[Studies of IgG subclasses of anti-erythrocyte antibodies contained in human plasma preparation products]

Anti-A and anti-B antibodies (1: 1-1: 1, 024) of IgM or IgG type of the titers 1: 1-1: 1, 024 were detected in all of the lots of heat-treated human plasma protein (38 Lots), albumin (15 Lots), factor VIII or IX products (9 Lots) and immune globulin preparations for intravenous use (IVIG) (20 Lots) examined. Twelve out of 20 lots of IVIG contained unexpected anti-erythrocyte antibodies of IgG type. Though IgG1 antibody was detected in all of these 12 lots, antibodies composed of all subclasses including IgG3 could be detected in only 8 lots of them, all showing the anti-erythrocyte antibody titer of IgG type over 1:64. Conversely, none of the lots, in which the titer was less than 1:32, contained IgG3 antibodies. A patient of chronic ITP, 28-year-old female of blood type A and Rh-positive, showed contradictive results between the main (A type) and the accessory test (O type) of red blood cell grouping, accompanied with hemolytic anemia, following intravenous high-dose immune globulin therapy (400 mg/kg x successive 5 days), which was attributable to the anti-A antibody of IgG type composed of IgG1,2,3,4 in the IVIG administered. For high dosage administration of human plasma preparation products, those containing only low titer of unexpected anti-erythrocyte antibody should be selected.

[Comparative evaluation of markers with reverse transcriptase inhibiting antibody in human immunodeficiency virus type 1 infection]

To investigate a non-RI test which is equivalent to the reverse transcriptase inhibiting antibody test, a reverse transcriptase inhibiting antibody was compared to the absolute number of CD-4 or CD-8 cells or CD-4/-8 ratio and also to photodensitometric analysis for western blotting. There is no correlation of the reverse transcriptase with any test for cell numbers and their ratio. In photodensitometry, relative units of anti-p65 and anti-p51 were compared with reverse transcriptase inhibiting antibody. The reverse transcriptase inhibiting antibody showed a higher correlation to the relative unit of p65 antibodies than that of p51 antibodies. The photodensitometric analysis of western blotting for a serum test may be a possible method to find a prognostic marker in HIV-1 infection.

Ultrastructural analysis of megakaryoblasts by simultaneous detection of platelet peroxidase and platelet glycoproteins

We studied the phenotype of megakaryoblasts (MKB) in two patients with blastic crisis of chronic myeloid leukemia by simultaneous detection of platelet peroxidase (PPO) activity and platelet glycoproteins (GP) with monoclonal antibodies at the ultrastructural level. When 227A (anti-GPIb) was used, the finding of GP correlated well with the presence of PPO in the majority of MKB, and a few MKB were found to express PPO but lack GP. When 224B (anti-GPIIb/IIIa) was applied, we found a few MKB of a further type, which expressed GP but lacked PPO. These results indicate that the expression of platelet markers is partially aberrant in neoplastic MKB, and that MKB are heterogenous in their phenotypic expressions. Thus, the detection of PPO or GP alone may miss some MKB. For the accurate identification of MKB and the demonstration of aberrant expression of platelet markers, simultaneous detection of the markers seems to useful.

[Analysis of anti-platelet antibody and platelet volume in idiopathic thrombocytopenic purpura]

We investigated platelets and plasma from patients with idiopathic thrombocytopenic purpura (ITP) to elucidate the antigenic determinants at which their autoantibodies are directed, and studied the relationship between anti-platelet antibody and platelet volume. We used flow cytometry to detect platelet-associated IgG (PAIgG), C3 (PAC3), IgM (PAIgM) and platelet volume, and also to determine the binding rate of monoclonal anti-platelet antibodies in patients with ITP. The following results were obtained. 1. Both anti-GPIIb/IIIa autoantibodies (21 of 71 patients) and anti-GPIb autoantibodies (3 of 71 patients) were found in ITP. 2. The decrease in platelet count in patients without anti-GPIIb/IIIa autoantibodies was significant. 3. The increase in platelet volume was found more frequently in patients with a platelet count less than 50,000 and in untreated patients. 4. There was a positive correlation between the platelet volume and PAIgM in patients with a platelet count less than 30,000 and high levels of PAIgM.

Exposure of fibrinogen-binding sites on stored platelets on stimulation by aggregating agents--an electron microscopic study

We studied the function of stored platelets by immunoelectron microscopy. The distribution of glycoprotein (GP) IIb/IIIa complex was demonstrated by the binding of a monoclonal anti-GP IIb/IIIa complex antibody (NNKY1-32) to platelets, and the binding of fibrinogen to platelets by use of an anti-fibrinogen antibody. The binding of NNKY1-32 decreased significantly in unstimulated platelets after storage for 5 days. When platelet aggregation was tested, 5-day-stored platelets did not aggregate in the presence of either ADP or epinephrine alone (40 microM each) or in combination (8 microM each), but did aggregate on stimulation with the combination of collagen and epinephrine (1 micrograms/ml and 1 microM, respectively). The 5-day-stored platelets stimulated with the combination of ADP and epinephrine scarcely bound fibrinogen, but did bind NNKY1-32. On stimulation with collagen and epinephrine, a large amount of fibrinogen bound to the surface membrane of 3- and 5-day-stored platelets, and the binding of NNKY1-32 also increased, reaching the same level seen in stored platelets stimulated with ADP and epinephrine. Our analysis of stored platelets revealed that the binding of NNKY1-32 decreased after storage for 5 days, but the binding increased even with subaggregating stimulation. The binding of fibrinogen correlated well with the rate of maximal platelet aggregation.

