Association between ambient carbon monoxide levels and hospitalization costs of patients with myocardial infarction: Potential effect modification by ABO blood group.

Previous researches have reported the association between air pollution and various diseases. However, few researches have investigated whether air pollutants are associated with the economic loss resulting from patients' hospitalization, especially the economic loss of hospitalization due to acute cardiovascular events. The purpose of our research was to explore the association between the levels of carbon monoxide (CO), taken as an index of pollution, and the hospitalization costs of myocardial infarction (MI), and the potential effect modification by the ABO blood group. A total of 3237 MI inpatients were included in this study. A multiple linear regression model was used to evaluate the association between ambient CO levels and hospitalization costs of MI patients. Moreover, we performed stratified analyses by age, gender, body mass index (BMI), season, hypertension, and ABO blood types. There was a positive association between the levels of CO in the air and the costs of hospitalization caused by MI. Furthermore, such association was stronger in males, BMI ≥25, <65 years, with hypertension, and non-O blood group. Interestingly, we found the association was particularly significant in patients with blood group B. Overall, our study first found that ambient CO levels could have an impact on the hospitalization costs for MI patients, and those with blood group B can be more sensitive.

Prevalence of p24 antigen among a cohort of HIV antibody negative blood donors in Sokoto, North Western Nigeria--the question of safety of blood transfusion in Nigeria.

INTRODUCTION: Blood transfusions remain a substantial source of HIV in SSA particularly among children and pregnant women. AIMS AND OBJECTIVES: This aim of this retrospective study was to investigate the prevalence of p24 antigen among HIV antibody seronegative blood donors in Sokoto, North West Nigeria. METHODS: A total of 15,061 HIV antibody negative blood donors with mean age and age range (29.2 ± 8.18 and 18-50 years) were screened for p24 antigen between January 2010 to July 2013 using the Diapro Diagnostic immunoassay kit for P24 antigen (King Hawk Pharmaceuticals Beijing China). RESULTS: The overall prevalence of p24 antigen among the HIV antibody negative donors sample was 5.84%. The yearly prevalence was 9.79, 8.12, 2.7 and 2.84% respectively in 2010, 2011, 2012 and 2013. Of the total number of blood donor tested, 14,968 (99.38%) were males while 93 (0.62%) were females. The prevalence of P24 antigen was significantly higher among male blood donors 873 (5.8%) compared to females 7(0.05%), (p= 0.001). P24 positivity was significantly higher among blood group O blood donors compared to A, B and AB donors (494 (3.29%) compared to 184 (1.89%), 196 (1.30%) and 6 (0.04%)) respectively, p = 0.001). The prevalence of P24 antigen was significantly higher among Rhesus positive blood donors compared to Rhesus negative (807 (5.36%) versus 73 (0.48%), p =0.001). CONCLUSION: Blood transfusion in Nigeria is associated with increased risk of HIV transmission. There is the urgent need to optimize the screening of blood donors in Nigeria by the inclusion of p24 antigen testing into the blood donor screening menu. The Nigerian government urgently need to adopt the WHO blood safety strategies to reduce the risk of transmission of HIV through blood transfusion.

Twelve years of the Brazilian External Quality Assessment Program in Immunohematology: benefits of the program.

The Brazilian External Quality Assessment Program in Immunohematology (BEQAPI) was introduced with the objective of evaluating the quality of diagnosis in immunohematology. From 1992 to 2003, proficiency tests for ABO grouping, Rh (D, C, c, E, e), K phenotyping, direct antiglobulin testing (DAT), antibody screening (AS), and antibody identification (AI) were performed. A total of 41 evaluations were carried out in 223 institutions. Over the period of 12 years, the program included 8,014 ABO typing, 8,000 RhD typing, 5,193 Rh typing (C, c, E, e), 5,101 K phenotyping, 7,939 AS, 4,533 AI, and 7,912 DATs. Erroneous responses were classified as clerical, technical, or undetermined. A substantial proportion of erroneous responses due to clerical errors occurred in ABO typing (76/76 errors), RhD typing (34/58 errors), and Rh phenotyping (50/73 errors). Technical errors occurred predominantly for weak D (91/95 errors), AS (252/301 errors), and AI (321/335 errors). Based on these results, since 1996, participants have received "Questions and Case Studies" in Immunohematology as an incentive for training and education. The results of the present study show an improvement in the performance of participants in the course of the program. We found that a well-organized external proficiency program can contribute to the improvement of quality of testing in Immunohematology.

