Lower platelet count and metastatic tumor are associated with increased risk of spontaneous bleeding in critically ill patients with cancer: An observational study.

BACKGROUND: Thrombocytopenia is common in critically ill patients with cancer. However, the association of platelet count with spontaneous bleeding is controversial in critically ill patients and the association with cancer-related characteristics is unknown. METHODS: This observational study includes patients with active cancer and severe thrombocytopenia. A logistic regression model adjusted for confounders was used to evaluate the association of daily platelet count and cancer-related characteristics (type of cancer and presence of metastasis) with spontaneous bleeding. Confounders were identified using directed acyclic graphs. RESULTS: We screened 5822 patients, 255 (4.4%) met eligibility criteria resulting in 1401 daily observations. Fifty-three patients (20.8%) had spontaneous bleeding during the intensive care unit stay, 64% presenting minor, and 36% major bleeding. The adjusted odds ratio (OR) for spontaneous bleeding with platelet count between 49 and 20 × 109 /L was 4.6 (1.1-19.6), with platelet count between 19 and 10 × 109 /L was 14.2 (3.1-66.2), and with platelet count below 10 × 109 /L was 39.6 (6.9-228.5). The adjusted OR for spontaneous bleeding in patients with hematologic malignancies was 0.6 (0.4-1.2), and 4.3 (2.0-9.0) for patients with metastatic tumor. CONCLUSIONS: In critically ill patients with active cancer and severe thrombocytopenia, lower counts of platelets and presence of metastasis are associated with increased risk of spontaneous bleeding, while hematologic malignancy is not associated with increased risk of spontaneous bleeding.

Titers of ABO antibodies in group O blood donors.

BACKGROUND: Plasma components of group O blood donations are rarely submitted to ABO antibody titrations even though it is well known that passively acquired antibodies may destroy the recipient's own red cells and tissue grafts. OBJECTIVE: Thus, group O donations stratified by gender and age were randomly titrated to identify the best source of products for apheresis and exsanguinous transfusion. METHODS: Samples from 603 blood donors were tested by ABO antibody titration using the conventional tube technique at room temperature. ABO antibody levels higher than 64 were considered high. After correction for gender, statistical analyses were performed using the Fisher exact and Kruskal-Wallis tests. RESULTS: Most donors in the blood bank were male (65.7%). ABO antibody titers ranged from 1 to 2048. The estimations of prevalence for the titers were: anti-A,B < 128 = 86.9% and = 128 = 2.16%; Anti-A = 128 = 9.29% and anti-B = 128 = 4.81%. Low mean titers for both anti-A and anti-B antibodies were found in over 50-year-old men (p-value = 0.040). High anti-B antibody levels were found in young women (p-value = 0.002). CONCLUSION: This study confirms that over 50-year-old O group men should be selected as blood donors in non-identical ABO transfusion situations. Also, titration of ABO antibodies in blood banks will increase safety in non-identical ABO transfusions.

Transfusion-transmitted malaria: case report of asymptomatic donor harboring Plasmodium malariae.

Malaria in Brazil is endemic in the Amazon region, but autochthonous cases with low parasitaemia occur in the Atlantic Forest area of the country. According to Brazilian legislation no test is mandatory for blood donors from non-endemic areas. However if they have traveled to malaria transmission regions they are deferred for six months before they can donate. This report describes a transfusion-transmitted malaria case in Sao Paulo, Brazil, where one recipient received infected blood and developed the disease. He lived in Sao Paulo and had no previous transfusion or trips to endemic areas, including those of low endemicity, such as Atlantic Forest. Thick blood smears confirmed Plasmodium malariae. All donors lived in Sao Paulo and one of them (Donor 045-0) showed positive hemoscopy and PCR. This asymptomatic donor had traveled to Juquia, in the Atlantic Forest area of S ao Paulo State, where sporadic cases of autochthonous malaria are described. DNA assay revealed P. malariae in the donor's (Donor 045-0) blood. Serum archives of the recipient and of all blood donors were analyzed by ELISA using both P. vivax and P. falciparum antigens, and IFAT with P. malariae. Donor 045-0's serum was P. malariae IFAT positive and the P. vivax ELISA was reactive. In addition, two out of 44 donors' archive sera were also P. vivax ELISA reactive. All sera were P. falciparum ELISA negative. This case suggests the need of reviewing donor selection criteria and deferral strategies to prevent possible cases of transfusion-transmitted malaria.

Titers of ABO antibodies in group O blood donors

BACKGROUND: Plasma components of group O blood donations are rarely submitted to ABO antibody titrations even though it is well known that passively acquired antibodies may destroy the recipient's own red cells and tissue grafts. OBJECTIVE: Thus, group O donations stratified by gender and age were randomly titrated to identify the best source of products for apheresis and exsanguinous transfusion. METHODS: Samples from 603 blood donors were tested by ABO antibody titration using the conventional tube technique at room temperature. ABO antibody levels higher than 64 were considered high. After correction for gender, statistical analyses were performed using the Fisher exact and Kruskal-Wallis tests. RESULTS: Most donors in the blood bank were male (65.7 percent). ABO antibody titers ranged from 1 to 2048. The estimations of prevalence for the titers were: anti-A,B < 128 = 86.9 percent and > 128 = 2.16 percent; Anti-A > 128 = 9.29 percent and anti-B > 128 = 4.81 percent. Low mean titers for both anti-A and anti-B antibodies were found in over 50-year-old men (p-value = 0.040). High anti-B antibody levels were found in young women (p-value = 0.002). CONCLUSION: This study confirms that over 50-year-old O group men should be selected as blood donors in non-identical ABO transfusion situations. Also, titration of ABO antibodies in blood banks will increase safety in non-identical ABO transfusions.

Estudo genético comparativo da populaçäo da cidade de Säo Paulo, SP, com populaçöes brancas Européias e negras Africanas no sistema ABO / Comparative genetic study of the population of Säo Paulo city, SP, with white European and African negroid population in the ABO system

O objetivo deste trabalho é o estudo comparativo dos grupos sangüíneos ABO entre a populaçäo de Säo Paulo e populaçöes brancas européias e negras africanas. As populaçöes-controles utilizadas no estudo foram as de Portugal, França, Espanha e Itália, para a branca; Costa do Marfim, República Centro-Africana, Camaröes e Zâmbia, para a negra. A comparaçäo foi realizada com o emprego do teste do X2 (Quiquadrado), dispondo dos dados em tabela de contigência de 2 por 4, onde as colunas representam os grupos sangüíneos e as fileiras as populaçöes empregadas para comparaçäo. Foi adotado como valor crítico 11.345 para a Quiquadrado (X2) e p = 0.01, como nível de significância. Para esse fim, foram realizadas determinaçöes do sistema ABO de 67.141 caucasóides e 9.540 negróides. Os testes foram realizados com o emprego do método de aglutinaçäo em meio salino e em tubos. Dos caucasóides estudados, 37.068 eram de fenotipo O, 20.479 do A, 5.036 do B e 4.558 do AB. Dos negróides, 6.116 eram do fenotipo O, 1.370 do A, 1.590 do B e 484 do AB. Os resultados demonstraram que nossa populaçäo caucasóide difere significativamente da de Portugal, França e Espanha e assemelha-se a da Itália. Os da populaçäo negróide mostraram diferenças significativas em relaçäo a Zâmbia, Camaröes e Costa do Marfim, assemelhando-se aos da República Centro-Africana