113名地中海贫血患者输注2629袋红细胞情况分析

目的掌握"地贫之家"患者的用血规律,为开展"地贫之家"的医院提供参考。方法对本院2016年6月开设"地贫之家"起至2019年5月的113名地中海贫血患者的2 629袋红细胞输注情况进行回顾性分析。结果 "地贫之家"患者ABO血型分布与所在的华南地区ABO血型分布大致相当。患者中位数年龄为9岁(6,15),93.8%(106/113)为30周岁以下,尤其以儿童及青少年为主。总体用血量逐渐增加,每年1月至2月和7月至8月的寒暑假回落,主要集中在非工作日输注。结论新建"地贫之家"用血有一定规律,输血科可参考患者的血型分布、用血周期变化制定储血计划,安排人力资源,合理安全使用血液资源。     

Class switching is differentially regulated in RBC alloimmunization and vaccination

Background

Studies of human patients have shown that most anti-RBC alloantibodies are IgG1 or IgG3 subclasses, although it is unclear why transfused RBCs preferentially drive these subclasses over others. Though mouse models allow for the mechanistic exploration of class-switching, previous studies of RBC alloimmunization in mice have focused more on the total IgG response than the relative distribution, abundance, or mechanism of IgG subclass generation. Given this major gap, we compared the IgG subclass distribution generated in response to transfused RBCs relative to protein in alum vaccination, and determined the role of STAT6 in their generation.

Study Design and Methods

WT mice were either immunized with Alum/HEL-OVA or transfused with HOD RBCs and levels of anti-HEL IgG subtypes were measured using end-point dilution ELISAs. To study the role of STAT6 in IgG class-switching, we first generated and validated novel STAT6 KO mice using CRISPR/cas9 gene editing. STAT6 KO mice were then transfused with HOD RBCs or immunized with Alum/HEL-OVA, and IgG subclasses were quantified by ELISA.

Results

When compared with antibody responses to Alum/HEL-OVA, transfusion of HOD RBCs induced lower levels of IgG1, IgG2b, and IgG2c but similar levels of IgG3. Class switching to most IgG subtypes remained largely unaffected in STAT6 deficient mice in response to HOD RBC transfusion, with the one exception being IgG2b. In contrast, STAT6 deficient mice showed altered levels of all IgG subtypes following Alum vaccination.

Discussion

Our results show that anti-RBC class-switching occurs via alternate mechanisms when compared with the well-studied immunogen alum vaccination.     

Timing of RhD-positive red blood cell administration is associated with D-alloimmunization in injured patients

Background

The D-alloimmunization rate in trauma patients does not appear to depend on the number of RhD-positive units transfused. The effect of the timing and pattern of RhD-positive transfusions has not been evaluated.

Methods

RhD-negative trauma patients who were transfused with RhD-positive red blood cells (RBC) or low titer group O whole blood (collectively called RBCs) on at least two separate calendar days and who had antibody detection tests performed at least 14 days after the second RhD-positive RBC transfusion without receiving RhIg were included in the analysis. Patients whose anti-D was detected within 14 days of the index RhD-positive RBC transfusion were excluded. Patient demographics and the dates of RhD-positive RBC transfusions and results of antibody detection tests performed after the index transfusion were collected on eligible patients.

Results

There were 44/61 (72.1%) patients in whom anti-D was not detected (non-alloimmunized) and 17/61 (27.9%) in whom anti-D was detected (alloimmunized). The patients had similar demographics with trends towards higher median admission heart rates and lower median admission Glasgow Coma Scale values in the alloimmunized group. Both groups received statistically identical median quantities of RhD-positive RBCs (non-alloimmunized 5 vs. alloimmunized 4 units, p = .53), however, the alloimmunized group received all their RhD-positive RBCs over a significantly shorter period of time compared to the non-alloimmunized (median 4 vs. 15 days, respectively, p = .01).

Conclusion

Receipt of all RhD-positive RBCs over a shorter period of time was associated with higher D-alloimmunization rates. These results need to be confirmed in larger studies.     

