Quantitative and multiplexed detection for blood typing based on quantum dot-magnetic bead assay.

BACKGROUND: Accurate and reliable blood grouping is essential for safe blood transfusion. However, conventional methods are qualitative and use only single-antigen detection. We overcame these limitations by developing a simple, quantitative, and multiplexed detection method for blood grouping using quantum dots (QDs) and magnetic beads. METHODS: In the QD fluorescence assay (QFA), blood group A and B antigens were quantified using QD labeling and magnetic beads, and the blood groups were identified according to the R value (the value was calculated with the fluorescence intensity from dual QD labeling) of A and B antigens. The optimized performance of QFA was established by blood typing 791 clinical samples. RESULTS: Quantitative and multiplexed detection for blood group antigens can be completed within 35 min with more than 105 red blood cells. When conditions are optimized, the assay performance is satisfactory for weak samples. The coefficients of variation between and within days were less than 10% and the reproducibility was good. The ABO blood groups of 791 clinical samples were identified by QFA, and the accuracy obtained was 100% compared with the tube test. Receiver-operating characteristic curves revealed that the QFA has high sensitivity and specificity toward clinical samples, and the cutoff points of the R value of A and B antigens were 1.483 and 1.576, respectively. CONCLUSION: In this study, we reported a novel quantitative and multiplexed method for the identification of ABO blood groups and presented an effective alternative for quantitative blood typing. This method can be used as an effective tool to improve blood typing and further guarantee clinical transfusion safety.

HCV infection in voluntary donors and its influence on recruitment of donors in Chongqing area.

Blood donor recruitment models have changed from paid donors to employer-organized donors and to voluntary donors in China. Reports on the hepatitis C virus (HCV) infection among voluntary blood donors in China have been rarely found at present. The prevalence of anti-HCV and genotypes among the first-time voluntary blood donors was investigated in Chongqing area of China. A total of 13,620 serum samples were collected from the first-time voluntary blood donors in Chongqing, China. Anti-HCV antibody was tested by ELISA. The Core/E2 region of HCV RNA from HCV seropositive samples was amplified by RT-PCR for genotyping. The results indicated that the prevalence of anti-HCV averaged 0.49% (67/13,620), and the highest rate (0.86%) was obtained in the group aged 40 to 49. A higher prevalence was observed among the more educated donors, and metropolitan donors. The ratios of following genotypes 1b, 2a, 3a and 3b were 4 (18%), 5 (23%), 9 (41%) and 4 (18%) in all the 22 samples respectively. Genotype 3 (3a and 3b) was the predominant genotype. In conclusion, the prevalence of anti-HCV was low among the population of voluntary blood donors in Chonqing area. The genotyping results showed the possibility of presence of druggies among the voluntary blood donors. Therefore, more attention should be paid to exclude those high-risk persons from the volunteers.

[Preliminary investigation on Paragonimus in Lvchun county of Yunnan province].

69 crabs were collected from Daxing, Gekui and Niukong townships of Lvchun county, Yunnan Province in 2006 and excysted metacercariae were only obtained from crabs of Niukong. The infection rate was 27.6% (8/29) with an average metacercaria number of 2.25 each crab. No encysted metacercariae were found. The excysted metacercariae were morphologically identified as Paragonimus proliferus.

[Analysis on mutations of GJB2 gene in Chinese population].

OBJECTIVE: To determine the prevalence and types of GJB2 mutations and to investigate the genetic mechanism in Chinese autosomal recessive deafness. METHODS: The subjects were four Chinese pedigrees (39 individuals) and 50 normal adults. GJB2 was amplified by PCR. The products were digested with restriction enzyme Apa I, then sequenced. RESULTS: Homozygous deletion C at position 232-235 of GJB2 (235delC),which resulted in frameshift mutation, was found in four affected individuals of two pedigrees; the compound heterozygous deletions (235delC/232G to A) were found in two affected individuals in one pedigree. One carrier with 235delC was found in normal controls (1% allele). Two kinds of polymorphisms 79G to A(V27I) and 3 41A to G(E114G) were found in both affected and normal controls. The frequencies of allele for 79G to A and 341A to G in normal controls were 30%, 21%, respectively. CONCLUSION: 235delC mutation of GJB2 was related with Chinese autosomal recessive deafness, and the 232G to A(Ala78Thr) missense mutation was found to be a novel mutation.

Clinical assessment of preventing febrile nonhemolytic transfusion reaction by leukocyte-depleted blood transfusion.

The objective was designed to assess the clinical efficiency of preventing febrile nonhemolytic transfusion reactions (FNHTR) with transfusion of leukocyte-depleted RBC and platelet concentrates. One hundred patients with cirrhosis of liver, gastric ulcer and cancer were selected to receive RBC concentrates with leukocyte filtration. Another group of 50 patients with liver necrosis, gastric ulcer and cancer were selected to receive non-filtered RBC concentrates. Two hundred and forty patients with acute or chronic leukemia, aplastic anemia, multiple myeloma, thrombocytopenia purpura, diabetes mellitus, cirrhosis of liver, upper gastrointestinal hemorrhage, severe hepatitis, burn and cancer post radioactive or chemical treatment were divided into two group with 120 patients in each one and selected randomly to receive platelet concentrates. The incidence rates of FNHTR in all patients were investigated. Results showed that there was no FNHTR in 100 transfusions with leukocyte-depleted RBC concentrates. Eight out of 50 patients with non-filtrated RBC concentrates showed FNHTR. The incidence of FNHTR was sixteen (16%) in non-filtrated transfusion. Twenty-five and 7 patients manifested FNHTR respectively in non-filtrated or filtrated platelets transfusions. The incidence of FNHTR was 20.83% and 5.83% respectively in non-filtrated or filtrated platelet transfusion. It is concluded that leukocyte-depleted RBC and platelet concentrates reduces FNH TR in blood transfusion.