Megakaryoblastic leukaemia (acute myelofibrosis): a report of three cases

Three patients with megakaryoblastic leukaemia are described. All three presented with pancytopenia, a few blast cells in the peripheral blood and absence of overt hepatosplenomegaly. In two of them bone marrow aspiration yielded a dry tap. Histological investigation of the bone marrow indicated that the megakaryocytic cell line was the dominant proliferating lineage. Cytochemical and EM investigation supported these findings. The isomorphic isoenzyme pattern of the elevated serum lactic dehydrogenase might be of diagnostic importance. Despite chemotherapy, there was a rapidly fatal terminal leukaemic phase with high blast cell counts. The differentiation from other haematological malignancies, especially acute (aleukaemic) leukaemias and the accelerated phase of primary (chronic) myelofibrosis, is discussed. The picture appears to be identical with acute (malignant) myelofibrosis.

Treatment of aplastic anaemia by antilymphocyte globulin with or without marrow infusion

Forty-one patients, suffering from severe aplastic anaemia were treated either with ALG alone (27 patients) or ALG followed by infusion of allogeneic bone marrow (14 patients). Eighteen patients (67 per cent) are presently alive after ALG alone at over 100 to over 550 days. Fourteen (52 per cent) showed sustained improvement of haematopoiesis, two are alive without change, one recovered autologous haematopoiesis after cyclophosphamide conditioning and transfusion of HLA identical marrow and one is lost to follow-up. Eight patients (57 per cent) are currently alive after ALG and transfusion of haplotype identical marrow with self-sustaining autologous haematopoiesis at over 200 days to over four and a half years. No lethal complications occurred and none of the bone marrow infusions led to permanent engraftment or graft-versus-host disease. The mechanism of action is not known, but our results support the hypothesis that unspecified autoimmune reactions block the normal outgrowth of haematopoietic precursor cells in a substantial number of patients with aplastic anaemia. This therapeutic approach seems to offer good chances of survival, especially for those patients who do not have an HLA identical sibling. Its value should be further investigated.

Treatment of aplastic anaemia by antilymphocyte globulin with and without allogeneic bone-marrow infusions

29 patients with severe aplastic anaemia were treated with either antilymphocyte globulin (A.L.G.) alone (15 patients) or A.L.G. followed by infusion of allogeneic bone-marrow (14 patients). The overall response to both forms of treatment in terms of 1-year survival was 55%; 12 of the 29 patients showed a sustained haematological improvement, during a period of observation of up to 4 1/2 years. No potentially fatal complications were observed. None of the bone-marrow infusions led to a permanent "take" or graft-versus-host disease. How A.L.G. acts is unknown, but our findings accord with the hypothesis that, in a substantial proportion of cases of aplastic anaemia, unspecified autoimmune reactions block the development of residual stem cells A.L.G. seems to offer a good chance of survival, especially for those patients who do not have HLA-matched siblings. Its value should be further established.

Acquired aplastic anemia in adults. IV. Histological and CFU studies in transplanted and non-transplanted patients

A follow-up study of 10 patients suffering from acquired aplastic anaemia, comprising methocrylate-embedded bone marrow biopsies and CFU cultures, is presented. The haematopoietic recovery patterns and changes in the inflammatory infiltration after permanent engraftment could be distinguished from those in non-transplanted patients. After anti-thymocyte globulin treatment followed by allogeneic bone marrow infusion, the recovery pattern resembled that in non-transplanted patients. The persistently low colony-forming capacity in some patients could be explained by the existence of lymphoid inhibitory cells, which suggests an immunologic auto-destructive mechanism.

Aplastic anaemia. Histological investigation of methacrylate embedded bone marrow biopsy specimens; correlation with survival after conventional treatment in 15 adult patients

Aplastic anaemia is a rare disease with a poor prognosis: 40% of the patients die within 6 months after diagnosis. The clinical condition and laboratory data show only a poor correlation with the chance of survival for longer than 6 months. Conventional bone marrow biopsy investigations did not have any predictive value, but methyl-methacrylate embedded biopsy material from 15 patients given only supportive care showed histological features considered important for the assessment of the prognosis. In 3 micron methacrylate sections non-myeloid cells, like lymphocytes, could be readily distinguished from erythropoietic cells. Three types of inflammatory infiltrate were easily distinguished according to amount and distribution. Seven of the eight patients with marked infiltration (Grade III) died within 6 months after biopsy, but none of the patients with a sparse infiltrate (Grade I), including five patients in remission. In six of 10 patients, who were not in remission, histological data permitted correction of the clinically estimated prognosis.

Acquired aplastic anaemia in adults. I. A retrospective analysis of 40 cases: single factors influencing the prognosis

In a retrospective analysis of 40 aplastic anaemia patients, an attempt was made to determine prognostic parameters permitting discrimination between short survivors (less than 6 months) and long-term survivors (greater than 6 months). Short survival proved to be significantly associated with a persistently low reticulocyte index and progressive neutropenia. Other factors such as bone marrow cellularity, HBF level, aetiology, or presenting signs were not indicative. Chromosomal aberrations were found in one third of the cases examined, but none had developed into a leukaemic stage after an observation period of 2--5 years. None of the patients with cytogenetic aberrations showed complete restoration of haematopoiesis, in contrast to several of the patients without chromosomal abnormalities. In this series, drug-associated aplastic anaemia was found more often in the short-survival group. These clinical findings indicate that the term 'aplastic anaemia' covers a heterogenous group of disorders.

Acquired aplastic anaemia in adults. II. Conventional treatment: retrospective study in 40 patients

The effect of conservative treatment of aplastic anaemia was evaluated retrospectively in 40 patients. No significant beneficial effect was provided by long-term high-dose oxymethalone in 20 patients or by metenolone, adrenstonolone, or testosterone in 14 patients. Splenectomy gave no improvement in the majority of cases, although in some it decreased the transfusion requirement. Immunosuppressive treatment was successful in 1 patient with a positive LE phenomenon. Until a specific treatment becomes available, the possibility offered by alternative treatment, e.g. bone marrow transplantation, in cases with poor prognostic parameters should be considered.

Trisomy 6 associated with aplastic anemia

A clone with 47 chromosomes was observed in the bone marrow of a patient with aplastic anemia and found to be trisomic for chromosome 6. The abnormal clone was not observed in the peripheral blood.