Abstract INTRODUCTION: Hepatitis B virus (HBV) infection is a public health problem; therefore, we aimed to report HBV genotypes in Ceará, Brazil. METHODS: A total of 103 HBsAg-positive samples were subjected to HBV genotyping and subgenotyping. RESULTS: The following genetic compositions of samples were found: F-54% (F2-83.33%), A-40% (A1-65%), D-6%, C2-1%, E-1%, and G-1%. CONCLUSIONS: Some genotypes are only prevalent in certain parts of the world; however, the State of Ceará is a hub for migration and has one of the most important liver transplantation centers in Brazil, which can explain the prevalence of the F genotype.

Hepatitis D virus (HDV) is endemic in the Amazon Region and its pathophysiology is the most severe among viral hepatitis. Treatment is performed with pegylated interferon and the immune response appears to be important for infection control. HDV patients were studied: untreated and polymerase chain reaction (PCR) positive (n = 9), anti-HDV positive and PCR negative (n = 8), and responders to treatment (n = 12). The cytokines, interleukin (IL)-2 (p = 0.0008) and IL-12 (p = 0.02) were differentially expressed among the groups and were also correlated (p = 0.0143). Future studies will be conducted with patients at different stages of treatment, associating the viral load with serum cytokines produced, thereby attempting to establish a prognostic indicator of the infection.

The retrovirus human T lymphotropic virus type 1 (HTLV-1) promotes spastic paraparesis, adult T cell leukaemia and other diseases. Recently, some human microRNAs (miRNAs) have been described as important factors in host-virus interactions. This study compared miRNA expression in control individuals, asymptomatic HTLV-1 carriers and HTLV-1 associated myelopathy (HAM)/tropical spastic paraparesis patients. The proviral load and Tax protein expression were measured in order to characterize the patients. hsa-miR-125b expression was significantly higher in patients than in controls (p = 0.0285) or in the HAM group (p = 0.0312). Therefore, our findings suggest that miR-125b expression can be used to elucidate the mechanisms of viral replication and pathogenic processes.

INTRODUÇÃO: A citólise mediada por grânulos é uma das mais importantes funções efetoras de linfócitos T citotóxicos e células natural killer. Recentemente, três polimorfismos de nucleotídeo único foram identificados nos éxons 2, 3 e 5 do gene da granzima B, resultando em um haplótipo em que três aminoácidos da proteína madura Q48P88Y245 são alterados para R48A88H245, o que leva à perda da atividade citotóxica da proteína. No presente estudo, avaliamos a frequência desses polimorfismos em populações brasileiras. MÉTODOS:Avaliamos a frequência desses polimorfismos em grupos étnicos brasileiros (brancos, afro-brasileiros e asiáticos) por sequenciamento. RESULTADOS: As frequências alélica e genotípica do polimorfismo 2364A/G no éxon 2 em indivíduos afro-brasileiros (42,3% e 17,3%) foram significativamente maiores (p < 0,0001 e p = 0,0007) quando comparadas a brancos e asiáticos. Os polimorfismos 2933C/G e 4243C/T também foram mais frequentes em afro-brasileiros, mas sem diferença significativa. O grupo afro-brasileiro apresentou maior diversidade de haplótipos e o haplótipo RAH foi mais frequente nesse grupo (25%), seguidos pelos brancos (20,7%) e asiáticos (11,9%), semelhante à frequência apresentada na literatura. CONCLUSÕES: Há uma maior frequência de polimorfismos em afro-brasileiros e o haplótipo RAH foi mais frequente nesses indivíduos. Acreditamos que novos estudos devem ter como objetivo a investigação da correlação deste haplótipo com doenças relacionadas com a imunidade mediada por linfócitos citotóxicos, e se essa correlação for confirmada, novas estratégias de tratamento poderão ser elaboradas.

INTRODUCTION: The cytolysis mediated by granules is one of the most important effector functions of cytotoxic T lymphocytes and natural killer cells. Recently, three single nucleotide polymorphisms (SNPs) were identified at exons 2, 3, and 5 of the granzyme B gene, resulting in a haplotype in which three amino acids of mature protein Q48P88Y245 are changed to R48A88H245, which leads to loss of cytotoxic activity of the protein. In this study, we evaluated the frequency of these polymorphisms in Brazilian populations. METHODS: We evaluated the frequency of these polymorphisms in Brazilian ethnic groups (white, Afro-Brazilian, and Asian) by sequencing these regions. RESULTS: The allelic and genotypic frequencies of SNP 2364A/G at exon 2 in Afro-Brazilian individuals (42.3% and 17.3%) were significantly higher when compared with those in whites and Asians (p < 0.0001 and p = 0.0007, respectively). The polymorphisms 2933C/G and 4243C/T also were more frequent in Afro-Brazilians but without any significant difference regarding the other groups. The Afro-Brazilian group presented greater diversity of haplotypes, and the RAH haplotype seemed to be more frequent in this group (25%), followed by the whites (20.7%) and by the Asians (11.9%), similar to the frequency presented in the literature. CONCLUSIONS: There is a higher frequency of polymorphisms in Afro-Brazilians, and the RAH haplotype was more frequent in these individuals. We believe that further studies should aim to investigate the correlation of this haplotype with diseases related to immunity mediated by cytotoxic lymphocytes, and if this correlation is confirmed, novel treatment strategies might be elaborated.