Micro-Droplet Platform for Exploring the Mechanism of Mixed Field Agglutination in B3 Subtype.

B3 is the most common subtype of blood group B in the Taiwanese population, and most of the B3 individuals in the Taiwanese population have the IVS3 + 5 G > A (rs55852701) gene variation. Additionally, a typical mixed field agglutination is observed when the B3 subtype is tested with anti-B antibody or anti-AB antibody. The molecular biology of the gene variation in the B3 subtype has been identified, however, the mechanism of the mixed field agglutination caused by the type B3 blood samples is still unclear. Therefore, the purpose of this study was to understand the reason for the mixed field agglutination caused by B3. A micro-droplet platform was used to observe the agglutination of type B and type B3 blood samples in different blood sample concentrations, antibody concentrations, and at reaction times. We found that the agglutination reaction in every droplet slowed down with an increase in the dilution ratio of blood sample and antibody, whether type B blood or type B3 blood was used. However, as the reaction time increased, the complete agglutination in the droplet was seen in type B blood, while the mixed field agglutination still occurred in B3 within 1 min. In addition, the degree of agglutination was similar in each droplet, which showed high reproducibility. As a result, we inferred that there are two types of cells in the B3 subtype that simultaneously create a mixed field agglutination, rather than each red blood cell carrying a small amount of antigen, resulting in less agglutination.

Osteopontin gene polymorphism in association with systemic lupus erythematosus in Chinese patients / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Osteopontin (OPN) is one kind of cytokine which can play a number of roles in promoting activation of T lymphocyte, regulating balance between Th1 and Th2, participating in cell-induced immunologic response and stimulating B lymphocyte to express multi-clone antibodies. Some researches have showed that OPN may be involved in the pathogenesis of systemic lupus erythematosus (SLE). The aim of this study was to investigate possible association of a single nucleotide polymorphism (SNP) at position 9250 in exon 7 of the OPN gene (OPN gene 9250) with SLE in Chinese patients.</p><p><b>METHODS</b>Totally 158 patients (18 males and 140 females) fulfilled the revised criteria for SLE by the American College of Rheumatology in 1982 and 180 healthy volunteer controls (34 males and 146 females), all from the south of China, consented to participate in the study. OPN gene 9250 polymorphism was detected by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP).</p><p><b>RESULTS</b>The frequency of TT genotype of the OPN gene 9250 was significantly lower (52.5% vs 70%, P < 0.05) and the frequency of TC genotype of the OPN gene 9250 was significantly higher (43.7% vs 29.4%, P < 0.05) in SLE patients than in controls. There were significant differences in OPN gene 9250 allele and phenotype frequencies between the SLE patients and controls (P < 0.05). When the SLE patients and controls were separated into men and women, significant differences of frequencies were noted in TT genotype, TC genotype and allele of the OPN gene 9250 in women (P < 0.05) but not in men (P > 0.05).</p><p><b>CONCLUSIONS</b>OPN gene 9250 polymorphism appears to be associated with susceptibility to SLE in Chinese Han ethnic population.</p>

Association of osteopontin gene polymorphism with lupus nephritis in Chinese Han population / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the possible association of a single nucleotide polymorphism (SNP) at position 9250 in exon 7 of osteopontin gene (OPN gene 9250) with lupus nephritis (LN) in southern Chinese patients.</p><p><b>METHODS</b>Altogether 109 patients with LN (12 males and 97 females) diagnosed according to the American College of Rheumatology criteria (revised in 1982) for systemic lupus erythematosus (SLE) and 180 healthy ethnically matched controls (34 males and 146 females), all Han people living in South China, were enrolled in this study with informed consent. Blood samples from all subjects were collected in EDTA tube for genomic DNA extraction according to the standard isolation procedures. OPN gene 9250 polymorphism was typed by PCR-restriction fragment length polymorphism (PCR-RFLP).</p><p><b>RESULTS</b>All the genotype frequencies of OPN gene 9250 were in Hardy-Weinberg equilibrium. Compared with the controls, LN patients showed significantly lower frequency of TT genotype of OPN gene 9250 (70% vs 51%, P<0.05) and significantly higher frequency of TC genotype (29.4% vs 45%, P<0.05). There were significant differences in OPN gene 9250 allele and phenotype frequencies between LN patients and the controls (P<0.05). Compared with the female controls, the frequency of TT genotype of OPN gene 9250 was significantly lower in female LN patients (68.5% vs 54%, P<0.05), and there was a significant difference in OPN gene 9250 allele frequency between them (P<0.05).</p><p><b>CONCLUSION</b>OPN gene 9250 polymorphism appears to be associated with the susceptibility to LN in southern Chinese Han population.</p>