated mononuclear cells from fetal liver and hematopoietic stem cells were identified and analyzed by cell surface marker CD34. CD34+ fetal liver HSPCs cells were separated by magnetic cell sorting positive selection method. HSPCs (CD34+) were cultured by using 5 cytokines, stem cell factor (SCF), granulocyte macrophages-colony stimulating factor (GM-CSF), interleukin-6 (IL-6), Fms-related tyrosine kinase 3 (FLT-3) and erythropoietin (EPO), in 4 different combinations along with supplements, in serum-free culture media for 21 days. Cell viability continued to be greater than 90% throughout 21 days of culture. The cells expanded best in a combination of media, supplements and 5 cytokines, namely SCF, FLT-3, IL6, EPO and GM-CSF to yield a large number of total (CD34+ & CD34-) cells. Even though the total number of nucleated cells increased in culture significantly, levels of CD34 antigen expression declined steadily over this period.

Ultrastructural aberrations, histological disruption and upregulation of the VEGF, CD34 and ASMA immunoexpression in the myocardium of anemic albino rats.

Iron deficiency anemia (IDA) is a global health problem affecting various body systems and tissues including the cardiovascular system. Several literatures described the associated physiological and clinical changes in the cardiovascular system and heart. However, the associated structural changes were poorly investigated. Therefore, the main aim of the present work was to elucidate whether IDA induces structural changes and alterations in the VEGF, CD34 and ASMA immunoexpression in the myocardium of albino rats. Thirty adult male albino rats were divided into two groups (fifteen rats each); control and anemic. Hematological data for all animals were assessed weekly and statistically analyzed. Three weeks later, animals were sacrificed, and heart specimens were obtained and processed for light and electron microscopy. All hematological parameters showed a statistically significant decrease in the anemic group. Structurally, the anemic group showed markedly degenerated, disrupted and disorganized cardiomyocytes in addition to markedly congested blood vessels, fibroblasts, collagen fibers deposition and perivascular cellular infiltration were noted. Also, positive immunostaining for VEGF, CD34 and ASMA was observed. Ultra-structurally, the myocardium of the anemic group showed disrupted and degenerated myofibrils with degenerated nuclei, perinuclear edema, widened interstitial spaces and marked collagen deposition. Mitochondria markedly increased with abnormal shapes. IDA induced myocardial injury that may propagate to regeneration through activated CD34 progenitor cells and increased VEGF or to degeneration and fibrosis through collagen fibers deposition and enhanced ASMA. So, early diagnosis and treatment of IDA is mandatory to avoid the associated myocardial structural changes.

Mechanisms That Underly T Cell Immunity in Graves' Orbitopathy.

Graves' orbitopathy (GO), also known as thyroid-associated ophthalmopathy, is the most common ocular abnormality of Graves' disease. It is a disfiguring, invalidating, and potentially blinding orbital disease mediated by an interlocking and complicated immune network. Self-reactive T cells directly against thyroid-stimulating hormone receptor-bearing orbital fibroblasts contribute to autoimmune inflammation and tissue remodeling in GO orbital connective tissues. To date, T helper (Th) 1 (cytotoxic leaning) and Th2 (antibody leaning) cell subsets and an emerging role of Th17 (fibrotic leaning) cells have been implicated in GO pathogenesis. The potential feedback loops between orbital native residential CD34- fibroblasts, CD34+ infiltrating fibrocytes, and effector T cells may affect the T cell subset bias and the skewed pattern of cytokine production in the orbit, thereby determining the outcomes of GO autoimmune reactions. Characterization of the T cell subsets that drive GO and the cytokines they express may significantly advance our understanding of orbital autoimmunity and the development of promising therapeutic strategies against pathological T cells.

"Ex-vivo" T-cell depletion in allogeneic hematopoietic stem cell transplantation: New clinical approaches for old challenges.

Allogeneic transplantation still remains as standard of care for patients with high-risk hematological malignancies at diagnosis or after relapse. However, GvHD remains yet as the most relevant clinical complication in the early post-transplant period. TCD allogeneic transplant is now considered a valid option to reduce severe GvHD and to provide a platform for cellular therapy to prevent relapse disease or to treat opportunistic infections.

Functional expression cloning of molecules inducing CD34 expression in bone marrow-derived stromal myofibroblasts.

