Ethnicity and route of HCV infection can influence the associations of HLA with viral clearance in an ethnically heterogeneous population.

Approximately 20% of hepatitis C virus (HCV) infected individuals clear the virus. Host factors that influence the course of HCV infection are still under investigation, and the data on the association of human leukocyte antigen (HLA) alleles and HCV clearance are scarce and controversial. The aims of this study were to investigate whether HLA alleles are associated with clearance of HCV infection in a highly admixed Brazilian population and whether these associations could be influenced by ethnicity and route of infection. HLA-A, -B, -C, -DRB1 and -DQB1 genotyping were performed in 135 HCV-infected Brazilian patients among which 45 cleared HCV infection (cases) and 90 had persistent viral infection (controls). Controls were matched by sex, ethnicity (withes and non-whites) and route of infection (high infectious dose or low infectious dose). No significant association was identified between HLA alleles and the outcome of HCV infection when analyzing the sample as a single group. However, a new protective association of HLA-DQB1*04 (P = 0.006; P(c) = 0.030) and a rarely described association of HLA-DRB1*08 (P = 0.004; P(c) = 0.048) were found only among white patients. The DRB1*11 allele, previously reported in homogeneous population, was associated with HCV clearance (P = 0.020) only among patients with expected high-dose exposure. These findings confirm the influence of ethnicity on the associations of HLA with spontaneous viral clearance of HCV infection and emphasize the possible influence of route of infection in this process.

Total and acid-soluble fluoride content of infant cereals, beverages and biscuits from Brazil.

Total fluoride (TF) and HCl 0.01 M ('gastric juice')-soluble fluoride (SF) were analysed in infant foods, beverages and calcium-rich biscuits. Samples were divided into seven categories: children cereals (A), chocolate-flavoured milk (B), soy beverages (C), filled biscuits (D), non-filled biscuits (E), wafer biscuits (F) and corn starch biscuits (G). Mean TF concentrations +/- SD (amplitude, unit microgram F ml-1 or microgram F g-1) were: (A) 4.25 +/- 3.04 (0.20-7.84, n = 6); (B) 0.34 +/- 0.47 (0.05-1.27, n = 6); (C) 0.15 +/- 0.07 (0.09-0.29, n = 8); (D) 8.44 +/- 1.76 (7.65-10.47, n = 4); (E) 12.41 +/- 1.15 (10.69-13.68, n = 4); (F) 0.35 +/- 0 (0.34-0.36, n = 4) and (G) 7.77 +/- 1.12 (6.86-8.68, n = 2). Five samples of cereals, one sample of chocolate-flavoured milk and 10 samples of biscuits were analysed for SF. In cereals analysed for SF, all fluoride was soluble, while for the chocolate-flavoured milk, approximately 50% of TF was soluble. Regarding the biscuits analysed for SF approximately 20% of TF was soluble. It was observed that some of the cereals and beverages, and most of the biscuits analysed, might be important contributors to total daily fluoride intake. When consumed just once per day, cereals and beverages might supply up to 25% of the maximum recommended daily fluoride intake (0.07 mg F kg-1 body weight) for a 2-year-old child (12 kg). For the filled, non-filled and corn starch biscuits, when 3, 32 or 20 units of them, respectively, are consumed just once per day, they may supply up to 16% of the maximum recommended daily fluoride intake. However, only approximately 25% of fluoride absorption occurs from the stomach and 75% from the small intestine. Therefore, a higher fluoride bioavailability is possible.