Interdonation intervals and patterns of return among blood donors in Brazil.

Background: In Brazil, most donations come from repeat donors, but there are little data on return behavior of donors.

Study Design And Methods: Donors who made at least one whole blood donation in 2007 were followed for 2 years using a large multicenter research database. Donation frequency, interdonation intervals, and their association with donor demographics, status, and type of donation were examined among three large blood centers in Brazil, two in the southeast and one in the northeast.

A different molecular pattern of beta-thalassemia mutations in northeast Brazil.

The main hereditary hemoglobin (Hb) disorders of clinical significance in Brazil are sickle cell disease and beta-thalassemia (thal). The sickle gene was introduced by the slave trade, whereas beta-thal was introduced later, due to a massive immigration (mostly by Italians) between 1870 and 1953, mainly to the southeast region of Brazil. Molecular studies performed in the southeast of the country showed a marked prevalence of the nonsense mutation at codon 39 (C --> T) (47-54%), leading to severe forms of beta0-thal.