Monitoring influenza virus oseltamivir resistance - our experience to date.

OBJECTIVE: The monitoring of influenza virus resistance is a routine part of influenza virus surveillance conducted by the National Reference Laboratory for Influenza and Non-Influenza Respiratory Viral Diseases (NRL/INI) at the National Institute of Public Health (NIPH). The aim is to detect neuraminidase inhibitor (oseltamivir) resistance in patients diagnosed with influenza. MATERIAL AND METHODS: A total of 326 influenza virus isolates from tissue culture were included in the study. They were obtained from inpatient and outpatient nasopharyngeal swabs which were referred to the NRL/INI during the seasons 2013/2014 to 2019/2020 and turned out to be RTPCR (reverse transcription polymerase chain reaction) positive for RNA (ribonucleic acid) of influenza virus A or B. The MDCK (Madin-Darby canine kidney) tissue culture cells were used for virus isolation from nasopharyngeal swabs. Oseltamivir resistance was tested using the NA-Star Influenza Neuraminidase Inhibitor Resistance Detection Kit (Applied Biosystems, Foster City, CA). RESULTS: Nine of 326 positive specimens were oseltamivir resistant. Resistant strains showed IC50 values 100 times as high on average as those in oseltamivir sensitive strains. CONCLUSIONS: Monitoring influenza virus resistance is helpful in controlling reasonable prescription of antivirals and thus becomes an integral part of influenza virus surveillance. Antiviral resistance monitoring is necessary not only in hospitalized patients on antivirals but also in symptomatically treated outpatients as the detection of antiviral drug resistant strains in the latter group can suggest the emergence and/or spread of antiviral drug resistance in the population.

Molecular and antigenic characterization of the H3 hemagglutinin of H3N2 influenza A virus strains collected in the Czech Republic during the 2014/2015 epidemic season.

The 2014/2015 influenza epidemic season was characterized by the predominance of the H3N2 subtype. The presented study investigated the genetic and antigenic heterogeneity of the H3N2 strains collected in the Czech Republic from November 2014 to March 2015. Phylogenetic analysis of the representative H3 hemagglutinin sequences was performed and the glycosylation status and crucial antigenic mutations were compared relative to the 2014 and 2015 vaccine strains (A/Texas/50/2012 and A/Switzerland/9715293/2013) and visualized in the H3 crystal structure. The molecular data were further supplemented by hemagglutination-inhibition test (HIT) results on fifteen H3N2 2014/2015 strains by using the A/Texas/50/2012 (H3N2) and A/Switzerland/9715293/13 (H3N2) antisera. Our data on the Czech H3N2 viruses from the 2014/2015 epidemic season could supplement the reports of official authorities with data from a particular geographi-cal area.

[The benefit from mumps virus IgG antibody avidity testing in the population with high vaccine coverage in the context of other serological methods for laboratory diagnosis of mumps and the current epidemiological]. / Prínos avidity IgG protilátek u príusnic ve vysoce proockované populaci v kontextu s ostatními sérologickými metodami laboratorní diagnostiky príusnic a soucasnou epidemiologickou situací.

