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PubMed2002

Evaluation of a new assay for hepatitis C virus genotyping and viral load determination in patients with chronic hepatitis C.

A new method for hepatitis C virus (HCV) genotyping that analyzes products generated with the HCV Amplicor Monitor Test has been developed. One hundred and sixty-two Japanese patients with chronic hepatitis C, including 59 patients with hemophilia, were tested for HCV genotypes and viral loads with this new test, and the results were compared with those of a genotyping assay that involved direct sequencing of the E1 region. HCV genotypes and viral loads were also compared between patients with and without hemophilia. There were no discrepancies between the two methods in determining genotypes 2a, 2b, and 3a. However, two patients infected with 1a were mistyped as 1b with the new assay. One patient not classified by this assay was genotype 4. Genotypes found in patients without hemophilia were 1b, 2a, and 2b. Genotypes 1a, 3a, and 4, which were minor variants in Japan, were detected only in patients with hemophilia. In addition, J type, which is a subtype of 1b that originated in Japan, was found at low frequency in hemophiliacs. Thus, the HCV genotypes in patients with hemophilia are likely to be of foreign origin. Overall, this new assay was accurate except for genotype 1a and 4, and allowed simultaneous assessment of genotype and viral load.

Adult↗

PubMed1998

Association of syncytium-inducing phenotype of HIV-1 with CD4 cell count, viral load and sociodemographic characteristics.

OBJECTIVES: To study whether syncytium-inducing (SI)/non-SI (NSI) phenotype of HIV-1 is associated with CD4+ lymphocyte count, plasma HIV RNA level, clinical stage and sociodemographic characteristics in antiretroviral-naive HIV-1-infected patients. DESIGN: Cross-sectional analysis of single centre cohort study data. METHODS: SI/NSI phenotype was determined using a cocultivation assay using patients' peripheral blood mononuclear cells and MT2 cells. Standard procedures were used for CD4+ cell counts and viral load measurements in plasma. Univariate and multivariate analyses of association of CD4+ cell counts, viral load, clinical stage, age, sex and mode of HIV transmission were performed. RESULTS: In univariate analysis, SI phenotype was significantly associated with lower CD4+ cell counts, higher HIV RNA plasma levels, symptomatic HIV disease, male sex and age 32-36 years (middle tercile). In multivariate analysis, only lower CD4+ cell counts were associated with SI phenotype (odds ratio per increase of 100 x 10(6)/l, 0.54; 95% confidence interval, 0.38-0.78). CONCLUSIONS: HIV-1 SI phenotype was associated with lower CD4+ cell counts but not with higher plasma viral load, clinical stage or sociodemographic variables.

Adolescent↗

PubMed2005

Quantitative PCR in the diagnosis of CMV infection and in the monitoring of viral load during the antiviral treatment in renal transplant patients.

Cytomegalovirus (CMV) infection is a significant problem in transplantation. In this study, a quantitative PCR test was compared with the CMVpp65 antigenemia assay not only in the diagnosis CMV infections but especially in the monitoring of viral loads during ganciclovir treatment of CMV disease in individual renal transplant patients. Altogether 342 blood specimens were obtained from 116 patients. Blood specimens were used for Cobas Amplicor Monitor plasma PCR and for the pp65 assay. Also shell vial culture was performed. The patients with a positive pp65 finding were monitored for CMV weekly during ganciclovir treatment and/or until the antigenemia subsided. CMV was detected in 31/116 (27%) patients, of whom 14 (12%) developed CMV disease and were treated with ganciclovir. CMV was found by shell vial culture in 13/14 cases, but by PCR and pp65 test in all 14 patients. CMV was detected in 156 (45%) samples; by PCR in 121/156 (range 344-103,000 copies/ml) and by pp65 test in 138/156 (range 1-1,000 positive cells/50,000 leukocytes) and by culture in 59/156 (38%) only. The peak viral loads were significantly (P<0.0001) higher in CMV disease than in untreated infections (19,650 vs. 379 copies/ml, and 100 vs. 5pp65 positive cells). In the monitoring of individual patients, the time-related CMV-DNAemia and pp65 antigenemia correlated well during the treatment of CMV disease. In conclusion, Cobas Amplicor Monitor plasma PCR and CMVpp65 antigen assays can be equally used in the diagnosis CMV infection and in the monitoring of viral load during antiviral treatment.

