Suppression of autoimmunity by CD5(+) IL-10-producing B cells in lupus-prone mice.

Systemic lupus erythematosus is a complex autoimmune disorder characterized by the production of pathogenic anti-nuclear antibodies. Previous work from our laboratory has shown that the introgression of a New Zealand Black-derived chromosome 4 interval onto a lupus-prone background suppresses the disease. Interestingly, the same genetic interval promoted the expansion of both Natural Killer T- and CD5(+) B cells in suppressed mice. In this study, we show that ablation of NKT cells with a CD1d knockout had no impact on either the suppression of lupus or the expansion of CD5(+) B cells. On the other hand, suppressed mice had an expanded population of IL-10-producing B cells that predominantly localized to the CD5(+)CD1d(low) compartment. The expansion of CD5(+) B cells negatively correlated with the frequency of pro-inflammatory IL-17 A-producing T-cells and kidney damage. Adoptive transfer with a single injection of total B cells with an enriched CD5(+) compartment reduced the frequency of memory/activated, IFNγ-producing, and IL-17 A-producing CD4 T-cells but did not significantly reduce autoantibody levels. Taken together, these data suggest that the expansion of CD5(+) IL-10-producing B cells and not NKT cells protects against lupus in these mice, by limiting the expansion of pro-inflammatory IL-17 A- and IFNγ-producing CD4 T-cells.

Outpatient myeloablative allo-SCT: a comprehensive approach yields decreased hospital utilization and low TRM.

Historically, myeloablative allogeneic hematopoietic SCT (HSCT) has required prolonged in-patient hospitalization due to the effects of mucosal toxicity and prolonged cytopenias. We explored the safety and feasibility of outpatient management of these patients. A total of 100 consecutive patients underwent a matched-related donor myeloablative allogeneic HSCT for a hematologic malignancy at a single institution. Patients were hospitalized briefly for stem-cell infusion and thereafter only for complications more safely managed in the in-patient setting. The median hospital length of stay from the start of the preparative regimen to day +30 and day +100 post-transplant was 12 and 15 days, respectively. Planned hospital discharge occurred in 79 patients after stem cell infusion. Patients were readmitted to hospital at median of day +7 post transplant, with neutropenic fever being the primary cause for readmission. In total, 18 patients required no in-patient care in the first 100 days. Non-relapse mortality at day 100 and 6 months was 10 and 15%, respectively, for all patients, and 0 and 5%, respectively, for standard risk patients. In summary, outpatient myeloablative allogeneic HSCT with expectant in-patient management can be accomplished safely with low treatment-related morbidity and mortality. Clinical outcomes seem comparable to those reported for traditional in-patient management.

Late onset of invasive aspergillus infection in bone marrow transplant patients at a university hospital.

Despite new antifungal treatment strategies, invasive aspergillosis (IA) remains a principal cause of infectious mortality after bone marrow transplantation (BMT). We reviewed the medical records of 93 allogeneic and 149 autologous transplant recipients during a 20 month period, with attention to cases of proven or probable IA. No autologous transplant recipient developed IA, whereas IA was seen in 15.1% of allogeneic recipients (including two of five patients with a prior history of IA despite prophylaxis), for an overall incidence of 5.8%. The median time to occurrence was 92 days post transplant, with no de novo cases developing prior to engraftment. Survival 100 days from diagnosis was 29%. Risk factors for the development of IA included > or = 21 days of corticosteroid therapy of >or= 1mg/kg/day and post-transplant cytomegalovirus (CMV) infection. These two risk factors were statistically linked. Our data illustrate a shift toward a later occurrence of post-transplant IA, suggesting a need for close, prolonged surveillance in the outpatient environment. The contributory role of protracted corticosteroid use is also highlighted. These data have important implications in an era of alternate donor transplants and more intense immunosuppression. Established strategies implementing newer, less toxic antifungal agents as prophylaxis in high-risk patients are needed.

Apoptosis of cells in aged samples as detected by the ProCOUNT reagent.

An unusual population of high side scatter, low nucleic acid dye binding, dim CD45 cells was found in aged blood samples stained with the ProCOUNT reagent. Cell surface staining showed that these cells have the surface phenotype of neutrophils. However, they have decreased expression of several surface antigens, bind annexin V, and stain more dimly than normal neutrophils with LDS-751. These characteristics indicate that the cells have become apoptotic. The decreased expression of the CD45 antigen on apoptotic neutrophils could have an impact on some methods for enumerating CD34-positive progenitor cells. Absolute CD34-positive cell counts are frequently obtained by multiplying CD34-positive cells as a percentage of the total cells by the white blood cell count from a hematologyanalyzer. Cells staining dimly with CD45 may not pass a flow cytometer threshold set on this parameter but appear to be detected by a hematology instrument thresholding on cell size. Thus the white blood cell counts from the two sources may not be identical, introducing error into the calculated absolute CD34 count. Absolute counts of CD34 cells based on simultaneous acquisition of a counting bead are not affected by the presence of this population, but purity estimates can be affected if the possible presence of these cells is not considered in aged samples.