Impact of the number of cryopreserved CD34+ cells in the infused blood grafts on hematologic recovery and survival in myeloma patients after autologous stem cell transplantation: Experience from the GOA study.

BACKGROUND: Prospective data on the impact of CD34+ cell loss during cryopreservation and the amount of cryopreserved CD34+ cells infused after high-dose therapy on hematologic recovery and post-transplant outcome in multiple myeloma (MM) are scarce. PATIENTS AND METHODS: This post-hoc study aimed to investigate factors associating with CD34+ cell loss during cryopreservation and the effects of the infusion of a very low number (<1.0 × 106 /kg, group A), low number (1-1.9 × 106 /kg, group B), and optimal number (≥2 × 106 /kg, group C) of thawed viable CD34+ cells on hematologic recovery, progression free survival, and overall survival after autologous stem cell transplantation among 127 patients with MM. RESULTS: In group C, pegfilgrastim use (P = 0.001), plerixafor use (P = 0.039), and older age ≥ 60 years (P = 0.026) were associated with less loss of CD34+ cells during cryopreservation. Better mobilization efficacy correlated with greater CD34+ cell loss in group B (P = 0.013 and P = 0.001) and in group C (P < 0.001 and P < 0.001). Early platelet engraftment was slowest in group A (20 d vs 12 d in group B vs 11 d in group C, P = 0.003). The infused viable CD34+ cell count <1.0 × 106 /kg seemed not to have influence on PFS (P = 0.322) or OS (P = 0.378) in MM patients. CONCLUSIONS: Cryopreservation impacts significantly on the CD34+ cell loss. A very low number of graft viable CD34+ cells did not affect PFS or OS.

CD34+ Cell Mobilization, Autograft Cellular Composition and Outcome in Mantle Cell Lymphoma Patients.

Backgound: Autologous stem cell transplantation (ASCT) is a standard treatment in transplant-eligible mantle cell lymphoma (MCL) patients after first-line chemoimmunotherapy. Study Design and Methods: This prospective multicenter study evaluated the impact of CD34+ cell mobilization and graft cellular composition analyzed by flow cytometry on hematologic recovery and outcome in 42 MCL patients. Results: During CD34+ cell mobilization, a higher blood CD34+ cell count (>30 × 106/L) was associated with improved overall survival (median not reached [NR] vs. 57 months, p = 0.04). The use of plerixafor did not impact outcome. Higher number of viable cryopreserved graft CD34+ cells (>3.0 × 106/kg) was associated with faster platelet (median 11 vs. 15 days, p = 0.03) and neutrophil (median 9 vs. 10 days, p = 0.02) recovery posttransplant. Very low graft CD3+CD8+ cell count (≤10 × 106/kg) correlated with worse progression-free survival (PFS) (HR 4.136, 95% CI 1.547-11.059, p = 0.005). On the other hand, higher absolute lymphocyte count >2.5 × 109/L at 30 days after ASCT (ALC-30) was linked with better PFS (median NR vs. 99 months, p = 0.045) and overall survival (median NR in either group, p = 0.05). Conclusions: Better mobilization capacity and higher graft CD3+CD8+ cell count had a positive prognostic impact in this study, in addition to earlier lymphocyte recovery (ALC-30>2.5 × 106/L). These results need to be validated in another study with a larger patient cohort.

Mobilization characteristics, blood graft composition, and outcome in diffuse large B-cell lymphoma after autologous stem cell transplantation: Results from the prospective multicenter GOA study.

BACKGROUND: Diffuse large B-cell lymphoma (DLBCL) is a common indication for autologous stem cell transplantation (auto-SCT). STUDY DESIGN AND METHODS: This prospective noninterventional study aimed to evaluate the impact of mobilization characteristics and graft cellular content on hematologic recovery and outcome after auto-SCT among 68 patients with DLBCL. RESULTS: Better mobilization capacity as manifested by blood CD34+ cell count >32 × 106 /L and CD34+ cell yield of the first apheresis >2.75 × 106 /kg correlated with faster neutrophil (P = .005 and P = .017) and platelet (P = .002 and P < .001) recovery. A higher number of infused CD34+ cells (> 2.65 × 106 /kg) was associated with better 5-year overall survival (OS; 95% vs 67%, P = .012). The graft CD34+ CD133+ CD38- cell count >0.07 × 106 /kg was predictive of better 5-year OS (87% vs 63%; P = .008) and higher graft CD3+ cell count (>23.1 × 106 /kg) correlated also with better 5-year OS (80% vs 40%, P = .008). In multivariate analysis only disease status of CR I at auto-SCT was associated with better progression-free survival (P = .014) and OS (P = .039). CONCLUSION: The mobilization capacity of CD34+ cells impacted on early hematologic recovery in patients with DLBCL after auto-SCT. Higher graft CD34+ cell count and both CD34+ CD133+ CD38- and CD3+ cells were also associated with better OS. The effect of optimal graft cellular composition on outcome in DLBCL should be evaluated in a randomized study.

