Danièle Sondag

Hematopoietic recovery in cancer patients after transplantation of autologous peripheral blood CD34+ cells or unmanipulated peripheral blood stem and progenitor cells

BACKGROUND: A study of CD34+ cell selection and transplantation was carried out with particular emphasis on characteristics of short‐ and long‐term hematopoietic recovery. STUDY DESIGN AND METHODS: Peripheral blood stem and progenitor cells (PBPCs) were collected from 32 patients, and 17 CD34+ cell‐selection procedures were carried out in 15 of the 32. One patient in whom two procedures failed to provide 1 × 10(6) CD34+ cells per kg was excluded from further analysis. After conditioning, patients received CD34+ cells (n = 10, CD34 group) or unmanipulated (n = 17, PBPC group) PBPCs containing equivalent amounts of CD34+ cells or progenitors. RESULTS: The yield of CD34+ cells was 53 percent (18–100) with a purity of 63 percent (49–82). The CD34+ fraction contained 66 percent of colony‐forming units‐granulocyte‐ macrophage (CFU‐GM) and 58 percent of CFU of mixed lineages, but only 33 percent of burst‐forming units‐erythroid (BFU‐E) (p < 0.05). Early recovery of neutrophils and reticulocytes was identical in the two groups, although a slight delay in platelet recovery may be seen with CD34+ cell selection. Late hematopoietic reconstitution, up to 1.5 years after transplant, was also similar. The two groups were thus combined for analyses of dose effects. A dose of 40 × 10(4) CFU‐GM per kg ensured recovery of neutrophils to a level of 1 × 10(9) per L within 11 days, 15 × 10(4) CFU of mixed lineages per kg was associated with platelet independence within 11 days, and 100 × 10(4) BFU‐E per kg predicted red cell independence within 13 days. However, a continuous effect of cell dose well beyond these thresholds was apparent, at least for neutrophil recovery. CONCLUSION: CD34+ cell selection, despite lower efficiency in collecting BFU‐E, provides a suitable graft with hematopoietic capacity comparable to that of unmanipulated PBPCs. In both groups, all patients will eventually show hematopoietic recovery of all three lineages with 1 × 10(6) CD34+ cells per kg or 5 × 10(4) CFU‐GM per kg, but a dose of 5 × 10(6) CD34+ cells or 40 × 10(4) CFU‐GM per kg is critical to ensure rapid recovery.

Influence of affinity of antibodies upon their detection by liquid phase radiobinding assay and solid phase enzyme linked immunosorbent assay. Demonstration using monoclonal antibodies raised against rDNA human proinsulin

SummaryHybridomas producing proinsulin antibodies were cloned by limiting dilution of cell cultures obtained by fusion of splenocytes of immunized mice with immortal myeloma cells. Some proinsulin monoclonal antibodies crossreacted with labelled insulin but none did with labelled C-peptide indicating that the involved epitopes were at one of the insulin/C-peptide junctions or included in the insulin moiety. Hybridoma supernatants were assayed for IgG concentration by a solid phase assay and for ligand binding by a radiobinding assay and an enzyme linked immunosorbent assay. The half-life of immune complexes formed with radioligand was measured and, as expected, correlated with affinity as measured by the method of Scatchard. Antibody titres determined by enzyme linked immunosorbent assay did not correlate to those measured by radiobinding assay. IgG concentration correlated to enzyme linked immunosorbent assay titres but not to radiobinding assay titres. Finally, a significant correlation was found between radiobinding assay titre and the product of enzyme linked immunosorbent assay titre by the period of immune complexes. It is concluded that, except for very low affinity antibodies, enzyme linked immunosorbent assay is a capacity assay whereas radiobinding assay is influenced by both antibody concentration and affinity. The former assay is thus best suited to detecting low affinity antibodies whereas the latter is more efficient in the presence of low levels of high affinity antibodies.

Guidelines for the transfusion of platelets.

Abstract Recommendations aiming at standardising and rationalising clinical indications for the transfusion of platelets in Belgium were drawn up by a working group of the Superior Health Council. To this end the Superior Health Council organised an expert meeting devoted to “Guidelines for the transfusion of platelets” in collaboration with the Belgian Hematological Society. The experts discussed the indications for platelet transfusions, the ideal platelet concentrate and the optimal platelet transfusion therapy. The recommendations prepared by the experts were validated by the working group with the purpose of harmonising platelet transfusion in Belgian hospitals.

Combination of Serological Markers to Predict the Presence or Absence of Viremia in HCV-Seropositive Blood Donors

Firstand second-generation anti-HCY screening assays have significantly contributed to the decline of posttransfusion hepatitis C (PTH-C) to a point where nosocomial transmission and iatrogenic procedures are currently being discussed as a possible remaining cause of hepatitis C in hospitalized patients [1]. This is excellent news for recipients but blood banks also have a responsibility towards their donors. Inthis regard the question ofinfectivity and its long-term consequences for HCY-seropositive donors begs for an answer. HCY-RNA assay by the polymerase chain reaction (PCR) is useful for the detection of viremia as a measure ofinfectivity [2]. However, PCR technology is still too complex and too costly for routine use in blood banks. Investigators have attempted to circumvent this difficulty by studying the predictive value ofmarkers readily available in blood banks for indirect detection of HCY viremia [3-5]. Several have noted an association between HCYRNA and abnormal alanine aminotransferase (ALT) levels [6], increased optical density (00) signals in anti-HCY screening tests [7], or the presence of complete antibody profiles in so-called supplemental assays [8]. Recent reports have documented an association between serum HCYRNA and HCY core IgM (lgM anti-HCc), and HCY core IgG antibodies (IgG anti-HCc) inpatients with chronic liver disease [9-11]. The aim of our study was to assess the predictive value, alone or incombination, ofanti-HCY seropositivity by thirdgeneration EIA (HCY EIA-3), the HCY antibody pattern by HCY supplemental EIA (HCY SA), HCY core IgG, HCY core IgM, and ALT as indirect markers of viremia ina cohort (n =131) of Belgian blood donors deferred from donating blood due to HCY seropositivity and/or elevated ALT.