Jurjen Schirm

Cytomegalovirus antigenemia as a useful marker of symptomatic cytomegalovirus-infection after renal-transplantation - a report of 130 consecutive patients

In earlier work we demonstrated that CMV immediate early antigens can be detected in peripheral blood leukocytes of patients with active CMV infection. We now report a comparison of the antigenemia assay and an anti-CMV ELISA in a prospective longitudinal study of 130 renal transplant recipients who were monitored for active CMV infection during the first 3 months after transplantation. Active CMV infection developed in 56 patients. The antigenemia assay had a sensitivity of 89% and a specificity of 93% in the diagnosis of active CMV infection; for the ELISA these figures were 95 and 100%, respectively. In 22 of the 56 patients a CMV syndrome occurred. Antigenemia was demonstrated in all 22 patients while an antibody response occurred in 21 of them. The antigenemia assay became positive 8 +/- 7 days before the onset of symptoms while the antibody response was observed 4 +/- 9 days after the onset of symptoms. The pattern of antigenemia was helpful for monitoring the course of the infection. The maximum level of antigenemia was significantly higher and its duration significantly longer in symptomatic than asymptomatic infection. We conclude that CMV antigenemia is a sensitive, specific, and early marker of CMV infection. The antigenemia assay is of great value in monitoring patients with a high risk of CMV infection.

European Proficiency Testing Program for Molecular Detection and Quantitation of Hepatitis B Virus DNA

ABSTRACT External quality control of hepatitis B virus (HBV) DNA detection remains an important issue. This study reports and compares the results obtained from two different proficiency panels for both the qualitative and quantitative assessment of HBV DNA. The panels were designed by the European Union Quality Control Concerted Action, prepared by Boston Biomedica, Inc., and distributed in May 1999 (panel 1) and February 2000 (panel 2). Each contained two negative samples and six positive samples with 103 to 107 copies/ml (panel 1) or 103 to 2 × 106 copies of HBV DNA per ml (panel 2). For panel 1, 42 laboratories submitted 20 qualitative (all in-house PCRs) and 37 quantitative (87% commercial assays) data sets. For panel 2, 51 laboratories submitted 25 qualitative (all in-house PCRs) and 47 quantitative (94% commercial assays) data sets. Five data sets (8.8%) in panel 1 and two data sets (2.8%) in panel 2 contained totals of six and two false-positives, respectively, corresponding to false-positive result rates of 5.3% for panel 1 and 1.4% for panel 2. The false-negative result rates of 10.5% for panel 1 and 17.4% for panel 2 were dependent on the detection levels of the assays employed as well as panel composition. In the qualitative analysis of all data sets, 47.4% (panel 1) and 51.4% (panel 2) had all samples correct. An adequate or better score (all correct or only the weak-positive sample missed) was obtained with 77.2% of the panel 1 samples and 68.1% of the panel 2 samples. In the quantitative analysis, 57.1% (panel 1) and 42.6% (panel 2) of the data sets achieved an adequate or better score (positive results within the acceptable range of the geometric mean ± 0.5 log10 of all positive results). These results demonstrate that while the qualitative performance of HBV detection has considerably improved compared to that of a previously published HBV proficiency study, the detection levels of many commercial quantitative assays are still too high to allow adequate quantitation of all relevant clinical samples.

Bell's palsy and herpes simplex virus

Bells palsy, which is defined as idiopathic peripheral facial paralysis of sudden onset, accounts for >50% of all cases of facial paralysis. Different theories on the etiology of Bells palsy have been proposed and investigated. Various clinical studies have suggested an etiological link between Bells palsy and herpes simplex virus (HSV). In addition, animal experiments have shown the ability of HSV to induce facial paralysis. In our opinion, the possible link between Bells palsy and HSV can only be explored properly by studying the human facial nerve, and especially the geniculate ganglion itself. Different groups have tried to detect hypothetically reactivated and hypothetically latent HSV in the facial nerves of Bells palsy patients and control patients, respectively. The isolation of infectious HSV from facial nerve tissue by conventional cell culture methods appeared to be very difficult, also when Bells palsy patients were tested. Instead, modern molecular methods, such as in situ hybridization and the polymerase chain reaction (PCR) could easily detect HSV DNA in geniculate ganglia. The detection of HSV‐specific latency‐associated transcripts in the ganglia of control patients provided further evidence for the hypothetically latent state of HSV in the geniculate ganglia in these patients. Recent PCR experiments performed by a Japanese group strongly suggest that the area adjacent to the geniculate ganglia does not usually contain any HSV at all, except in patients with Bells palsy. This well‐controlled study provides conclusive evidence that reactivation of HSV genomes from the geniculate ganglia is the most important cause of Bells palsy. Consequently, it has been suggested that “Bells palsy” be renamed as “herpetic facial paralysis”.

