Michiko Takenaka

Extensive polymorphism of ABO blood group gene: three major lineages of the alleles for the common ABO phenotypes

Polymorphism of the ABO blood group gene was investigated in 262 healthy Japanese donors by a polymerase chain reactions-single-strand conformation polymorphism (PCR-SSCP) method, and 13 different alleles were identified. The number of alleles identified in each group was 4 for A1 (provisionally called ABO*A101, *A102, *A103 and *A104 according to the guidelines for human gene nomenclature), 3 for B (ABO*B101, *B102 and *B103), and 6 for O (ABO*O101, *O102, *O103, *O201, *O202 and *O203). Nucleotide sequences of the amplified fragments with different SSCP patterns were determined by direct sequencing. Phylogenetic network analysis revealed that these alleles could be classified into three major lineages, *A/*O1, *B and *O2. In Japanese, *A102 and *13101 were the predominant alleles with frequencies of 83% and 97% in each group, respectively, whereas in group O, two common alleles, *O101 (43%) and *O201 (53%), were observed. These results may be useful for the establishment of ABO genotyping, and these newly described ABO alleles would be advantageous indicators for population studies.

Different alleles cause an imbalance in A2 and A2B phenotypes of the ABO blood group

Background and Objectives: In several populations, including the Japanese, the frequency of the A2B phenotype is significantly higher than expected based on the A2 phenotype frequency. To understand the genetic basis of this ‘excess’ of A2B, we examined ABO alleles in individuals with A2‐related phenotypes. Materials and Methods: ABO alleles were identified by means of polymerase chain reaction single‐strand conformation polymorphism (SSCP) and nucleotide sequence analyses. Results: The frequencies of A2‐related alleles (*A105, *A106, *A107, *A111 and *R101) were clearly different between the A2 and A2B phenotypes. In particular, a putative recombinant allele, *R101, was uncommon in the A2 but common in the A2B phenotype individuals. This allele was also detected in 4 of 401 (1%) unrelated A1 phenotype (AO genotype) individuals. Conclusion: *R101 is presumably expressed as phenotype A1 in *R101/*O heterozygous individuals, but as phenotype A2 in *R101/*B heterozygotes, thus giving rise to a high A2B phenotype frequency.

Clinical evaluation of repeat apheresis donors in Japan.

AbstractBackground and Objectives: To ascertain the safety of repeat apheresis donation, hematological and biochemical tests were performed on 511 donors with a donation rate of over 6 times per year for a period of 12–19 months. Materials and Methods: Repeat donors who had apheresis more than 6 times in the previous year were chosen. Data for the repeat donors at the start of the experiments were compared with those at the end of the end of the study. Blood samples were taken prior to donation. Serum protein, albumin, immunoglobulin G, A, and M, serum ferritin levels were determined by biochemical tests. Results: When compared to prospective donors of 400 ml, WBC, lymphocytes, and serum ferritin levels were lower in a roughly frequency‐dependent manner in female and male donor groups at the beginning of the study. All the data for the male group remained almost constant with increasing frequency of apheresis donation. However, in the female group, ferritin levels significantly decreased with over 21 donations. Conclusions: The present data showed that the serum ferritin level of the female donors decreased the most with increasing frequency of apheresis donation. The cumulative RBC left in the collecting chamber and for the laboratory test is discussed in relation to a possible cause of iron deficiency in frequent apheresis donors.

Consequences of Nucleic Acid Amplification Testing for Blood Transfusion Centres

This article is also accessible online at: http://BioMedNet.com/karger Blood banks and transfusion centres are faced with the imminent introduction of nucleic acid amplification testing (NAT), or genomic amplification testing of plasma pools used by the plasma industry. The Committee for Proprietary Medicinal Products (CPMP) in Europe requires that all manufactured plasma pools should be tested for HCV RNA by NAT by July 1, 1999. To avoid the destruction of large NAT-reactive plasma pools, the CPMP strongly advises to implement a system for the screening of minipools of plasma by NAT. In future, genomic screening of individual donations for blood-borne viruses is expected to become obligatory. At present, genomic screening of individual donations cannot be routinely performed, and NAT minipool screening (i.e. a pool of plasma of 100 donations) is not (well) standardized, is costly and time-consuming, especially when the individual positive donors from a positive pool have to be sorted out. An especially difficult and ethical question is what should be decided concerning the release of red cell products and especially platelets when minipool screening is implemented. Either these cellular products will be blocked for at least several days, creating shortage and loss of product, or the results of minipool screening tests will not affect these products. This may create different levels of safety and serious ethical problems by informing (or not informing) recipients of these products after a positive result has been obtained. Fourteen experts in the field were asked for their opinion, answers were obtained from 10 of them on the following questions.