We have previously shown a fraction of stromal fibroblasts/myofibroblasts (Fibs) from leukemic bone marrow cells expresses leukemia-specific transcripts along with hematopoietic and Fib-related markers. Normal bone marrow-derived Fibs (nFibs) do not express CD34 or CD45; however, nFibs may express hematopoietic markers with some specific stimulations. CD34 expression was detected in nFib cultures following the addition of a culture supernatant of blood mononuclear cells stimulated with phytohemagglutinin (PHA)-P. To identify the molecules responsible for inducing CD34 expression in nFibs, cDNA clones were isolated using functional expression cloning with a library constructed from PHA-P-stimulated human blood mononuclear cells. Positive clones inducing CD34 transcription in nFibs were selected. We confirmed that an isolated positive cDNA clone encoded human interleukin (IL)-1 beta (ß). CD34 expression was observed in the nFib cultures with recombinant human (rh) IL-1ß protein. And CD34 transcription was suppressed when a rhIL-1ß neutralizing antibody was added to the IL-1ß-stimulated nFib cultures. nFibs expressed gp130 and IL-6 receptors, and CD45 expression was detected in nFibs cultured with rhIL-1ß and rhIL-6. Chronic myelogenous leukemia (CML) cells reportedly respond well to IL-1ß. When CML-derived Fibs were cultured with rhIL-1ß and rhIL-6, CD45-positive cells increased in number. Cell fate may be influenced by an external specific stimulation without gene introduction.

Correlation between peripheral blood neutrophil-lymphocyte ratio and CD34 expression in prostate cancer.

BACKGROUNDS: The association of neutrophil-lymphocyte ratio (NLR) and CD34 expression level with PSA level, Gleason score, and clinical stage was investigated in patients with prostate cancer. The correlation between NLR and CD34 expression was also investigated to provide evidence supporting the use of NLR for predicting the prognosis of prostate cancer patients. METHODS: Clinical data of 75 patients diagnosed with prostate cancer by prostate aspiration biopsy were retrospectively analyzed. The correlation between NLR, CD34 expression, and clinicopathological characteristics was analyzed using the χ2 test and one-way analysis of variance. The correlation between NLR and CD34 was determined using the Pearson coefficient. Disease free survival was estimated by Kaplan-Meier analysis. RESULTS: Both NLR and CD34 expression were significantly positively correlated with PSA, Gleason score, and clinical stage (P < 0.05 both). Patients in the NLRHigh/CD34High group were characterized by high PSA level and Gleason score and late clinical stage. NLR was positively correlated with CD34 expression (r = 0.529, P < 0.001). CONCLUSIONS: Pretreatment NLR was a valuable marker of prognosis in prostate cancer. NLR is positively correlated with CD34 expression.

Antitumor effect of a pyrazolone-based-complex [Cu(PMPP-SAL)(EtOH)] against murine melanoma B16 cell in vitro and in vivo.

Pyrazolone-based derivative metal complexes were reported to have cytotoxicity in some tumor cells. In this study, the antitumor effect of [Cu(PMPP-SAL)(EtOH)] (PMPP-SAL = N-(1-phenyl-3-methyl-4-propenylidene-5-pyrazolone)- salicylidene hydrazide anion) in murine melanoma B16 cells in vitro and in vivo was investigated. The results showed that [Cu(PMPP-SAL)(EtOH)] inhibited the survival of B16 cells in vitro, and the IC50 value was superior to cisplatin (DDP) (p < 0.001). B16 cell apoptosis was significantly higher in comparison to the control group (DMSO) (p < 0.01), and cell cycle arrest occurred at the G0/G1 phase. When challenged C57 BL/6J mice were treated with [Cu(PMPPSAL)(EtOH)], a smaller volume of B16 solid tumors were reported than the control group (p < 0.01), with lower positive expression indices of CD 34, vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) (p < 0.01). Moreover, the tumor growth was suppressed in mice due to the induction of apoptosis, as detected by the TUNEL assay (p < 0.001). In summary, [Cu(PMPP-SAL)(EtOH)] effectively inhibited the growth of B16 cells in vitro and in vivo due to the induction of apoptosis and the inhibition of intra-tumoral angiogenesis, demonstrating its therapeutic potential in melanoma treatment.

A prospective comparison of pegfilgrastim and lipegfilgrastim combined with chemotherapy in the mobilization of CD34+ cells in NHL patients.

