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


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.
Maluf
Eliane
E
Centro de Pesquisa Clínica, Instituto Israelita de Ensino e Pesquisa Albert Einstein, Avenida Albert Einstein 627/701, Piso Chinuch, São Paulo (SP), Brazil.
Hamerschlak
Nelson
N
Cavalcanti
Alexandre Biasi
AB
Júnior
Alvaro Avezum
AA
Eluf-Neto
José
J
Falcão
Roberto Passetto
RP
Lorand-Metze
Irene G
IG
Goldenberg
Daniel
D
Santana
Cézar Leite
CL
Rodrigues
Daniela de Oliveira Werneck
Dde O
Passos
Leny Nascimento da Motta
LN
Rosenfeld
Luis Gastão Mange
LG
Pitta
Marimilia
M
Loggetto
Sandra
S
Ribeiro
Andreza A Feitosa
AA
Velloso
Elvira Deolinda
ED
Kondo
Andrea Tiemi
AT
Coelho
Erika Oliveira de Miranda
EO
Pintão
Maria Carolina Tostes
MC
de Souza
Hélio Moraes
HM
Borbolla
José Rafael
JR
Pasquini
Ricardo
R
D000293:Adolescent; D000328:Adult; D000380:Agranulocytosis / Q000453:epidemiology* / Q000209:etiology / Q000473:pathology; D000741:Anemia, Aplastic / Q000453:epidemiology* / Q000209:etiology / Q000473:pathology; D001555:Benzene Derivatives / Q000633:toxicity; D001853:Bone Marrow; D001938:Brazil / Q000453:epidemiology; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004781:Environmental Exposure / Q000009:adverse effects; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012307:Risk Factors
D001555:Benzene Derivatives