Autograft cellular composition and outcome in myeloma patients: Results of the prospective multicenter GOA study.

BACKGROUND: Autologous stem cell transplantation (auto-SCT) is a widely used treatment option in multiple myeloma (MM) patients. The optimal graft cellular composition is not known. STUDY DESIGN AND METHODS: Autograft cellular composition was analyzed after freezing by flow cytometry in 127 MM patients participating in a prospective multicenter study. The impact of graft cellular composition on hematologic recovery and outcome after auto-SCT was evaluated. RESULTS: A higher graft CD34+ cell content predicted faster platelet recovery after auto-SCT in both the short and long term. In patients with standard-risk cytogenetics, a higher graft CD34+ count (>2.5 × 106 /kg) was linked with shorter progression-free survival (PFS; 28 vs. 46 months, p = 0.04), but there was no difference in overall survival (OS) (p = 0.53). In a multivariate model, a higher graft CD34+ CD133+ CD38- (>0.065 × 106 /kg, p = 0.009) and NK cell count (>2.5 × 106 /kg, p = 0.026), lenalidomide maintenance and standard-risk cytogenetics predicted better PFS. In contrast, a higher CD34+ count (>2.5 × 106 /kg, p = 0.015) predicted worse PFS. A very low CD3+ cell count (≤20 × 106 /kg, p = 0.001) in the infused graft and high-risk cytogenetics remained predictive of worse OS. CONCLUSIONS: Autograft cellular composition may impact outcome in MM patients after auto-SCT. More studies are needed to define optimal graft composition.

CD34+ cell mobilization, blood graft composition, and posttransplant recovery in myeloma patients compared to non-Hodgkin's lymphoma patients: results of the prospective multicenter GOA study.

BACKGROUND: Autologous stem cell transplantation is an established treatment option for patients with multiple myeloma (MM) or non-Hodgkin's lymphoma (NHL). STUDY DESIGN AND METHODS: In this prospective multicenter study, 147 patients with MM were compared with 136 patients with NHL regarding the mobilization and apheresis of blood CD34+ cells, cellular composition of infused blood grafts, posttransplant recovery, and outcome. RESULTS: Multiple myeloma patients mobilized CD34+ cells more effectively (6.3 × 106 /kg vs. 3.9 × 106 /kg, p = 0.001). The proportion of poor mobilizers (peak blood CD34+ cell count <20 × 106 /L) was higher in NHL patients (15% vs. 3%, p < 0.001). Plerixafor was added to rescue the mobilization failure in 17 MM patients (12%) and in 35 NHL patients (26%; p = 0.002). The infused grafts contained more natural killer (NK) and CD19+ cells in MM patients. Blood platelet and NK-cell counts were higher in MM patients posttransplant. Early treatment-related mortality was low in both groups, but NHL patients had a higher late (>100 days) nonrelapse mortality (NRM; 6% vs. 0%, p = 0.003). CONCLUSIONS: Non-Hodgkin's lymphoma and MM patients differ in terms of mobilization of CD34+ cells, graft cellular composition, and posttransplant recovery. Thus, the optimal graft characteristics may also be different.

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.

Mast Cells Are a Marked Source for Complement C3 Products That Associate with Increased CD11b-Positive Cells in Keratinocyte Skin Carcinomas.

By using immunohistochemistry and antibodies that identify complement C3c (in C3 and C3b) or CD11b receptor, we report that the proportion C3c+ mast cells and the number of CD11b+ cells are increased in basal cell carcinoma (BCC). Instead, only CD11b+ cells are increased in squamous cell carcinoma/Bowen's disease, and only slightly so in actinic keratosis. Only C3c+ mast cells are increased in psoriasis. Furthermore, C3c+ mast cells correlated positively with CD11b+ cells, and iC3b immunoreactivity was detected around tryptase+ mast cells. Therefore, mast cells may convey immunoregulatory signals through C3, C3b, and iC3b to CD11b+ cells, especially in BCC.