BACKGROUND: Autologous stem cell transplantation (auto-SCT) is a treatment approach in non-Hodgkin lymphoma (NHL) patients. The options for mobilization of CD34+ cells to support high-dose therapy are granulocyte-colony stimulating factors (G-CSFs) alone or after chemotherapy. Limited data exist on the efficacy of lipegfilgrastim (LIPEG) in the mobilization field. PATIENTS AND METHODS: The present prospective nonrandomized study compared LIPEG 6 mg (n = 40) with pegfilgrastim (PEG) 6 mg (n = 37) in the mobilization of blood CD34+ cells after chemotherapy in NHL patients with comparable mobilizing chemotherapy and disease status before auto-SCT. RESULTS: Significantly higher blood CD34+ cell (B-CD34+ ) counts were observed in the LIPEG group at the start of the first apheresis (44 vs 23 × 106 /L, P = .009), in line with a higher collection yield of the first apheresis (3.3 vs 2.1 × 106 /kg, P = .086) and total yield of CD34+ cells (4.7 vs 2.9 × 106 /kg, P = .004). LIPEG proved to be a more effective G-CSF, resulting in a higher B-CD34+ cell peak (60 vs 32 × 106 /L, P = .030) and higher proportion of excellent mobilizers (33% vs 8%, P = .008). The superiority of LIPEG was confirmed in the multivarite analysis concerning the CD34+ cell yield of the first apheresis day (P = .010) and the total yield (P = .001). CONCLUSION: The mobilization of blood grafts with LIPEG added to chemotherapy was associated with higher CD34+ cell apheresis yields than with PEG. A randomized study is warranted to verify these findings.

Higher efficacy of intermediate dose cytarabine + G-CSF compared to cyclophosphamide + G-CSF in hematopoietic stem cell mobilization in patients with multiple myeloma.

BACKGROUND: There are several regimens used in hematopoietic stem cell (HSC) mobilization in multiple myeloma (MM). Cyclophosphamide (Cy) is one of the most commonly used agents, although it does not always result in collecting adequate number of CD34+ cells. Recently, cytarabine (Ara-C) has been proposed as potentially efficient and safe option. AIMS: Since the data regarding Ara-C in HSC mobilization is limited, the aim of our study was to compare retrospectively the efficiency and toxicity of G-CSF combined with either Ara-C or Cy in MM patients. MATERIALS & METHODS: Of a total of 89 patients, 43 received low or intermediate doses of Cy, and 46 were treated with 800 mg/m2 /day of Ara-C administered for two days. RESULTS: The mean peak of CD34+ cells/ul in peripheral blood was 132 (range, 84-202) in Ara-C and 51 (range, 29-69) in Cy cohort (p < 0.001). The median number of collected CD34+ cells (×106/kg) was 10.3 (range, 4.2-17.9) vs 4.5 (range, 2.7-8.9), respectively (p < 0.001). Mobilization failure was observed in one patient in Ara-C cohort (2%) and in 8 patients treated with Cy (19%) (p = 0.013). In the Ara-C group 98% of patients obtained more than 4×106 CD34+ cells/kg required for tandem transplantation. Moreover, we observed a trend toward increased paraprotein levels measured at transplant compared to before HSC mobilization in Ara-C cohort and significantly higher transfusion rates in that group. CONCLUSION: Our findings confirm higher HSC mobilization efficacy of Ara-C compared to Cy in MM patients. However, lower transfusions rate and better disease control of Cy may justify its use in some cases.

A new protocol for improving efficiency of autologous peripheral blood stem cell collection in patients with high white blood cell counts.

BACKGROUND: Collection efficiency (CE) of peripheral blood stem cell (PBSC) collections is negatively affected by increasing white blood cell (WBC) counts of the patient. This study compared a new optimized mononuclear cell (MNC) collection protocol (OPP) to the standard MNC collection protocol recommended by the manufacturer (STP) for PBSC collection in patients with WBC counts >35 000/µL. STUDY DESIGN AND METHODS: Single-center, retrospective, and observational study of 81 autologous PBSC collections on Fenwal Amicus cell separators in 70 adult patients. RESULTS: Median peripheral WBC count (×103 /µL; 44.2 in OPP group vs 46.5 in STP group) and median CD34+ count (105/µL in OPP group vs 40/µL in STP group) at the beginning of PBSC collection did not differ significantly. Median CE2 (45% vs 31%; P < .001) as well as CD34+ yield of the apheresis product both with regards to median absolute CD34+ content (×106 ; 793 vs 188; P = .001) as well as median CD34+ content (×106 )/kg body weight (8.93 vs 2.51; P = .002) were significantly higher for the OPP. Overall, 18/21 (86%) patients with the OPP obtained their target CD34+ amount with a single apheresis session, compared to 25/50 (50%) with the STP (P = .005). PBSC collections using OPP lasted significantly longer (median 377 minutes vs 260 minutes; P < .001) than with the STP. CONCLUSIONS: The OPP significantly improves CE2 for PBSC collections on Fenwal Amicus cell separators in patients with pre-apheresis WBC counts >35 000/µL and significantly reduces the necessity for multiple apheresis sessions. The OPP is therefore suited to reduce both patient burden and cost in autologous PBSC collection.

Purinergic P2Y2 receptors modulate endothelial sprouting.

