Evaluation of the murex hybrid capture cytomegalovirus DNA assay versus plasma PCR and shell vial assay for diagnosis of human cytomegalovirus viremia in immunocompromised patients

Evidence of a Link between Hepatitis E Virus Exposure and Glomerulonephritis Development

Viruses can trigger glomerulonephritis (GN) development. Hepatitis viruses, especially Hepatitis C virus and Hepatitis B viruses, are examples of the viruses that trigger GN initiation or progression. However, the proof of a correlation between GN and Hepatitis E virus infection is not clear. Some studies confirmed the development of GN during acute or chronic HEV infections, mainly caused by genotype 3. While others reported that there is no relation between HEV exposure and GN development. A recent study showed that a reduced glomerular filtration rate was developed in 16% of acute HEV genotype 1 (HEV-1) infections that returned to normal during recovery. HEV-1 is endemic in Egypt with a high seroprevalence among villagers and pregnant women. There is no available data about a link between HEV and GN in Egypt.

METHODS

GN patients (n = 43) and matched healthy subjects (n = 36) enrolled in Assiut University hospitals were included in this study. Blood samples were screened for hepatotropic pathogens. Tests for HEV markers such as HEV RNA and anti-HEV antibodies (IgM and IgG) were performed. Laboratory parameters were compared in HEV-seropositive and HEV-seronegative GN patients.

RESULTS

Anti-HEV IgG was detected in 26 (60.5%) out of 43 GN patients. HEV seroprevalence was significantly higher in GN than in healthy controls, suggesting that HEV exposure is a risk factor for GN development. None of the GN patients nor the healthy subjects were positive for anti-HEV IgM or HEV RNA. There was no significant difference between seropositive and seronegative GN patients in terms of age, gender, albumin, kidney function profiles, or liver transaminases. However, anti-HEV IgG positive GN patients had higher bilirubin levels than anti-HEV IgG negative GN patients. HEV-seropositive GN patients had a significantly elevated AST level compared to HEV-seropositive healthy subjects.

CONCLUSION

exposure to HEV infection could be complicated by the development of GN.

Characteristics and outcomes of acute hepatitis of unknown etiology in Egypt: first report of adult adenovirus-associated hepatitis

Purpose

Several outbreaks of acute hepatitis of unknown etiology (AHUE) in children were reported in 2022 in many countries, with adenovirus identified as the etiological agent in most of them. We aimed to evaluate the characteristics and outcomes of AHUE cases in Egypt.

Methodology

Hospitalized patients with acute hepatitis were included in the study. Drug-induced, alcoholic hepatitis, autoimmune hepatitis, and Wilson’s disease were identified either by medical history or by routine laboratory diagnosis. Molecular and serological approaches were used to investigate common viral causes of hepatitis, such as hepatitis A–E viruses, cytomegalovirus, Epstein–Barr virus, herpes simplex viruses (HSV1/2), adenovirus, parvovirus B19, and coxsackie virus.

Results

A total of 42 patients were recruited and divided into two groups: 24 cases of unknown hepatitis after excluding the common causes and 18 cases of known hepatitis. About two-thirds of the patients were male (61.9%), and the mean age was 34.55 ± 16.27 years. Jaundice, dark urine, abdominal pain and diarrhea were recorded at a higher incidence in group 1, while jaundice and fever were frequent in group 2. Fulminant hepatitis occurred in 28.6% of the cases, but the two groups did not differ significantly in terms of patient outcome, duration of hospitalization, ascites, and development of fulminant hepatitis. Adenovirus was detected in five cases (20.8%) in group 1, and one case co-infecting with hepatitis E virus in group 2. Herpes simplex virus 1/2, coxsackie virus, and parvovirus B19 were not detected in any case, while etiologies of 75% of the cases were still not confirmed. One out of the six adenovirus-infected patients died. The outcome significantly correlated with the severity of the liver disease.

Conclusion

This is the first report describing etiologies and characteristics of AHUE cases in Egypt, and interestingly, adenovirus was detected in adults. Further studies are required to determine the prevalence of this newly emerging viral hepatitis pathogens.

A follow up study of cytomegalovirus infection in a group of Turkish renal transplant recipients using molecular assays

The clinical value of an in-house cytomegalovirus nested polymerase chain reaction (CMV-PCR) and a commercial molecular assay hybrid capture CMV DNA assay (HCA) was evaluated in monitoring a group of renal transplant patients for six months follow up. In this study, the sensitivity, specificity, positive predictive value, and negative predictive value of nested CMV DNA PCR assay and HCA at the beginning of the study were 70, 42.9, 46.7, 66.7, and 60, 78.6, 66.7, and 73.3% respectively. After six months, they were 80, 66.7, 80, 66.7 for CMV PCR and 73.3, 88.9, 91.7, 66.7% for HCA respectively. These results indicate that in monitoring and predicting CMV infections in renal transplant recipients, not only qualitative but also quantitative assays must be used together in order to decide the preemptive strategies.