An assessment of the clinical utility of routine antenatal screening of pregnant women at first clinic attendance for haemoglobin genotypes, haematocrit, ABO and Rh blood groups in Port Harcourt, Nigeria.

This prospective study was designed to provide the frequencies of the haemoglobin genotypes, ABO and Rh blood groups and their effects on the haematocrit values among pregnant women in Port Harcourt. One hundred and eighty (180) pregnant women at their first clinic attendance and in their first pregnancy (parity - 0) participated in this study. The overall frequencies obtained for ABO and Rh blood groups were: 26.67% for group A, 18.33% for B, 2.22% for AB and 52.78% for O. Rh D positive was 95.56% while Rh D negative was 4.44%. The frequencies of haemoglobin genotypes were 70.00% for HbAA, 29.44% for HbAS and 0.56% for HbSS. HbAC and SC did not occur in this study population. The mean haematocrit value was 34.64%. This was found to be independent of the ABO and Rh blood groups (P > 0.05). On the other hand, haemoglobin genotypes were found to exert significant effects on the haematocrit values (F = 8.01, P = 0.0005). No significant relationship was found to exist between age and the haematocrit values. (F = 0.91, P > 0.05). Since pregnancy in sickle cell disease is associated with morbidity, proper antenatal monitoring and counselling will be necessary to prevent fatal outcomes.

Significant numbers of apheresis-derived group O platelet units have "high-titer" anti-A/A,B: implications for transfusion policy.

Transfusion of group O single-donor apheresis PLTs (SDP) to group A recipients has resulted in intravascular hemolysis and mortality. Owing to low availability of type-specific SDPs, transfusion services sometimes issue ABO-mismatched PLTs. After observing two cases of acute hemolysis following infusion of O SDPs to group A patients, where both recipient eluates revealed anti-A specificity, a prospective study to determine the prevalence of "high-titer" anti-A/A,B in group O SDPs was commenced. One hundred group O SDP samples were tested. Titers of at least 64 and/or 256 from either buffered (generally reflective of IgM antibodies) or anti-IgG gel cards, respectively, were considered critically high. Twenty-eight and 39 percent of samples revealed critically high anti-A/A,B IgM and IgG titers, respectively. IgM titers were at 1:64 (18%), 128 (6%), and 256 (4%), whereas IgG titers were at 1:256 (28%), 512 (7%), 1024 (2%), and 2048 (2%). The prevalence of critical anti-A/A,B titers in group O SDPs is relatively high. Thus, the risk of minor side ABO mismatch and potential intravascular hemolysis during group O SDP transfusion to group A recipients may be significant. Based on these data, a policy was instituted to test anti-A/A,B titers in O SDPs prior to "out-of-group" transfusion.

[Blood group frequencies and ABO and RhD incompatibilities in La Paz, Baja California Sur, Mexico]. / Frecuencias de grupos sanguíneos e incompatibilidades ABO y RhD, en La Paz, Baja California Sur, México.

