Fibrosis progression in chronic hepatitis C in patients coinfected with human immunodefi ciency virus and hepatitis C virus

[1]. Laboratório de Biologia Molecular, Hemocentro de Botucatu, Faculdade de Medicina, Universidade Estadual Paulista, Botucatu, São Paulo, Brasil. [2]. Departamento de Bioprocessos e Biotecnologia, Faculdade de Ciências Agronômicas, Universidade Estadual Paulista, Botucatu, São Paulo, Brasil. [3]. Departamento de Clínica Médica, Faculdade de Medicina de Botucatu, Universidade Estadual Paulista, Botucatu, São Paulo, Brasil.

Fibrosis progression is a complex event in patients with chronic hepatitis C. Fibrosis progression occurs when the components of the extracellular matrix are deposited in excess in the liver, leading to the substitution of functional hepatic tissue with non-functional fi brotic tissue.Although several studies have investigated the mechanisms of fi brosis development, fi brosis progression still constitutes a public health problem.In patients with chronic hepatitis C, fi brosis progression has been associated with several factors, including host genetic polymorphism.Like human leukocyte antigen (HLA), human platelet antigen (HPA) has also been demonstrated to infl uence fi brosis progression.However, these study were conducted with patients who were monoinfected with hepatitis C virus (HCV).The study by Picelli et al. (1) is the fi rst to have evaluated the infl uence of HPA polymorphism in fi brosis progression using patients with human immunodefi ciency virus and hepatitis C virus (HIV/HCV) coinfection.Although the study included 36 patients, they were representative of the entire population of HIV/HCV coinfected patients who were assisted at the Specialized Outpatient Service of Domingos Alves Meira and at the Department of Internal Medicine, Gastroenterology Division, Botucatu School of Medicine [São Paulo State University (UNESP), Botucatu, SP, Brazil].This study showed that HPA-1, -3, and -5 polymorphisms do not infl uence fi brosis progression in HIV/HCV coinfected patients.Therefore, although there are demonstrated associations between HPA polymorphism and fi brosis progression in HCV monoinfected patients, similar associations are not observed in HIV/HCV coinfected patients.Accordingly, additional studies could be conducted to evaluate other factors that may have associations with fi brosis progression in coinfected populations.
Associations have already been reported between diseases and genetic host factors, such as HLA and other polymorphisms (2) .Similarly, previous studies have already shown that HPA system polymorphisms are associated with viral diseases (3) (4) and disease progressions, including fi brosis progression in patients with chronic hepatitis C (5) .
In the study of Picelli et al. (5) that was cited in this letter to the editor, the associations between HPA-1, -3, and -5 systems and fi brosis progression were investigated in patients with HIV/ HCV coinfection.When comparing patients with HIV/HCV coinfection and either lower stages of fi brosis (F1/F2-Group 1) or higher stages of fi brosis (F3/F4-Group 2), Picelli et al. (1) observed no deviations from the Hardy-Weinberg equilibrium in the HPA systems that were evaluated.No differences were observed between G1 and G2 according the distributions of the allelic and genotypic frequencies of the HPA systems.
Thus, the role of HPA system polymorphisms in fi brosis progression was differed for patients with HCV monoinfection (5) and those with HIV/HCV coinfection (1) .
It is important to consider that HPA is not a soluble factor, unlike platelet-derived growth factor or transforming growth factor β1. HPA systems are polymorphic antigenic determinants that reside in proteins of the platelet membranes (6) .Therefore, HPA molecules could be cited in the letter in the same manner as those receptors and membrane proteins.