CHARACTERISTICS OF RISK BEHAVIOR AMONG HIV-POSITIVE VOLUNTARY BLOOD DONORS AND MEASURES ENSURING BLOOD SAFETY IN JAPAN

HIV-infected voluntary blood donors have increased to more than 80 a year in the last 5 years. There are concerns that blood donation is being used for HIV testing by persons with high-risk behaviors, whose blood in the window period might result in HIV infection of recipients.A questionnaire was sent to 366 AIDS Care Core Hospitals, asking them to report the number of consultation by and characteristics of HIV-positive blood donors found by testing donations over the last 3 years. There were 185 HIV-positive donors reported, 158 (85%) of whom were male. Only 22 donors sought testing (12%), which increased to 13% over the last 5 years compared to 8% in previous years (not significant). However, 132 donors (71%) had high-risk behaviors including men who have sex with men (MSM: 57%) and multiple heterosexual partners (15%), but no intravenous drug users. Among the male donors, irrespective of whether they agreed to, denied or were undecided about donation for the purpose of HIV testing, MSM were the highest in each group (90%, 59%, and 77%, respectively), showing a remarkable increase to 71% over the last 5 years compared to 55% in 1993-1997 and 27% in 1986-1992. In addition, the fact that most infected donors did not approve of donation for the purpose of testing but revealed high-risk behavior once consulted a doctor in the hospitals shows a clear contradiction to their attitude at donation, at which time they ignored notices against donations for HIV testing or by those with high-risk behaviors before, at the time of, and after donation. Therefore, it should be considered that most but not all HIV-positive donors, particularly MSM, donated in order to obtain a HIV test.To ensure safety, it is recommended that MSM should be denied donating blood, and that donor recruitment should be focused on repeat donors, since HIV infection rates in first-time donors were three times higher than those in repeat donors.

QUESTIONNAIRE SURVEY ON BLOOD DONOR OPINIONS ON PRESENTING IDENTIFICATION CARDS AT INTERVIEWS AND ACCEPTING TESTING RESULTS FOR INFECTIOUS MARKERS INCLUDING HIV

HIV-positive rates among voluntary blood donors in Japan have increased yearly for more than 10 years. This trend has emphasized the need to ensure blood safety, since more donors with infected blood in window periods could be undetected by nucleic acid amplifying testing (NAT).A questionnaire survey on the idea of requesting identification cards (ID) in interviews at the time of donation, and notifying donors of all blood testing results including infectious markers, especially HIV, was performed in 4 Japanese Red Cross Blood Centers (JBC). ID presentation was acceptable to 81% of donors on average, of whom over 90% would continue blood donations with ID presentation. Notification of HIV testing results was agreed to by 47%, denied by 21%, undetermined in 30% and not commented on by 2%. The rates of donors who did not want to be notified of any testing results (no notification) were 0.4-5.1% at each JBC, with the JBC which has introduced a photocard system with the donors photograph having the lowest rate. The rates of donors, who did not get mailed notification of all testing results to be sent back to the JBC (no acceptance) were 0.4-0.8% at each JBC. However, the rates of approval for no notification and no acceptance for only infectious markers increased to 0.4-16.8% and 0-5.6%, respectively. In particular, the rate of both no notification and no acceptance for syphilis testing results was 41.7% dramatically higher in the JBC, which is the highest in both the number and rate of HIV infection among donors every year.These results indicate that ID presentation in interviews has already been accepted by almost all donors, but that HIV notification is approved by only half. However, most donors would agree to notification of HIV infection if they were able to understand its importance to both public and individual health as well as to blood safety by proper education and information on HIV infection.