Comparative efficacy and safety of restrictive versus liberal transfusion thresholds in anemic preterm infants: a meta-analysis of 12 randomized controlled trials.

The comparative efficacy and safety of restrictive with liberal transfusion thresholds remain controversial in anemic preterm infants. This meta-analysis aimed to compare the efficacy and safety of these two transfusion thresholds for anemic preterm infants. We searched PubMed, Embase, Cochrane Library, and China National Knowledge Infrastructure (CNKI) for relevant randomized controlled trials (RCTs) comparing restrictive with liberal transfusion thresholds in anemic preterm infants through April 30, 2022. Two independent investigators screened literature, extracted data, and appraised the methodological quality of eligible studies. Meta-analysis was conducted using RevMan version 5.3.5. Twelve RCTs with 4380 preterm infants were included. Liberal transfusion threshold significantly increased the level of hemoglobin after transfusion (mean difference (MD): -10.03; 95% confidence interval (CI): -15.98 to -4.08; p=0.001; I2=94%) and hematocrit (MD: -3.62; 95%CI: -6.78 to -0.46; p=0.02; I2=80%) compared with restrictive transfusion. Infants' age at first transfusion in restrictive transfusion group was higher than that of infants in liberal transfusion group (MD: 5.08; 95%CI: 2.27 to7.89; p=0.004; I2=54%); however, restrictive transfusion was associated with more time on supplemental oxygen (MD: 3.56; 95%CI: 1.93 to 5.18; p<0.001; I2=62%) and ventilator or CPAP (MD: 3.31; 95%CI: 1.42 to 5.20; p=0.006; I2=75%). For the remaining outcomes, two transfusion strategies were comparable. Furthermore, a series of sensitivity analyses confirmed the robustness of the level of hemoglobin after transfusion, age at first transfusion, time on ventilator or CPAP, and safety outcomes. Evidence with substantial heterogeneity indicates that liberal and restrictive transfusion thresholds are effective and safe blood cell transfusion strategies in anemic preterm infants, but the liberal strategy may be more effective in shortening the length of necessary respiratory support.

[Genetic Polymorphism of Antigens in Twelve Rare Blood Group Systems of Li Nationality in Hainan Province].

OBJECTIVE: To explore the distribution characteristics of main antigen gene frequencies of Duffy,Diego,Kidd,Dombrock,MNS,Lutheran,Kell,Colton,Scianna,Yt,Knops and Indian in red blood cell blood group system of Li nationality in Hainan Province. METHODS: Antigens in twelve rare blood group systems of 214 Li people in Hainan Province were genotyped and analyzed by polymerase chain reaction-sequence specific primers (PCR-SSP). RESULTS: The gene frequency of antigens in twelve rare blood group systems of 214 Li people in Hainan Province including: the gene frequency of Duffy blood group system: fya=0.9556，fyb=0.0444；the gene frequency of Diego blood group system: Dia=0.0678，Dib=0.9322；the gene frequency of Kidd blood group system：JKa=0.4533，JKb=0.5467；the gene frequency of Dombrock blood group system：DOa=0.1051，DOb=0.8949；the gene frequency of MNS blood group system：M=0.8131，N=0.1869,S=0.0327，s=0.9673，Mur+=0.5748，Mur-=0.4252；the gene frequency of Lutheran blood group system：AUa=0.8318，AUb=0.1682；the Kell, Colton, Scianna, Yt, Knops and Indian blood type systems showed a monomorph and the genotype was kk, coacoa, Sc1Sc1, YtaYta, KnaKna and InbInb. The observed and expected genotype values in twelve rare blood group systems of Li nationality in Hainan province were obeyed by the Hardy-Weinberg genitic rules. The difference between the observed and expectated values of the Kidd blood group system showed significant differences（χ2=17.1946，P=0.0002）. CONCLUSION: The genetic distribution and genetic status in twelve rare blood group systems of Li nationality in Hainan Province are relatively stable. The gene distribution of Duffy, Diego, Kidd, Drombrock, MNS and Lutheran blood group systems are polymorphic and show unique distribution characteristics compared with other regions and different nationalities. The gene frequency distribution of Kell、Colton、Scianna、Yt、Knops、Indian blood group systems are monomorphic.