PARATHYROID HORMONE RELATED PROTEIN IN HYPERCALCAEMIA IN CLL

National Institute of Haematology PIROSKA PALDI-HARIS Blood Transfusion and Immunology, JANOS FOLD[ Department of Molecular Genetics, Budapest, Hungary relapse, we have plotted in Fig 1 the relative amount of chimaera mRNA in blood against the same data from the marrow sample of all our patients. BMT patients (nos. 10-16). Data from three out of the seven are shifted away from the optimal diagonal line by at least a magnitude of 1. Patient 16. 6$ years after BMT, the blood sample was bcr negative. 6 months later the marrow already presented 1% relative chimaera bcr-abl content. Since that time we could follow the relapse by alternate checking of bone marrow and blood samples. The relative chimaera content simultaneously increased in both, but it reached the 1% value in blood with a delay of 3 months. Non-treated patients (nos. 1-9). Three samples out of the nine are shifted extremely leftward (magnitude 2-6). Patient 2. On admission the patient’s blood was bcr negative. 2 months later the marrow was fully positive, but the blood presented only a very low chimaera mRNA content AlML patient (no. 17). The sample is shifted leftward by a magnitude of 4. Our data suggest that using only the peripheral blood sample for follow-up of BMT in CML patients might lead to a more optimistic judgement of the patient’s mixed chimaerism or to a delay in detection of reappearance of bcr’ cells, which might affect the choice of treatment. According to Lion et at (1993). the increase in bcr positivity has clinical importance rather than the positivity itself. This is the reason why the measurement of bcr positivity only in blood for follow-up may be sufficient in those cases, when MRD is not REFERENCES