Jed Gorlin

Tandem High-Dose Therapy in Rapid Sequence for Children With High-Risk Neuroblastoma

PURPOSE Advances in chemotherapy and supportive care have slowly improved survival rates for patients with high-risk neuroblastoma. The focus of many of these chemotherapeutic advances has been dose intensification. In this phase II trial involving children with advanced neuroblastoma, we used a program of induction chemotherapy followed by tandem high-dose, myeloablative treatments (high-dose therapy) with stem-cell rescue (HDT/SCR) in rapid sequence. PATIENTS AND METHODS Patients underwent induction chemotherapy during which peripheral-blood stem and progenitor cells were collected and local control measures undertaken. Patients then received tandem courses of HDT/SCR, 4 to 6 weeks apart. Thirty-nine patients (age 1 to 12 years) were assessable, and 70 cycles of HDT/SCR were completed. RESULTS Pheresis was possible in the case of all patients, despite their young ages, with an average of 7.2 x 10(6) CD34(+) cells/kg available to support each cycle. Engraftment was rapid; median time to neutrophil engraftment was 11 days. Four patients who completed the first HDT course did not complete the second, and there were three deaths due to toxicity. With a median follow-up of 22 months (from diagnosis), 26 of 39 patients remained event-free. The 3-year event-free survival rate for these patients was 58%. CONCLUSION A tandem HDT/SCR regimen for high-risk neuroblastoma is a feasible treatment strategy for children and may improve disease-free survival.

Multicenter Evaluation of the Performance Characteristics of the Bayer VERSANT HCV RNA 3.0 Assay (bDNA)

ABSTRACT In this multicenter evaluation, the VERSANT HCV RNA 3.0 Assay (bDNA) (Bayer Diagnostics, Tarrytown, N.Y.) was shown to have excellent reproducibility, linearity, and analytical sensitivity across specimen collection matrices (serum, EDTA, ACD-A), and hepatitis C virus (HCV) genotypes 1 to 6. The VERSANT HCV bDNA Assay has a reportable range of 615 to 7,690,000 (7.69 × 106) IU/ml. The total coefficient of variation (CV) ranged from 32.4% at 615 IU/ml to 17% at 6.8 × 106 IU/ml. The assay was linear across the reportable range. Analytical specificity of 98.8% was determined by testing 999 specimens from volunteer blood donors. Evaluation of HCV genotypes using RNA transcripts of representative clones of 1a, 1b, 2a, 2b, 2c, 3a, 4a, 5a, and 6a and patient specimens showed that the largest difference between genotype 1, upon which the assay is standardized, and non-1 genotypes was within 1.5-fold. Testing of potentially interfering endogenous substances and exogenous substances and conditions found no interference in HCV-positive or HCV-negative specimens except for unconjugated bilirubin at concentrations of ≥20 mg/dl and protein at concentrations of ≥9 g/dl. Biological variability was estimated from 29 clinically stable individuals not on HCV therapy who were tested weekly over an 8-week period. The combined estimate of total (biologic plus assay) variability was 0.15 log10 standard deviation (CV, 36.1%), a fold change of 2.6. Thus, the observed fold change between any two consecutive HCV RNA measures is expected to be less than 2.6-fold (equivalent to 0.41 log10 IU/ml) 95% of the time in clinically stable individuals.

Purification of Salmon Clotting Factors and Their Use as Tissue Sealants

Fibrin sealant prepared from the blood of farmed Atlantic salmon (Salmo salar) represents a potential source of well-controlled natural material with utility in a variety of clinical settings. A potential advantage of this material is a lower probability of viral or bacterial infection that has limited general approval of fibrin glues made from human or bovine proteins. This report describes the purification of fibrinogen from salmon blood, the use of fibrin glues derived from this material to promote wound healing in rats, and the antigenic response to this material. While the low ambient temperature of these cold water fish significantly lessens the probability of infectious transmission to humans, fibrinogen and factor XIII derived from S. salar are activated by human thrombin at 25 degrees C and 37 degrees C to form clots equivalent to those formed by human fibrin. We compare the reactivity of salmon and human fibrinogen with human and bovine thrombin and the structure and viscoelastic properties of the resulting fibrin gels over a range of pH and salt concentrations. The efficacy of salmon fibrin glues in a wound healing assay and the low antigenic response to salmon fibrinogen suggest that this material may substitute for proteins derived from mammalian sources with lower probability of infections.

Rapid-sequence tandem transplant for children with high-risk neuroblastoma.

Background The majority of patients with high risk neuroblastoma (NB) still relapse. Procedure We designed a Phase II trial for children with advanced NB utilizing a program of induction chemotherapy followed by tandem high-dose chemoradiotherapy with stem cell rescue (HDC/SCR) in rapid sequence. Fifty-five patients were evaluable, ages 1–14 years, and 97 cycles of HDC/SCR have been completed to date. Pheresis was possible for every patient, despite their young age, with an average of 7.2 × 106 CD34+ cells/kg available to support each HDC/SCR cycle. Results Engraftment was rapid, with median time to neutrophil engraftment of 11 days. Five patients who completed the first HDC course did not complete the second and there were four toxic deaths. With a median follow-up of 24 months from diagnosis, 38 of 55 patients (3-year EFS 59%) remain event-free. A subset of the patients received stem cells purged by CD34 selection. The engraftment and EFS of these patients are similar to the overall group. Conclusion This work demonstrates that a tandem transplant regimen for high-risk NB is a feasible treatment strategy in children and may improve disease-free survival. Med. Pediatr. Oncol. 35:696–700, 2000.

