Incidence and risk factors of aplastic anemia in Latin American countries: the LATIN case-control study

• Published in: Haematologica (Roma) Vol. 94; no. 9; pp. 1220 - 1226
• Main Authors: Maluf, Eliane, Hamerschlak, Nelson, Cavalcanti, Alexandre Biasi, Junior, Alvaro Avezum, Eluf-Neto, Jose, Falcao, Roberto Passetto, Lorand-Metze, Irene G, Goldenberg, Daniel, Santana, Cezar Leite, de Oliveira Werneck Rodrigues, Daniela, Passos, Leny Nascimento da Motta, Rosenfeld, Luis Gastao Mange, Pitta, Marimilia, Loggetto, Sandra, Feitosa Ribeiro, Andreza A, Velloso, Elvira Deolinda, Kondo, Andrea Tiemi, de Miranda Coelho, Erika Oliveira, Pintao, Maria Carolina Tostes, de Souza, Helio Moraes, Borbolla, Jose Rafael, Pasquini, Ricardo
• Format: Journal Article
• Language: English
• Published: Pavia Ferrata Storti Foundation 01-09-2009
• Subjects: Adolescent; Adult; Agranulocytosis - epidemiology; Agranulocytosis - etiology; Agranulocytosis - pathology; Anemia, Aplastic - epidemiology; Anemia, Aplastic - etiology; Anemia, Aplastic - pathology; Benzene Derivatives - toxicity; Biological and medical sciences; Bone Marrow; Brazil - epidemiology; Case-Control Studies; Child; Child, Preschool; Environmental Exposure - adverse effects; Female; Hematologic and hematopoietic diseases; Humans; Incidence; Leukemias. Malignant lymphomas. Malignant reticulosis. Myelofibrosis; Male; Medical sciences; Middle Aged; Original; Risk Factors; America; Latin America; Brazil; risk factors; Hematology; Bone marrow failure; Countries; Benzene; Aplastic anemia; Risk factor; Hemopathy; Case control study; Epidemiology; Incidence
• ISSN: 0390-6078; 1592-8721
• DOI: 10.3324/haematol.2008.002642

1 Hospital Israelita Albert Einstein/Instituto Israelita de Ensino e Pesquisa Albert Einstein, São Paulo, Brazil
2 Hospital das Clínicas da Universidade Federal do Paraná, Curitiba, Brazil
3 Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
4 Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo, Ribeirão Preto, Brazil
5 Faculdade de Ciências Médicas da Universidade Estadual de Campinas, Campinas, Brazil
6 Hospital de Clínicas José de San Martín, Buenos Aires, Argentina
7 Instituto de Hemoterapia de Goiânia, Goiânia, Brazil
8 Hemocentro Regional de Juiz de Fora, Juiz de Fora, Brazil
9 Fundação de Hematologia e Hemoterapia do Amazonas (HEMOAM), Manaus (AM), Brazil
10 Fundação Hemope, Recife, Brazil
11 Hemocentro Regional de Uberaba, Uberaba, Brazil
12 Hospital San José Tec de Monterrey, Monterrey, México, Centro de Hematologia de São Paulo
Correspondence: Nelson Hamerschlak, Centro de Pesquisa Clínica, Instituto Israelita de Ensino e Pesquisa Albert Einstein, Av. Albert Einstein, 627/701, Piso Chinuch, São Paulo (SP), Brazil, CEP 05651-901. E-mail: hamer{at}einstein.br
Background: Associations between aplastic anemia and numerous drugs, pesticides and chemicals have been reported. However, at least 50% of the etiology of aplastic anemia remains unexplained.
Design and Methods: This was a case-control, multicenter, multinational study, designed to identify risk factors for agranulocytosis and aplastic anemia. The cases were patients with diagnosis of aplastic anemia confirmed through biopsy or bone marrow aspiration, selected through an active search of clinical laboratories, hematology clinics and medical records. The controls did not have either aplastic anemia or chronic diseases. A total of 224 patients with aplastic anemia were included in the study, each case was paired with four controls, according to sex, age group, and hospital where the case was first seen. Information was collected on demographic data, medical history, laboratory tests, medications, and other potential risk factors prior to diagnosis.
Results: The incidence of aplastic anemia was 1.6 cases per million per year. Higher rates of benzene exposure ( 30 exposures per year) were associated with a greater risk of aplastic anemia (odds ratio, OR: 4.2; 95% confidence interval, CI: 1.82–9.82). Individuals exposed to chloramphenicol in the previous year had an adjusted OR for aplastic anemia of 8.7 (CI: 0.87–87.93) and those exposed to azithromycin had an adjusted OR of 11.02 (CI 1.14–108.02).
Conclusions: The incidence of aplastic anemia in Latin America countries is low. Although the research study centers had a high coverage of health services, the underreporting of cases of aplastic anemia in selected regions can be discussed. Frequent exposure to benzene-based products increases the risk for aplastic anemia. Few associations with specific drugs were found, and it is likely that some of these were due to chance alone.
Key words: aplastic anemia, incidence, risk factors, benzene.