Thierry Guillaume

Zygomycosis after Prolonged Use of Voriconazole in Immunocompromised Patients with Hematologic Disease: Attention Required

We describe 4 cases of zygomycosis that occurred after prolonged use of voriconazole in severely immunocompromised patients with hematologic disease. An invasive infection was present in 3 patients who died soon after the diagnosis at 12, 13, and 45 days. Physicians should be mindful of this potential risk after treatment with voriconazole.

Long-Term Disease-Free Survival After Gemtuzumab, Intermediate-Dose Cytarabine, and Mitoxantrone in Patients With CD33+ Primary Resistant or Relapsed Acute Myeloid Leukemia

PURPOSE To determine the antitumor activity and safety of a combination of gemtuzumab ozogamicin (GO), intermediate-dose cytarabine, and mitoxantrone (MIDAM) in patients with refractory or relapsed CD33(+) acute myeloid leukemia (AML). PATIENTS AND METHODS We treated 62 patients with refractory (n = 18) or relapsed (n = 44) CD33(+) AML. Median age was 55.5 years. Salvage regimen consisted of GO 9 mg/m(2) on day 4, cytarabine 1 g/m(2) every 12 hours on days 1 through 5, and mitoxantrone 12 mg/m(2)/d on days 1 through 3. Median follow-up time was 26.5 months. RESULTS Thirty-one patients (50%) achieved complete remission (CR), and eight patients (13%) had CR with delayed platelet recovery (CRp); the overall response (OR; CR + CRp) rate was 63%. A significantly higher OR rate was achieved in patients who had relapsed versus refractory AML (73% v 39%, respectively; P = .007) and patients with CD33 expression more than 98% of the blast population versus less than 98% (79% v 52.3%, respectively; P = .03). The overall, event-free, and disease-free survival rates were 41%, 33%, and 53% at 2 years, respectively. Leukocytosis more than 20,000/microL at MIDAM therapy, high-risk cytogenetics, and absence of postremission therapy were adverse prognostic factors. Age, disease status, and/or CD33 expression did not influence survival parameters. Four early toxic deaths occurred; a grade 3 to 4 hyperbilirubinemia rate of 16% was observed, and two patients had veno-occlusive disease (3%). CONCLUSION The MIDAM regimen seems to be an effective salvage regimen for refractory/relapsed CD33(+) AML patients. These encouraging results support the need for a randomized phase III trial before considering this combination of GO and chemotherapy as superior or the standard of care treatment for refractory/relapsed CD33(+) AML patients.

Receptor for the globular heads of C1q (gC1q‐R, p33, hyaluronan‐binding protein) is preferentially expressed by adenocarcinoma cells

Combinatorial Ig libraries with phage display allow in vitro generation of human Ig fragments without the need to maintain hybridomas in ongoing cell culture or to select circulating Ig from human serum. Identifying tumor‐associated antigens on the surface of intact tumor cells, as opposed to purified proteins, presents a challenge due to the difficulty of preserving complex 3‐D epitopic sites on the cell surface, the variable expression of antigens on different malignant cell types and the stereotactic interference of closely associated proteins on the intact membrane surface limiting accessibility to antigenic sites. A combinatorial Ig library of 1010 clones was generated from the cDNA of PBMCs derived from patients with breast adenocarcinoma. Following subtractive panning, the library was enriched for Ig (Fab fragment) binding to intact adenocarcinoma cells and the resultant Fabs were screened against a cDNA expression library, itself generated from breast cancer cells. Using this approach, we isolated clones from the cDNA library expressing gC1q‐R, a glycoprotein comprising the major structure of C1, the first component of the complement system. gC1q‐R is a 33 kDa glycoprotein expressed not only on the cell surface but also intracellularly, with motifs that target it to mitochondria and complete homology with HABP and human HeLa cell protein p32, which is copurified with pre‐mRNA SF2. Sequencing of the gene encoding tumor‐associated gC1q‐R did not reveal any consistent tumor‐specific mutations. However, histochemical staining with anti‐gC1q‐R MAb demonstrated marked differential expression of gC1q‐R in thyroid, colon, pancreatic, gastric, esophageal and lung adenocarcinomas compared to their nonmalignant histologic counterparts. In contrast, differential expression was not seen in endometrial, renal and prostate carcinomas. Despite high expression in breast carcinoma, gC1q‐R was also expressed in nonmalignant breast tissue. Although the precise relation of gC1q‐R to carcinogenesis remains unclear, our finding of tumor overexpression and the known multivalent binding of gC1q‐R to not only C1q itself but also a variety of circulating plasma proteins as well as its involvement in cell‐to‐cell interactions suggest that gC1q‐R may have a role in tumor metastases and potentially serve in molecule‐specific targeting of malignant cells.