Prospective study of relationship between cytomegalovirus pneumonia and viral load in renal transplant recipients

The present study prospectively examined the relationship between cytomegalovirus interstitial pneumonia (CMV-IP) and viral load among 56 renal transplant recipients. We sought to identify the cutoff of viral load to predict CMV-IP. Blood samples were obtained weekly within the first 2 months and every second week during 2 to 6 months after kidney transplantations. A commercial real-time polymerase chain reaction (PCR)-method was applied to quantify CMV-DNA in plasma or in leukocytes. Among 54 renal transplant recipients who were analyzed for CMV-DNA in the blood (96.4%), 8 experienced CMV-IP (14.3%) and 2 died (3.6%). After kidney transplantation, CMV-DNA loads were near 0 in plasma before the week 4 and before the week 3 in leukocytes among both groups. From week 5 (week 4, in leukocytes), plasma CMV-DNA loads in the CMV-IP group increased, the peak value reached at week 8 in plasma and the week 9 in leukocytes. Whereas, the CMV-DNA loads both in plasma and in leukocytes in the non-CMV-IP group fluctuated at lower levels, those in plasma were significantly different between the 2 groups at the weeks 5, 7, and 9. For CMV-DNA in leukocytes, there were significant differences between 2 groups from week 6 to week 11. The present study demonstrated that dynamic determination of CMV-DNA may predict the occurrence of CMV-IP. Viral loads over 10(4) copies/mL plasma continuing for 3 weeks may serve as a cutoff to predict CMV-IP.

Impact of Cytomegalovirus Match on Survival after Cardiac and Lung Transplantation

Acute cytomegalovirus (CMV) disease and indirect effects caused by the virus alter the outcome after solid organ transplantation. Long-term results after 54 lung and 139 cardiac transplants at a single center have been retrospectively analyzed with regard to CMV status. Standard CMV prophylaxis consisted of ganciclovir for 100 days. Lung recipients were pretransplant CMV negative in 32 per cent as compared to heart recipients with 23 per cent. Patient survival after mismatch transplants (donor positive, recipient negative) was significantly reduced as compared to the other match groups (42% vs 76% at five years, P = 0.01). In heart recipients, CMV positive patients receiving a CMV negative graft showed best survival, whereas in the group of lung recipients negative/negative matched transplants produced best results. In both groups, CMV negative grafts had a better outcome than CMV positive grafts, and a survival difference between heart and lung recipients was only observed in recipients of a CMV positive grafts. Despite ganciclovir prophylaxis, CMV match remains an important factor for survival follwing heart and, even more profoundly, lung transplantation. Because survival was least favorable in the mismatched group, prophylactic regimens warrant improvement. For CMV negative lung recipients, CMV matching might be considered.

Cytomegalovirus infection after liver transplantation: viral load as a guide to treating clinical infection

BACKGROUND

Quantitative commercial assays for early and accurate detection of active cytomegalovirus (CMV) infection after liver transplantation are widely available. However, meaningful interpretation of viral load measurements is hampered by the lack of definitive cutoff points that correlate with clinically significant disease.

METHODS

One hundred fifty liver allograft recipients were prospectively monitored for the presence of CMV DNA for the first 12 weeks after orthotopic liver transplantation using the Murex hybrid capture system. The first CMV DNA value after liver transplantation, a weekly rise in CMV DNA (gradient value), and the CMV DNA value on clinical detection of active infection (critical value) were analyzed as risk factors for CMV infection.

RESULTS

Forty-four (29.3%) of 150 patients had detectable CMV DNA within 12 weeks of transplantation, and 20 (13.3%) experienced symptomatic CMV infection. Multiple regression analysis demonstrated that baseline CMV DNA level above 10 pg/mL, positive weekly increase in CMV DNA level, and critical CMV DNA level above 13 pg/mL were independent risk factors for clinically significant infection. Using Cox's multiple regression model, the hazard ratio was 13.9 for baseline CMV DNA above 10 (P =0.0001; 95% confidence interval, 3.5-54) and 13 for a weekly increase in the gradient (P =0.0003; 95% confidence interval, 3.5-50). Critical CMV DNA level above 13 correlated with active infection (100% sensitivity, 98% specificity, 90% positive predictive value, 100% negative predictive value).