CD40 Ligand Is Increased in Mast Cells in Psoriasis and Actinic Keratosis but Less So in Epithelial Skin Carcinomas.

The expression of CD40 ligand (CD40L) in mast cells was investigated in biopsies from lesional and non-lesional skin samples of patients with psoriasis, actinic keratosis (AK), basal cell carcinoma, and squamous cell carcinoma using a sequential double-staining technique. The percentage of CD40L+ mast cells was higher in the lesional than in the non-lesional skin (p < .003). Interestingly, this percentage was lower in both carcinomas than in psoriasis and actinic keratosis (p < .025). Cells immunopositive for CD40 receptor were increased in all lesion types but especially so in carcinomas. The results suggest a dysregulated anti-tumoral immune response by mast cell CD40L in skin carcinomas.

Impact of lenalidomide-based induction therapy on the mobilization of CD34+ cells, blood graft cellular composition, and post-transplant recovery in myeloma patients: a prospective multicenter study.

BACKGROUND: Lenalidomide is an immunomodulatory drug that is also currently used in transplant-eligible patients with multiple myeloma. Previous studies have suggested a negative impact of lenalidomide on the mobilization of CD34+ cells. No data are available regarding the more detailed composition of blood grafts after lenalidomide. STUDY DESIGN AND METHODS: In a multicenter, prospective study, we analyzed the mobilization of CD34+ cells, graft cellular composition, and post-transplant hematologic recovery in 26 patients with multiple myeloma after lenalidomide-based induction and in 34 lenalidomide-naive controls with multiple myeloma. All patients were mobilized with low-dose cyclophosphamide plus granulocyte-colony-stimulating factor. The cellular composition of the grafts was analyzed from thawed, cryopreserved samples with flow cytometry. Graft function was evaluated by engraftment data and by complete blood counts until 12 months after the graft infusion. RESULTS: Patients in the lenalidomide arm had lower median peak CD34+ counts and approximately 40% lower CD34+ cell yields from the first apheresis session, but these differences were not significant. The median total number of CD34+ cells collected was comparable (6.4 vs. 7.5 × 106 /kg). The number of apheresis sessions was higher in the lenalidomide group (2 vs. 1; p = 0.039). The blood graft composition was comparable between the groups. Hematologic recovery within 12 months post-transplant did not differ between the groups. CONCLUSION: Lenalidomide-based induction seems to have an impact on the number of aphereses performed, but not on the total yields of the CD34+ cells in the graft. Neither cellular composition of the grafts nor post-transplant recovery was affected by the limited pre-transplant exposure to lenalidomide.

Blood graft cellular composition and posttransplant outcomes in myeloma patients mobilized with or without low-dose cyclophosphamide: a randomized comparison.

BACKGROUND: Autologous stem cell transplantation is a standard treatment in multiple myeloma (MM). Blood grafts are usually collected after mobilization with granulocyte-colony-stimulating factor (G-CSF) alone or in a combination with cyclophosphamide (CY). There is limited knowledge of the possible effects of different mobilization regimens on blood graft characteristics and posttransplant outcomes. STUDY DESIGN AND METHODS: Thirty-eight patients with MM were included in this study. The patients were randomly assigned at registration to mobilization with either low-dose CY plus G-CSF (Arm A) or G-CSF alone (Arm B) and received three cycles of lenalidomide, bortetzomib, and dexamethasone induction. Flow cytometry analysis of lymphocyte subsets in the blood grafts after cryopreservation was performed. Hematologic and immune recovery were evaluated up to 12 months posttransplant. RESULTS: The blood grafts in Arm A contained significantly more CD34+ cells but in Arm B there was a greater proportion of CD34+CD38- cells and higher numbers of T and B lymphocytes as well as natural killer (NK) cells. The engraftment was comparable but lymphocyte count at 15 days posttransplant was higher in Arm B (0.8 × 10(9) /L vs. 0.5 × 10(9) /L, p = 0.033). At 3 and 6 months posttransplant the total number of NK cells was also higher in G-CSF-mobilized patients. There was no difference in progression-free survival between the study arms. CONCLUSION: CY plus G-GSF yields more CD34+ cells but seems to diminish lymphocyte and NK cell counts in the grafts and hampers immune recovery after transplantation. Thus G-CSF alone might be a preferred mobilization method due to more rapid immune recovery posttransplant.

Blood graft cellular composition and posttransplant recovery in non-Hodgkin's lymphoma patients mobilized with or without plerixafor: a prospective comparison.

