Tazobactam-induced haemolytic anaemia, possibly caused by non-immunological adsorption of IgG onto patient's red cells.

A patient with pneumonia was treated with Tazocin (piperacillin/tazobactam). However, the expected haemoglobin (Hb) increment after transfusion was not achieved. Plasma bilirubin and lactate dehydrogenase were raised. The direct antiglobulin test (DAT) was positive (4+) for immunoglobulin G (IgG) only, but no RBC antibodies were demonstrable in the plasma or an eluate from the patient's RBCs. Drug-induced haemolysis was suspected. After discontinuing Tazocin administration, Hb and bilirubin levels returned to expected values. The patient's plasma gave a positive (3+) indirect antiglobulin reaction only with RBCs pretreated with tazobactam. However, random patient plasmas also gave weak (+/- to 1+) reactions, indicating non-immunological adsorption of IgG onto RBCs rather than specific anti-tazobactam antibodies. Subsequently, plasma samples with varying IgG levels (0.8-89.7 g L(-1)) were tested against RBCs pretreated with tazobactam. The amount of plasma IgG non-immunologically adsorbed onto the drug-coated RBCs was found to correlate directly with the plasma IgG level. The patient had a high plasma IgG level (41.6 g L(-1)) which explains why the antiglobulin test was stronger with the patient's plasma than with random plasma samples. Previous reports (Garratty & Arndt, (1998) British Journal of Haematology, 100, 777-783; Arndt & Garratty (2000) Transfusion, 40, 29S) suggested that non-immunological coating of RBCs with IgG may affect RBC survival; our results would support that suggestion. This is the first reported case of haemolytic anaemia associated with tazobactam.

A newly identified nonsecretor allele of the human histo-blood group alpha(1,2)fucosyltransferase gene (FUT2).

BACKGROUND AND OBJECTIVES: The human Secretor alpha(1, 2)fucosyltransferase gene determines the ABH secretor status and influences the Lewis phenotype of an individual. Studies were carried out on the Lewis (a+b-) nonsecretors of different groups indigenous to Taiwan to demonstrate their se genotypes. METHODS: The Lewis phenotype of the blood samples was determined by a microplate method. The se genotypes of the individuals with the Lewis (a+b-) phenotype were analyzed by a polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method designed for the se alleles reported previously. PCR and cloning techniques were used to determine the coding sequence of the novel se gene. RESULTS: A new se allele, se685, with a three-nucleotide deletion of GTGGT to GT in the coding region of nucleotides 685 through 689 was identified in a Le (a+b-) nonsecretor from the Ami tribe indigenous to Taiwan. The deletion predicts the loss of the amino acid Val230 in the corresponding secretor enzyme's C-terminal segment. The distribution of the se685 allele in the Ami tribe was further verified by PCR-RFLP analysis. CONCLUSION: The Se gene exhibits heterogeneity with some Se alleles being common but others displaying a unique distribution in different ethnic populations. The newly identified se685 allele seems to exist only in the Ami tribe indigenous to Taiwan.

Immunohematology in Taiwan.

There are major differences in the distribution of blood group antigens and antibodies between the different population groups of Taiwan and whites. As a result, standard Western pretransfusion testing procedures have been modified for use in Taiwan, resulting in great reductions in cost and labor. These differences, in addition to their influence on the clinical practise of transfusion medicine in Taiwan, are also important anthropologically, and it is hoped that more population groups in Asia can be investigated in the near future. Further DNA studies on the B3 phenotype, the MiIII phenotype, and the Lewis phenotypes among our different population groups are in progress and further interesting findings are awaited.

Heterogeneity of the human H blood group alpha(1,2)fucosyltransferase gene among para-Bombay individuals.

BACKGROUND AND OBJECTIVES: The para-Bombay phenotype has a relatively high frequency of about 1 in 8,000 Taiwanese. Studies were carried out on eight healthy and unrelated Taiwanese with the para-Bombay phenotype to cast light on its immunogenetic basis. MATERIALS AND METHODS: Blood and saliva samples were tested with standard hemagglutination techniques. Salivary ABH substances were determined by hemagglutination inhibition. PCR techniques were used to amplify the coding region of the H genes. RESULTS: Five different h alleles, designated as h1, h2, h3, h4 and h5, were identified in the Taiwanese with the para-Bombay phenotype. The h1 allele loses one of the three AG repeats located at the nucleotides 547-552 of the H gene, whereas two of the three T repeats located at the nucleotides 880-882 are deleted in the h2 allele. The h3 allele contains a C658 to T missense mutation, whereas two missense mutations, C35 to T and A980 to C were identified in the h4 allele. A T460 to C missense is present in the h5 allele. The h5 allele was identified in an individual whose red blood cells contain blood group A antigen but not H antigen, and thus may be considered a weak variant of the H gene. CONCLUSIONS: So far no biologic relevance of the H antigen has been discovered, and its deficiency does not seem to produce any deleterious effects. There may be better understanding of the evolutionary basis for the polymorphisms at these loci after systematic study of different ethnic populations.

