Direct evidence for new T-cell generation by patients after either T-cell-depleted or unmodified allogeneic hematopoietic stem cell transplantations

Successful allogeneic hematopoietic stem cell transplantation (HSCT) requires reconstitution of normal T-cell immunity. Recipient thymic activity, biologic features of the allograft, and preparative regimens all contribute to immune reconstitution. We evaluated circulating T-cell phenotypes and T-cell receptor rearrangement excision circles (TRECs) in 331 blood samples from 158 patients who had undergone allogeneic HSCTs. All patients had received myeloablative conditioning regimens and were full donor chimeras in remission. Younger patients exhibited more rapid recovery and higher TRECs (P =.02). Recipients of T-cell-depleted allografts initially had lower TRECs than unmodified allograft recipients (P <.01), but the difference abated beyond 9 months. TREC level disparities did not achieve significance among adults with respect to type of allograft. Measurable, albeit low, TREC values correlated strongly with severe opportunistic infections (P <.01). This finding was most notable during the first 6 months after transplantation, when patients are at greatest risk but before cytofluorography can detect circulating CD45RA(+) T cells. Low TRECs also correlated strongly with extensive chronic graft-versus-host disease (P <.01). Recipients of all ages of either unmodified or T-cell-depleted allografts therefore actively generate new T cells. This generation is most notable among adult recipients of T-cell-depleted allografts, most of whom had also received antithymocyte globulin for rejection prophylaxis. Low TREC values are significantly associated with morbidity and mortality after transplantation. T-cell neogenesis, appropriate to age but delayed in adult recipients of T-cell-depleted allografts, justifies interventions to hasten this process and to stimulate desirable cellular immune responses.     

Correction to: An exploration of sacral morphology using geometric morphometrics and three-dimensionally derived interlandmark distances

International Journal of Legal Medicine -     

The impact of symptom severity on the cost of Alzheimer's disease

OBJECTIVES: ITo examine the economic impact of Alzheimer's disease (AD) as the disease progresses on patients' medical costs and caregivers' productivity. DESIGN: A 12-page, self-administered mail survey, fielded in November 1999. SETTING: Households with AD caregivers, selected from a nationwide (U.S.) consumer database. PARTICIPANTS: One thousand seven hundred fifteen caregivers of noninstitutionalized AD patients. MEASUREMENTS: Disease progression was measured using a scale of symptom frequency and measures of instrumental and physical functioning. Cost components included hospital days, physician visits, and emergency room visits. Lost productivity was assessed using hours per week that caregivers provided care and the number of days that they missed from work because of caregiving. RESULTS: The direct costs of caring for AD patients for 6 months totaled $3,129, whereas the indirect costs were $26,080. Patients with more-frequent symptoms used all healthcare resources, including the hospital, emergency room, and physicians, more often than those with less-frequent symptoms. Those with lower levels of physical and instrumental functioning also used the hospital and physicians more often than those with higher levels of physical and instrumental functioning. Caregivers of these more severely impaired patients spent more hours providing care and reported missing more work than those caring for higher-functioning patients. These relationships remained after controlling for potentially confounding factors. CONCLUSIONS: This large study of patients at all stages of AD shows that the direct and indirect costs of AD are considerably lower for patients with fewer symptoms. Longitudinal studies will determine the impact on the overall cost of care of interventions that reduce symptoms and maintain patients at earlier stages of the disease.     

Fludarabine-based cytoreductive regimen and T-cell-depleted grafts from alternative donors for the treatment of high-risk patients with Fanconi anaemia

Eighteen consecutive patients aged 5·5–24 years with Fanconi anaemia and diagnoses of aplastic anaemia ( n  = 8), myelodysplastic syndrome ( n  = 4), acute myeloid leukaemia ( n  = 6), received allogeneic haematopoietic stem cell transplants from alternative donors. All patients had been transfused, 13 had previously been treated with androgens and 14 had a history of infection. Donors were related human leucocyte antigen (HLA) mismatched for eight patients, unrelated HLA mismatched for seven patients and unrelated HLA matched for three patients. Cytoreduction included single dose total body irradiation (450 cGy), fludarabine (150 mg/m²) and cyclophosphamide (40 mg/kg). Immunosuppression included antithymocyte globulin and tacrolimus. Grafts were granulocyte colony-stimulating factor-mobilized, CD34⁺ T-cell-depleted peripheral blood stem cells in 15 patients and T-cell-depleted marrows in three. All 18 patients engrafted with 100% donor chimaerism; only one patient developed graft-versus-host disease (GVHD). With a median follow-up of 4·2 years, 13/18 patients were alive, 12 of these were disease-free. Five-year overall survival and disease-free survival were 72·2% and 66·6% respectively. Immune reconstitution was achieved at approximately 6 months post-transplant for most patients. These are encouraging results of T-cell-depleted transplants from alternative donors using fludarabine-based cytoreduction in 18 high-risk patients with Fanconi anaemia, with no evidence of rejection and minimal GVHD.     