BACKGROUND: Autologous stem cell transplantation is commonly used to treat non-Hodgkin's lymphomas (NHLs). Cellular composition of the blood grafts apparently has a role in the posttransplant hematologic and immune recovery. Plerixafor increases the mobilization of CD34+ cells and higher amounts of various lymphocyte subsets have been reported in the grafts. Limited prospective data are available in regard to graft cellular composition, hematologic and immune recovery, and patient outcomes in NHL patients who receive plerixafor added to chemomobilization. STUDY DESIGN AND METHODS: Forty-one patients with NHL participated in this prospective study. All patients received chemomobilization and 15 poor mobilizers also received plerixafor. CD34+ cell subsets and lymphocyte subsets of cell grafts, posttransplant hematologic and immune recovery, and outcome were evaluated. RESULTS: Blood grafts in the plerixafor group contained a significantly higher proportion of CD34+133+CD38- cells and more lymphocytes of all major subsets except B lymphocytes. Neutrophil engraftment was comparable and platelet recovery slightly slower in the plerixafor group. Natural killer cell recovery was significantly faster in patients mobilized with plerixafor. Otherwise hematologic and immune recovery as well as short-time outcome were comparable even though there was a trend for progression-free survival and overall survival benefit in the plerixafor group. CONCLUSIONS: In poorly mobilizing NHL patients, plerixafor added to chemomobilization is safe and effective. It also modifies the blood graft composition in many ways, some of which have been linked to better outcomes in previous studies. Larger sets of patients and longer follow-up are needed to see whether plerixafor-mobilized grafts are associated with superior outcome of the patients.

Loss of CD34+ Cells and Effect of the Number of Viable Cryopreserved CD34+ Cells in the Infused Blood Grafts on Hematologic Recovery, Progression-Free Survival and Overall Survival in NHL Patients After Autologous Stem Cell Transplantation.

PATIENTS: This post-hoc study aimed to find out factors affecting graft viable CD34+ cell loss during processing and cryopreservation in 129 non-Hodgkin lymphoma (NHL) patients receiving autologous stem cell transplantation (auto-SCT) and the impact of a low (< 2.0 × 106/kg, group A) and a decent number (≥ 2 × 106/kg, group B) of viable CD34+ cells infused on the hematologic recovery, progression-free survival (PFS) and overall survival (OS) after auto-SCT. RESULTS: The median loss of viable CD34+ cells during cryopreservation was higher in group A (47% vs. 19%, p < .001). A higher yield of CD34+ cells at the first apheresis in group B (p = .002) was linked with greater loss of viable graft CD34+ cells after cryopreservation. Filgrastim (FIL) use for mobilization seemed to associate with higher viable CD34+ cell loss compared to pegfilgrastim (PEG) or lipegfilgrastim (LIPEG) in both groups (in group A FIL 66 vs. PEG 35%, p = .006; in group B FIL 37 vs. PEG 15 vs. LIPEG 13%, p < .001). Hematologic recovery after auto-SCT was faster in group B. Neither viable CD34+ cell loss during storage nor viable CD34+ cell number < 2.0 × 106/kg infused affected on PFS or OS. CONCLUSIONS: G-CSF type used in mobilization and mobilization capacity were found to correlate with viable CD34+ cell loss during processing and storage. Most importantly, low infused viable CD34+ cell count did not seem to impact on PFS or OS.

Forced usage of positively charged amino acids in immunoglobulin CDR-H3 impairs B cell development and antibody production.

Tyrosine and glycine constitute 40% of complementarity determining region 3 of the immunoglobulin heavy chain (CDR-H3), the center of the classic antigen-binding site. To assess the role of D(H) RF1-encoded tyrosine and glycine in regulating CDR-H3 content and potentially influencing B cell function, we created mice limited to a single D(H) encoding asparagine, histidine, and arginines in RF1. Tyrosine and glycine content in CDR-H3 was halved. Bone marrow and spleen mature B cell and peritoneal cavity B-1 cell numbers were also halved, whereas marginal zone B cell numbers increased. Serum immunoglobulin G subclass levels and antibody titers to T-dependent and T-independent antigens all declined. Thus, violation of the conserved preference for tyrosine and glycine in D(H) RF1 alters CDR-H3 content and impairs B cell development and antibody production.

Lysosomal-mitochondrial axis in zoledronic acid-induced apoptosis in human follicular lymphoma cells.

