Parallel enzyme-linked immunosorbent assay screening for human immunodeficiency virus among blood donors in five Chinese blood centres: a retrospective analysis

AIMS

To evaluate the strategy of parallel screening with different enzyme-linked immunosorbent assays (ELISA) among Chinese blood donors.

BACKGROUND

Parallel screening with ELISA has been the main strategy to detect human immunodeficiency virus (HIV) in blood donations in China for more than a decade. The performance of the strategy should be analysed.

METHODS

A total of 821,927 donations collected from five Chinese blood centres in 2008-2010 were tested using two third-generation ELISAs by different manufacturers licenced and confirmed by the Western blot (WB) in this study. The confirmatory positive predictive values (PPV), false positive rates (FPR), false negative rates (FNR) and potential risks for transfusion resulting from single or sequential ELISA screening were evaluated.

RESULTS

A total of 5318 (0·647%) of donations screened HIV reactive and were discarded. WB confirmatory results on 1668 available samples suggested that PPVs for dual ELISA, one round ELISA reactive and grey zone samples were 75·1, 0·7 and 0·5%, respectively. Eight out of 1124 one round ELISA reactive and 1 out of 195 grey zone samples were WB confirmed positive. All but one ELISA assay displayed comparable PPVs but variable FPRs and FNRs that differed by blood centre.

CONCLUSIONS

In the absence of nucleic acid testing (NAT), parallel ELISA screening prevented a substantial number of HIV infected donations from entering the Chinese blood supply. However, the loss of false positive donors should be re-evaluated especially given the frequently reported blood supply shortage in China.

First-time donors responding to a national disaster may be an untapped resource for the blood centre

BACKGROUND

On 12 May 2008, a severe earthquake struck Sichuan in China. Many people donated blood for the first time, leading us to question whether these donors might become repeat donors in the future. The return pattern of post-earthquake first-time donors (PEFTD) was compared with that of first-time donors (FTD) in a comparable period.

METHODS

Demographic characteristics, transfusion-transmissible infection rates and 1-year return rates were compared between 5147 PEFTD (5/13-5/19, 2008) and 3176 FTD (5/13-5/19, 2009) from five Chinese blood centres using chi-squared tests. Adjusted logistic regression was used to detect earthquake effect on donor return.

RESULTS

Post-earthquake first-time donors were more frequently between 26 and 45 years, men, and better educated compared with the control group. Slightly higher but not statistically significant increased rates of hepatitis B virus surface antigen (HBsAg) (0·87% vs. 0·50%, P=0·054), hepatitis C virus (HCV) (0·70% vs. 0·63%, P=0·414), syphilis (0·9% vs. 0·7%, P=0·489) and lower rates of human immunodeficiency virus (HIV) (0·31% vs. 0·60%, P=0·078) reactivity were detected for PEFTD. The 1-year return rate for PEFTD was significantly lower than that of the controls (8·0% vs. 13·0%, P<0·001). After adjusting for demographic factors, donation volume and sites, the PEFTD were less likely to return in 1 year than the controls (OR: 0·520; 95% CI: 0·442, 0·611).

CONCLUSION

Post-earthquake first-time donors may be less likely to donate again without continuing motivation strategies. Further studies on PEFTD's lack of motivation to return for donation are needed to design recruitment strategies to convert PEFTD to become repeat donors to continuously replenish the blood supply.

Knowledge, attitude and practice survey regarding blood donation in a Northwestern Chinese city

Recruitment of low-risk blood donors in developing countries is challenging. We studied the attitudes towards blood donation in several populations in a city in Western China. A survey of knowledge, attitude and practice was performed including 1280 individuals from eight distinct populations in Urumqi, Xinjiang Uyghur Autonomous Region, China. Included were Han Chinese and Uyghur populations of blood donors, non-donors, injection drug users, students and factory workers. Knowledge about blood donation varied between the groups. Factors motivating blood donation included social pressure, desire to know screening results and altruism. Inhibiting factors included fear of contracting an infection and other adverse health effects, including loss of vitality. Misconceptions about the effects of blood donation are widespread, even among educated persons in Urumqi. Fear of acquiring a serious infection may have been increased by the reports of HIV acquisition during plasma donations in China.

Single-donor platelets reduce the risk of septic platelet transfusion reactions

BACKGROUND

Septic platelet transfusion reactions (SPTRs) are the most common, serious risk of transfusion. Because SPTRs result from donor skin flora or asymptomatic bacteremia, the use of single-donor platelets (SDPs) has been proposed to reduce the risk of SPTRs from the risks with pools of platelet concentrates (PCs).

STUDY DESIGN AND METHODS

Beginning in 1986, all febrile transfusion reactions were evaluated by culture of the platelet bag. Confirmed SPTRs were identified by isolation of the same bacteria from the bag and the patient's blood or by positive Gram's stain of the bag that confirmed a positive platelet culture. In 1987, a program to minimize PC use in favor of SDP use was initiated as a means of reducing SPTRs.

RESULTS

In 12 years, the use of SDPs increased from 51.7 percent to 99.4 percent of all platelet transfusions at one institution. SPTRs fell from three events in 1 year to the current rate of one event per year. The incidence of SPTRs decreased from 1 in 4,818 transfusions to 1 in 15,098 transfusions. The rate of SPTRs due to PCs was 5.39 times higher than that of SPTRs due to SDPs (95% CI, 1.89,12.9).