Blood bank issues associated with red cell exchanges in sickle cell disease

Sickle cell disease (SCD) patients are prone to develop complications that include stroke, acute chest syndrome, and other crises. Some of these complications require chronic transfusion therapy or red cell exchange (RCE), either for therapeutic or prophylactic reasons. Due to a discrepancy of red cell antigens between African Americans and Caucasians (majority blood donors), the incidence of alloantibody formation is very high, which makes it difficult to find compatible red cell units, especially for urgent RCE. Some of the above conditions require immediate oxygen delivery to the tissues. Thus, SCD patients undergoing RCE should receive red blood cells with special attributes that include matching for Rh and Kell blood group antigens; RBCs should be fresh in order to provide (1) immediate oxygen delivery and (2) longer surviving cells to reduce the interval between RCE. Also, these units should be pre-storage leukoreduced to prevent febrile non-hemolytic reactions and screened for sickle cell traits to avoid transfusing red cells containing HbS. This requires a concerted effort between the apheresis unit, the local blood bank, and the central blood supplier.     

Comparison of efficacy of packed red blood cell transfusion based on its hemoglobin content versus the standard transfusion practice in thalassemia major patients (HEMOCON study)

The hemoglobin (Hb) content of packed red blood cell (PRBC) units is heterogenous. The efficacy of a transfusion episode can be assessed if the Hb content of the PRBC is known and the patient’s post-transfusion Hb increment is also determined. This prospective study compared the efficacy of PRBC transfusion based on its Hb content versus the standard transfusion practice. A total of 160 thalassemia major patients were enrolled and randomly divided into two equal groups: Group I (n = 80) – they received ABO/RhD identical PRBCs after determining its Hb content (≥50 g); and Group II (n = 80) – they received randomly selected ABO/RhD identical PRBCs. Hb estimation and a direct antiglobulin test were performed on the post-transfusion sample (1 h). The mean Hb content of the PRBC units was significantly higher (p = 0.000) in group I (67.86 ± 8.07 g; range: 50.80–92.13 g) than group II (60.92 ± 8.29 g; range: 40.86–86.76 g). The mean Hb increment was also significantly higher in group I patients (p = 0.04). In both the groups, there was a significant negative correlation between Hb increment and weight, age, body surface area and blood volume (p < 0.05). There was a significant positive correlation between Hb increment and Hb dose adjusted for body surface area as well as blood volume (p < 0.05). PRBC transfusion was more efficacious in patients who were transfused with PRBCs having a Hb content ≥50 g as compared to those who received randomly selected PRBCs.     

珠蛋白生成障碍性贫血孕妇MCV与RDW水平变化及意义

目的探讨珠蛋白生成障碍性贫血(又称地中海贫血,简称地贫)孕妇红细胞平均体积(MCV)与红细胞分布宽度(RDW)的变化及意义。方法检测并比较26例α地贫孕妇、24例轻型β地贫孕妇、26例中间型β地贫孕妇及76例健康孕妇MCV及RDW水平。结果α地贫孕妇和中间型β地贫孕妇MCV、RDW水平与健康孕妇比较差异有统计学意义(P<0.05)。结论 MCV、RDW检测可用于地贫筛查;孕妇MCV下降、RDW升高并排除缺铁性贫血时,应进行血红蛋白电泳分析。     

Title: Effect of multiple maternal red cell alloantibodies on the occurrence and severity of Hemolytic Disease of the Fetus and Newborn

IntroductionAntenatal antibody screening in India is focused on the detection of anti-D in RhD-negative mothers. HDFN outcome can also be affected by the presence of antibodies other than anti-D. We planned this study to find the impact of ‘anti-D in combination with additional antibodies’ on the development and severity of HDFN compared with ‘anti-D alone’.MethodsThis is a retrospective study performed at a referral center in northern India from October 2015 to March 2018. Antibody screening was performed on women with complicated obstetric history. Women with anti-D antibody were included in the study and categorized on the basis of presence of additional antibody (anti-D alone or in combination with other antibody). Various clinical, laboratory & interventional parameters were used to define HDFN and severe HDFN. Perinatal outcome was then compared between the two groups.ResultsA total of 176 women with anti-D antibody were included in the study. Of these, 136 cases (77.3%) had anti-D alone while at least one additional antibody was present in 40 (22.7 %) cases. Most common additional antibodies were anti-C, anti-E and anti-c. After excluding 46 women for various reasons, 130 women were left for final analysis. Approximately 57% and 78% of cases were affected by severe HDFN amongst women with anti-D alone and in combination, respectively. Relative risk of developing severe HDFN was 1.7 times higher in women with additional antibody.ConclusionsPatients with combination antibodies were found to have more severe HDFN compared to the ones with anti-D alone.     

