British Journal of Haematology

Galli, Monica; Finazzi, Guido; Barbui, Tiziano

doi: 10.1046/j.1365-2141.1996.390969.xpmid: 8611440

Ghielmini, Michele; Pettengell, Ruth; Coutinho, Lucia H.; Testa, Nydia; Crowther, Derek

doi: 10.1046/j.1365-2141.1996.4731015.xpmid: 8611477

This is a phase I/II study of the GM‐CSF/IL‐3 fusion protein PIXY321. Patients were treated with PIXY321 at a daily subcutaneous dose of 500, 750 and 1000 μg/m2 for 14 d. Side‐effects were mild and consisted mainly of injection‐site reactions and constitutional symptoms. A biphasic modest increase of white blood count (2.5‐fold) and platelets (1–1.5‐fold) was seen, accompanied by an increased bone marrow cellularity and an increase in circulating progenitors. Colony‐forming cells in the blood rose to a median of 184 granulocyte/macrophage‐colony forming cells (GM‐CFC)/ml, eight Mix‐CFC/ml, 250 burst forming units‐erythroid (BFU‐E)/ml and 140 CFU‐megakaryocytes/ml, corresponding to a 10‐, 2.5‐, 8‐ and 30‐fold increase respectively. When seeded for long‐term culture on irradiated bone marrow stroma, the mobilized cells were not able to sustain haemopoiesis in vitro to the same degree as bone marrow. Taken together, these results indicate that PIXY321 has a biological effect in humans more similar to that of IL‐3 than to that of GM‐CSF.

Angchaisuksiri, Pantep; Carlson, Patricia; Dessypris, Emmanuel

doi: 10.1046/j.1365-2141.1996.4761013.xpmid: 8611445

In serum‐free cultures of human CD34 cells, recombinant human thrombopoietin (TPO) induced megakaryocyte colony formation in a dose‐dependent fashion that was further enhanced by the presence of interleukin‐3 (IL‐3) and stem cell factor (SCF), but not by IL‐6, IL‐11 or erythropoietin. TPO gave rise to much smaller colonies and at an earlier time than IL‐3, indicating that TPO affects predominantly more mature megakaryocytic progenitors. In liquid cultures, TPO increased the percentage and the absolute number of ≥8N megakaryocytes, but it did not shift their modal ploidy from 2N. TPO‐induced endomitosis was totally inhibited by the presence of, or previous exposure of cells to, IL‐3 and/or SCF. The mechanism by which TPO overcomes in vivo the negative effects of IL‐3 and SCF on megakaryocyte ploidy remains unknown.

TAKESHITA, AKIHIRO; SHINJO, KAORI; OHNISHI, KAZUNORI; OHNO, RYUZO

doi: 10.1046/j.1365-2141.1996.459996.xpmid: 8611458

We examined the multidrug resistant P‐glycoprotein (P‐gp) on normal bone marrow (BM) cells and acute myeloid leukaemia (AML) cells, using newly devised flow cytometric multi‐parameter analysis with CD33, CD34 and MRK16 monoclonal antibodies. In both normal BM cells and AML cells, CD34+CD33− cells expressed P‐gp strongly, CD34+CD33+ cells moderately, and CD34−CD33+ cells weakly. Acute promyelocytic leukaemia, mainly expressing CD34−CD33+ but not CD34+CD33− at diagnosis, expressed less P‐gp. P‐gp expression of AML cells at diagnosis was increased as compared with normal cells of the same phenotype. P‐gp expression was more increased in relapsed cases, especially in immature subpopulations.

Rameshwar, Pranela; Chang, Victor T.; Gascón, Pedro

doi: 10.1046/j.1365-2141.1996.4631004.xpmid: 8611464

Myelofibrosis (MF) is characterized by bone marrow (BM) fibrosis and excessive deposits of extracellular matrix (ECM) proteins which include fibronectin (FN), collagen type I and hyaluronic acid (HA). We have previously reported that adhesion to polystyrene overactivates MF monocytes. We now confirm their activation by increased CD25 expression and tyrosine phosphorylation. We hypothesize that ECM protein‐adhesion molecule interactions induce overproduction of fibrogenic cytokines in MF monocytes leading to BM fibrosis. In this study we found that FN, collagen type I and HA induce 2–3‐fold more TGF‐β and 6–9‐fold more interleukin (IL)‐1 in MF monocytes than normal controls (NC). Since CD44 can function as the natural ligand for these proteins, its role was studied. We found that CD44 mediated most of the TGF‐β and IL‐1 produced. Immunoprecipitation of CD44 revealed three proteins at approximately 110 kD in MF monocytes and one in NC. Our results indicate that adhesion is important in overproduction of TGF‐β and IL‐1, and that their production is at least partly mediated by adhesion molecule–ECM protein interactions. These results implicate at least one adhesion molecule, CD44, in the pathophysiology of BM fibrosis.