CONCLUSION

The use of SDPs is a simple means of reducing SPTRs. Other measures such as sterilization will be required to eliminate all SPTRs.

Premature adiposity rebound in children treated for acute lymphoblastic leukemia

The adiposity rebound (AR), when body mass index begins to increase after its nadir in childhood, is a critical period for the regulation of energy balance and adult obesity risk. The aim of the present study was to test whether children treated for acute lymphoblastic leukemia (ALL) experience premature AR. This might, in part, explain their tendency to develop obesity. Timing of AR was assessed by visual inspection of body mass index plots in 68 patients treated for ALL in first remission. This sample comprised all eligible patients treated in Scotland between 1991 and 1998, age 30 months or less at the time of diagnosis. Timing of AR in patients was compared against a cohort of 889 healthy British children studied during the 1990s using the same method. AR occurred significantly earlier in the patients treated for ALL (chi(2) test, P < 0.001). The AR had occurred in 43% (29 of 68) of the patients and 4% (40 of 889) of the comparison group by age 37 months. At 49 months AR had occurred in 81% (55 of 68) of the patients and 21% (190 of 889) of the comparison group. Treatment of ALL is associated with a significantly advanced AR. This might, in part, explain the extremely high prevalence of obesity in long-term survivors. Clinical management should focus on minimizing excess weight gain during therapy to reduce long-term obesity risk.

Understandings of health. How individual perceptions of health affect health promotion needs in organizations

The purpose of the study was to discover what the concept of health means to the participants and to determine how an organization can assist its members in developing and maintaining their notion of health. The participants for this study were drawn from the employees at a post secondary educational institution. Tape recorded interviews were transcribed by the researcher, and the transcripts were analyzed for common topics and predominant themes. Imbedded in the data were four themes that provided an over arching conceptual framework from which to view health and health promoting activities: well being as a broad definition of health; the concept of balance as a prime contributor to health; the notion of self efficacy in determining one's health, and the value of caring as a significant determinant of health. Findings of the study have significance for individual health, organizations and health, health promoters, and further research.

Effect of extracorporeal membrane oxygenation on platelets in newborns

OBJECTIVES

To examine the effect of extracorporeal membrane oxygenation (ECMO) therapy on platelet function and number and to determine the in vivo survival of transfused platelets during ECMO.

DESIGN

Prospective study of all neonates treated with ECMO during a 6-month period.

SETTING

Neonatal intensive care unit in a tertiary referral center.

PATIENTS

Ten infants, < 1 wk of age, with respiratory failure requiring ECMO.

INTERVENTIONS

None.

MEASUREMENTS

Platelet counts were measured at timed intervals to determine the effect of ECMO on platelet counts. The change in platelet counts after transfusion was also measured. Whole blood platelet aggregation studies were performed to determine the effect of ECMO on platelet function.

MAIN RESULTS

A mean decrease of 26% from the baseline platelet count was found 15 mins after the initiation of ECMO, with an additional mean decrease of 16% by the end of 1 hr (p < .05). Fifteen minutes after platelet transfusions, a 17% mean increase in platelet counts was measured (p < .05). One hour after platelet transfusion, the platelet count had decreased to pretransfusion values. Platelet aggregation studies 15 mins after starting ECMO showed a 46% mean decrease in the response to collagen from baseline (p > .05), and a significantly (p < .05) reduced response to ristocetin and to adenosine 5'-diphosphate. Platelet adenosine triphosphate release was also significantly reduced. Single-unit platelet transfusions failed to correct platelet aggregation abnormalities. Resolution of platelet aggregation abnormalities and normalization of platelet counts occurred 8 hrs off ECMO.

CONCLUSIONS

The results of these studies show that qualitative and quantitative platelet changes occur while a neonate is receiving ECMO. The survival rate of transfused platelets is reduced, and the acquired platelet dysfunction is not reversed by the transfusion of platelets with normal function while the patient is receiving ECMO.

Probenecid induced immune hemolytic anemia

We report a patient who, while receiving probenecid and colchicine for acute gouty arthritis, developed severe hemolytic anemia in association with a generalized rash. The hemolysis was immune mediated as shown by a positive direct Coombs' test. In vitro hematologic studies showed that a probenecid dependent antibody was present.

Autoimmune hemolytic anemia with reticulocytopenia. A medical emergency

In four cases of autoimmune hemolytic disease, rapidly developing anemia was associated with reticulocytopenia despite intensely erythroid bone marrow. Transfusions had been withheld because compatible blood could not be obtained, and each patient was virtually moribund on admission. Type-specific RBCs were administered promptly without reaction. From 2 to 84 carefully selected units were required to sustain life during the reticulocytopenic episodes, which lasted from a few days to more than six months. Transfusion in patients with autoimmune hemolytic anemia generally is unwise, because the autoantibody in the serum usually reacts with the RBCs of all potential donors, making a satisfactory cross match impossible. However, reticulocytopenia with profound anemia may present as a medical emergency in which prompt, careful transfusion is lifesaving.