[Allogeneic hematopoietic stem cell treatment after non-myeloablation (minigraft)]

Allogeneic haematopoietic stem cell transplantation is the best treatment option for many patients suffering from severe haematologic diseases. Allogeneic transplantation is generally preceded, by a myeloablative conditioning regimen consisting of high doses of chemo/radiotherapy. The use of those high dose conditionings is restricted to young patients (< 55 years of age) without significant comorbidities. Unfortunately, median patient age at diagnosis of most haematological malignancies ranges from 60 to 70 years. It has been accepted since the late 1970s that the occurrence of acute and/or chronic graft-versus-host disease (a life-threatening complication of allogeneic transplantation consisting of host organ destruction by donor T cells present in the graft) leads to a dramatic decreased risk of relapse thanks to the destruction of host tumour cells by donor T cells (graft-versus-tumour effects). These observations led several groups of investigators to develop non-myeloablative conditionings for allogeneic haematopoietic stem cell transplantation (also termed mini-transplant) based nearly exclusively on graft-versus-tumour effects for tumour eradication. After a brief introduction, this article reviews preliminary results of nonmyeloablative transplantation and then present some perspectives aimed at increasing the efficacy while decreasing the toxicity of this approach.

Biodiversity of psychrotrophic bacteria of the Bacillus cereus group collected on farm and in egg product industry

The aim of the present study was (i) to type, by genotypic and phenotypic methods, a collection of psychrotrophic bacteria belonging to the Bacillus cereus group collected in a farm and in 6 egg breaking industries during a period covering a warm and a cold season, and (ii) to characterize the egg product spoilage (growth in liquid whole egg) and the sanitary risk potential (cytotoxic activity on Caco-2 cells and adhesion on stainless steel) of each isolate of the collection. The investigation of specific psychrotrophic and mesophilic signatures together with the study of ability to grow at 6 °C and/or at 43 °C on optimal agar medium allowed highlighting twelve profiles, the major one corresponding to the species Bacillus weihenstephanensis (46.2% of the collection). The diversity of the profiles depended on the season and on the origin of the isolates. In terms of food spoilage, all the isolates were able to grow at the same level in liquid whole egg and in optimal medium, even at low temperature. Under the same conditions, the cytotoxic activity depended on the isolate, the medium and the temperature. At 10 °C, no isolate was cytotoxic at 10 °C in liquid whole egg and only one, belonging to the Bacillus weihenstephansensis species, in the optimal medium. All the isolates were able to adhere on stainless steel at various levels, from 2.6±0.2 log cfu/cm(2) to 4.9±0.1 log cfu/cm(2). A large majority (80.8%) was strongly adhering and could lead to the formation of biofilms in industrial equipments.

[Mantle cell lymphoma]

Mantle cell lymphoma comprises 3 to 10% of non-Hodgkin's lymphomas. Cyclin D1 expression due to t(11 ;14) (q13 ;32) is considered as a hallmark of this lymphoma and plays a pivotal role in the pathophysiology of lymphoma transformation. Median age at diagnosis ranges from 60 to 70 years, and diagnosis is often made at an advanced stage with widespread lymphadenopathy and extranodular (particularly bone marrow and gastrointestinal) infiltration. First line treatment consists of combination chemotherapy followed with autologous hematopoietic cell transplantation (HCT) in younger patients, while allogeneic HCT following non-myeloablative conditioning might have a role in patients relapsing after autologous HCT.

[Chronic graft-versus-host disease: a multidisciplinary approach]

Chronic Graft-Versus-Host Disease (GVHD) is a frequent complication of allogeneic hematopoietic cell transplantation. This review article describes recent advances in the classification and treatment of chronic GVHD.

[Secondary malignancies after allogeneic hematopoietic cell transplantation]

This article reviews the incidence, risk factors and prevention of secondary malignancies after allogeneic hematopoietic cell transplantation.

[Cerebral toxoplasmosis complicating an allograft with hematopoietic stem cells from peripheral blood]

We report the occurrence of a cerebral toxoplasmosis 52 days after a non-myeloablative allogeneic stem cell transplantation as treatment for acute myeloid leukemia.