CONCLUSION

Baseline and gradient CMV DNA viral load levels correlate with active CMV infection in liver allograft recipients. These data indicate that CMV viral load detection by hybridization methodology is useful in predicting active CMV infection and could be used in a preemptive strategy in liver allograft recipients.

Human cytomegalovirus load in the peripheral blood determined by quantitative competitive polymerase chain reaction

Primary human cytomegalovirus infection and the viral reactivation from latency are major complications in organ transplant recipients. In the peripheral blood the replicating virus can be detected either by nucleic acid based tests or by demonstrating the HCMV structural proteins in antigenemia test. We developed a quantitative competitive PCR method to assess the HCMV load in the peripheral blood. The viral load in nine healthy blood donors and in four renal transplant recipients with negative antigenemia test was in the same range: 5-124 (median: 18) HCMV copies/10(6) beta-globin copies for healthy blood donors and 16-48 (median: 37) HCMV copies/10(6) beta-globin copies for the transplant recipients. Three antigenemia positive renal transplant recipients had a HCMV load of 2.2 x 10(5)/10(6) beta-globin, 1.5 x 10(4)/10(6) beta-globin and 6.5 x 10(3)/10(6) beta-globin, respectively. In conclusion, the quantitative measurement of HCMV load in the peripheral blood correlated well with the routine HCMV antigenemia test. The DNA-based test, however can detect earlier the reactivation of the HCMV infection.

Qualitative plasma PCR assay (AMPLICOR CMV test) versus pp65 antigenemia assay for monitoring cytomegalovirus viremia and guiding preemptive ganciclovir therapy in allogeneic stem cell transplantation

The performances of a commercially available qualitative plasma PCR assay (AMPLICOR CMV test; Roche Diagnostics) and the pp65 antigenemia assay (AG) were evaluated for the monitoring of cytomegalovirus (CMV) viremia in 43 allogeneic stem cell transplant recipients. In addition, the suitabilities of both assays for triggering the initiation of preemptive ganciclovir therapy were assessed. A total of 37 CMV viremic episodes were detected in 28 patients. Positivity of plasma PCR testing in one or more consecutive specimens was the only marker of CMV viremia in 18 of the 37 episodes (PCR positive and AG negative, n = 50 specimens). Five episodes were diagnosed on the basis of a single positive AG result (AG positive and PCR negative, n = 5 specimens); both assays were eventually positive (PCR positive and AG positive, n = 27 specimens) for 14 viremic episodes; for these episodes, conversion of the PCR assay result to a positive result occurred an average of 1 week before conversion of the AG result. Overall, the concordance between the two methods was 90%, and the sensitivities of the plasma PCR assay and AG for the detection of CMV viremic episodes were 86.5 and 51.3%, respectively. Two patients who tested positive by both assays simultaneously progressed to CMV end-stage organ disease, despite the initiation of preemptive ganciclovir therapy. Conversion of the AG result to a negative result upon administration of preemptive ganciclovir therapy occurred a median of 7.5 days earlier than conversion of the plasma PCR assay result. Nineteen of the 28 patients with CMV viremia received AG-guided preemptive ganciclovir therapy; had the positivity of the plasma PCR assay triggered the initiation of preemptive therapy, 9 additional patients would have been unnecessarily treated since none of them developed CMV end-stage organ disease. Although the AMPLICOR CMV assay is more sensitive than AG, the latter appears to be more suitable both for guiding the initiation of preemptive therapy and for monitoring a patient's response to antiviral therapy.

Evaluation of CMV viral load using TaqMan CMV quantitative PCR and comparison with CMV antigenemia in heart and lung transplant recipients

BACKGROUND

Quantitative assessment of cytomegalovirus (CMV) infection using the antigenemia test has been used to monitor CMV infection in heart and lung transplant patients enabling a preemptive treatment strategy. However, the method is labour intensive, samples have to be processed within a few hours and requires skilled interpretation. A comparative prospective evaluation of a real-time TaqMan CMV quantitative PCR (QPCR) with the CMV antigenemia was undertaken.

METHODS

A real-time quantitative TaqMan CMV PCR from EDTA bloods was developed. In this study 25 heart transplant and single-lung transplant patients were monitored posttransplantation by antigenemia and TaqMan CMV QPCR. CMV DNA extracted from EDTA blood was amplified by TaqMan QPCR using primers and probe designed from the CMV glycoprotein B (gB) gene. Quantification of the genome copies is extrapolated from a standard curve generated from amplification of quantified standards.

