Alain M. Ngoma

Microparticle formation in apheresis platelets is not affected by three leukoreduction filters

Microparticles in blood components might contribute to transfusion‐related immunomodulation or other side effects. To elucidate the role of leukofiltration, we compared three commercially available filters for their effect on platelet (PLT)‐derived (PDMP), leukocyte‐derived (LDMP), and red blood cell–derived (RDMP) microparticle formation in apheresis PLTs.

Prevalence of Social Isolation in Community-Dwelling Elderly by Differences in Household Composition and Related Factors: From a Social Network Perspective in Urban Japan

Objective: The aim of this study was to measure the prevalence of social isolation in community-dwelling elderly and related factors based on household composition differences. Method: We used the six-item Lubben Social Network Scale to measure social isolation in 2,000 individuals. Multiple logistic regression analysis was performed to examine factors related to social isolation with household composition after adjusting for gender and age. Results: The prevalence of social isolation was 31.0% for elderly living alone and 24.1% for those living with family. For both, poor mental health and lack of social support from nonfamily members were associated with social isolation risk. For elderly living with family, low intellectual activities and poor health practice were associated with social isolation risk. Discussion: This study showed high prevalence of social isolation. For prevention, promoting mental health and encouraging them to make friends may be important. For elderly living with family, promoting intellectual activities and good health practice is recommended.

Red blood cell alloimmunization in transfused patients in sub-Saharan Africa: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVES Previous studies of Sub-Saharan Africans show significant alloimmunization to red blood cell (RBC) antigens, but country-specific data are limited. Thus, the aim of this study was to estimate, by meta-analysis, the overall proportion of red blood cell alloantibodies among transfused patients. METHODS We systematically searched Medline, Embase, and the Africa-Wide Information database to identify relevant studies in any language. Case reports, comments, letters, conference abstracts, editorials, and review articles were excluded. Of the 269 potentially relevant articles, 11 studies fulfilled our selection criteria. RESULTS Overall proportions of alloimmunization were 6.7 (95% CI: 5.7, 7.8) per 100 transfused patients. With regard to antibody specificity, among clinically significant antibodies, anti-E ranked as the most common, followed by anti-K, anti-C and anti-D. CONCLUSION Meta-analysis of available literature quantifies and qualifies the clinical challenge of RBC alloimmunization among transfused patients in Sub-Saharan Africa. These results should drive policy decisions in favour of routine testing of RBC antigens and irregular antibodies for transfused patients as a standard of care throughout Sub-Saharan Africa.

Analysis of blood donor deferral in Japan: Characteristics and reasons

BACKGROUND AND OBJECTIVES To ensure an adequate and safe blood supply, it is crucial to select suitable donors according to stringent eligibility criteria. This study aims to evaluate donor deferral rates, causes of deferral, and characteristics of deferred Japanese donors. MATERIALS AND METHODS Computerized records of blood centers in Miyagi and Fukushima Prefectures from March 2010 through March 2011 were retrospectively analyzed. RESULTS Among 231,361 individuals presenting during this period, 186,513 had complete data. Of these 160,763 (86%) attempted donation and 25,750 (14%) were deferred. The overall proportion of deferrals was higher among those less than 20 years old (24% vs 13%, P<0.0001), female (26% vs 7%, P<0.0001), and first-time donors (28% vs 12%, P<0.0001). Factors that were significantly associated with deferral status were female sex [Odds ratio (OR)=4.40], first-time donation attempt (OR=2.42), and donation at Fukushima blood centers (OR=0.57). Main reasons for temporary deferral were low hemoglobin and questionnaire-based interview decisions. CONCLUSIONS First-time and female were more frequently deferred whereas those presented at Fukushima blood centers were less frequently deferred. Low hemoglobin was the major contributor for female donors. Strategies to minimize deferral are needed to ensure an adequate and safe blood supply.

CD34+ cell enumeration by flow cytometry: a comparison of systems and methodologies.

CONTEXT An increasing number of medical centers can collect bone marrow, peripheral blood, or umbilical cord stem cells. Pathology laboratories should accommodate this trend, but investment in additional equipment may be impractical. OBJECTIVES To compare CD34(+) cell counting results by using 2 widely available flow cytometry systems, with and without the use of a separate hematology analyzer (ie, single-platform versus dual-platform methodologies). DESIGN Whole blood and peripheral blood stem cell (PBSC) samples were analyzed from 13 healthy allogeneic PBSC donors and 46 autologous PBSC donors with various malignancies. The Cytomics FC500 (Beckman Coulter, Fullerton, California) was compared with the FACSCalibur (BD Biosciences, San Jose, California). Dual-platform CD34(+) cell counting incorporated data from a KX-21 hematology analyzer (Sysmex, Kobe, Japan). RESULTS Subtle differences in CD34(+) cell counting between 2 systems and 2 methods did not achieve statistical significance. CONCLUSION Different systems and methods for CD34(+) cell enumeration, properly validated, can support care for patients undergoing transplants and provide meaningful data for multicenter studies or meta-analyses.