AIM: Regular vaccination against mumps resulted in a significant reduction in epidemic mumps in the Czech Republic. However, mumps cases have recently shown an upward trend, even in the vaccinated population where a considerable proportion of cases have occurred. The aim of this study was to find out, by mumps virus IgG antibody avidity testing, whether the high incidence of mumps in the vaccinated population is a result of primary or secondary vaccine failure and whether the vaccinated differ from the naturally immunised in anamnestic antibody avidity. Given the problematic laboratory diagnosis of mumps in the population with high vaccination coverage, the informative value of the detected IgM, IgA, and IgG antibodies was also considered as well as the potential of antibody avidity testing for improving laboratory diagnosis from a single sample of blood, the most commonly analysed clinical material, in patients with suspected mumps. MATERIAL AND METHODS: Sixty-four patients laboratory confirmed with mumps, whose vaccination status was known, were included in the study (groups 1 and 2). Other study groups were 30 healthy naturally immunised subjects (group 3) and 22 vaccinated children 2-4-years of age with no etiological link to the mumps virus (group 4). The avidity index (AI) was determined using the Siemens Enzygnost Anti-Mumps/IgG kit and 6M urea, able to induce the dissociation of antigen-antibody bonds proportionally to the antibody avidity. IgM, IgG, and IgA antibodies were tested using the Siemens Enzygnost Anti-Mumps/IgM and /IgG, and Mast Diagnostica Mastazyme Mumps IgA kits. The EPIDAT system served as the data source. RESULTS: The results showed that the mumps virus induces antibodies with a low AI after both vaccination, even recent, and natural immunisation. Antibodies with a high AI were only detected in convalescent sera of the vaccinated patients or in re-infected, naturally immunised persons, as a result of recent contact with the mumps virus. The comparison of the results of acute sera testing revealed that in the vaccinated patients, 56% of cases were laboratory confirmed based on IgA positivity, i.e. 20% more cases in comparison with routine detection of IgM antibodies, while of unvaccinated cases, 87% were IgA positive and 74% IgM positive. CONCLUSION: The results of mumps virus IgG antibody avidity testing suggest that the high proportion of cases in the vaccinated patients result from secondary vaccine failure, also known as waning immunity. Diagnostic benefit from antibody avidity testing has been observed in convalescent sera and/or acute sera from both vaccinated and naturally immunised patients collected from day 6 after the onset of the disease when significant increase in AI occurs.The comparison of the serological methods for the detection of IgM, IgG, and IgA antibodies in acute sera revealed that the highest percentage of mumps infection was detected by IgA antibody testing. The addition of this serological method to mumps laboratory diagnosis made the latter considerably more effective, particularly in the vaccinated patients.

[Differential diagnosis of the viral etiology of suspected mumps in a population with high vaccine coverage]. / Diferenciální diagnostika virové etiologie suspektních príusnic ve vysoce proockované populaci.

AIM: In this study, buccal swabs from patients with the clinical picture of parotitis epidemica in whom mumps virus (MV) infection was not confirmed by direct detection or serologically were tested. The aim was to detect by molecular methods nucleic acids (NAs) of other respiratory viruses possibly involved in salivary gland swelling. At the same time, paired sera, if available, were tested. MATERIAL AND METHODS: The study group consisted of 72 buccal swabs from patients of the Clinic of infectious, tropical, and parasitic diseases, Na Bulovce Hospital. Paired sera were available from ten patients. Samples were collected in 2013 to 2015. Buccal swabs were tested by PCR for the presence of NAs of adenoviruses (AdV), bocaviruses (hBoV), parainfluenza viruses of types 1-4 (HPIV), human metapneumovirus (hMPV), coronaviruses (HCoV: NL63, OC43, HKU1, and 229E), respiratory syncytial virus (RSV), influenza A virus, influenza B virus, and Epstein-Barr virus (EBV). Paired sera were screened by the complement fixation test (AdV and influenza A and B viruses), hemagglutination inhibition test (HPIV types 2 and 3), ELISA (AdV, EBV), and immunofluorescence (EBV). RESULTS: NAs from viruses other than the mumps virus were detected in 27 of 72 patients with clinical symptoms of parotitis epidemica, and serological tests revealed etiological links with parainfluenza viruses in three more cases. Overall, 30 (41.7%) of 72 patients with suspected mumps tested positive for one or more viruses from the study panel. The most commonly detected viruses were AdV 11/72 (15.3%), EBV 9/72 (12.5%), and HPIV 3/72 (4.2%), but influenza A virus (H3N2) 1/72 (1.4%) was also found. Some patients tested positive for more than one virus: 2/72 (3%) for AdV plus hBoV and 1/72 (1.4%) for HPIV plus HCoV. In addition, examination of paired sera revealed HPIV positivity in three more patients. PCR and serology detected etiological link with HPIV in six (8.3%) of 72 patients tested. CONCLUSION: In our study group, nearly 42% of patients with the clinical picture of parotitis epidemica in whom mumps virus (MV) infection was not confirmed by direct detection or serologically tested positive for viruses other than the mumps virus. Thorough laboratory diagnosis of suspected mumps in vaccinated persons is important not only for the treatment of patients and adoption of isolation and other measures, but also for a better understanding of the epidemiology of the disease and outcomes of the immunisation programmes.