Gill, Vikki; Shattock, Robin J.; Freedman, Andrew R.; Robinson, Grant; Griffin, George E.; Gordon‐Smith, Edward C.; Gibson, Frances M.

doi: 10.1046/j.1365-2141.1996.4801017.xpmid: 8611471

Haematological abnormalities are often seen in patients infected with HIV. A number of mechanisms are thought to contribute to this bone marrow suppression, including impaired stromal function and direct infection of progenitor cells. Evidence suggests that both bone marrow progenitor cells and perhaps stromal cells are open to infection by HIV, which raises the possibility that bone marrow stromal cells may serve as a reservoir for HIV. This study investigated the cellular targets and kinetics of in vitro infection of stroma in long‐term bone marrow culture (LTBMC) using both mono‐ and lymphocytotropic strains of HIV‐1. p24 ELISA and reverse transcriptase (RT) assay demonstrated that stroma could be infected with HIV and release infectious virions. The target cells for infection were shown to be macrophages by immunohistochemistry (APAAP), dual immunofluorescence staining (using CD68 and p24) and electron microscopy.

Ingrosso, Diego; D’Angelo, Stefania; Perrotta, Silverio; D’Urzo, Giovanna; Iolascon, Achille; Perna, Alessandra F.; Galletti, Patrizia; Zappia, Vincenzo; Miraglia del Giudice, Emanuele

doi: 10.1046/j.1365-2141.1996.451990.xpmid:

STOPPA, Anne Marie; VEY, Norbert; SAINTY, Danielle; ARNOULET, Christine; CAMERLO, Jacques; CAPPIELLO, Maria Antonietta; GASTAUT, Jean Albert; MRANINCHI, Dominique

doi: 10.1046/j.1365-2141.1996.453993.xpmid: 8611473

Ogata, Kiyoyuki; Yokose, Norio; An, Emi; Kamikubo, Keiko; Tamura, Hideto; Dan, Kazuo; Sakamaki, Hisashi; Onozawa, Yasusuke; Hamaguchi, Hiroyuki; Nomura, Takeo

doi: 10.1046/j.1365-2141.1996.4641003.xpmid:

Gale, R. E.; Bunch, C.; Moir, D. J.; Patterson, K. G.; Goldstone, A. H.; Linch, D. C.

doi: 10.1046/j.1365-2141.1996.4751014.xpmid: 8611475

Autologous bone marrow or peripheral blood stem cell transplantation may carry an increased risk of secondary myelodysplasia (MDS) and acute myeloid leukaemia (AML), which are already recognized as complications of conventional treatment for lymphoid malignancies. In order to ascertain whether it is possible to detect the evolution of such a clone at an early stage in its development we have studied X‐chromosome inactivation patterns (XCIPs) in three informative females who developed abnormal myelopoiesis after high‐dose chemotherapy and ABMT. In one patient transplanted for relapsed Hodgkin's disease a leukaemic clone comprising approximately 50% of the patient's myeloid cells was detectable by comparison of peripheral blood granulocyte and T‐cell XCIPs when the full blood count and morphology were normal. She presented with AML 7 months later. In two patients transplanted for AML, XCIP analysis was complicated by constitutively skewed Lyonization patterns, nevertheless a progressive alteration could be demonstrated by serial analyses. In one patient a difference was detectable 28 months before presentation with MDS. In the other patient, despite evident mild pancytopenia and alterations in her XCIPs over the past 4 years, she has developed no definitive myelodysplastic features and oligoclonality due to stem cell failure cannot be excluded. These studies show that XCIPs can be used to predict development of MDS/AML in some patients, but the technique is limited by technical variability and frequent constitutional skewing in the haemopoietic system.