Blood Donor Deferral among Students in Northern Japan: Challenges Ahead

Background: As Japans aging society needs more blood, young students comprise a progressively smaller portion of the donor pool. To ensure a safe and sustainable blood supply, it is crucial to select suitable donors. This study aims to evaluate donor deferral rates, causes of deferral, and characteristics of deferred Japanese students. Methods: Computerized records of blood centers in northern Japan (Miyagi and Fukushima Prefectures) from March 2010 through March 2011 were retrospectively analyzed. Results: Among 231,361 individuals visiting during the 12-month period, 24,778 were students. Of these, 19,193 (77%) attempted donation, and 5,585 (23%) were deferred. Low hemoglobin, questionnaire-based interview decisions, and medication were the main reasons for temporary deferral. Age, sex, and blood center location were associated with low hemoglobin; donation history and blood center location were associated with medication-based deferral. The odds ratio among female students deferred for low hemoglobin was 35.48 with a 95% CI of 27.74-45.38. Conclusions: These results suggest that continued efforts are needed to motivate deferred potential donors to return, to prevent low hemoglobin especially among females, and to review medical interview decisions, while paying close attention to regional differences.

Risk Factors for Early Fatal Outcomes Among Children with Hemophagocytic Lymphohistiocytosis (HLH): A Single-Institution Case-Series in Vietnam

Hemophagocytic lymphohistiocytosis (HLH) is a rare and fatal hematological syndrome that causes a disturbance of the immune system. Overall mortality of HLH is greater than 50% and the majority of patients who die do so within the first 8 weeks of chemotherapy treatment. To find clinical parameters relating to high-risk HLH patients, this study examined associations between an early fatal outcome and potential prognostic clinical factors and laboratory findings on admission. Eighty-nine pediatric HLH patients were prospectively recruited in Childrens Hospital No. 1, Ho-Chi-Minh City, Vietnam, during the period from January 2010 to August 2012. Associations between early fatal outcome and clinical and laboratory findings, including a cerebrospinal fluid examination and virological test on admission, were examined. During the 8-week therapy, 25 (28%) HLH patients died. Persistent fever (>2 weeks), severe thrombocytopenia (<75 × 109/L), hyperbilirubinemia, and prolonged activated partial thromboplastin time (APTT) (>33 sec) were significant risk factors of early fatal outcome. Multivariate logistic regression analysis revealed that thrombocytopenia and prolonged APTT (P for trend was 0.054 and 0.013, respectively) were independently associated with the early fatal outcome. Persistent fever, severe thrombocytopenia, hyperbilirubinemia, and prolonged APTT on admission will be useful and practical predictors to determine high-risk HLH patients.

Barriers and motivators to blood donation among university students in Japan: development of a measurement tool

Despite growing demand for transfusion, the number of voluntary young blood donors has steadily decreased over recent years in Japan. This study aimed to develop an easy‐to‐use survey tool to assess barriers and motivators to blood donation among Japanese university students.

Platelet-, leucocyte- and red cell-derived microparticles in stored whole blood, with and without leucofiltration, with and without ionising radiation.

BACKGROUND Storage lesion, including microparticle formation, has been partially characterised in whole blood, but not in all combinations of pre-storage leucofiltration and/or irradiation. MATERIALS AND METHODS Single-donor whole blood products were processed into four subunits: with and without leucofiltration, with and without X-irradiation (25 Gy). Platelet-, leucocyte-, and erythrocyte-derived microparticles and free haemoglobin were measured periodically throughout 42 days of storage. RESULTS Pre-storage leucofiltration substantially reduced platelet- and leucocyte-derived microparticle counts throughout storage. Irradiation, in contrast, had no significant effect on microparticle counts. A gate for all microparticles showed a substantial time-dependent increase in unfiltered whole blood. A time-dependent increase in free haemoglobin was greatest in unfiltered, irradiated whole blood. DISCUSSION This study indicates that leucofiltration can prevent the formation of leucocyte- and platelet-derived microparticles, and might reduce haemolysis in irradiated whole blood, either by removing factors that provoke haemolysis, or by selective retention of senescent or effete red cells most prone to haemolysis.

A systematic review of red blood cell alloimmunization in pregnant women in Africa: time to do better

The presence of red blood cell (RBC) alloantibodies in pregnant women has been linked to the significant perinatal morbidity and mortality. A limited number of African studies have assessed alloimmunization to RBC antigens in pregnant women, but this literature has not been systematically reviewed. Thus, the aim of this study was to synthetize, by systematic review, the current evidence on RBC alloantibodies among pregnant women in Africa.