Bone marrow transplantation for paroxysmal nocturnal haemoglobinuria.

Paroxysmal nocturnal haemoglobinuria (PNH) is an acquired clonal disorder of the haemopoietic stem cells for which the only curative treatment is bone marrow transplantation. There are few reports on the use of allogeneic transplantation for PNH, and nearly all of them include only a few patients. Between September 1978 and December 1997, 16 patients underwent marrow transplantation for PNH at the Hospital Saint Louis. The 5-year survival rate for the 16 patients was 58 +/- 13%. Two factors, an absolute neutrophil count >1.0 x 109/l and haemoglobin level >9 g/dl at transplant, were found to be statistically associated with a better outcome.

Arsenic trioxide and melarsoprol induce apoptosis in plasma cell lines and in plasma cells from myeloma patients.

Recent data have renewed the interest for arsenic-containing compounds as anticancer agents. In particular, arsenic trioxide (As2O3) has been demonstrated to be an effective drug in the treatment of acute promyelocytic leukemia by inducing programmed cell death in leukemic cells both in vitro and in vivo. This prompted us to study the in vitro effects of As2O3 and of another arsenical derivative, the organic compound melarsoprol, on human myeloma cells and on the plasma cell differentiation of normal B cells. At pharmacological concentrations (10(-8) to 10(-6) mol/L), As2O3 and melarsoprol caused a dose- and time-dependent inhibition of survival and growth in myeloma cell lines that was, in some, similar to that of acute promyelocytic leukemia cells. Both arsenical compounds induced plasma cell apoptosis, as assessed by 4',6-diamidino-2-phenylindole staining, detection of phosphatidylserine at the cell surface using annexin V, and by the terminal deoxynucleotidyl transferase-mediated nick end labeling assay. As2O3 and melarsoprol also inhibited viability and growth and induced apoptosis in plasma-cell enriched preparations from the bone marrow or blood of myeloma patients. In nonseparated bone marrow samples, both arsenical compounds triggered death in myeloma cells while sparing most myeloid cells, as demonstrated by double staining with annexin V and CD38 or CD15 antibodies. In primary myeloma cells as in cell lines, interleukin 6 did not prevent arsenic-induced cell death or growth inhibition, and no synergistic effect was observed with IFN-alpha. In contrast to As2O3, melarsoprol only slightly reduced the plasma cell differentiation of normal B cells induced by pokeweed mitogen. Both pokeweed mitogen-induced normal plasma cells and malignant plasma cells showed a normal nuclear distribution of PML protein, which was disrupted by As2O3 but not by melarsoprol, suggesting that the two arsenical derivatives acted by different mechanisms. These results point to the use of arsenical derivatives as investigational drugs in the treatment of multiple myeloma.

Transplantation for Fanconi's anaemia: long-term follow-up of fifty patients transplanted from a sibling donor after low-dose cyclophosphamide and thoraco-abdominal irradiation for conditioning.

We describe the long-term follow-up of 50 Fanconi's anaemia patients who were transplanted from a related donor with a median follow-up of >6 years. The survival estimate was 74.4% at 54 months and 58.5% at 100 months. All patients were conditioned with low-dose cyclophosphamide and thoraco-abdominal irradiation. Acute graft-versus-host disease (GvHD) of grade II or more developed in 26 patients and chronic GvHD developed in 30/43 (69.9%) patients. The survival of patients without chronic GvHD (n = 13) was 100%. In addition to chronic GvHD, 20 pre-transplant transfusions was shown to have an adverse impact on survival by multivariate analysis (relative risk = 7.08, P = 0.0003). Prospective follow-up of growth and endocrine function could be performed in 31 patients. Of 20 boys, six have already reached normal puberty within the expected time. Among the 11 girls, three were at the pubertal age at the time of analysis. Growth retardation was common, whereas late complications (e.g. peripheral hypothyroidism, cataract) were rare. However, the most important long-term complication was the occurrence of cancer in seven patients (8-year projected incidence 24%). Among the 32 survivors, 27 (84.5%) had a normal and four a moderately reduced performance status, and all achieved complete engraftment with donor cells. Therefore transplantation was able to cure these patients who remain at high risk for developing late complications. Clearly, a genetic predisposition and chronic GvHD could have led to the development of these cancers. However, we cannot completely rule out irradiation as a cofactor in the genesis of these cancers, and therefore no longer use irradiation for the conditioning of Fanconi's anaemia patients.

Immunological typing of acute lymphoblastic leukemia: concurrent analysis by flow cytofluorometry and immunocytology.

For 60 cases of acute lymphoblastic leukemia (ALL) immunological typing was done concurrently by the avidin-biotin-peroxidase method using cytocentrifuged smears and by flow cytofluorometry for the study of surface antigens. The use of a large panel of antibodies detecting differentiation antigens allowed us to sub-classify 57/60 cases as 43 B-lineage ALLs and 14 T-lineage ALLs. The two types of ALL can be accurately distinguished by the expression of the antigens recognized by the antibodies of the clusters of differentiation CD19 (B4) and CD7 (Leu 9). Almost perfect agreement was obtained between the results of the two methods for antigens DR, CD10 (cALLA;J5) and CD7. A number of discordances were observed with other antigens [CD19 (B4), CD20 (B1), CD22 (To15), CD1 (T6), CD2 (T11), CD4 (T4), CD8 (T8), CD3 (T3), T9, T10]. In spite of these discordances, the avidin-biotin-peroxidase method can predict the lineage involved in most ALLs with a high degree of reliability. Nevertheless, for weakly expressed surface antigens (such as B4 and B1) the immunocytological method is less sensitive than flow cytofluorometry and can only approximately determine the stage of differentiation of neoplastic cells. Furthermore, the existence of cases which are at the same time negative with flow cytofluorometry and positive with immunocytology is consistent with the intracytoplasmic expression of certain differentiation antigens. Thus in the course of lymphoid differentiation, intra-cytoplasmic expression of T3, To15 and possibly J5 precedes their expression at the cell surface.