No abstract

Five patients, four women and one man, age 32–8- yr, all whites, had refractory anemia with the same abnormal bone marrow karyotype, i.e., a partial deletion of the long arm of the No. 5 chromosome. The hematologic syndrome was practically the same in these five cases. Examination of the blood revealed a moderate to severe, generally macrocytic anemia with slight leukopenia but normal or elevated platelet count. The bone marrow showed a depressed erythroid series and some abnormalities of the granulocytic series with an occasional excess of myeloblasts. Most of the megakaryocytes had a nonlobulated nucleus. These features, as well as cytogenetic, electron microscopic, isotopic, platelet function, and immunologic studies, are described in detail. The relationship of this newly established syndrome to other hematologic diseases is discussed. The syndrome constitutes another example of the association between a specific abnormal chromosome and a distinct hematologic disorder.

Sickle celi anaemia is still responsible for severe crippling and death in young patients living in developing countries. Apart from prophylaxis and treatment of infections, no active treatment can be safely proposed in such areas of the world. Therefore a bone marrow transplantation was performed in 12 patients staying in Belgium and planning to return to Africa.Twelve patients, aged between 11 months and 23 years (median 4 years), underwent a HLA identical bone marrow transplantation. The conditioning regimen included oral busulphan for four consecutive days (4 mg/kg) followed by four days of intravenous cyclophosphamide (50 mg/kg). In 10 patients the engraftment was rapid and sustained. A further patient suffered transient red cell hypoplasia and another underwent a second bone marrow transplantation from the same donor at day 62 because of graft rejection. All patients are alive and well with a follow up ranging from 9-51 months (median 27 months). In all cases a complete cessation of vaso-occlusive episodes and haemolysis was observed as was a change in the haemoglobin pattern in accordance with the donor's electrophoretic pattern.

Bone marrow samples of 16 patients (two adults and 14 children) with a B lineage acute lymphoblastic leukaemia (ALL), and in whom Ig heavy chain gene rearrangements were detectable at diagnosis using polymerase chain reaction (PCR), were studied during evolution using PCR. The VDJ junctional fragment of the Ig heavy chain rearranged gene was amplified at diagnosis. After length reduction by restriction digestion, the amplified fragment was recovered by chromatography, labelled using a specific hexamer as a primer and directly used as a clonospecific probe. The sensitivity of the PCR ranged from 1:10(4) to 1:10(5) cells, depending on the patient's rearrangement. Residual disease (MRD) was detected in most of the patients achieving a complete remission after induction therapy, regardless of the long-term outcome of treatment. However, in patients remaining in complete remission, the level of MRD showed a tendency to decrease and ultimately become undetectable for variable periods of time, while in patients eventually relapsing there was a trend for MRD to persist at stable levels and even to increase before relapse was clinically evident. We conclude that the use of a simplified methodology for obtaining a clonospecific probe from the Ig heavy chain gene, though less sensitive than the sequencing methodology, is a valuable and readily available tool to monitor MRD in a high proportion of B lineage ALL.

We sought evidence of BCR/ABL transcripts in the peripheral blood of nine CML patients in complete clinical and cytogenetic remission after treatment by bone marrow transplantation (BMT) or interferon and in one patient who entered spontaneous remission. Six patients were investigated at different times during their follow-up. We compared results obtained with the polymerase chain reaction (PCR) using (a) a single-stage PCR comprising 30 cycles of amplification with selected oligomers, and (b) a two-stage procedure in which the reaction product from the first stage was subjected to a further 30 cycles with nested amplimers. Special care was taken to assess contamination, including for each patient simultaneous co-extraction of a negative control. Blood cells from all patients showed no evidence of BCR/ABL transcripts in the one-stage PCR but 9/17 specimens were positive in the two-stage procedure. Patients in complete remission for a long time (greater than 2 years) appeared negative. These results serve in part to explain the discordant findings reported in other studies and emphasize the importance of carefully selecting the technical conditions most likely to give results that are prognostically relevant for individual patients.