[Enterovirus sequencing as a new approach to the laboratory diagnosis for clinical and epidemiological purposes]. / Sekvenace enteroviru jako nový prístup k laboratorní diagnostice pro klinické i epidemiologické úcely.

OBJECTIVE: Introducing enterovirus sequencing as an advanced approach to classify the viruses isolated according to the novel nomenclature and to characterize isolates in detail. MATERIAL AND METHODS: Seventy-five specimens collected from 64 patients in two hospitals, Liberec Regional Hospital, and Plzen University Hospital, were analyzed. The study patients' age ranged from four to 54 years, with a median of 15 years in males and 16 years in females. In most patients, the reasons for admission were intense headache, fever, vomiting, tiredness, meningeal symptoms, intestinal symptoms (in two patients), and skin symptoms (in one patient). The specimens collected were rectal and throat swabs, cerebrospinal fluid (CSF) and stool specimens. Molecular detection and typing were performed using the RT-PCR method. A segment of the 5´non-coding RNA was selected for typing. Specimens were amplified using single-step PCR with external primers and with the same primers extended to include M13 sequences (Generi-Biotech). The LASERGENE software (DIASTAR) was used in sequence editing, alignment, and quality check. The sequences obtained were checked against the central GenBank sequence database using the BLAST algorithm. RESULTS: The identification of the study isolates resulted in 61 ECHO viruses 30, three coxsackie viruses B1, one coxsackie virus B3, one coxsackie virus A9, one enterovirus 86, one enterovirus 71, Two ECHO viruses 13/coxsackie virus B5, one ECHO virus 7/30/coxsackie virus B4, one coxsackie virus B4/enterovirus B, one enterovirus 87/ECHO virus 30/enterovirus B, and one ECHO virus 3. All viruses isolated, except enterovirus 71 classified into group A, were of group B. CONCLUSION: The enteroviruses were identified unambigously, although the sequencing only targeted a short, conserved segment that showed considerable variability. The sequencing was an effective alternative to enterovirus identification by the neutralisation test and allowed for detailed characterization of the isolates. The predominance of ECHO 30 as the cause of aseptic meningitis is in accordance with the literature data.

[Contribution of the detection of IgA antibodies to the laboratory diagnosis of mumps in the population with a high vaccination coverage]. / Prínos stanovení protilátek IgA pro laboratorní diagnostiku príusnic ve vysoce proockované populaci.

STUDY OBJECTIVE: Serological diagnosis of epidemic mumps can be difficult in vaccinated persons, particularly due to the absence of specific IgM antibodies. The aim was to find whether adding the detection of IgA antibodies to the currently used routine serological diagnosis of mumps (detection of IgM and IgG antibodies in an acute serum sample) would make the serological diagnosis of mumps more effective in a population with a high vaccination coverage. At the same time, ELISA kits for the detection of early IgA and IgM antibodies against the mumps virus were compared and statistical analysis of the results was performed. MATERIAL AND METHODS: Sixty-four acute sera from patients with laboratory confirmed diagnosis of mumps were included in the study. Clinical specimens were collected at the onset of clinical symptoms. To test the sera, the MASTAZYME ELISA Mumps IgA kit (MAST DIAGNOSTICA, Germany) with the MASTSORB sorbent (RF and IgG) and Enzygnost Anti-Parotitis-Virus/IgM kit (Siemens, Germany) were used. A panel of 121 acute sera with no epidemiological link to mumps virus served as specificity controls for the IgA assay. The epidemiological data were derived from the EPIDAT system. The level of agreement was assessed using the McNemara test and Cohen's coefficient kappa. The Stata 9.2 software (Stata Corp LP, College Station, USA) was used for statistical analysis. RESULTS: The detection of IgA and IgM antibodies against the mumps virus yielded concordant results in 50/64 acute sera, 32 positive and 18 negative, i.e. an agreement of 78.12 %. Of the remaining 14 samples, 13 were only IgA positive and one was only IgM positive. The controls showed non-specific IgA positivity in 5/121 samples which indicates a 96% specificity. CONCLUSION: The absence of specific IgM antibodies against mumps virus is relatively often seen in vaccinated indivi-duals; nevertheless, the test is routinely used in patients with suspected active infection. The test for IgA antibodies, which is not routinely performed, significantly increased the detection rate of the disease. Based on the results of the present study, it can be concluded that the combination of the anti-mumps IgM and IgA assays increased the effectiveness of the serological diagnosis at the onset of clinical symptoms from less than 52% to nearly 72%.

