del(15)(q11q15) associated with transformation of chronic myelomonocytic leukemia.

Nonrandom cytogenetic abnormalities have been described in a variety of human malignancies including myelodysplastic syndromes (MDS). Acquisition of new chromosomal abnormalities may herald onset of a more aggressive disease. We report a patient with chronic myelomonocytic leukemia (CMMoL) who initially had a normal karyotype, but in whom the clonal interstitial deletion of chromosome 15 (q11-q15) was coincident with development of acute myeloid leukemia (AML) one year later. To date, this chromosomal change has not been reported in CMMoL, AML, or any other human malignancy.

Chronic myelomonocytic leukaemia associated with T cell receptor delta gene rearrangement.

Morphological, immunophenotypic, and genetic analyses were carried out on peripheral blood, bone marrow, and pharyngeal biopsy material from a patient with chronic myelomonocytic leukaemia (CMML). Morphological analysis of bone marrow was diagnostic of CMML; immunophenotypic analysis of peripheral blood and bone marrow were negative for B and T cell antigens, and immunochemistry performed on the pharyngeal extramedullary infiltrate showed the presence of large monocytoid cells which stained positively for muramidase. Genotypic analysis, however, showed clonal rearrangement of the T cell receptor (TCR) delta chain gene, a marker of T cell or, less commonly, B cell lymphoid neoplasms. Other TCR genes, beta and gamma, were germline in all tissues examined. TCR delta is rearranged in precursor B cell and most T lymphoid neoplasms. A small proportion of cases (10%) of acute myeloid leukaemia (AML) also show rearrangement of the TCR delta gene. To date TCR delta rearrangement has not been described in CMML. The aberrant TCR delta rearrangement shown in this patient with CMML provides further evidence of the clonal nature of this disorder.

Which tests are most useful in distinguishing between reactive thrombocytosis and the thrombocytosis of myeloproliferative disease?

In an attempt to distinguish between thrombocytosis in myeloproliferative disease (MPD) and reactive thrombocytosis (RT) the following aspects of platelet structure and function were evaluated: platelet size, platelet aggregation and adhesion, dense granule and alpha granule components. In addition plasma fibrinogen and von Willebrand factor antigen (vWFag) were measured. In all parameters measured there was a significant difference between normals and both categories of thrombocytosis, however there was considerable overlap between MPD and RT. Plasma fibrinogen emerged as the best single test to discriminate between MPD and RT, levels of less than 5.0 g/l indicating MPD and greater than 5.0 g/l indicating RT.

The use of aprotinin in thrombocytopenic patients: a preliminary evaluation.

Previous studies have shown that high dose aprotinin successfully reduces blood loss in patients undergoing cardiac or vascular surgery, but the use of this approach to reduce bleeding associated with thrombocytopenia has not been studied. We report the results of high dose aprotinin treatment in five patients with thrombocytopenia of differing aetiology. Aprotinin was effective in controlling bleeding in all five patients, some of whom would otherwise have had a poor prognosis. These results suggest that this agent may have a role in the supportive treatment of thrombocytopenia and point to the need for controlled trials of high dose aprotinin treatment in such individuals.

White clot syndrome and continuous arteriovenous haemofiltration.

Severe heparin associated thrombocytopenia is a rare complication of heparin therapy. We report a patient who developed heparin associated thrombocytopenia during continuous arteriovenous haemofiltration and discuss its implications and alternative anticoagulant treatment.

High-dose intravenous immunoglobulin in the treatment of autoimmune haemolytic anaemia.

Conventional doses of intravenous immunoglobulin (i.v. Ig) (0.4 g/kg/day for 5 days) commonly produce a remission in immune thrombocytopenia (ITP) but have only rarely been successful in autoimmune haemolytic anaemia (AIHA). There are a few reports of higher doses of i.v. Ig being more effective in AIHA. We have treated two patients with AIHA with high-dose i.v. Ig (0.5 g/kg/day for 5 days). In one patient with an associated ITP a prompt rise in platelet count but no change in Hb concentration occurred. The second patient with AIHA associated with chronic lymphatic leukaemia showed a prompt response, with a rise in Hb concentration and fall in plasma bilirubin. The poor response to i.v. Ig seen in AIHA may be related to the expansion of the reticulo-endothelial system seen in AIHA but not ITP. Clearance of antibody-coated red cells and platelets may occur at different rates and/or sites in the reticulo-endothelial system and this may account for the differential response seen in case 1. Higher doses of i.v. Ig, in the range 0.5-1 g/kg/day for 5 days, are required in AIHA, particularly if significant splenomegaly is present, and may be effective in refractory cases.