Bisphosphonates (BPs) are potent inhibitors of osteoclast function, widely used to treat excessive bone resorption associated with bone metastases, that also have anti-tumor activity. Zoledronic acid (ZOL) represents a potential chemotherapeutic agent for the treatment of cancer. ZOL is the most potent nitrogen-containing BPs, and it inhibits cell growth and induces apoptosis in a variety of cancer cells. Recently we demonstrated that accumulation of isopentenyl pyrophosphate and the consequent formation of a new type of ATP analog (ApppI) after mevalonate pathway inhibition by nitrogen-containing BPs strongly correlates with ZOL-induced cell death in cancer cells in vitro. In this study we show that ZOL-induced apoptosis in HF28RA human follicular lymphoma cells occurs exclusively via the mitochondrial pathway, involves lysosomes, and is dependent on mevalonate pathway inhibition. To define the exact signaling pathway connecting them, we used modified HF28RA cell lines overexpressing either BclXL or dominant-negative caspase-9. In both mutant cells, mitochondrial and lysosomal membrane permeabilization (MMP and LMP) were totally prevented, indicating signaling between lysosomes and mitochondria and, additionally, an amplification loop for MMP and/or LMP regulated by caspase-9 in association with farnesyl pyrophosphate synthetase inhibition. Additionally, the lysosomal pathway in ZOL-induced apoptosis plays an additional/amplification role of the intrinsic pathway independently of caspase-3 activation. Moreover, we show a potential regulation by Bcl-XL and caspase-9 on cell cycle regulators of S-phase. Our findings provide a molecular basis for new strategies concomitantly targeting cell death pathways from multiple sites.

Blood Graft and Outcome After Autologous Stem Cell Transplantation in Patients With Primary Central Nervous System Lymphoma.

BACKGROUND: Autologous stem cell transplantation (auto-SCT) is a treatment option for patients with primary central nervous system lymphoma (PCNSL). METHODS: In this prospective multicenter study, the effects of blood graft cellular content on hematologic recovery and outcome were analyzed in 17 PCNSL patients receiving auto-SCT upfront. RESULTS: The infused viable CD34+ cell count > 1.7 × 106/kg correlated with more rapid platelet engraftment (10 vs. 31 days, P = 0.027) and with early neutrophil recovery (day + 15) (5.4 vs. 1.6 × 109/L, P = 0.047). A higher number of total collected CD34+ cells > 3.3 × 106/kg infused predicted worse 5-year progression-free survival (PFS) (33% vs. 100%, P = 0.028). In addition, CD3+CD8+ T cells > 78 × 106/kg in the infused graft impacted negatively on the 5-year PFS (0% vs. 88%, P = 0.016). CONCLUSION: The cellular composition of infused graft seems to impact on the hematologic recovery and PFS post-transplant. Further studies are needed to verify the optimal autograft cellular content in PCNSL.

Regulation of repertoire development through genetic control of DH reading frame preference.

In jawed vertebrates most expressed Ig H chains use only one of six possible D(H) reading frames. Reading frame (RF)1, the preferred reading frame, tends to encode tyrosine and glycine, whereas the other five RFs tend to be enriched for either hydrophobic or charged amino acids. Mechanisms proposed to favor use of RF1 include a preference for deletion over inversion that discourages use of inverted RF1, RF2, and RF3; sequence homology between the 5' terminus of the J(H) and the 3' terminus of the D(H) that promotes rearrangement into RF1; an ATG start site upstream of RF2 that permits production of a truncated Dmicro protein; stop codons in RF3; and, following surface expression of IgM, somatic, presumably Ag receptor-based selection favoring B cells expressing Igs with tyrosine- and glycine-enriched CDR-H3s. By creating an IgH allele limited to the use of a single, frameshifted DFL16.1 D(H) gene segment, we tested the relative contribution of these mechanisms in determining reading frame preference. Dmicro-mediated suppression via an allelic exclusion-like mechanism dominated over somatic selection in determining the composition of the CDR-H3 repertoire. Evidence of somatic selection for RF1-encoded tyrosine in CDR-H3 was observed, but only among the minority of recirculating, mature B cells that use D(H) in RF1. These observations underscore the extent to which the sequence of the D(H) acts to delimit the diversity of the Ab repertoire.

Autograft cellular composition and outcome in NHL patients: results of the prospective multicenter GOA study.