RESULTS

Antigenaemia levels and TaqMan CMV QPCR genome copies showed a linear correlation between the two assays (R=0.843, P=0.001). A clinically significant threshold of 50 CMV pp65 antigen positive polymorphonuclear leucocytes (PMNLs) per 200 000 cells previously reported was used to extrapolate an equivalent value of 40 000 (log 4.6) genome copies per ml of blood for the TaqMan CMV QPCR.

CONCLUSIONS

The TaqMan system enables a rapid high-throughput of samples. The TaqMan CMV QPCR can be used as an accurate and robust alternative to the antigenemia test to predict CMV disease and to monitor effectiveness of treatment.

Evaluation of diagnostic methods for the detection of cytomegalovirus in recipients of allogeneic stem cell transplants

BACKGROUND

Although several diagnostic methods are available for the surveillance of patients at risk of human cytomegalovirus (CMV) infection and disease, little data is available on their comparative performances in the diagnostic setting.

OBJECTIVES

To compare different assays for CMV detection, especially assays based on (quantitative) DNA and mRNA detection.

STUDY DESIGN

Eight allogeneic bone marrow and stem cell transplant recipients at high risk for developing CMV disease (donor CMV-negative, recipient positive) were regularly tested for 7-20 weeks post-transplant by spin-amplification rapid culture from urine (viruria), antigenemia (pp65 assay), pp67 mRNA in whole blood (NASBA), and CMV DNA both qualitatively (in-house PCR, whole blood) and quantitatively (in-house PCR, plasma; Cobas Amplicor CMV Monitor Test, plasma and whole blood; Hybrid Capture, whole blood).

RESULTS

Four patients (50%) suffered CMV reactivation during follow-up. Out of 104 sample dates, 41 (39.4%) yielded a positive CMV result in at least one assay. Out of the 28 samples tested by all assays, the highest percentage of positive results was obtained with the in-house quantitative PCR (60.7%), followed by the Hybrid Capture system (39.3%), the Cobas Amplicor CMV Monitor Test, plasma version (35.7%), the Cobas Amplicor CMV Monitor Test, whole blood version (32.1%), in-house qualitative PCR (28.6%), and the mRNA assay (21.4%). Viruria was positive in one sample and pp65 antigenemia was found in two samples.

CONCLUSIONS

Despite a considerable incidence of CMV reactivations, pre-emptive anti-CMV chemotherapy prevented the development of CMV disease with the exception of one case. The molecular assays had superior sensitivity to conventional ones. The antigenemia assay proved unsuitable for the surveillance of hematological transplant patients. However, none of the tests recognized all timepoints with CMV reactivation. Further comparative studies are needed to determine their respective diagnostic values.

Analysis of human cytomegalovirus DNA in urines of newborns and infants by means of a new ultrarapid real-time PCR-system

BACKGROUND

Amplification techniques such as PCR are becoming increasingly popular in the field of diagnosis of human cytomegalovirus (HCMV) also, thus substituting conventional techniques like the time consuming HCMV antigen or cell culture assays. Current PCR protocols however, are labor intensive, and moreover, the need for extensive postamplification manipulations increases the risk of false positive results due to contamination with amplified products.

OBJECTIVES

to overcome these shortcomings, the new ultrarapid and semi-automated real-time LightCycler PCR-system (LC-PCR), which combines amplification and detection in a closed capillary system, was tested for its suitability in diagnosis of HCMV in urines.

STUDY DESIGN

73 urine samples from 64 newborns and infants suspected of having congenitally or postnatally acquired HCMV were tested with the LC-PCR and results were compared with those obtained in parallel with a conventional PCR-ELISA and the rapid shell vial assay for detection of HCMV early antigen (EA-assay).

RESULTS

with these methods, 31 newborns/infants were found to be infected with HCMV. HCMV DNA was detected in 39 urines while the EA-assay was positive in 33 urines. All the EA positive samples were also positive for HCMV DNA. In the urines of the remaining 33 newborns (34 urine samples) neither HCMV DNA nor EA were detectable. The overall agreement of the two PCR tests was 100% while a 92% agreement was obtained between the PCR and the EA-assays. As the sensitivity of the three tests turned out to be quite similiar, the discrepancy observed in the positive rate between PCR and EA-assay is due to other factors which will be discussed in detail. However, while LC-PCR takes only about 2 h from sample preparation to result generation, the EA-assay, such as the conventional PCR-ELISA, needs 24-48 h. Furthermore, due to its capability to perform cycle-by-cycle monitoring, the LC instrument enables semi-quantitative analysis of HCMV viral-load.

