Initial screening and retest mode in apheresis platelet donors: a comparative analysis / 中国输血杂志

【Objective】 To investigate the effectiveness of current indicators in initial screening and retest before donation and access the optimal testing strategies. 【Methods】 Data of initial screening (rate method for ALT, colloidal gold method for HBsAg) and retest (rate method for ALT, ELISA for HBsAg) of 18 510 platelet donors in our center from January 2019 to December 2021 were collected, and the results were retrospectively analyzed and compared in terms of different years and number of donations. 【Results】 From 2019 to 2021, data of initial screening and retest of platelet donors were as follows: 1) the deferral rate of ALT and HBsAg was 12.98% (2 403/18 510) vs 0.26%(40/15 412); 2) the deferral rate of ALT was 13.19% (712/5 398) vs 0.20%(9/4 410)in 2019, 13.33% (873/6 549) vs 0.06%(3/5 387)in 2020 and 11.05% (725/6 563) vs 0.07%(4/5 615)in 2021; for initial screening, significant difference was noticed in ALT reactivity in 2021 as in comparison to other two years(P<0.05); 3) the reactive rate of HBsAg was 0.43% (23/5 398) vs 0.18%(8/4 410)in 2019, 0.66% (43/6 549) vs 0.20%(11/5 387)in 2020 and 0.41% (27/6 563) vs 0.09%(5/5, 615) in 2021. For initial screening, HBsAg deferral in 2021 was significantly different from 2019, while similar with 2020. 4) Among ALT deferral samples in the retest, 68.75% (11/16) were ALT≥45 U/L. Among HBsAg reactive samples, 91.67% (22/24) were reactive by single reagent. 【Conclusion】 Setting the threshold value of ALT for platelet donors in initial screening as less than 45 U/L can effectively reduce the reactive rate in the retest. HBsAg screening only for first-time platelet donors can reduce the detection cost. Adding pre-donation detection indicators according to local prevalence of transfusion transmitted diseases is conductive to reduce the discarding rate of platelets.

The polymorphism of HPA-1-6w, HPA-15 and HPA-32bw-35bw in platelet donors from Deyang, Sichuan / 中国输血杂志

【Objective】 To explore the polymorphism of HPA-1-6w, HPA-15 and 32bw-35bw in platelet donors in Deyang, Sichuan, and estimate whether to include the detection of 32bw-35bw in the platelet bank. 【Methods】 Polymerase chain reaction with sequenced based typing (PCR-SBT) was used to sequence the HPA-1-6w, HPA-15 and 32bw-35bw loci of 205 platelet donors in Deyang. Allele frequencies were calculated by the direct counting method. The frequencies of HPA-1-6 and 15 alleles in northern and southern Chinese, Japanese and Australian population were compared, and those HPA loci and HPA-32bw-35bw were searched in the Chinese Millionome Database (CMDB) and genomAD to obtain the polymorphism data. Then the Chi-square test was performed with the data of this study through GraphPad Prism 9 software. 【Results】 The allele frequencies of HPA-1b, 2b, 3b, 5b, 6bw and HPA-15b were 0.005(2/410), 0.037(15/410), 0.471(193/410), 0.020(8/410), 0.010(4/410) and 0.461(189/410), respectively, b allele of HPA-32bw-35bw and HPA-4 was not detected. Statistical significance was observed between the HPA-1b allele frequency of this study and northern Chinese, Australian population and genomAD global population sample (P< 0.05, 0.005 vs 0.014 vs 0.145 vs 0.122). The frequency of HPA-2b alleles in this study, Japanese population and genomAD global population samples was 0.037 vs 0.120 vs 0.100, with statistical difference(P<0.05). Comparison of HPA-5b and HPA-6bw allele frequencies with those of genomAD global population showed a statistical difference (P<0.05, 0.020 vs 0.089 and 0.010 vs 0.000 008, respectively). 【Conclusion】 The polymorphisms of HPA-1-6w and HPA-15 of donors in Deyang has characteristics of the southern Chinese. The frequencies of HPA-32bw-35bw were extremely low, which could be excluded from the platelet bank in Deyang.

Changes in hematological parameters of long-term high-frequency platelet donors / 中国输血杂志

【Objective】 To understand the effect of long-term high-frequency platelet donation on the health, safety and platelet quality of blood donors. 【Methods】 From August 2020 to July 2022, blood donors who donated platelets for single collection in the station were selected as two groups: those who donated for 20-29 times and those who donated for 30-44 times. Such 14 test indexes as red blood cell count (RBC), hemoglobin (Hb), hematocrit (Hct), mean corpuscular volume (MCV), platelet count (Plt), white blood cell count (WBC), large platelet ratio (P-LCR), lymphocyte (LYM) , neutrophil (NE), mean hemoglobin content (MCH), mean hemoglobin concentration (MCHC), platelet specific volume (PCT), mean platelet volume (MPV) and platelet distribution width (PDW) were grouped and statistically analyzed for 5 times in each group. In addition, blood donors who have donated platelets more than 100 times in the station were chosen; the changes of their 5 parameters as RBC, Hb, Hct, PLT and WBC, as well as the correlation with the total number of platelet donations were analyzed through statistical analysis of the first 100 donations(10 donations/group). 【Results】 During 2 years, the hematological parameters were similar between 20-29 donation group(n=30) and 30-44 donation group(n=11) (P>0.05). For donors with donations≥100 occasions, RBC, Hb, Hct and WBC were negatively correlated with the number of blood donations, while Plt was positively correlated. There were significant differences in Hb, Hct, WBC and Plt among groups (P<0.05). Hb, Hct and WBC showed a downward trend, while Plt showed an upward trend. 【Conclusion】 With the increase of blood donations and units of blood donated, some changes in hematological parameters are observed among long-term high-frequency platelet donors. Monitoring and health education should be strengthened to ensure the safety and quality of blood donors.