Reliability of Nucleic Acid Amplification Methods for Detection of Chlamydia trachomatis in Urine: Results of the First International Collaborative Quality Control Study among 96 Laboratories

ABSTRACT The first European Quality Control Concerted Action study was organized to assess the ability of laboratories to detect Chlamydia trachomatis in a panel of urine samples by nucleic acid amplification tests (NATs). The panel consisted of lyophilized urine samples, including three negative, two strongly positive, and five weakly positive samples. Ninety-six laboratories in 22 countries participated with a total of 102 data sets. Of 204 strongly positive samples 199 (97.5%) were correctly reported, and of 506 weakly positive samples 466 (92.1%) were correctly reported. In 74 (72.5%) data sets correct results were reported on all samples, and 17 data sets (16.7%) showed either one false-negative or one false-positive result. In another 11 data sets, two or more incorrect results were reported, and two data sets reported a false-positive result on one negative sample. The Roche COBAS Amplicor test was performed in 44 (43%) data sets, the Abbott LCx assay was performed in 31 (30%) data sets, the Roche Amplicor manual assay was performed in 9 (9%) data sets, an in-house PCR was performed in 9 (9%) data sets, the Becton Dickinson ProbeTec ET assay was performed in 5 (4.9%) data sets, and the GenProbe TMA assay was performed in 4 (3.9%) data sets. The results of the Roche Amplicor manual (95.6% correct), COBAS Amplicor (97.0%), and Abbott LCx (94.8%) tests were comparable (P = 0.48). The results with the in-house PCR, BD ProbeTec ET, and GenProbe TMA tests were reported correctly in 88.6, 98, and 92.5% of the tests, respectively. Freeze-drying of clinical urine specimens proved to be a successful method for generating standardized, stable, and easy-to-transport samples for the detection of C. trachomatis by using NATs. Although the results, especially the specificity, for this proficiency panel were better than most quality control studies, sensitivity problems occurred frequently, underlining the need for good laboratory practice and reference reagents to monitor the performance of these assays.

External Quality Assessment Program for Qualitative and Quantitative Detection of Hepatitis C Virus RNA in Diagnostic Virology

ABSTRACT To assess the performance of laboratories in detecting and quantifying hepatitis C virus (HCV) RNA levels in HCV-infected patients, we distributed two proficiency panels for qualitative and quantitative HCV RNA testing. The panels were designed by the European Union Quality Control Concerted Action, prepared by Boston Biomedica Inc., and distributed in May 1999 (panel 1) and February 2000 (panel 2). Each panel consisted of two negative samples and six positive samples, with HCV RNA target levels from 200 to 500,000 copies/ml. Panel 1 had four samples with at least 50,000 copies/ml, and panel 2 had two samples with at least 50,000 copies/ml. Fifty-seven laboratories submitted 45 qualitative and 35 quantitative data sets on panel 1, and 81 laboratories submitted 75 qualitative and 48 quantitative data sets on panel 2. In both panels, about two-thirds of the qualitative data sets and >90% of the quantitative data sets were obtained with commercial assays. With each panel, two data sets gave one false-positive result, corresponding to false-positivity rates of 1.3% and 0.8% for panel 1 and panel 2, respectively. Samples containing at least 50,000 copies/ml were found positive in 97% and 99% of the cases with panel 1 and panel 2, respectively. In contrast, the positive samples containing ≤5,000 copies/ml were reported positive in only 71% and 77% of the cases with panel 1 and panel 2, respectively. Adequate or better scores on qualitative results (all results correct or only the low-positive samples missed) were obtained in 84% (panel 1) and 80% (panel 2) of the data sets. In the analysis of quantitative results, 60% (panel 1) and 73% (panel 2) of the data sets obtained an adequate or better score (≥80% of the positive results within the range of the geometric mean ± 0.5 log10). Our results indicate that considerable improvements in molecular detection and quantitation of HCV have been achieved, particularly through the use of commercial assays. However, the lowest detection levels of many assays are still too high, and further standardization is still needed. Finally, this study underlines the importance of proficiency panels for monitoring the quality of diagnostic laboratories.

Acute hepatitis B in a healthcare worker: A case report of genuine vaccination failure

BACKGROUND Individuals who reach the antibody threshold level of 10IU/l against the surface protein of the hepatitis B virus (HBV) after completion of a series of hepatitis B vaccination are considered to be long-term protected against a clinically manifest HBV infection. CASE REPORT Here we describe an acute hepatitis B infection in a patient who received five hepatitis B vaccinations. Although his initial response to vaccination was moderate, he finally reached an excellent hepatitis B surface antibody level (anti-HBs) titres of more than 1000 IU/l in response to a booster vaccination with a recombinant DNA vaccine. Nevertheless, he developed full-blown acute hepatitis due to an HBV infection 14years after this booster vaccination. A DNA analysis of the surface protein encoding region followed by phylogenetic analysis showed that our patient was infected with a normal HBV strain that is circulating among men who have sex with men. To our knowledge, this is the first report of a genuine hepatitis B vaccination failure in someone who acquired a high anti-HBs level in response to a recombinant DNA hepatitis B vaccine. CONCLUSION Healthcare workers whose response to the initial hepatitis B vaccination is moderate might be vulnerable to hepatitis B virus infection.