Comparison of the Lewis phenotypes among the different population groups of Taiwan.

In Caucasians, three red cell Lewis phenotypes are observed, namely Le (a+b-), Le (a-b+) and Le (a-b-). For Chinese living in Taiwan the Le (a+b-) phenotype is replaced by the Le (a+b+) phenotype so that the three red cell Lewis phenotypes observed in Chinese are Le (a+b+), Le (a-b+) and Le (a-b-). In addition, Chinese individuals with Le (a-b-) red cells can be subdivided into two groups, namely those who secrete both ABH and Lewis substances in saliva and those who secrete only ABH substances in saliva. However, four red cell Lewis phenotypes Le (a+b-), Le (a+b+), Le (a-b+) and Le (a-b-) are observed among some of the indigenous groups living in Taiwan. Red cell Le (a+b-) individuals among these indigenous groups can also be subdivided into at least two groups, namely those with Le(a) and Le(b) in saliva (plus varying amounts of ABH substances) and those with just Le(a) in saliva. The former are most likely a weak form of the red cell Le (a+b+) phenotype while the latter appear to be similar to the Caucasian red cell Le (a+b-) phenotype. There was also one red cell Le (a+b-) individual whose saliva had a small amount of A substance as well as Lea substance and therefore appeared to be intermediate between the above two forms of the Le (a+b-) phenotype.

The development of ABO isohemagglutinins in Taiwanese.

To evaluate the developmental pattern of ABO isohemagglutinins in Taiwanese, 644 blood samples (349 males, 295 females), including cord blood, were collected from individuals with ages ranging from newborn to 83 years. Synthesis of anti-A and anti-B could be demonstrated in most Taiwanese infants by 2-4 months of age, increasing progressively to reach adult levels (titers of 1:32-1:256) at around 1 year of age. Peak levels were reached at between 3-10 years of age and then declined with advancing years, with individuals of 80 years of age and over showing reduced levels similar to those seen in 6- to 12-month-old infants. Sex and parity did not appear to influence ABO isohemagglutinin development.

The distribution of the MiIII (Gp.Mur) phenotype among the population of Taiwan.

The MiIII (Gp.Mur) phenotype is rare among Caucasians but has a much higher incidence among some Oriental populations. In Taiwan the population is relatively heterogenous and, as expected, the incidence of the MiIII phenotype was found to vary markedly among the different ethnic groups. The highest frequencies of the MiIII phenotype were found among some of the indigenous groups, namely the Ami, Yami and Puyuma groups, being 88.4%, 34.3% and 21.2%, respectively, which are also the highest frequencies among any population group reported so far. Antibody screening cells and antibody identification panels containing the MiIII phenotype can obviously be obtained very easily from Ami blood donors and compatible blood for patients with anti-"Mia' can most easily be obtained from Chinese blood donors, except those living on the east coast.

Heterogeneity of the human Secretor alpha(1,2)fucosyltransferase gene among Lewis(a+b-) non-secretors.

The human Secretor alpha (1,2)fucosyltransferase gene determines the ABH secretor status and influences the Lewis phenotype of an individual. Two different se alleles with point mutations, C571 to T and G849 to A respectively, in the coding region were identified in Le(a+b-) non-secretors from one of the Taiwanese indigenous groups. The base substitutions predict the alteration of Arg191 and Trp283 to stop codons respectively, resulting in deletion of the Secretor enzyme's C-terminal segment. Both alleles of the Secretor locus in all Le(a+b-) non-secretors, but not in Le(a+b-) secretors, were further demonstrated to be either one of these two se alleles with nonsense mutations. These results suggest two new molecular bases for the null se allele responsible for the formation of the non-secretor phenotype.

Correlation of a missense mutation in the human Secretor alpha 1,2-fucosyltransferase gene with the Lewis(a+b+) phenotype: a potential molecular basis for the weak Secretor allele (Sew).

A missense mutation (A385 to T), predicting an Ile129 to Phe substitution, in the human Secretor alpha 1,2-fucosyltransferase gene was present in double dose in Lewis(a+b+) individuals, but not in Lewis(a-b+) individuals. Co-segregation of the Lewis(a+b+) phenotype with homozygosity for the mutation was also verified. These results yield a potential molecular basis for the weak Secretor allele (Sew) accounting for the Lewis(a+b+) phenotype.