Influence of acoustic stress by noise on gastrointestinal motility in dogs

The effects of acoustic stress (AS) on gastrointestinal motility and their prevention by previous treatment with naloxone, phentolamine, propranolol, muscimol, and diazepam were investigated in intact and vagotomized fasted dogs fitted with chronically implanted strain gauges on the antrum at 10 cm from pylorus and on the jejunum at 70 and 140 cm from the pylorus. These effects were compared to those produced by intracerebroventricular administration of ovine corticotropin releasing factor (oCRF). Beginning 40–50 min after the occurrence of a gastric migrating motor complex (MMC), a 1-hr hearing of prerecorded intense music through earpieces (<100 dB) delayed the occurrence of the next gastric MMC observed after 2.8±1.2 hr, while jejunal MMC were still present at a normal frequency. During AS, heart rate and plasma cortisol were significantly increased by 32.7 and 215%, respectively, 10–15 min after the beginning of hearing. The AS-induced lengthening of the gastric MMC cycle as well as cortisol increase were abolished after previous administration of diazepam (0.5 mg/kg intramuscular) or muscimol (10 g/kg intravenous), while they were still present after naloxone (0.1 mg/kg intravenous), phentolamine (0.2 mg/kg intravenous), or propranolol (0.1 mg/kg intravenous). CRF administered intracerebroventricularly (100 ng/kg) also delayed the occurrence of gastric MMC without affecting jejunal motility, and this effect was not antagonized by previous treatment with diazepam or muscimol. Both the effects of AS and CRF were abolished after bilateral thoracic vagotomy. These results suggest that the selective inhibition of gastric motility induced by noise in dog is due to the CNS release of CRF which affects, in turn, the vagal output to the stomach. The suppressive action of diazepam or GABA agonist on noise-induced gastric hypomotility may be related to blockade of the AS-induced CRF release.     

B-cell differentiation following autologous, conventional, or T-cell depleted bone marrow transplantation: a recapitulation of normal B-cell ontogeny.

The circulating lymphocytes of 88 consecutive patients following autologous, conventional, or T-cell depleted bone marrow transplantation were serially analyzed for B-cell surface antigen expression and function. In the majority of patients, except for those who developed chronic graft-versus-host disease, the number of circulating CD20+ B cell normalized by the fourth posttransplant month. The earliest detectable B cells normally expressed HLA-DR, CD19, surface immunoglobulin (slg), CD21, Leu-8, and lacked expression of CD10 (CALLA). In addition, the circulating B cells expressed CD1c, CD38, CD5, and CD23 for the first year following transplant, antigens that are normally expressed on a small percentage of circulating B cells in normal adults, but highly expressed on cord blood B cells. Similar to cord blood B cells, patient B cells isolated during the first year following transplant, proliferated normally to Staphylococcus aureus Cowan strain I (SAC), and produced IgM, but minimal or no IgG when stimulated with pokeweed mitogen and SAC, unlike normal adult B cells that produce both. The similar phenotype and function of posttransplant and cord blood B cells, and their similar rate of decline in patients and normal children adds further evidence to support the hypothesis that B-cell differentiation posttransplant is recapitulating normal B-cell ontogeny.     

Diamond-Blackfan anemia: promotion of marrow erythropoiesis in vitro by recombinant interleukin-3

To clarify the defective erythropoiesis in eight patients with Diamond- Blackfan anemia, we studied their bone marrow response in vitro to recombinant human interleukin-3 (IL-3) and recombinant granulocyte- macrophage colony-stimulating factor (GM-CSF). In an erythropoietin- containing assay system, specimens from six of the eight patients yielded low numbers of erythroid colonies compared to control values, and in five of these no erythropoietin dose-response could be elicited. Addition of IL-3, GM-CSF or both to cultures from the six patients had no effect on CFU-E-derived colonies. In contrast, IL-3 but not GM-CSF induced a marked increase in the number (183%) and size of the BFU-E- derived colonies in five of the six cases and partially corrected the impaired dose-response to erythropoietin in four. Bone marrow from the other two patients yielded numbers of CFU-E and BFU-E colonies comparable to controls and manifested similar increments in colonies with increasing concentrations of erythropoietin. When IL-3 was added to these cultures, further increments were observed in the number and size of BFU-E colonies. We conclude that IL-3 enhanced the marrow erythropoiesis in most of the patients and exerted a corrective effect on the aberrant colony formation in the presence of erythropoietin. The data raise the possibility of IL-3 as a therapeutic agent in Diamond- Blackfan anemia.