Elevated serum erythropoietin concentration is associated with coordinated changes in red blood cell and reticulocyte indices of pregnant women at term

The aim of this study was to evaluate the relationship between the erythropoietin (EPO) concentration and both the advanced cellular indices reflecting the haemoglobin contents of red blood cells and reticulocytes and the serum markers of iron status. The study population comprised pregnant women at term (n = 210). The serum EPO, transferrin receptor (TfR), ferritin, the percentages of hypochromic red blood cells (%HYPOm) or reticulocytes (%HYPOr) and the cellular haemoglobin in mature red blood cells (CHm) or in reticulocytes (CHr) were measured in maternal blood before delivery. The EPO concentration was elevated above the reference limit (>31.5?mIU/mL) in 16?% of all pregnant women, and appeared to correlate in a linear fashion, especially with %HYPOm (r = 0.52, p<0.001), %HYPOr (r = 0.57, p<0.001) and CHr (r = ?0.45, p<0.001). The significant (p<0.05) predictors of EPO in the multivariate stepwise regression analysis were %HYPOr, Hb, %HYPOm and MCV. In general, the lower the cellular haemoglobin content, the higher the overall maternal EPO production. In conclusion, elevated %HYPOm and %HYPOr reflecting iron‐deficient erythropoiesis are associated with an increase in EPO concentration in maternal blood. This could be explained by subclinical iron deficiency being accompanied by a compensatory EPO response.     

Microcirculation and red cell transfusion in patients with sepsis

Early identification of sepsis followed by diagnostic blood cultures and prompt administration of appropriate intravenous antibiotics covering all likely pathogen remains the corner stone in the initial management of sepsis. Source control, obtained by harvesting microbiological cultures and removal or drainage of the infected foci, is mandatory. However, optimization of hemodynamically unstable patients including volume support supplemented with vasopressor, inotropic and transfusion of red blood cells (RBCs) in case of persistent hypoperfusion have the potential to reduce morbidity and mortality. Given the imbalance between the ability of the cardiovascular system to deliver enough oxygen to meet the oxygen demand, transfusion of RBCs should theoretically provide the ideal solution to the challenge. However, both changes in the septic patients’ RBCs induced by endogenous factors as well as the storage lesion affecting transfused RBCs have negative effects on the microcirculation. RBC morphology, distribution of fatty acids on the membrane surface, RBC deformability needed for capillary circulation and the nitrogen oxide (NO) signaling systems are involved. Although these deteriorating effects develop during storage, transfusion of fresh RBCs has not proven to be beneficial, possibly due to limitations of the studies performed. Until better evidence exists, transfusion guidelines recommend a restrictive strategy of RBC transfusion i.e. transfuse when hemoglobin (Hb) <7 g/dL in septic patients.     

T细胞大颗粒淋巴细胞白血病合并纯红细胞再生障碍的临床特征

目的 提高对T细胞大颗粒淋巴细胞白血病(T-LGLL)合并纯红细胞再生障碍(PRCA)的认识.方法 回顾性分析我院2000年1月至2006年8月间确诊的T-LGLL合并PRCA患者临床及实验室检查特征.结果14例T-LGLL合并PRCA患者中男7例,女7例,中位年龄61岁.患者呈慢性病程,主要表现贫血症状,9例患者脾脏轻、中度肿大,1例患者同时伴轻度肝脏肿大,1例患者浅表淋巴结肿大.初诊时患者中位Hb 61.5 g/L,中位WBC 4.30(2.70～7.95)×109/L,中位淋巴细胞比例0.59(0.30～0.87),外周血大颗粒淋巴细胞中位比例和中位绝对值分别为0.36(0.14～0.77)和1.9(0.4～4.5)×109/L,骨髓有核细胞中大颗粒淋巴细胞中位比例0.165(0.085～0.410).部分患者血清学检查异常.12例患者常规染色体检查无异常.给予环孢素和(或)糖皮质激素为主的免疫抑制治疗,患者总有效率91%.结论 合并PRCA的T-LGLL患者临床及实验室特征与经典T-LGLL者相似,以贫血为突出表现,脾脏肿大多见.外周血白细胞正常或减少,大颗粒淋巴细胞相对增多.对免疫抑制治疗反应良好.