Identification of variant glycophorins of human red cells by lectinoblotting: application to the Mi.III variant that is relatively frequent in the Taiwanese population.

BACKGROUND: Detection of normal and variant glycophorin electrophoretic bands with T- and Tn-specific lectins is based on the possibility of glycophorin transformation into T or Tn antigens by simple chemical modifications in the blot. STUDY DESIGN AND METHODS: Human red cell membrane proteins were fractionated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and blotted onto nitrocellulose. The blots were submitted to mild acid hydrolysis (desialylation of glycophorins exposing T antigens) and then to Smith degradation (degalactosylation of asialo-glycophorins exposing Tn antigens). The modified glycophorin bands were detected with biotinylated lectins and horseradish peroxidase-conjugated avidin. RESULTS: The lectins from Artocarpus integrifolia (jacalin, anti-T/Tn), Amaranthus hybridus (anti-T), Salvia sclarea (anti-Tn), and Vicia villosa (anti-Tn) were used. The lectins detected normal glycophorin bands in control and variant red cells and characteristic additional bands in Mi.III (GP.Mur) red cells. The sensitivity of the method is comparable to that obtained by immunoblotting with glycophorin monoclonal antibodies. Comparison of the electrophoretic mobility of normal and variant bands is helpful in the classification of glycophorin variants. CONCLUSION: Lectinoblotting, based on carbohydrate recognition, enables the detection in a red cell sample, with high sensitivity, of all normal and variant glycophorin bands. The method can be also applied to other purposes, such as the identification of poly-O-glycosylated glycoproteins in other cells or the characterization of glycosylation of glycophorins and other poly-O-glycosylated proteins.

The Le(a) antigen and neonatal hyperbilirubinemia in Taiwan.

Neonatal jaundice is known to be more severe in Taiwanese infants than in Caucasian infants. Although ABO fetomaternal incompatibility and glucose-6-phosphate dehydrogenase deficiency have been shown to play a role in the etiology of neonatal jaundice in some Taiwanese infants, the etiology in the majority of cases is unknown. In this study we found that in Taiwanese newborn infants, the red cell Le(a) antigen appeared later in infants who were jaundiced (peak serum bilirubin levels of > 12 mg/dl during the first week of life) than in infants who were not. However, the Leb antigen, and hence the transferase encoded by the Se and Se(w) genes, did not appear to be similarly involved in the etiology of physiological jaundice. Thus it would appear that the Le gene-specified transferase is less active or has a delayed function, in jaundiced infants. The relationship between the Le gene-specified transferase and bilirubin has yet to be established.

The incidence and significance of anti-"Mia" in Taiwan.

BACKGROUND: The incidence of the Mill phenotype among Chinese blood donors in Taiwan is 7.3 percent. Anti-"Mia" is the most frequently occurring alloantibody of potential clinical significance encountered among Chinese patients in Taiwan, with a frequency of 0.28 percent. CASE REPORTS: A case of hemolytic disease of the newborn and a transfusion reaction due to anti-"Mia" are described. CONCLUSION: It may be important to include the Mill phenotype in the antibody screening of sera from Chinese patients.

Modification of standard Western pretransfusion testing procedures for Taiwan.

Due to significant differences in blood group antigen and antibody frequencies between Taiwanese and Caucasians, standard Western pretransfusion testing procedures have been modified for use in Taiwan. Pretransfusion testing consists simply of ABO grouping and antibody screening/major cross-matching using the manual Polybrene method without any antiglobulin phase. The manual Polybrene method is preformed using regents prepared in house and is rapid (about 3 min), inexpensive and easy to perform. Rh(D) typing of patients is unnecessary as the frequency of D in Taiwanes is 99.67% and the occurrence of anti-D in patients (or in haemolytic disease of the newborn) is uncommon. Great reductions in both cost and labour have resulted from these modifications, and it is suggested that other countries may consider similar modifications.

Hemolytic disease of the newborn caused by maternal anti-Dib: a case report in Taiwan.

Possibly the first case of hemolytic disease caused by anti-Dib in a Chinese infant is reported. The infant developed jaundice soon after birth; based on study, the jaundice has been diagnosed as a result of maternal anti-Dib which was most likely induced by previous pregnancies. The phenotype of the mother's red cells was Di (a+b-). The frequency of the Dia antigen among Chinese in Taiwan is 3.2%. In Orientals, hemolytic disease of the newborn caused by maternal anti-Dib is likely to be more severe than that caused by anti-Dia.