An indirect immunofluorescence technique for the detection of alloantibodies against granulocytes was developed. A major problem was the unspecific fluorescence of granulocytes, due to unspecific adherence of immunoglobulins to the cell membrane. This could be suppressed by the prefixation of the granulocytes with paraformaldehyde. The developed test proved to be specific and sensitive and to have a high reproducibility. Strongly positive reactions were obtained with antisera containing granulocyte-specific agglutinins or granulocyte-cytotoxins, but also with some sera that did not react in either the agglutination or the cytotoxicity test. HLA antisera also gave positive reactions, but strong anti-A, anti-B or anti-D sera did not react. With this technique leucocyte antibodies can be detected in a higher percentage of patients with febrile transfusion reactions.

SummaryIt has been reported that blood trombopoietin (TPO) levels can discriminate between thrombocytopenia due to increased platelet destruction and decreased platelet production. With our TPO ELISA and a glycocalicin ELISA we analysed a large group of patients in detail and could confirm and amplify the above notion in detail.TPO levels were determined in plasma from 178 clinically and serologically well-defined thrombocytopenic patients: 72 patients with idiopathic autoimmune thrombocytopenia (AITP), 29 patients with secondary AITP, 5 patients with amegakaryocytic thrombocytopenia and 72 patients who suffered from various diseases (46 in whom megakaryocyte deficiency was not and 26 in whom it was expected). In addition, we measured the level of glycocalicin as a marker of total body mass of platelets.In all patients with primary AITP and secondary AITP, TPO levels were within the normal range or in some (n = 7) cases only slightly increased. The level of glycocalicin was not significantly different from that of the controls (n = 95). The patients with amegakaryocytic thrombocytopenia had strongly elevated TPO levels and significantly decreased glycocalicin levels. Similarly, among the 72 thrombocytopenic patients with various disorders, elevated TPO levels were only found in patients in whom platelet production was depressed. The mean level of glycocalicin in these patients was decreased compared to that in controls and patients with AITP, but was not as low as in patients with amegakaryocytic thrombocytopenia.In conclusion, all patients with depressed platelet production had elevated levels of circulating TPO, whereas the TPO levels in patients with an immune-mediated thrombocytopenia were mostly within the normal range. Therefore, measurement of plasma TPO levels provides valuable diagnostic information for the analysis of thrombocytopenia in general.Moreover, treatment with TPO may be an option in AITP.

A serological follow-up study was undertaken in 47 patients with bone-marrow failure, who were repeatedly transfused with random donor granulocytes and/or platelets. Sera, obtained at regular intervals, were investigated in the leucoagglutination test, the lymphocytotoxic test and the immunofluorescence test on paraformaldehyde-fixed platelets, granulocytes and lymphocytes. The frequency of alloimmunization was high (73%). Not only HLA antibodies, but also blood-cell-specific alloantibodies were detected in the sera of the alloimmunized patients, e.g. lymphocyte-specific, platelet-specific and granulocyte-specific antibodies. The immunofluorescence test on platelets was also used as a crossmatch, and when this test was positive it was always found that after platelet transfusion the increment value was nil.

Summary. Clinical, haematological and cytogenetic data of all patients with an acquired 5q ‐ abnormality, diagnosed in four cytogenetic laboratories, were studied. The 5q‐ arose de novo in 24 patients, while 10 patients exhibited it after radiation and/or chemotherapy. Sixteen cases with a dysmyelopoietic syndrome (DMPS) and one case with acute nonlymphocytic leukaemia (ANLL) had no chromosome abnormalities other than 5q‐ . All nine patients with refractory anaemia (RA) belonging to the de novo group had a normal cell line. So far none of them has transformed to acute leukaemia, while three patients with refractory anaemia with excess of blasts (RAEB), pure red cell aplasia (PRCA) and acquired idiopathic sideroblastic anaemia (AISA), having the 5q‐ in 100% of the cells showed such a transformation. The second group consisted of nine patients with a 5q‐ and additional chromosome abnormalities: three of them died of progression of the disease, while four died of unrelated causes. Eight out of nine patients with a 5q‐ and acute leukaemia, either de novo (five) or secondary (four) to radiation and/or chemotherapy, had additional chromosome abnormalities. Among the changes (partial) monosomy of chromosome 7 was most frequently found. The median survival time of the group of patients with an isolated 5q‐ in the presence of a normal cell line was significantly longer than that of patients with additional chromosomal changes with or without acute leukaemia. All patients with an isolated 5q‐ abnormality showed the previously reported megakaryocytic abnormalities (small mono‐ or bilobulated). In most of the other patients these megakaryocytic abnormalities were also found, whereas others were definitely normal in this respect. A striking and unexplained preponderance of females (1 2 out of 16) was found in the group with an isolated 5q‐ anomaly. All deletions studied with banding techniques appeared to be interstitial but the breakpoints were variable. The shortest region of overlap is near band 5q22.