[Phylogenetic and molecular analysis of A/H1N1pdm influenza viruses isolated in the epidemic season 2012/2013 from hospitalised patients with -symptoms of influenza-like illness]. / Fylogenetická a molekulární analýza viru chripky A/H1N1pdm izolovaných v epidemické sezone 2012/2013 od pacientu hospitalizovaných s príznaky ILI.

AIM: To perform phylogenetic and molecular analysis of A/H1N1pdm influenza viruses isolated in the epidemic season 2012/2013 from hospitalised patients with symptoms of influenza-like illness (ILI). MATERIAL AND METHODS: The study set included 34 strains of the A/H1N1pdm influenza virus isolated in the Czech Republic in the epidemic season 2012/2013. The strains were analysed by partial or whole-genome sequencing. The genome segments were compared at the nucleotide and amino acid levels, absolute and percentage sequence identity were determined, and phylogenetic relations were identified. The last steps were the comparison of the H1 molecule with that of the most recent vaccine strain and identification of the genotypic structure and molecular markers linked to the pathogenicity and antiviral resistance. RESULTS: Phylogenetic analysis of the H1 molecule suggested that all 34 A/H1N1pdm isolates from the 2012/2013 season in the Czech Republic should be assigned to H1 group 6 divided into sublineages 6A and 6B. The comparison of the known antigenic regions of the H1 molecule with those in the most recent vaccine strain revealed two stable changes in antigenic regions Sb and Ca1. Furthermore, sporadic mutations were identified in antigenic regions Ca2, Cb, and Sb. Genotyping revealed co-circulation of two related but clearly distiguishable genotypes of A/H1N1pdm. All isolates showed sensitivity to oseltamivir. One strain consisted of two N1 sub-populations, one oseltamivir sensitive and the other oseltamivir resistant, in nearly equimolar proportions. CONCLUSION: All A/H1N1pdm isolates from the epidemic season 2012/2013 in the Czech Republic formed a phenotypically uniform group. At the nucleotide level, the divergence was relatively more pronounced and H1 sublineages and discrete genotypes were possible to identify. H1 molecules were highly identical to those of the vaccine strain A/California/7/2009 (H1N1) which showed that the current vaccine was protective enough. All strains were sensitive to oseltamivir; however, the selection of oseltamivir resistant N1 subpopulations was observed.

[Clinical and epidemiological characteristics of patients hospitalized with severe influenza in the season 2012-2013]. / Klinické a epidemiologické charakteristiky pacientu hospitalizovaných pro tezký prubeh chripky v sezone 2012-2013.