Genotyping of HPA-1-29bw in platelet donors in Nanjing, China / 中国输血杂志

【Objective】 To analyze the allele frequencies of the human platelet antigens 1-29 system (HPA-1-29bw) in Nanjing Han platelet donors, so as to provide references for compatible platelet transfusion. 【Methods】 HPA genotyping was performed by Sanger sequencing method in 900 Nanjing Han regular platelet donors who donated at Jiangsu Province Blood Center from February to September 2019. The frequencies of alleles and genotype were calculated using direct counting method. 【Results】 The HPA allele frequencies in Nanjing Han platelet donors were HPA-1a 0.9950, 1b 0.0050, 2a 0.9467, 2b 0.0533, 3a 0.5850, 3b 0.4150, 4a 0.9989, 4b 0.0011, 5a 0.9822, 5b 0.0178, 6a 0.9828, 6b 0.0172, 11a 0.9994, 11b 0.0006, 15a 0.5317, 15b 0.4683, 21a 0.9928 and 21b 0.0072, respectively. Only a allele was detected in HPA-7-10w, -12-14w, -16-20w and -22-29bw systems.The highest mismatch rate of HPA genes in 900 platelet donors was HPA-15 system, followed by HPA-3 system, with the rate of 37.40%(337/900) and 36.77%(331/900), respectively. One heterozygote was detected in HPA-11w system. 【Conclusion】 The chracteristics of HPA alleles frequencies in Nanjing Han platelet donors is that HPA-15 and HPA-3 are the most common heterozygotes, which should be paid attention to in local clinical transfusion.

Deferral causes of apheresis platelet donors during primary screening and the countermeasures, Qinghai / 中国输血杂志

【Objective】 To explore the deferral causes of apheresis platelet donors during primary screening in Qinghai, so as to take appropriate measures to improve the pass rate of donors. 【Methods】 The primary screening results of 6 673 apheresis donors from January 2018 to January 2020 in Qinghai were analyzed retrospectively. And the deferral results of donors were compared according to high(>2 500 m), middle(about 2 000 m) and low(<1500 m) altitude. 【Results】 41.7%(531) of those high-altitude blood donors were deferred, as low Plt accounted for 13.2%(168), high ALT 11.9%(151), high Hct/Hb/RBC 11.8%(150), and limepic blood 4.0%(51). 8.1% of the middle-altitude donors were deferred. As for low-altitude donors, low HCT, Hb and RBC(0.6%, 8 cases) were the dominant reason. 【Conclusion】 The different altitudes and living habits of blood donors may result in their deferral. Appropriate measures should be carried out for apheresis donors from areas of different altitudes when recruiting donors, so as to elevate the pass rate.

Screening of Apheresis Platelet Donors for Human Parvovirus B19 by Gel Card Test / 대한수혈학회지

BACKGROUND: As apheresis platelet concentrates are widely used recently, the risk of transfusion associated infections is increased. Parvovirus B19 causes transfusion associated infections especially in chronic hemolytic anemia, haemophilia or immunosuppressed patients. We evaluated the significance of Parvovirus B19 antigen test to be one of the apheresis platelet donor screening test. METHODS: Three hundred forty eight serum (or plasma) samples from apheresis platelet donors were tested for Parvovirus B19 antigen test which was based on haemagglutination in gel technology. The tubes arranged in special gel cards (DiaMed) were added with 25 microL P antigen positive red cell and 10 microL patient's serum and then centrifuged at room temperature, 85 g for 10 minutes without incubation. The result was read and scored from 0 to 4 positive. Also the antibody screening test was performed for all of the positive samples on the Parvovirus B19 gel card test to exclude false positive reaction due to red cell alloantibody. We investigated directed recipient's disease state for all of positive donors and compared the result of the Parvovirus B19 antigen test with the routine screening test. RESLUTS: Six of the 348 samples were positive for Parvovirus B19 antigen test, the frequency was 1.7%. All of the six positive samples on gel card test reveal negative result by the antibody screening test. All of four directed recipients are immunosuppressed states. If the Parvovirus B19 antigen test was included in routine screening test, the rejection rate is expected to be increased about 1.4%. CONCLUSION: Screening for Parvovirus B 19 in apheresis platelet donors is considered to prevent transfusion mediated viral infection of susceptible recipients including immunocompromised patients.

Genetic polymorphism of HPA-1 to-5,HPA-15 alloantigen system in Qingdao Han population / 中国输血杂志

Objective To study the polymorphism of human platelet antigen HPA-1 to HPA-5,and HPA-15 system in Qingdao Han population.Methods A total of 918 samples from regular voluntary platelet donors in Qingdao were genotyped for HPA-1 to-5 and HPA-15 by PCR-SSP.Results The gene frequencies of HPA-1a,-1b;HPA-2a,-2b;HPA-3a,-3b;HPA-4a,-4b;HPA-5a,-5b;HPA-15a,-15b were 0.9940,0.0060;0.9319,0.0681;0.5822,0.4178;0.9897,0.0104;0.9804,0.0196;0.4913,0.5087,respectively.Both a and b alleles were found in each of the 6 HPA systems,and a/a homozygosity was more common in HPA-1,-2,-4 and-5 systems.The HPA genotype frequencies followed Hardy-Weinberg principle.HPA-1 frequency of Qingdao people was significantly different from that of North China(P