Peripheral blood neutrophils from hepatitis C virus-infected patients are replication sites of the virus

Background and Objectives. Hepatitis C virus (HCV) is able to cause not onl y acute and chronic liver disease, but also immunologic and hematologic dis orders. In order to clarify the extra-hepatic tropism of HCV, and to unders tand the pathogenetic meek of HCV infection, we evaluated viral repliction in peripheral blood mononuclear cells. Design and Methods. The presence of genomic and (replicative) forms of HCV in B- and T- lymphocytes, monocytes, and polymorphonuclear leukocytes (PML) was determined by reverse transcriptase-polymerase chain reaction in 54 HC V-RNA patients and, as control groups, in 10 patients who had recovered fro m HCV infection without evidence of serum HCV-RNA, and in 10 HCV-negative s ubjects. Results. In HCV-RNA positive patients, the genomic RNA was found In 94% of a-cells, in 14% of T-cells, In 40% of monocytes and in 77% of PML, while 1 of the HCV-RNA negative subjects showed in B-cells, The anti-genomic form o f HCV-RNA was found in 52% of B-cells, in 3% of monocytes In 31% of PML. By contrast, It was never detected in T-cells and in HCV-RNA negative subject s. Neither genomic nor anti-genomic forms were found in HCV-negative cases. Interpretation and Conclusions. These data suggest that PML are replication sites of HCV. Whether the infection occurs at the level of the stem cells or subsequently during myeloid cell differentiation is, as yet, unknown. Th e absence of correlation between the presence of replicative forms and any clinical and/or laboratory data opens the question of the role of HCV repli cation In extra-hepatic sites. (C) 2000, Ferrata Storti Foundation.