AIM OF THE STUDY: To characterize the clinical and epidemiological features of patients hospitalized with moderate to severe influenza infection at the infec-tious diseases department of a tertiary care hospital in the epidemic season 2012-2013. MATERIAL AND METHODS: A prospective observational study of patients hospitalized with influenza infection in the season 2012-2013 was carried out at the Infectious Diseases Department, Na Bulovce Hospital in Prague. Influenza infection was diagnosed by real-time quantitative polymerase chain reaction (RT-qPCR) in nasopharyngeal swab or tracheal aspirate specimens. Demographic, clinical, and laboratory data were recorded along with the disease course and outcome. RESULTS: One hundred and ninety-nine patients, 85 females and 114 males (age median 47, range 1-87 years), were hospitalized with confirmed influenza in the epidemic season 2012-2013. Only seven of them got the influenza vaccine. Altogether 136 patients were diagnosed with influenza type A (91 with H1N1pdm, 33 with H3N2, and 12 with an unknown subtype), 66 patients with type B, and three patients with both types A and B. One hundred and eight patients (54%) had an underlying chronic disease, most often cardiovascular or pulmonary. The main symptoms of influenza were fever, cough, headache, myalgia, and arthralgia. Pneumonia was the most common complication: twenty-one patients suffered from primary viral pneumonia and 35 from bacterial pneumonia. Twenty-three patients (12%) needed intensive care. Six patients died and the leading cause of death was heart failure. CONCLUSION: During the epidemic influenza season 2012-2013, more patients were hospitalized than in the pandemic season 2009-2010. Also the proportions of complicated cases and case fatality ratios were fully comparable in both seasons. The fact that most patients were not vaccinated clearly supports the recommendation to vaccinate every year both the individuals at high risk of complications due to comorbidities and the healthy population.

Early and unexpectedly severe start of influenza epidemic in the Czech Republic during influenza season 2012-13.

A sudden increase in severe influenza has been registered in the Czech Republic since the end of 2012, with 264 cases requiring intensive care, including 51 deaths. Most patients had at least one risk factor. Severe influenza in patients with obesity, smoking and/or haematological disorders including haematological cancers was more frequent than in the pre-pandemic period. The seasonal influenza vaccination status of the cases indicates indirect efficiency of the current vaccine in preventing severe influenza.

Stability of influenza virus as evaluated by integrity of its RNA.

UNLABELLED: Various methods of handling samples of avian influenza prior to detecting influenza viruses can significantly influence both, the detection of the virus and the quantification of viral nucleic acids. The quantity of influenza viral RNA remaining in different collecting buffers and kept at temperatures of -20°C, +4°C or +22°C for various lengths of time, was determined. The quantity of viral RNA remained the same for 120 days at -20°C, but decreased when the samples were stored at either +4°C or +22°C. The quantity of RNA was influenced by the composition of the collecting buffer. The influenza virus sample that is to be used for RNA quantification can be stored at +4°C and freeze and thaw cycles should be avoided during transport. Our results clearly indicate that the quality and quantity of influenza virus nucleic acid depends on the chemical composition of used buffer and also that the samples can be protected from degradation even if they are not stored at ultra-low temperatures. However, repeated thaw and freeze cycles will damage viral RNA even if kept in stabilizing buffers. KEYWORDS: influenza virus; degradation; RNA; buffer.

Stimulation of protective and cross-protective immunity against influenza B virus after adjuvant mucosal immunization of mice.

Intratracheal immunization of mice with inactivated influenza B virus and delipidated Bacillus firmus as adjuvant increases protection of mice against infection with the homologous virus strain and induces cross-protection: mice immunized by influenza virus B/Yamanashi 166/98 were protected even against phylogenetically distant virus drift variant B/Lee/40 lethal for mice.

Adjuvant effect of Bacillus firmus in intranasal immunization of guinea pigs with inactivated type B infuenza virus.

Intranasal immunization of guinea pigs with inactivated type B influenza virus plus inactivated Bacillus firmus as an adjuvant compared to the virus alone yields higher titers of serum hemagglutination-inhibiting antibodies and virus-neutralizing antibodies. This phenomenon could be useful in standard serology, especially in the preparation of immune sera against highly pathogenic strains for in vitro diagnosis.

[Simultaneous vaccination against influenza and invasive pneumococcal disease in chronic dialysis patients]. / Simultánní ockování proti chripce a invazivnímu pneumokokovému onemocnení pacientu v pravidelné dialyzacní lécbe.