OBJECTIVE: To determine genic and phenotypic frequencies and predict the risk of incompatibility and maternal alloimmunization in the population of La Paz. MATERIAL AND METHODS: This descriptive study evaluated 1809 voluntary blood donors attending in 1998 the Hospital General de Zona of Instituto Mexicano del Seguro Social (Zone General Hospital of the Mexican Institute of Social Security) in La Paz, Baja California Sur, Mexico. Blood donors were typified by tube agglutination. The gene frequencies were estimated assuming equilibrium conditions, and incompatibilities and alloimmunization were statistically assessed with the chi 2 test. RESULTS: Percent frequencies were as follows: blood group O, 58.49%; A, 31.40%; B, 8.40%; AB, 1.71%; RhD, 95.36%; and RhD negative, 4.64%. Genic frequencies were: i, 0.7648; IA, 0.1821; IB, 0.0519; D, 0.7845; and d, 0.2155, respectively. Incompatibilities between couples and mother-child were 0.3023 and 0.1685 for ABO, 0.0442 and 0.0364 for RhD, and 0.0134 and 0.0061 for double incompatibility, respectively. The probability of maternal alloimmunization was estimated at 0.0309. CONCLUSIONS: The O and RhD groups were the most common in La Paz, although frequencies were among the lowest in Mexico, contrary to the case of A and RhD negative groups. The probabilities of maternal alloimmunization and of incompatibilities were also high. Ancestral white, black, and indigenous groups admixed in the northwestern part of Mexico; after migrating to Baja California Sur the admixture of the population probably became similar to that of the remainder of the northwestern area.

Frecuencias de grupos sanguíneos e incompatibilidades ABO y RhD, en La Paz, Baja California Sur, México / Blood group frequencies and ABO and RhD incompatibilities in La Paz, Baja California Sur, Mexico

OBJECTIVE: To determine genic and phenotypic frequencies and predict the risk of incompatibility and maternal alloimmunization in the population of La Paz. MATERIAL AND METHODS: This descriptive study evaluated 1809 voluntary blood donors attending in 1998 the Hospital General de Zona of Instituto Mexicano del Seguro Social (Zone General Hospital of the Mexican Institute of Social Security) in La Paz, Baja California Sur, Mexico. Blood donors were typified by tube agglutination. The gene frequencies were estimated assuming equilibrium conditions, and incompatibilities and alloimmunization were statistically assessed with the chi 2 test. RESULTS: Percent frequencies were as follows: blood group O, 58.49; A, 31.40; B, 8.40; AB, 1.71; RhD, 95.36; and RhD negative, 4.64. Genic frequencies were: i, 0.7648; IA, 0.1821; IB, 0.0519; D, 0.7845; and d, 0.2155, respectively. Incompatibilities between couples and mother-child were 0.3023 and 0.1685 for ABO, 0.0442 and 0.0364 for RhD, and 0.0134 and 0.0061 for double incompatibility, respectively. The probability of maternal alloimmunization was estimated at 0.0309. CONCLUSIONS: The O and RhD groups were the most common in La Paz, although frequencies were among the lowest in Mexico, contrary to the case of A and RhD negative groups. The probabilities of maternal alloimmunization and of incompatibilities were also high. Ancestral white, black, and indigenous groups admixed in the northwestern part of Mexico; after migrating to Baja California Sur the admixture of the population probably became similar to that of the remainder of the northwestern area.

[Immunologic risk analysis of blood transfusion: 1991-1998]. / Analyse des risques immunologiques en transfusion sanguine: période 1991-1998.

The immunologic risk associated to erythrocyte transfusions is bound to the polymorphism of blood group systems and to the respect of blood transfusion regulations. The results of three studies are presented, which were carried out respectively by the French Society of Blood Transfusion, the National Institute of Blood Transfusion and the National Haemovigilance Network. Two hundred and twenty-seven cases of immunologic accidents are analysed using the Kaplan's interpretation model and the traditional method of process analysis. The results show three critical factors in the occurrence of this type of incident: the relevance of the clinical examinations prescribed, the way in which the biological results are taken into account, and the relationship/exchange of information between private and public hospitals, and blood transfusion centers.

Mothers at risk of alloimmunization to the Rh (D) antigen and availability of gamma-globulin at the Mexican Institute of Social Security.

