HCV-RNA positivity in peripheral blood mononuclear cells of patients with chronic HCV infection: does it really mean viral replication?
OBJECTIVE
To analyze the association of HCV-RNA with peripheral blood mononuclear cells (PBMC) and to answer the question whether HCV-RNA positivity in PBMC is due to viral replication.


METHODS
HCV-RNA was monitored in serum and PBMC preparations from 15 patients with chronic HCV infection before, during and after an IFN-alpha therapy using a nested RT/PCR technique. In a second approach, PBMC from healthy donors were incubated in HCV positive plasma.


RESULTS
In the IFN-alpha responding patients,HCV-RNA disappeared first from total RNA preparations of PBMC and then from serum. In contrast, in relapsing patients, HCV-RNA reappeared first in serum and then in PBMC. A quantitative analysis of the HCV-RNA concentration in serum was performed before and after transition from detectable to non detectable HCV-RNA in PBMC-RNA and vice versa. When HCV-RNA was detectable in PBMC preparations, the HCV concentration in serum was significantly higher than the serum HCV-RNA concentration when HCV-RNA in PBMC was not detectable. Furthermore, at no time during the observation period was HCV specific RNA observed in PBMC, if HCV-RNA in serum was under the detection limit. Incubation of PBMC from healthy donors with several dilutions of HCV positive plasma for two hours showed a concentration dependent PCR positivity for HCV-RNA in reisolated PBMC.


CONCLUSIONS
The detectability of HCV-RNA in total RNA from PBMC seems to depend on the HCV concentration in serum. Contamination or passive adsorption by circulating virus could be the reason for detection of HCV-RNA in PBMC preparations of chronically infected patients.
Meier
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V
Georg-August-Universität Gottingen, Zentrum innere medizin, Abteilung FUr Gastroenterologie Und Endokrinologie, Robert Koch Strasse 40, 37075 Göttingen, Germany.
Mihm
S
S
Braun Wietzke
P
P
Ramadori
G
G
D000328:Adult; D000368:Aged; D000998:Antiviral Agents / Q000627:therapeutic use; D005260:Female; D016174:Hepacivirus / Q000235:genetics*; D019698:Hepatitis C, Chronic / Q000097:blood / Q000188:drug therapy / Q000821:virology*; D006801:Humans; D016898:Interferon-alpha / Q000627:therapeutic use; D007963:Leukocytes, Mononuclear / Q000821:virology*; D008297:Male; D008875:Middle Aged; D012367:RNA, Viral / Q000097:blood*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019562:Viral Load; D014779:Virus Replication
D000998:Antiviral Agents; D016898:Interferon-alpha; D012367:RNA, Viral