STUDY OBJECTIVE: To evaluate the antibody response to simultaneous vaccination against influeza and pneumococcal disease in chronic dialysis patients. METHODS: Fifty-four chronic dialysis patients were vaccinated with subunit influenza vaccine Influvac. Thirty-five of these patients were vaccinated with both influenza vaccine and Pneumo 23 vaccine while 19 patients received influenza vaccine alone. Antibodies against influenza vaccine antigens were determined in paired sera by the hemagglutination inhibition test. The geometric mean titre (GMT) of antibodies, protection level (PR), seroconversion (SC) and conversion factor (CF) were calculated. The levels of antibodies against pneumococcal vaccine antigens were detected by the EIA and the geometric mean concentrations of antibodies were calculated from the results. RESULTS: Simultaneous vaccination did not induce adequate PR for antigens A H1N1 and A H3N2, SC and CF for A H3N2 and B. Influenza vaccination alone resulted in inadequate PR and SC for A H3N2, with CF being adequate for all of the antigens. The geometric mean titres of antibodies were higher in the patients vaccinated with influenza vaccine alone, the difference not being statistically significant. Good responsiveness to the pneumococcal vaccine was observed, with the geometric mean concentrations of antibodies increasing 4.8 times after vaccination but decreasing to 1/3 a year later. CONCLUSION: The antibody response to influenza vaccine was negatively influenced by immunodeficiency due to underlying diseases in dialysis patients. Although poorer results were achieved in patients vaccinated with influenza vaccine alone compared to those vaccinated with the two vaccines, the difference was not significant. An adjuvant influenza vaccine is expected to be more promising.

A study of excess mortality during influenza epidemics in the Czech Republic, 1982-2000.

Influenza related mortality rates have been established in many countries; nevertheless, studies focusing on the Central European population have been rare to date. We assess mortality attributable to influenza by comparing all cause mortality and mortality due to diseases of the circulatory system during influenza epidemic and non-epidemic periods, as defined by acute respiratory infection surveillance data. Data on total mortality, mortality due to diseases of the circulatory system and surveillance data for influenza and other respiratory infections were used in a general linear model with a logarithmic link for dependence of left censored mortality data over time, and week as a categorical factor. Results of the analysis show statistically significant (p <0.001) differences in excess mortality rates between influenza epidemic and non-epidemic periods in the Czech Republic between 1982 and 2000. We estimate that 2.17% of all cause mortality, and 2.57% of mortality due to diseases of the circulatory system throughout the study period was attributable to influenza, with an estimated annual average of 2661 and 1752 deaths respectively. The highest numbers of deaths were reported during seasons when influenza A/H3N2 was the predominant circulating strain. Improving vaccination coverage against influenza is considered to be the primary strategy for prevention of influenza associated mortality.

Harmonisation of the acute respiratory infection reporting system in the Czech Republic with the European community networks.

Respiratory virus activity is detected in Europe each winter, yet the precise timing and size of this activity is highly unpredictable. The impact of influenza infection and/or acute respiratory infection in European countries is continuously monitored through a variety of surveillance systems. All of these sources of information are used to assess the nature and extent of activity of influenza and other respiratory viruses, and to offer guidance on the prevention and control of morbidity and mortality due to influenza at a local, national and international level. The early warning system for a forthcoming influenza epidemic is mainly based on the use of a set of thresholds. In the Czech Republic, the acute respiratory infection (ARI) reporting system, with automated data processing, uses a statistical model for the early detection of unusual increased rates of the monitored indicators. The collected data consists of the number of ARI, the number of complications due to ARI and the population registered with the reporting general practitioners and paediatricians, all collected separately in five age groups. To improve the reporting system in the Czech Republic, clinical data on the weekly incidence of influenza-like illness (ILI) within the same population and the same age groups was started in January 2004. These data fit the European Commission's recently adopted ILI case definition and allows a better comparison of data with other countries in Europe, in particular those participating in EISS (European Influenza Surveillance Scheme).

Immune response after adjuvant mucosal immunization of mice with inactivated influenza virus.

Satisfactory mucosal immunity in the respiratory tract is very important for protection against influenza. It can be achieved only by mucosal immunization. Mucosal vaccination with inactivated influenza virus may not be sufficiently effective and suitable adjuvants are therefore sought. We tested intratracheal immunization of mice with inactivate B type influenza virus in a mixture with formolized G+ bacterium Bacillus firmus, whose adjuvant effects have previously been documented in another system. The treatment resulted in a marked increase of both systemic and mucosal antibody response in IgG and IgA classes. Stimulation of T lymphocytes after adjuvant immunization was very mild, no proliferation taking place after specific stimulation with antigen in vitro. However, slightly increased systemic (spleen) and local (lungs) production of cytokines without perceptible Th1/Th2 polarization was determined. B. firmus is an efficient adjuvant in respiratory tract immunization while with subcutaneous immunization it lowers the antibody response.