Natural history of hepatitis C in HIV-negative patients with congenital coagulation disorders

BACKGROUND/AIMS Knowledge of the natural history of hepatitis C is useful for counselling patients and planning treatment. More data are needed from unselected patient groups without concomitant disease. The aim of this study was to describe the natural history of hepatitis C, two decades after infection, in a homogeneous and well-defined group of HIV-negative patients with congenital coagulation defects who had not received specific therapy for chronic hepatitis C. METHODS Medical history, physical examination, laboratory tests and abdominal ultrasonography were performed in 45 HCV-RNA positive, HIV-negative patients, mainly haemophiliacs, from a single centre. Patients were classified according to results of ultrasonography. RESULTS Two patients had experienced an episode of variceal bleeding; all others were asymptomatic. None had ascites. HCV-RNA titres were >500000 copies/ml in 23 patients, genotype was 1 in 31 patients. Forty (89%) had elevated transaminases, liver synthesis function was diminished in 7 (16%), and platelet count in 8 (18%). Ultrasonography was normal in 26 (58%) patients, 12 (27%) had isolated splenomegaly, and 7 (16%) had liver nodularity compatible with cirrhosis. Univariate analysis disclosed higher transaminases and gammaGT, higher age at acquisition of infection and higher present age as risk factors for more advanced disease. Of these, only higher present age was an independent predictor in multivariate analysis. CONCLUSIONS Median 19 years after infection, 58% of patients had no other signs of liver disease than raised transaminases, 16% had cirrhosis on ultrasonography. Only 2/45 patients had symptomatic disease. Higher present age is the main risk factor for advanced disease in this group.

IS SEROLOGY OF ANY USE WHEN SEARCHING FOR CORRELATIONS BETWEEN CHLAMYDIA-TRACHOMATIS INFECTION AND MALE-INFERTILITY

Evidence on Chlamydia trachomatis causing male infertility is conflicting. We therefore collected data on epidemiological and clinical correlates of chlamydial infection and male fertility in 184 males visiting our Fertility Unit. Antibodies against Chlamydia trachomatis in serum and semen were also determined. Significant correlations were demonstrated between current chlamydial urethral infection and semen immunoglobulin (Ig) A, serum IgA and serum IgG. These parameters, however, were neither related to a history of sexually transmitted disease nor to lifetime number of sexual partners. Why, in the male, serology does not correlate with chlamydial infection in a more remote past is explained. Our data support, on epidemiological as well as serological grounds, the conclusion that chlamydial infection probably does not contribute significantly to male infertility.

Comparison of two commercial molecular assays for simultaneous detection of respiratory viruses in clinical samples using two automatic electrophoresis detection systems.

Abstract Two molecular assays were compared with real-time RT-PCR and viral culture for simultaneous detection of common viruses from respiratory samples: a multiplex ligation-dependant probe amplification (MLPA) and a dual priming oligonucleotide system (DPO). In addition, the positive detections of MLPA and DPO were identified using two different automatic electrophoresis systems. A panel of 168 culture-positive and negative samples was tested by the molecular assays for the presence of influenza A and B virus, respiratory syncytial virus, human metapneumovirus, rhinovirus, coronaviruses, parainfluenza viruses and adenovirus. One hundred and twenty-nine (77%) samples were positive as detected by at least one method. Sixty-nine (41%) samples were positive by cell culture (excluding human metapneumovirus and coronaviruses), 116 (69%) by RT-PCR, 127 (76%) by MLPA and 100 (60%) by DPO. The MLPA yielded results in one attempt for all samples included while 12 (7.2%) samples had to be repeated by the DPO assay due to inconclusive results. The MLPA assay performed well in combination with either electrophoresis system, while the performance of the DPO assay was influenced by the electrophoresis systems. Both molecular assays are comparable with real-time RT-PCR, more sensitive than viral culture and can detect dual infections easily. Results can be obtained within 1 day.

Comparison of COBAS AMPLICOR Neisseria gonorrhoeae PCR, Including Confirmation with N. gonorrhoeae-Specific 16S rRNA PCR, with Traditional Culture

ABSTRACT A total of 3,023 clinical specimens were tested for Neisseria gonorrhoeae by using COBAS AMPLICOR (CA) PCR and confirmation of positives by N. gonorrhoeae-specific 16S rRNA PCR. The sensitivity of CA plus 16S rRNA PCR was 98.8%, compared to 68.2% for culture. Confirmation of CA positives increased the positive predictive value from 54.8 to 96.6%.