CONCLUSIONS

LC-PCR is a suitable new tool for routine analysis of HCMV in the urines of newborns and infants. Compared to the conventional PCR-ELISA a considerable increase in test rapidity and reliability is achieved without the need to sacrifice sensitivity.

Cytomegalovirus is not associated with IgM anti-myelin-associated glycoprotein/sulphate-3-glucuronyl paragloboside antibody-associated neuropathy

Monoclonal antibodies reactive with the HNK-1 epitope of myelin-associated glycoprotein (MAG) and the sulphate-3-glucuronyl paragloboside (SGPG)-like glycolipids are often found in the serum of patients with IgM paraprotein-associated demyelinating neuropathy. The presence of such antibodies in patients with chronic polyneuropathy has recently been associated with evidence of active cytomegalovirus (CMV) infection by the polymerase chain reaction. We wished to test these findings and examined sera from patients with MAG-reactive or MAG-nonreactive paraproteinemic neuropathy and patients with paraproteinemia only for the presence of CMV DNA and anti-CMV antibodies. CMV DNA was not detected in sera from any patient group. Furthermore, anti-CMV antibody prevalence was normal and similar in all 3 groups. We therefore report no evidence of an association between CMV infection and anti-MAG/SGPG antibodies associated with paraproteinemic peripheral neuropathy.

Evaluation of the AmpliSensor PCR and the SHARP signal detection system for the early prediction of symptomatic CMV infection in solid transplant recipients

BACKGROUND

Cytomegalovirus (CMV) is associated with high morbidity and mortality in transplant patients. Specific antiviral treatment at an early stage of CMV infection may effectively ameliorate, but not eliminate CMV disease in these patients. Presently, the pp65 antigenemia test on peripheral leukocytes is the method most widely used for predicting and monitoring transplant patients for active CMV infection. Nucleic acid amplification methods are less well defined since they lack standardisation.

OBJECTIVE

A seminested fluorometric PCR assay (AmpliSensor-CMV, BAG, Germany) and a one-step PCR with a signal-amplification step (SHARP, Abbott, Germany) specific for the fragments of the CMV UL 122 and UL 123 genes, respectively, were evaluated for the early diagnosis of CMV infection.

DESIGN

A total of 26 recipients of heterogeneous solid organs were monitored prospectively for a median of 99 days after transplantation. By testing 371 clinical samples parallel with the pp65-antigen assay and IgM and IgG EIA assays the sensitivity, specificity, correlation and quantitation potential of both PCRs was evaluated.

RESULTS

Eight out of 26 patients developed active CMV infection. A total of 48 samples of these patients exceeded a CMV-DNA load threshold of 15 genome equivalents/10(5) leukocytes (AmpliSensor-CMV) and 41 samples exceeded the critical cut-off for the SHARP system. The AmpliSensor PCR exceeded its threshold consistently before the clinical onset of CMV disease (median 8 days). There was very good agreement between symptomatic CMV infection in patients and AmpliSensor-PCR, SHARP PCR, and pp65-antigen results (kappa-coefficient > 0.900). IgM and IgG EIA showed moderate agreement (kappa-coefficient = 0.591 and 0.552, respectively).

CONCLUSION

Both PCRs and pp65 antigen assay correlated significantly better with CMV disease than serodiagnosis. The AmpliSensor PCR allowed more precisely than the SHARP system a quantitative determination of viral load and an early and reliable prediction of active CMV infection. The use of AmpliSensor PCR may improve the diagnosis and management of active CMV infection in organ transplant recipients.

Molecular pathogenesis of human cytomegalovirus infection

Despite progress in diagnosis and treatment of human cytomegalovirus (CMV) infection, we do not understand why, in hosts with comparable levels of immunosuppression, some CMV infections result in symptomatic CMV disease while others are limited to asymptomatic virus shedding with no discernible clinical consequences. CMV viral detection and quantification are useful for identifying those at highest risk, but do not consistently predict clinical outcome. Factors such as host genotype and immune response are active areas of research. However, the importance of CMV strain variability, recognized since 1976, is now receiving attention. Advances in technology that allow the rapid sequencing of viral DNA for purposes of strain characterization have fueled the renewed interest. The focus of this review will be to summarize our evolving knowledge of CMV strain variability and to document where possible a potential relationship to strain virulence. Studies with the UL55 (gB) envelope glycoprotein will be emphasized because of the ability to clearly identify naturally occurring variants, as well as the increasing number of reports that there are differences in biological activities that may contribute to virulence.