[Chronic hepatic porphyria and hepatitis B and C virus infections]. / Chronická jaterní porfyrie a infekce virem hepatitidy B a C.

BACKGROUND: It is known that in patients with porphyria cutanea tarda (PCT) there is an increased prevalence of the hepatitis B virus (HBV) and the hepatitis C virus (HCV). The incidence of anti-HCV in PCT in our country is 21.7% in estimations by the second generation method, however, the incidence of HBV in PCT was not assessed so far. METHODS AND RESULTS: In 60 patients with PCT antigens and antibodies against HBV and HCV were assessed (by the anti-HCV third generation ELISA method) and in subjects with signs of HBV or HCV. HBV DNA and HCV RNA were assessed by the method of the polymerase chain reaction. PCT without detectable HBV or HCV infection was found in 45 subjects (68%). HBV infection only was confirmed in seven subjects (10.6%), however none of the patients had positive HBsAg in serum. All had only antibodies against HBV. HCV infection only was detected in seven patients (10.6%) and HBV and HCV co-infection also in seven patients (10.6%). In the group of patients with HBV and HCV co-infection there was not a single HBsAg positive subject. The mean ALT serum activity was significantly higher as compared with subjects with HBV or HCV infection only (p < 0.05) and the histological finding on liver biopsy was more serious. CONCLUSION: HBV (21%) and HCV (21%) infection participates significantly in the clinical picture of PCT. A special subgroup is formed by patients with PCT and HBV and HCV co-infection who have as a rule a higher ALT activity and more severe histological changes in the liver. The incidence of HBV and HCV infection in PCT in the Czech Republic is double as compared with Germany or Great Britain.

[Detection of HCV RNA in anti-HCV positive patients with chronic hepatic porphyria]. / Prkaz HCV RNA u anti-HCV pozitivních nemocných chronickou jaterní porfyrií (PCT).

BACKGROUND: In 1994 the authors published first results of anti-HCV antibodies in the group of 92 porphyria cutanea tarda patients, tested with ELISA second generation enzymatic method. Positivity, found in 21.7 per cent of them, was significantly higher when compared with the results of healthy blood-donors. Anti-HCV reactivity thus ascertained can be, however, non-specific in some cases and need not necessarily indicate existence of an active replication of hepatitis C-virus. The authors have therefore subsequently tried to verify the above results by the more sensitive polymerase chain reaction (PCR), enabling the proof of viral RNA and thus an assessment of the replication-activity of HCV. This study completes their previous findings for the evidence of viraemia in anti-HCV reactive PCT-patients. METHODS AND RESULTS: 21 of 92 PCT-patients were reactive when examined with the second generation ELISA method (Sanofi, Pasteur). HCV RNA was examined in 20 subjects from the above group (one patient died in the meantime) by means of PCR. Positive HCV RNA was found in 17 patients, i.e. in 85 percent of them. Percutaneous liver biopsy without visual control was performed in 17 anti-HCV reactive and HCV RNA positive patients and in 46 anti-HCV negative porphyrics. The biopsy-findings were significantly worse in the HCV RNA-positive group. Also the average activity of ALT and AST was significantly higher in the patients with positive HCV RNA when compared with anti HCV-negative subjects. CONCLUSIONS: High frequency of HCV-infection (21.7 percent) was found in our group of 92 PCT-patients. Viraemia was present in the vast majority (85 per cent) of them, for they had also positive HCV RNA besides anti-HCV reactivity. These patients had also higher ALT- and AST-activity and more severe histological liver-changes. HCV-infection is the main virological cause of their liver lesion, beside ethylism. Hepatocellular carcinoma is rather exceptional in our porphyria patients in spite of their frequent HCV-infection.