Hemolytic disease of the newborn develops mainly when an Rh negative (D-) mother becomes sensitized and produces anti-Rh positive (anti-D) antibodies capable of hemolysing D+ fetal erythrocytes. Maternal alloimmunization can be prevented by the administration of anti-D gamma-globulin immediately after the birth of each Rh positive child. In order to identify the frequency of prevention of alloimmunization at the Instituto Mexicano del Seguro Social (IMSS), the amount of mothers at risk of sensitization from 1985 to 1995 was estimated from Rh and ABO blood group frequencies and with the number of deliveries and abortions at the Medical Institutions. Also, information in regard to the dose of gamma-globulin units purchased by the Institute of Social Security from 1985 to 1993 was obtained. The number of mothers at risk steadily increased from 16,616 in 1985 to 21,071 in 1995, amounting to a total of 203,203 in the 10-year period, while only 120,800 gamma-globulin units were purchased in that same period. The findings in this study suggest the need to define reasonable policies for the acquisition of gamma-globulin lots to prevent alloisoimmunization of mothers at risk.

Retrieval and allocation of organs for transplantation: the Michigan experience.

The Organ Procurement Agency of Michigan (OPAM) is now in its twenty-third year of service to the transplant community in Michigan. From a beginning with one coordinator in 1971, it now employs 53 individuals, including 8 laboratory technologists for its own on-site histocompatibility laboratory, a dozen procurement coordinators stationed throughout the state, 6 organ placement coordinators in the main office, 6 screening coordinators who provide around-the-clock coverage at the office, a tissue recovery section, as well as additional finance, education, and administrative support staff. This chapter outlines the history and growth in organ recoveries of the organization. More importantly, the chapter also analyzes the Michigan experience regarding racial distribution of kidneys. While African-Americans comprise 14% of the general population of the state, they comprise 40% of the waiting kidney recipients and only 26% of the actual recipients. Depending upon blood type, average waiting time for a kidney for African-Americans can be up to 4 months longer than for Whites. The analysis attributes this variance primarily to the allocation methodology for kidney distribution, which is largely driven by antigen matching and secondarily to the generally greater frequency and higher degree of blood sensitization among African-Americans, which causes a substantially higher frequency of positive-crossmatch results between potential donor and recipient. The authors conclude that changes in the present allocation system could be made to achieve greater equity for African-American patients, without removing the advantages inherent in transplanting kidneys with closely matched antigens.

The UK National External Quality Assessment Scheme in Blood Group Serology. ABO and D grouping and antibody screening 1982-1983.

In seven surveys of blood grouping the overall rates of major error were 0.12% and 0.37% for uncomplicated ABO and D grouping respectively. Of 17 errors of ABO grouping, 13 were errors of transposition or interpretation and four were apparently technical. Of 52 errors of D grouping, 20 appeared to be errors of transposition or interpretation and 32 were apparently technical. Of the 32 technical errors of D grouping, 31 were D-negative grouped as Du (29) or D-positive (2) and most of these errors were due to misgrouping in the antiglobulin test. Causes of error in D grouping by antiglobulin test include anti-Bg and other contaminating immune antibodies, residual unabsorbed anti-A and the inherently high rate of false positive results obtained in the antiglobulin test. In view of the lack of benefit of Du testing to blood recipients or to pregnant women and of the possible adverse consequences of misgrouping D-negative patients as Du or D-positive, it is recommended that Du testing be abandoned in these groups of patients. The surveys of antibody screening demonstrated lack of standardisation and error rates similar to those previously reported in the UK for compatibility testing.

Blood units for patients with irregular blood group antibodies: frequency and supply.

Blood banks face significant problems supplying blood units compatible with erythrocyte antigens other than ABO and rhesus D. In this study the number of such units was evaluated between 1973 and 1982, and it was found that 1.5% of the total number of blood units were compatible with other antigens than ABO and rhesus D. Based on data of the number of units requested for each such antigen and the frequency of the antigen in the European population, a logistical system providing sufficient numbers of 'antibody-compatible' blood units is proposed.