Serologic screening of United States blood donors for Babesia microti using an investigational enzyme immunoassay

The tick‐borne pathogen Babesia microti has become recognized as the leading infectious risk associated with blood transfusion in the United States, yet no Food and Drug Administration–licensed screening tests are currently available to mitigate this risk. The aim of this study was to evaluate the performance of an investigational enzyme immunoassay (EIA) for B. microti as a screening test applied to endemic and nonendemic blood donor populations.

A prospective evaluation of chronic Babesia microti infection in seroreactive blood donors

Babesia microti is the foremost infectious risk to the US blood supply for which a Food and Drug Administration (FDA)‐licensed test is unavailable for donation screening. Characterization of the antibody response to B. microti and correlation with parasitemia is necessary to guide screening and donor management policies.

Cytomegalovirus-safe blood: the unclear effect of sickle hemoglobin

Cytomegalovirus-safe blood: the unclear effect of sickle hemoglobin Transfusion-transmitted cytomegalovirus (CMV) remains a significant concern for at-risk patients, especially transplant recipients. CMV has been associated with increased morbidities that include graft-versus-host disease, rejection, and susceptibility to secondary infection as well as increased mortality. Antiviral medications are available, but they are not without side effects, nor do they completely prevent sequelae. For previously CMV-negative patients, transfusion is rarely confirmed as the source of infection, but it is often suspected. Seronegative and leukoreduced blood products have residual CMV transmission rates of 1 to 2% and 2 to 3%, respectively. Of these two approaches, prestorage leukoreduction is most widely used to provide “CMV-safe” blood products, because it is logistically easier to implement and decreases the rate of febrile nonhemolytic transfusion reactions and human leukemic antigen (HLA) alloimmunization. However, at least one major prospective study showed significantly higher rates of CMVassociated disease in patients who received leukoreduced versus seronegative transfusions. Interestingly, preclinical data suggest that sickle trait (HbAS) donor red blood cells (RBCs) decrease leukoreduction efficacy, which has not been taken into account in clinical studies to date. Given the widespread use of leukoreduction, the effect of sickle hemoglobin on the rate of transfusion-transmitted CMV deserves consideration and further study. Blood collection centers use statistical process control to detect leukocyte reduction failures, typically testing approximately 1% of units. Factors that increase the binding of RBCs to the filter may decrease sites available for leukocyte binding and, thus, leukoreduction efficacy. The same process can also completely occlude the filter. This problem has been reported for HbAS RBCs, in which the efficacy of leukoreduction seems to be related to filtration time. Because of this issue, US Food and Drug Administration guidance requires additional testing in certain scenarios. For instance, if filtration requires longer than the filter manufacturer’s stated maximum filtration time, then that unit must be individually tested. There are problems with this approach: studies demonstrate that, although about one-half of HbAS units filter within the allowed time, many of these units show suboptimal leukoreduction. CMV DNA has been detected in 0.004 to 0.01% of circulating mononuclear cells from CMV seropositive individuals (50%-70% of the healthy donor population) after granulocyte colony-stimulating factor-mobilization. CMV DNA has also been detected in some seronegative individuals. CMV infects marrow progenitor cells, but monocytes are the primary circulating mononuclear cell type infected by CMV. The number of CMV DNA copies per 10,000 monocytes varies by age, from 8.6 (standard deviation, 38) for individuals younger than 70 years to 249 (standard deviation, 59) for those older than 70 years. Assuming a normal peripheral blood monocyte count, a unit collected from a latently infected donor and reduced to 5 3 10 white blood cells could contain from 86 to 430 copies of CMV DNA or more. In mice, the minimum infectious dose appears to be approximately 1000 murine CMV genomes, with a dose-dependent increase in transmission rates above that level. Thus, even a 10% decrease in leukoreduction efficiency (as previously reported in some HbAS-positive units) may lead to a significant increase in the CMV transmission rate. With an estimated sickle trait prevalence of approximately 0.8% in US blood donors and marked geographic variation, these units may account for a non-negligible percentage of CMV transmissions when using leukocyte-reduced products. The current response to this potential risk is inconsistent. At least one large US blood center tests donors for sickle hemoglobin if they self-identify as being of African descent and voluntarily opt to join a “sickle cell program.” If they are positive, then the donor is deferred for RBC donation. Another large US blood supplier only defers known sickle trait donors if their donated blood does not reliably filter, which can be advantageous, because these donors might provide hard to find antigen-negative blood for alloimmunized patients of African descent. Large clinical studies would be needed to determine whether HbAS increases the transmission risk when leukoreduction is used to provide CMV reduced-risk units to patients; in vitro and animal studies may be more tractable approaches to further address this question. Similar approaches could be used for a preliminary assessment of whether febrile nonhemolytic transfusion reactions or HLA alloimmunization rates may also be increased in recipients who received leukoreduced units from sickle trait donors. Until additional data become available, and depending on what is deemed an acceptable level of risk for transfusion-transmitted CMV, it may be necessary to implement additional testing of leukocyte-reduced units from HbAS donors. An alternative approach to ensure a low risk of CMV transmission would be pathogen inactivation (once available for RBC units). doi:10.1111/trf.14138