Targeting Retroviral Vectors to CD34-Expressing Cells: Binding to CD34 Does Not Catalyze Virus-Cell Fusion

We have attempted to engineer murine leukemia virus (MuLV)-based retroviral vectors to specifically transduce cells expressing human CD34, an antigen present on the surface of undifferentiated hematopoietic stem cells. A number of chimeric ecotropic MuLV envelope (Env) proteins were constructed that contained anti-CD34 single-chain antibody variable fragments (scFvs). The scFv-Env proteins were generated either by replacing the receptor-binding domain of Env with the scFv or by inserting the scFv into the N terminus of the Env protein. Only chimeric Env proteins with scFv insertions between amino acids 6 and 7 were incorporated into viral particles, and coexpression of native MuLV Env did not rescue incorporation-defective proteins. In addition, the efficiency of incorporation varied with the specific anti-CD34 scFv that was used. Retroviral vectors containing the scFv-Env proteins bound to CD34+ cells and transduced NIH 3T3 cells expressing human CD34 (3T3-CD34 cells) at approximately twice the efficiency of the parental NIH 3T3 cells. However, the introduction of the mutation D84K, which prevents binding to the ecotropic MuLV receptor mcat-1, prevented transduction of both NIH 3T3 and 3T3-CD34 cells. Complementation cell-cell fusion assays [Zhao et al. (1997). J. Virol. 71, 6967-6972] in 3T3-CD34 cells revealed that although the scFv-Env proteins could contribute postbinding entry functions when bound to mcat-1, they were unable to do so when bound to CD34. Taken together, these data suggest that although the interaction with CD34 effectively increased the concentration of virus on 3T3-CD34 cells, entry could occur only through an interaction with mcat-1; CD34 alone was not capable of triggering the appropriate postbinding changes that lead to viral entry.

Human herpes virus 6 infection is a hallmark of cord blood transplant in adults and may participate to delayed engraftment: a comparison with matched unrelated donors as stem cell source

Occurrence of CMV, EBV and human herpes virus 6 (HHV6) infections and immune reconstitution were compared in 15 adult patients receiving a cord blood transplantation (CBT) and 40 patients who received an allogeneic transplantation from a matched unrelated donor (MUD). Herpes virus DNA quantifications in the blood (459 samples) were performed before and then monthly up to 9 months after transplant and the main lymphocytes populations were counted at 3, 6 and 9 months. Incidence of HHV6 infection was significantly higher in the CBT group (80 vs 42.5%; P<0.0001), with higher viral load (P<0.0001). In multivariate analysis, the use of a CBT and a myeloablative conditioning regimen were found to increase the risk of HHV6 infection (odds ratio (OR)=5.4, P=0.02 and OR=3.5, P=0.04, respectively). Incidences of CMV were similar between the two groups whereas MUD increased the risk of EBV infection, in univariate analysis only. HHV6 reactivation translated toward delayed neutrophils and plts engraftment in the two groups. MUD and CBT do not share the same immune reconstitution patterns, notably for B and CD8 lymphocytes and NK cells. There is a strong and specific relationship between HHV6 infection and the use of cord blood cells.

Features of Epstein-Barr Virus (EBV) reactivation after reduced intensity conditioning allogeneic hematopoietic stem cell transplantation

This single centre study assessed the incidence, kinetics and predictive factors of Epstein-Barr Virus (EBV) reactivation and EBV-related lymphoproliferative diseases (LPDs) in 175 consecutive patients who received a reduced-intensity conditioning (RIC) before allogeneic hematopoietic stem cell transplantation (allo-HSCT). The cumulative incidence of EBV reactivation at 6 months after allo-HSCT defined as an EBV PCR load above 1000 copies of EBV DNA/105 cells was 15%, and none of these patients experienced any sign or symptom of LPD. A total of 17 patients, who had EBV DNA levels exceeding 1000 copies/105 cells on two or more occasions, were pre-emptively treated with rituximab. With a median follow-up of 655 (range, 92–1542) days post allo-HSCT, there was no statistically significant difference in term of outcome between those patients who experienced an EBV reactivation and those who did not. In multivariate analysis, the use of antithymocyte globulin as part of the RIC regimen was the only independent risk factor associated with EBV reactivation (relative risk=4.9; 95% confidence interval, 1.1–21.0; P=0.03). We conclude that patients undergoing RIC allo-HSCT using anti-thymocyte globulin as part of the preparative regimen are at higher risk for EBV reactivation. However, this did not impact on outcome, as quantitative monitoring of EBV viral load by PCR and preemptive rituximab therapy allowed for significantly reducing the risk of EBV-related LPD.