[Immune recovery following allogeneic hematopoietic cell transplantation]

Allogeneic hematopoietic stem cell transplantation (alloHCT) is frequently used as treatment for patients with hematological malignancies. Its efficacy depends in part on the destruction of recipient tumor cells by donor immune cells contained in the graft (graft-versus-tumor effects), underlying the interest of studying donor immune recovery after alloHCT. Further, donor immune cells play an important role in the prevention and treatment of infections after alloHCT, and are the cause of graft-versus-host disease (GVHD). This article reviews the mechanisms of immune recovery after allogeneic hematopoietic cell transplantation (alloHCT), as well as techniques currently used to monitor immune function following alloHCT.

[How I treat... Acute myeloid leukemia in older patients with good performance status]

This article describes the treatment of acute myeloid leukemia in older patients with good performance status, and then discusses briefly some future therapeutic perspectives.

Estimations of repeatability and heritability of egg albumen antimicrobial activity and of lysozyme and ovotransferrin concentrations

1. The repeatability and heritability of growth inhibition by egg albumen of two major pathogenic bacteria, a Gram-negative (Salmonella Enteritidis) and a Gram-positive (Staphyloccocus aureus) and of two antimicrobial albumen proteins, lysozyme and ovotransferrin, were estimated in commercial pedigree hens. 2. Repeatability was evaluated in 100 egg-type hens at the beginning, middle and end of the laying cycle on eggs collected for 3 weeks. Heritabilities were estimated at 36 to 40 weeks of age on 400 pedigree hens (2 eggs/hen), which were the offspring of 25 sires each mated with 4 dams. Ovotransferrin and lysozyme were quantified by ELISA. Salmonella Enteritidis (S.E.) and Staphyloccocus aureus (S.A.) were inoculated into a sample of sterilised albumen and enumerated after incubation. 3. Total protein content in albumen decreased with age of laying hens, whereas there were increases in lysozyme or ovotransferrin concentrations and in the bacteriostatic effect of albumen. 4. Repeatability for bacterial growth in albumen ranged from 0.29 to 0.39 for the number of S.E. (log cfu/ml) one day post inoculation (p.i.) but was lower and more variable at 5 d p.i. or for S.A. number. It ranged from 0.27 to 0.38 for S.E. and S.A. number at the mid period of the laying cycle. Repeatabilities were low and variable for total egg albumen protein or lysozyme and ovotranferrin concentrations (0 to 0.22). 5. Negative phenotypic correlations were observed between lysozyme concentrations and S.E. number but that between lysozyme and S.A. number was not significant. 6. Heritabilities were low (0.01 to 0.09) for protein traits. They were 0.11 for S.A. number and 0.16 for S.E. number one day p.i. 7. It appears to be more efficient to select on global bacterial growth than on specific antimicrobial proteins. The most promising trait is the number of S.E. one day p.i.

[Evaluation of thymopoiesis: clinical applications]

In the precedent article, we have described how T-cell generation in the thymus (thymopoiesis) may be currently evaluated through quantification by PCR of T-cell receptor excision circles (TREC) generated by intrathymic random recombination of the gene segments coding for variable parts of T-cell receptor for antigen (TCR). In hematology, TREC methodology helps in a better understanding of immune reconstitution after graft of hematopoietic stem cells: first there is a proliferation of mature T cells present in the graft, then a differentiation of naive T cells. In geriatrics, the homeostasis of the peripheral T-cell repertoire is maintained through proliferation of peripheral memory T cells rather than through thymic generation of naive T cells. In addition, TREC quantification constitutes a novel major tool for deciphering the tight control of thymopoiesis by the neuroendocrine system.

[Clinical evaluation of thymic function]

The essential role of the thymus is to install an extremely diverse repertoire of T lymphocytes that are self-tolerant and competent against non-self, as well as to generate self-antigen specific regulatory T cells (Treg) able to inactivate in periphery self-reactive T cells having escaped the thymic censorship. Although indirect, techniques of medical imaging and phenotyping of peripheral T cells may help in the investigation of thymic function. Nowadays however, thymopoiesis is better evaluated through quantification by PCR of T-cell receptor excision circles (TREC) generated by intrathymic random recombination of the gene segments coding for the variable parts of the T-cell receptor for antigen (TCR). The TREC methodology is very valuable in the circumstances not associated with intense proliferation or apoptosis of peripheral T lymphocytes.

[Current therapies in hematology]

This article focuses on recent advances in four important areas of hematology: aggressive lymphomas, allogeneic hematopoietic stem cell transplantation, multiple myeloma, and molecular therapy of cancer.