(NZW x BXSB)F1 mouse. A new animal model of idiopathic thrombocytopenic purpura

A decrease in thrombocyte count was observed in (NZW x BXSB)F1 (W/B F1) mice at the age of greater than 5 mo, whereas megakaryocyte counts were found to increase in such mice. FACS analyses revealed the presence of both platelet-associated antibodies (PAA) and circulating antiplatelet antibodies. There is a correlation between the presence of these antibodies and the degree of thrombocytopenia. The transplantation of normal bone marrow cells from BALB/c nu/nu mice to W/B F1 mice was found to have preventative and curative effects on thrombocytopenia; the mice showed normal platelet counts and no evidence of circulating antiplatelet antibodies. These results indicate that thrombocytopenia in W/B F1 mice is due to the presence of antibodies to platelets. We therefore think that W/B F1 mice serve as a useful animal model of idiopathic thrombocytopenic purpura (ITP) not only for elucidating the mechanism of the development of antiplatelet antibodies, but also for characterizing autoantibodies to platelets.

[Efficacy and safety of cefbuperazone in severe infections complicating hematologic diseases Hanshin Infection Study Group]

Cefbuperazone (CBPZ) was administered to patients with severe infections complicating hematologic diseases to assess its efficacy and safety under such clinical conditions. Primary diseases in this series of 78 cases included; acute leukemia in 41 cases, chronic leukemia in 6 cases, other leukemia in 9 cases, malignant lymphoma in 13 cases, multiple myeloma in 3 cases, aplastic anemia in 5 cases and 1 other case. Types of infection included sepsis; proven or suspected, in 59 cases, pulmonary infection in 8 cases, upper respiratory infection in 5 cases, and other cases. CBPZ was infused by an intravenous drip method at a dosage of 4-8 g daily. Patients' ages ranged from 14 to 85 years. Clinical response to the CBPZ regimen was excellent in 24 cases, good in 22 cases, fair in 2 cases, and poor in 30 cases. Thus the overall efficacy rate (percentage of cases showing an excellent or good response) was 59.0%. Efficacy rates for individual types of infection were: documented sepsis 16.7%, suspected sepsis 58.5%, lower respiratory infection 62.5%, and upper respiratory infection 100%. CBPZ also proved to be effective in 61.0% of cases with a neutrophil count of less than 500/mm3 prior to therapy. Side effects encountered were diarrhea in 1 case, gastric discomfort in 1 case and hepatic dysfunction in 5 cases. These side effects, however, were not dose-related, and none were serious. These results indicate that CBPZ has a high therapeutic efficacy even in patient with compromised immunodefenses.

A new nitrosourea derivative for the treatment of chronic myelogenous leukemia

A new water-soluble nitrosourea derivative, methyl 6-[3-(2-chloroethyl)-3-nitrosoureido]-6-deoxy-alpha-D-glucopyranoside (MCNU), was found to be useful for the treatment of chronic myelogenous leukemia (CML) in the chronic phase. To compare the efficacy of MCNU with that of busulfan, patients were randomized. In the 40 patients administered MCNU, the median time to the achievement of a complete remission (CR) was 50 days. This value was shorter than that observed in 37 patients administered busulfan (126 days, p less than 0.05). There were no differences in the rate of CR achieved, mortality, median time to the onset of blast crisis (BC), BC rate, or survival rate during the observation period. The overall incidence of side effects was higher for MCNU (31%) than for busulfan (15%), but the symptoms were mild, transient and tolerable for most patients. These results suggest that MCNU is a safe and valuable addition to the therapeutic repertoire for the control of CML.

Effects of EDTA on the membrane glycoproteins IIb-IIIa complex--analysis using flow cytometry

We developed new monoclonal antibodies (NNKY1-32, NNKY2-6, NNKY2-18) that react with a determinant specific to the GPIIb-IIIa complex, and studied the distribution of GPIIb/IIIa on the platelet surface in vivo and some factors that influence the structure of GPIIb/IIIa using flow cytometry. 1. The surface of large platelets is richer in GPIIb/IIIa than that of small platelets. 2. Incubation of intact platelets with EDTA at 37 degrees C causes progressive dissociation of GPIIb-IIIa complexes, and this influence is marked in small platelets. 3. Addition of Ca2+ or Mg2+ to dissociated GPIIb-IIIa complexes causes reassociation, and additionary ADP after the cation treatment further increases the binding of monoclonal antibodies. 4. Prolonged incubation of intact platelets with EDTA at 37 degrees C induces a peculiar change of structure in the GPIIb/IIIa.