Confirmation of the HLA-C*16:97 allele in multiple individuals, a new common and well-defined allele?

The HLA-C*16:97 allele was found in multiple donors from the Bone Marrow Registry in South Tyrol.

Target value tailored (TVT) apheresis approach for blood progenitor cell collection after high-dose chemotherapy and rh-G-CSF.

Twenty-eight patients with different hematological diseases (17 non-Hodgkin's lymphoma, one Hodgkin's disease and 10 multiple myeloma) underwent peripheral blood progenitor cell (PBPC) collection after cyclophosphamide 7 g/m2 and rh-G-CSF. Fifty-eight leukaphereses were carried out with a fully automated PBPC collection procedure. Progenitor cell release was monitored by standardized determination of CD34+ cells in the peripheral blood. After a profound aplasia, a continuous increase in CD34+ cells in the peripheral blood was seen for at least 3-4 days. In 82% of our patients more than 2.5 x 10(6) CD34/kg could be collected using a standard apheresis of 10 l. There was a high correlation between the CD34+ cells in the peripheral blood and CD34+ cells/kg harvested. (r2 = 0.91). A relatively constant ratio (median 14.3, range 3.2-22.6) was found between CD34+ cells/kg and CFU-GM/kg. Based on the CD34 values of the pre-apheresis blood and the body weight of an individual patient and using the mathematical model of regression analysis (y = mx + b) for the correlation between the CD34+ cells/microliter in the pre-apheresis blood and the CD34+ cells/kg, it was possible to create a formula allowing for target value tailored apheresis. Using this formula, the blood volume which needs to be processed in order to harvest a desired number of CD34+ cells/kg can be calculated. This strategy can be applied to reduce the time for and the number of aphereses. Nineteen leukaphereses were carried out applying the formula. In 18 of 19 leukaphereses the expected CD34+/kg values were correctly achieved or exceeded. The formula was most reliable when the CD34 value was higher than 15/microliter and when the WBC count was below 20 x 10(9)/l in the pre-apheresis blood. For mobilizations using hematopoietic growth factors alone our formula is not applicable, because in most cases the pre-apheresis white blood cell count is higher than 20 x 10(9)/l and the collection efficacy of lymphomonocytoid cells decreases with a high pre-apheresis white blood cell count. The formula also works with other mobilization regimens that induce a pronounced aplasia.

Cytoplasmic immunoglobulins in chronic lymphocytic leukemia B cells.

It is generally assumed that chronic lymphocytic leukemia of B cell origin (B-CLL) is characterized by the presence of surface membrane immunoglobulins (SmIg) and by the absence of cytoplasmic immunoglobulins (CyIg). In a variable number of cases SmIg are not detectable because of their low density on the cellular surface. Because a constant presence of CyIg in 20 subjects suffering from B-CLL has been reported recently, we reexamined 15 SmIg-negative and 10 SmIg-positive B-CLL patients by SmIg and CyIg determinations. We used a direct immunofluorescence method on peripheral blood mononuclear cells for the detection of SmIg and, after fixation, for CyIg. CyIg were detectable in 24 out of 25 cases, with a fluorescence intensity ranging from weak to moderate. The existence of frequent negative results for CyIg determination in B-CLL reported in the literature probably depends on the low sensitivity of the method used. We conclude that CyIg determination is useful in phenotyping every B-CLL patient, especially SmIg-negative ones.

Emergency splenectomy in hairy cell leukemia.

The role of splenectomy in the treatment of hairy cell leukemia (HCL) is now well established. There are however some particular situations which indicate splenectomy as a possible emergency therapy in markedly cytopenic cases with severe antibiotic-resistant infections. The aim of the emergency splenectomy in such conditions is to temporarily increase neutrophils and to permit the improvement of the infectious disease. We describe 2 cases of HCL with severe infectious disease, successfully splenectomized.