Drug-dependent IgG antibodies (DDAb) induced by sulfamethoxazole (SMX) and sulfisoxazole (SIX) were identified by flow cytometry in 15 patients who developed thrombocytopenia while taking one of these medications. Fourteen of the 15 DDAb were specific solely for the glycoprotein (GP)IIb/IIIa complex, and 13 of these reacted wholly or in part with epitopes present only on the intact GPIIb/IIIa heterodimer. None of 12 SMX-induced DDAb cross-reacted with SIX, but one of three SIX-induced antibodies reacted with SMX. Each of 10 SMX-induced DDAb tested reacted with the N1-acetyl metabolite of SMX, but only one reacted fully with the N4-acetyl derivative. Detection of the SMX- and SIX-dependent antibodies was facilitated by using bovine serum albumin (BSA) to achieve suspension of these weakly soluble drugs in an aqueous medium. Our findings indicate that DDAb induced by SMX and SIX, in contrast to those induced by quinidine and quinine, are mainly specific for GPIIb/IIIa and react preferentially with calcium-dependent epitopes present only on the intact GPIIb/IIIa heterodimer.

No abstract

A simple, accurate, and inexpensive DNA-based PCR-SSP method was established for Di genotyping. The typing results can be visualized on a single photograph within 3 hours, making this reliable method suitable for large-scale typing of potential blood donors without serologic backup.

Most laboratories were able to identify the majority of HPA antibodies; however, significant disparities were observed in proficiency testing. MAIPA assay sensitivity is influenced by the monoclonal antibody clone used. DNA with new mutations and EBV cell lines are valuable samples to ensure accurate genotyping. A sensitive and specific drug-dependent antibody assay performed well in the hands of participants.

The Dombrock blood group system (ISBT 014, DO) was discovered 36 years ago and has been associated with haemolytic transfusion reactions [1,2]. Two common antigens, DO1 (Do a ) and DO2 (Do b ), and other three high-incidence antigens -DO3 (Gy a ), DO4 (Hy) and DO5 (Jo a ) -were identified using serological methods [1,[3][4][5]. Usually it is difficult to obtain monospecific DO-typing reagents and there are only limited DO gene-frequency studies, especially in the Chinese population [2,6]. As serological DO typing has severe limitations, establishing a DNA-based DO genotyping technique appears to be essential. Recently in a linkage study the DO locus was assigned to chromosome 12p12.3-p13.2 (chromosome 12, short arm, region 1, band 2, sub-band 3, through band 3, sub-band 2) [7]. More recently, the DO gene has been successfully cloned, ending a long period of searching for the molecular basis of the DO1 / DO2 polymorphism [8]. Homology studies suggested that the DO molecule is a member of the adenosine 5 ′ -diphosphate (ADP)-ribosyltransferase ectoenzyme gene family [8]. DO1 and DO2 alleles are the result of a single nucleotide substitution causing an amino acid change within an encoded arginine-glycine-aspartic acid (RGD) motif of the molecule [8]. On the basis of these findings, we have developed, for the first time, a polymerase chain reaction with sequence-specific primers (PCR-SSP)-based DO1 and DO2 genotyping method using newly designed allele-specific primers.The DO gene comprises 3 exons spanning 13 743 base pairs (bp) and predicts a peptide of 314 amino acid residues. A single nucleotide change from A to G at nucleotide position 892 (numbering according to the DOK1 clone, GenBank acc. no.: AF29004) within exon 2 results in the substitution of asparagine (N) for aspartic acid (D) at position 265 of the protein sequence. Serological testing indicated that N265 and D265 corresponded to the phenotypes DO:1,-2 [DO(a+b-) ] and DO:-1,2 [DO(a-b+) ], respectively [8]. In order to detect A892G substitution, two allele-specific reverse primers and a single forward-consensus primer were designed according to the DOK1 clone sequence and the human