Purinergic P2 receptors are critical regulators of several functions within the vascular system, including platelet aggregation, vascular inflammation, and vascular tone. However, a role for ATP release and P2Y receptor signalling in angiogenesis remains poorly defined. Here, we demonstrate that blood vessel growth is controlled by P2Y2 receptors. Endothelial sprouting and vascular tube formation were significantly dependent on P2Y2 expression and inhibition of P2Y2 using a selective antagonist blocked microvascular network generation. Mechanistically, overexpression of P2Y2 in endothelial cells induced the expression of the proangiogenic molecules CXCR4, CD34, and angiopoietin-2, while expression of VEGFR-2 was decreased. Interestingly, elevated P2Y2 expression caused constitutive phosphorylation of ERK1/2 and VEGFR-2. However, stimulation of cells with the P2Y2 agonist UTP did not influence sprouting unless P2Y2 was constitutively expressed. Finally, inhibition of VEGFR-2 impaired spontaneous vascular network formation induced by P2Y2 overexpression. Our data suggest that P2Y2 receptors have an essential function in angiogenesis, and that P2Y2 receptors present a therapeutic target to regulate blood vessel growth.

Variability of CD34 Expression in Sinonasal Glomangiopericytoma: A Potential Diagnostic Pitfall.

Sinonasal glomangiopericytoma (GPC) is an uncommon primary sinonasal neoplasm showing a perivascular myoid differentiation. Originally perceived as an intranasal counterpart to soft tissue hemangiopericytomas, initial immunohistochemical reports showed mostly negative to focal weak reactivity for CD34 as useful in separating GPC (almost always benign) from morphologic mimics, mainly solitary fibrous tumor (potentially aggressive). In anecdotally encountering cases of GPC with CD34 reactivity beyond the expected weak/negative immunoprofile, we sought to formally evaluate CD34 staining in 10 cases of GPC from two different vendors in conjunction with a meta-analysis of other GPC series reporting CD34 staining. Ten cases of GPC were retrieved from the authors' pathology archives (left nasal cavity = 7, right nasal cavity = 3; 5 men, 5 women; average age 59.0 years with range of 43-77 years). Follow-up showed no evidence of disease after complete resection from all 10 cases (average follow-up length of 53.3 months, range 6-106 months). All 10 GPC cases (100%) showed positivity using CD34 from Leica (QBend10 clone), with most showing moderate to diffuse staining intensity and moderate extent, while only 2 of 10 cases (20%) showed positivity using CD34 from Ventana (QBend10 clone), with both positive cases showing weak staining intensity and focal extent. Literature review of other studies (reporting ≥ 5 GPC cases) found a wide spectrum of CD34 positivity ranging from 0 to 100%; including our GPC cases, CD34 showed a cumulative positivity of 28%. Although negative CD34 reactivity has been historically regarded as prototypic for GPC, in this study we have exposed laboratory variability in CD34 expression and have shown that reliance on expected negative reactivity in GPC can be a clinically relevant diagnostic pitfall. Our findings suggest a panel approach in selecting diagnostic immunostains rather than relying on CD34 alone in the assessment of spindle cell neoplasms in the sinonasal tract with admixed prominent staghorn-like vasculature.

Smoking is an important factor that affects peripheral blood progenitor cells yield in healthy male donors.

BACKGROUND: Smoking could reduce the CD34+ cells in peripheral blood of healthy individual. This study aimed to investigate the correlation between smoking load and the effect of peripheral blood hematopoietic progenitor cells (PBPCs) mobilization by granulocyte colony-stimulating factor (G-CSF) alone in healthy donors. METHODS: Retrospective analysis was performed on 145 healthy adult PBPCs donors who underwent PBPCs mobilization and collection. Smoking factors were evaluated and correlated with mobilization responses, as indicated by the collected CD34+ cells concentration. RESULTS: The collected CD34+ cells concentration was closely related to pre-CD34 (P < .001) and CD34+ cells collected per volume blood processed (P < .001) which suggested that collected CD34+ cells concentration was a reliable indicator of PBPCs mobilization efficiency. The heavy smoking donors revealed significantly lower collected CD34+ cells concentration, compared to that of the nonsmoking (P < .001) and light smoking donors (P < .05). The levels of collected CD34+ cells in light smoking were also obviously lower than that in nonsmoking donors (P < .05).There were no obvious differences in the collected CD34+ cells concentration, overall processed blood volume and total collected CD34+ cells between nonsmoking and smoking cessation groups (P = .490; P = .464; P = .819). CONCLUSION: Cigarette smoking is an important factor that affects the yield of PBPCs in male donors, especially when the smoking load is more than five pack-years. Mobilization of PBMCs could be restored by smoking cessation in chronic smokers.