Journal of Clinical Virology 25 (2002) 237 /238 www.elsevier.com/locate/jcv
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‘An atypical pattern of HCV INNO-LiPATM subtype’ Drug addiction, blood transfusion and sporadically acquired infections represent the risk factors of Hepatitis C virus (HCV) infection. Studies on HCV genotypes may have a sound clinical impact as epidemiological markers and clues for tracing transmission routes, as tools to assess the efficiency of HCV diagnostic assays, as factors associated to the progression of disease and finally as predictive factors for the HCV response to therapy (Zein, 2000). During a study assessing changes in the prevalence of HCV genotypes within an area of Southern Italy (Matera et al., 2002), we found a serum sample with atypical reactivity from an Italian patient presenting with HCV infection. An accurate evaluation of the HCV genotyping strip pattern obtained from our case sample prompted us to observe and assess this atypical band profile. Unusual reactivity patterns might erroneously be interpreted as dual infections, but they have been also reported as associated with newly discovered and sequenced subtypes (Stuyver et al., 1996). HCV-RNA was detected in serum using two commercial polymerase chain reaction (PCR) assays including a qualitative assay (Cobas Amplicor HCV test, v2.0) and a quantitative assay (Cobas Amplicor HCV MonitorTM test, v2.0) from Roche Diagnostics, Italy. PCR products were analyzed for genotyping using hybridization of the amplified product by a line probe assay (INNO-LiPATM HCV II, Innogenetics, Belgium). A 51-year-old woman was admitted to hospital to undergo surgical intervention for hemorrhoidectomy and polypectomy. The routine blood test indicated only a slight increase of gamma-globulin percentage (21.5%, normal values 13/21%) and HCV-antibody positivity by EIA and RIBA.
The attending physician referred the patient to our laboratory for HCV molecular analysis, including the qualitative and quantitative HCVRNA and for genotyping of the HCV isolate. HCV-RNA was positive with 564,000 IU/ml HCV-RNA. After six months the viral load was re-evaluated, and a value of 1,260,000 IU/ml was found. Genotyping of the HCV isolate showed an atypical pattern (band 19) by INNO-LiPATM HCV genotype, which could not be immediately interpreted from the chart provided by the INNOLiPA HCV II genotype kit manufacturer (Fig. 1). An atypical subtype exactly matching our sample pattern had been obtained from an isolate referred to as FR13 (Stuyver et al., 1996). This isolate was classified as 2i by Stuyver and Maertens (1997), and it has been reported as subtype 1a by Nguyer et al. (1998). Biological sequencing of the 5? UTR region of our isolate was consistent with the INNO-LiPATM result and suggested a subtype of genotype 2 (data not shown). However, further sequencing of other regions of the genome and phylogenetic tree of HCV genome are in process (manuscript in preparation). Conclusive classification as well as clinical, epidemiological, prognostic and therapeutic features of the isolate reported here are presently unknown. The presence of band 19 alone within the pattern of genotype 2 might indicate a subtype not yet included in the interpretation chart of INNO-LiPATM. Therefore, we encourage the users of this method to carefully interpret banding patterns to avoid misleading diagnosis, and to report new patterns to contribute to a better
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Fig. 1. LiPA HCV strips with reactivity patterns close to our atypical band profile. Strips were incubated with the following samples: 1, our isolate with atypical band profile; 2, a clinical isolate with subtype 2a/2c; 3, a clinical isolate with subtype 5a. Conj., conjugate; ampl., amplification.
classification of HCV subtypes, which reportedly are increasing due to the particular biology of HCV.
References Matera G, Lamberti A, Quirino A, et al. Changes in the prevalence of Hepatitis C Virus (HCV) genotype 4 in Calabria, Southern Italy. Diagn Microb Infect Dis 2002;42:169 /73. Nguyer QT, Leruez-Ville M, Ferriere F, et al. Hepatitis C virus genotypes implicated in mixed cryoglobulinemia. J Med Virol 1998;54:20 /5. Stuyver L, Maertens G. Genotypes and genetic variations of hepatitic C virus. In: Harrison TJ, Zuckerman AJ, editors.
The molecular medicine of viral hepatitis. John Wiley & Sons Ltd, 1997:183 /233. Stuyver L, Wyseur A, van Arnhem W, Hernandez F, Maertens G. Second-generation line probe assay for hepatitis C virus genotyping. J Clin Microbiol 1996;34:2259 /66. Zein NN. Clinical significance of hepatitis C virus genotypes. Clin Microbiol Rev 2000;13:223 /35.
Giovanni Matera, Giorgio S. Barreca, Angelo G. Lamberti, Angela Quirino, Domenico Foca`, Maria Carla Liberto Department of Medical Sciences, Institute of Microbiology, University of Catanzaro, Via T. Campanella 115, I-88100 Catanzaro, Italy E-mail:
[email protected]