Autologous stem cell transplantation (auto-SCT) is an established treatment option in patients with non-Hodgkin lymphoma (NHL). In this prospective multicenter study, the effect of infused blood graft cellular composition on post-transplant outcome was analyzed in 129 NHL patients. Higher graft CD34+ cell content (>2.5 × 106/kg) correlated with better progression-free survival (PFS) (p=.009) and overall survival (OS) (p=.004). Higher graft CD34+CD133+CD38- counts (>0.08 × 106/kg) were also linked with better PFS (p=.03) and OS (p=.004), and these survival benefits retained in multivariate analyses. Higher infused CD3+CD4+ cell count (>37 × 106/kg) predicted better PFS (p=.013) and OS (p=.007) in multivariate analysis. Autograft cellular composition seems to impact outcome in NHL patients. These observations regarding composition of optimal graft in autologous setting should be validated in an independent patient series or in a randomized study.

The involvement of mitochondria and the caspase-9 activation pathway in rituximab-induced apoptosis in FL cells.

Despite the wide use of anti-CD20 antibody rituximab in the cancer treatment of B cell malignancies, the signalling pathways of CD20-induced apoptosis are still not understood. By using dominant negative (DN)-caspase-9 overexpressing follicular lymphoma cells we demonstrated that the activation of caspase-9 was essential for rituximab-mediated apoptosis. The death receptor pathway mediated by caspase-8 activation was not involved in rituximab-mediated apoptosis since overexpression of FLIP(short) or FLIP(long) proteins, inhibitors of caspase-8 activation, could not inhibit rituximab-induced apoptosis. However, the death receptor pathway activation by anti-Fas antibodies showed an additive effect on rituximab-induced apoptosis. The stabilisation of the mitochondrial outer membrane by Bcl-x(L) overexpression inhibited cell death, showing the important role of mitochondria in rituximab-induced apoptosis. Interestingly, the rituximab-induced release of cytochrome c and collapse of mitochondrial membrane potential were regulated by caspase-9. We suggest that caspase-9 and downstream caspases may feed back to mitochondria to amplify mitochondrial disruption during intrinsic apoptosis.

Co-cultivated damp building related microbes Streptomyces californicus and Stachybotrys chartarum induce immunotoxic and genotoxic responses via oxidative stress.

Oxidative stress has been proposed to be one mechanism behind the adverse health outcomes associated with living in a damp indoor environment. In the present study, the capability of damp building-related microbes Streptomyces californicus and Stachybotrys chartarum to induce oxidative stress was evaluated in vitro. In addition, the role of oxidative stress in provoking the detected cytotoxic, genotoxic, and inflammatory responses was studied by inhibiting the production of reactive oxygen species (ROS) using N-acetyl-l-cysteine (NAC). RAW264.7 macrophages were exposed in a dose- and time-dependent manner to the spores of co-cultivated S. californicus and S. chartarum, to their separately cultivated spore-mixture, or to the spores of these microbes alone. The intracellular peroxide production and cytotoxicity were measured by flow cytometric analysis, nitric oxide production was analyzed by the Griess method, DNA damage was determined by the comet assay, and cytokine production was measured by an immunochemical ELISA (enzyme-linked immunosorbent assay). All the studied microbial exposures triggered oxidative stress and subsequent cellular damage in RAW264.7 macrophages. The ROS scavenger, NAC, prevented growth arrest, apoptosis, DNA damage, and cytokine production induced by the co-culture since it reduced the intracellular level of ROS within macrophages. In contrast, the DNA damage and cell cycle arrest induced by the spores of S. californicus alone could not be prevented by NAC. Bioaerosol-induced oxidative stress in macrophages may be an important mechanism behind the frequent respiratory symptoms and diseases suffered by residents of moisture damaged buildings. Furthermore, microbial interactions during co-cultivation stimulate the production of highly toxic compound(s) which may significantly increase oxidative damage.

Importance of early immune recovery after autologous hematopoietic cell transplantation in lymphoma patients.

Lymphomas constitute the second most common indication for autologous hematopoietic cell transplantation (AHCT). Graft infusion is followed by a rapid hematological recovery and slower immune recovery. The number of natural killer cells and CD3+ T lymphocytes achieve normal counts usually within a month, whereas the recovery of CD3+CD4+ T lymphocytes is much slower. Early immune recovery is usually defined as the absolute lymphocyte count (ALC) ≥0.5 × 109/L, which has been associated with improved progression-free and even overall survival. Several factors have been associated with early immune recovery, including higher infused lymphocyte and CD34+ cell doses, both of which are affected by the choice of mobilization. This review summarizes the clinical importance of early immune recovery for long-term success of AHCT in lymphomas. Factors known to affect early immune recovery are discussed and suggestions made how to improve mobilization and collection processes to optimize immune recovery and post-transplant outcomes.