Impact of Cyclosporine-A Concentration on the Incidence of Severe Acute Graft-versus-Host Disease after Allogeneic Stem Cell Transplantation

This single-center retrospective study analyzed 85 consecutive patients who underwent allogeneic stem cell transplantation (allo-SCT) with the aim to assess whether there is a correlation between exposure to cyclosporine-A (CsA; as measured by CsA concentrations during the first month after allo-SCT) and the risk for developing severe grade III-IV acute graft-versus-host disease (aGVHD). The median concentrations of CsA in the blood at 1, 2, 3, and 4 weeks after allo-SCT were 348 (range: 172-733), 284 (range: 137-535), 274 (range: 107-649), and 247 (range: 37-695) ng/mL, respectively. Overall, grade II-IV aGVHD occurred in 36 patients (42%) at a median of 29 (range: 6-100) days after allo-SCT. The incidence of grade III-IV aGVHD (n = 20) was 23% (95% confidence interval [CI], 14%-32%). In univariate analysis, patients receiving allo-SCT from an HLA-matched unrelated donor had a higher risk of grade III-IV aGVHD, and patients having the lowest CsA concentration in the first and second weeks after allo-SCT had a significantly higher risk of grade III-IV aGVHD. In a multivariate logistic regression analysis, a higher CsA concentration measured during the first week following graft infusion was the strongest parameter significantly associated with a reduced risk of severe grade II-IV aGVHD (P = .012; relative risk [RR] = 0.24; 95% CI, 0.08-0.73). Of note, when adjusted by donor type, CsA concentration in week 1 remained significantly associated with risk of severe grade II-IV aGVHD (P = .014). We conclude that precise monitoring of CsA concentrations and adjustment of CsA dose early after allo-SCT may be effective to prevent onset of severe aGVHD.

Infectious Complications after Unrelated Umbilical Cord Blood Transplantation in Adult Patients with Hematologic Malignancies

Unrelated umbilical cord blood (UCB) is being increasingly used as an alternative stem cell source for allogeneic stem cell transplantation (allo-SCT). This retrospective study assessed infectious complications occurring in adult patients after UCB transplantation (UCBT). 31 patients received a single (n=4) or double UCBT (n=27) with a median dose of 4.7x10(7) nucleated cells/kg (range: 2.4-7.7). Patients received either a reduced-intensity conditioning (RIC; n=23) or a standard myeloablative (MA) regimen (n=8). The cumulative incidence of neutrophil recovery was 90%. Neutrophil recovery was achieved at a median time of 24 (range: 8-60) days after UCBT. The cumulative incidences of bacterial, fungal, and parasitic infections were, respectively, 16%, 10%, and 6%. Bloodstream infections were neither lethal nor required any intensive care therapy. Similarly, invasive fungal infections and parasitic infections did not cause any death in those patients with sustained engraftment. Although the cumulative incidence of cytomegalovirus (CMV) recurrence was 21%, no CMV disease was observed. With a median follow-up of 10 (range: 3-30) months, 10 patients have died (relapse, n=5; nonrelapse mortality, [NRM] n=5). Overall, the cumulative incidence of infectious-related mortality (IRM) was 8%. In conclusion, this data suggests that UCBT can be performed in adult patients with hematologic malignancies with an acceptable incidence of IRM provided a sufficient dose of nucleated cells is infused to the patient.

Azacitidine salvage therapy for relapse of myeloid malignancies following allogeneic hematopoietic SCT.

Patients with hematopoietic malignancies relapsing after allogeneic hematopoietic SCT (allo-HSCT) have a poor prognosis. We retrospectively analyzed the patients who received azacitidine in our center in the course of treatment of their post-transplant relapse. We identified 31 patients. Relapse occurred at a median of 3.7 (1.7–37.6) months following allo-HSCT. Patients received a median number of three cycles (1–12) of azacitidine (7 days, 75 mg/m2 daily). Thirty-nine percent of patients had either a monosomal karyotype or a complex karyotype. Eleven patients (35%) received at least one DLI. Eleven patients responded to azacitidine, with four patients achieving a CR (13%). Median time to best response was 92 (35–247) days, with a median duration of 209 (64–751) days. One-year estimated survival rate was 14%. In conclusion, azacitidine may reinduce durable remissions in very few patients with AML or myelodysplastic syndrome. The toxicity related to azacitidine was high, although it may be difficult to distinguish between treatment-related side effects, namely due to cytopenia and toxicity due to the relapse or disease progression itself. Early administration of azacitidine after transplant followed by DLI should be considered as a pre-emptive therapy for potential relapse in patients with minimal residual disease or high-risk myeloid malignancies.

Reduced-toxicity conditioning with fludarabine, once-daily intravenous busulfan, and antithymocyte globulins prior to allogeneic stem cell transplantation: results of a multicenter prospective phase 2 trial.

The optimal intensity of myeloablation delivered as part of a reduced‐intensity/toxicity conditioning (RIC/RTC) regimen to decrease the recurrence rate, without increasing nonrecurrence mortality (NRM), remains to be established.