Machiko Oshida

Acid Treatment of Platelets as a Simple Procedure for Distinguishing Platelet-Specific Antibodies from Anti-HLA Antibodies: Comparison with Chloroquine Treatment

Abstract. The identification of antibodies to platelet‐specific antigens is important for correctly diagnosing neonatal alloimmune thrombocytopenia, posttransfusion purpura and refractoriness due to platelet‐specific antibodies. However, the serologic identification of these platelet‐specific antibodies is complicated by the presence of anti‐HLA antibodies. We examined and compared the diagnostic usefulness of acid‐treated and chloroquine‐treated platelets for the discrimination of platelet‐specific antibodies from anti‐HLA antibodies. The viability of acid‐treated platelets is 83.4%, which is better than that of chloroquine‐treated platelets (52.6%). The antigenicity of HLA class I antigens of acid‐treated platelets was significantly reduced compared with that of PBS‐ or chloroquine‐treated platelets. On the other hand, platelet surface glycoprotein Ib and glycoprotein IIb/IIIa, and platelet‐specific antigens were stable following acid or chloroquine treatment. Chloroquine‐treated platelets were not suitable targets for analysis by immunofluorescence flow cytometry because of nonspecific fluorescence derived from platelet damage. We conclude that acid‐treated platelets are more suitable targets than chloroquine‐treated platelets for screening for platelet‐specific antibodies and also for analyses of the specificity of platelet‐specific antibodies.

Collaborative study of irregular erythrocyte antibodies in Japan: Results from the Japanese study group of allo-immunity and antigen diversity in Asian populations

As a national study, we evaluated the frequencies of irregular erythrocyte antibodies (Abs) by gender and history of transfusion or pregnancy. In total, data from 248,785 patients were analyzed, from whom 4222 irregular erythrocyte Abs were detected in 3554 cases (1.43%). Abs frequencies in these 4222 cases were as follows: anti-E, 26%; anti-Le(a), 26%; anti-P(1), 11%; anti-M, 6%; anti-E+c, 4%; anti-Fy(b), 4%; anti-Di(a), 3%; anti-Le(b), 3%; and anti-D, 2%. In pregnancy, anti-D (5%), anti-Jr(a) (3%) and anti-E+c (6%) Abs were, with statistical significance, more frequent. Among transfused patients, anti-E (38%), anti-E+c (8%), anti-Jk(a) (4%), anti-e+C (2%) and anti-E+Jk(a) (1%) Abs were, with statistical significance, more frequent.

Report on ABO-Incompatible Transfusions in 12 University Hospitals in Kinki Districts.

We investigated the incidence and the causes of ABO-incompatible transfusion in 12 university hospitals in the Kinki district during the 5-year period from 1993 through 1997. Over 5 years, 648, 553 units of red cell components (RBC) and 2, 545, 880 units of fresh frozen plasma (FFP) or platelet concentrate (PC) were transfused, and a total of 26 ABO-incompatible transfusions occurred. Incompatible RBC were transfused to 17 patients and FFP or PC were transfused to the remaining 9 patients. In cases of RBC transfusion, half of errors (8 cases) were due to misidentification of blood units and the other half of errors (8 cases) were due to incorrect typing. Twenty of 26 errors occurred during night shifts and the majority of errors occurred in the ward (17 cases) or operating room (5 cases). Various measures were taken to prevent ABO-incompatible transfusion at the participating universities. We conclude that continued data collection and analysis are necessary to prevent ABO-incompatible transfusion.

A case of immune hemolytic anemia due to "auto" anti-A1 antibody induced by group O homograft in renal transplantation recipient.

A case of severe auto-immune hemolytic anemia after a living, ABO-incompatible renal transplantation is reported.The recipient, a 34 years old man, blood group A1, Rh0 (D) positive receieved a renal transplant from father whose blood group O, Rh0(D) positive donor. Cyclosporine, prednisolone and mizoribine were used for immunosuppresion.The recipient devloped severe immune hemolytic anemia within 2 weeks of renal transplantation. The recipients serum contained anti-A1 IgG autoantibody and anti-B IgG antibody on day 18 post-transplantation. The IgG subclass of these antibodies was IgG3.

ELISA for detection of red cell antibodies using red cell ghosts coated plates. The detection of Rh and other antibodies.

An ELISA using micro-plates coated with red cell ghosts was developed for analysis of red cell antibodies.Antibodies against MNSs, Kell, Duffy and Kidd antigens were detected using this ELISA. Rh antibodies in patients sera could be also detected by this assay, but the elution technique was needed when the titer of antibody was low.We considered that this assay was quantitative, objective and sensitive compared with indirect antiglobulin test, and easy to perform compared with ELISA of tube method using red cell suspensions.