Chemokine receptor 5 and primary biliary cirrhosis: a two-centre genetic association study

Frequency of CCR5Δ32 allele in healthy Bosniak population

Recent evidence has demonstrated the role of CCR5Δ32 in a variety of human diseases: from infectious and inflammatory diseases to cancer. Several studies have confirmed that genetic variants in chemokine receptor CCR5 gene are correlated with susceptibility and resistance to HIV infection. A 32-nucleotide deletion within the CCR5 reading frame is associated with decreased susceptibility to HIV acquisition and a slower progression to AIDS. Mean frequency of CCR5Δ32 allele in Europe is approximately 10%. The highest allele frequency is observed among Nordic populations (about 12%) and lower in the regions of Southeast Mediterranean (about 5%). Although the frequency of CCR5Δ32 was determined in numerous European populations, there is a lack of studies on this variant in the Bosnia and Hercegovina population. Therefore, the aim of our study was to assess the frequency of CCR5Δ32 allele in the cohort of Bosniaks and compare the results with European reports. CCR5Δ32 was detected by sequence-specific PCR in a sample of 100 healthy subjects from Bosnia and Herzegovina (DNA collected 2011-2013). Mean age of the cohort being 58.8 (± 10.7) years, with 82% of women. We identified 17 heterozygotes and one mutant homozygote in study group, with mean ∆32 allele frequency of 9.5%. CCR5∆32 allele frequency among Bosniaks is comparable to that found in Caucasian populations and follows the pattern of the north-southern gradient observed for Europe. Further studies on larger cohorts with adequate female-to-male ratio are necessary.

Liver fibrosis: from animal models to mapping of human risk variants

Liver fibrosis is the sequel of chronic liver diseases and the main reason for increased mortality in affected patients. The extent of liver fibrosis displays great interindividual variation, even after controlling for exogenous factors. Thus, host genetic factors are considered to play an important role in the process of liver scarring. From a genetic perspective, liver fibrosis is a complex trait with many genes contributing to the expression of the phenotype. In genetically manipulated and inbred animals several risk loci for liver fibrosis have been identified. Some of these loci have been replicated in case-control studies of patients with hepatitis C infection. In humans, genetic risk loci were identified by single marker studies, haplotype studies or the combination of single markers. Recently, the first genome-wide association studies have also been performed in patients with liver diseases. Some of the identified gene variants have been functionally characterized in vitro, thereby opening the potential for novel therapeutic approaches and risk stratification.

[Genetic background of multifactorial liver and bile duct diseases]

The majority of liver diseases, are complex. They are the results of interactions between several genes and environmental factors. Familial aggregation and higher concordance rate of monozygotic twins compared to those of dizygotic twins provide evidence for the importance of genetic factors in the pathogenesis. There are only limited data in connection with the genetic background of multifactorial liver diseases. In the future, the genetic background may permit prevention, early, accurate diagnosis, prediction of disease course, complications, prognosis, as well as treatment response.