Antigens, Viral↗

PubMed2005

Frequent hypermethylation of RASSF1A and TSLC1, and high viral load of Epstein-Barr Virus DNA in nasopharyngeal carcinoma and matched tumor-adjacent tissues.

We examined the promoter hypermethylation of tumor-suppressor genes RASSF1A and TSLC1, quantitated EBV DNA load in nasopharyngeal carcinoma (NPC) tissues (T tissues), and matched tumor-adjacent tissues outside 0.5 cm (P tissues) and outside 1.0 cm (Z tissues) to evaluate the role of promoter hypermethylation of RASSF1A and TSLC1 as well as viral load in the pathogenesis of NPC. Methylation-specific polymerase chain reaction (PCR) for RASSF1A and TSLC1 and quantitative real-time PCR analysis of EBV DNA were performed on matched T, P, and Z tissues (n = 28) as well as chronic nasopharyngitis tissues (n = 8). Hypermethylated RASSF1A was frequently detected in the T (82%) and P tissues (75%), but less frequently in Z tissues (46%). he average quantities of EBV DNA (copies/microg DNA) in matched T, P, and Z tissues were 673,000, 90,000, and 7000. The differences of promoter hypermethylation of RASSF1A and EBV viral load among T, P, and Z tissues were statistically significant, with more frequent methylation and higher viral load detected when tissues examined were nearer to the NPC tissues. Our results suggest that aberrant hypermethylation of RASSF1A and high EBV load might be important events in NPC pathogenesis, and they may be useful molecular diagnostic markers for this cancer.

Adult↗

PubMedDate not supplied

Effect of co-trimoxazole prophylaxis on morbidity, mortality, CD4-cell count, and viral load in HIV infection in rural Uganda.

BACKGROUND: Prophylaxis with co-trimoxazole (trimethoprim-sulphamethoxazole) is recommended for people with HIV infection or AIDS but is rarely used in Africa. We assessed the effect of such prophylaxis on morbidity, mortality, CD4-cell count, and viral load among people with HIV infection living in rural Uganda, an area with high rates of bacterial resistance to co-trimoxazole. METHODS: Between April, 2001, and March, 2003, we enrolled, and followed up with weekly home visits, 509 individuals with HIV-1 infection and their 1522 HIV-negative household members. After 5 months of follow-up, HIV-positive participants were offered daily co-trimoxazole prophylaxis (800 mg trimethoprim, 160 mg sulphamethoxazole) and followed up for a further 1.5 years. We assessed rates of malaria, diarrhoea, hospital admission, and death. FINDINGS: Co-trimoxazole was well tolerated with rare (<2% per person-year) adverse reactions. Even though rates of resistance in diarrhoeal pathogens were high (76%), co-trimoxazole prophylaxis was associated with a 46% reduction in mortality (hazard ratio 0.54 [95% CI 0.35-0.84], p=0.006) and lower rates of malaria (multivariate incidence rate ratio 0.28 [0.19-0.40], p<0.0001), diarrhoea (0.65 [0.53-0.81], p<0.0001), and hospital admission (0.69 [0.48-0.98], p=0.04). The annual rate of decline in CD4-cell count was less during prophylaxis than before (77 vs 203 cells per microL, p<0.0001), and the annual rate of increase in viral load was lower (0.08 vs 0.90 log(10) copies per mL, p=0.01). INTERPRETATION: Daily co-trimoxazole prophylaxis was associated with reduced morbidity and mortality and had beneficial effects on CD4-cell count and viral load. Co-trimoxazole prophylaxis is a readily available, effective intervention for people with HIV infection in Africa.

AIDS-Related Opportunistic Infections↗

PubMed1998

The influence of pregnancy on human immunodeficiency virus type 1 infection: antepartum and postpartum changes in human immunodeficiency virus type 1 viral load.

OBJECTIVE: Our objective was to examine the influence of pregnancy on human immunodeficiency virus type 1 viral load by measuring human immunodeficiency virus type 1 ribonucleic acid levels during pregnancy and post partum. STUDY DESIGN: One or more plasma or serum specimens obtained before and during the third trimester, and at 2, 12, and 24 months post partum were available for 160 human immunodeficiency virus type 1-seropositive women enrolled in the Mothers and Infants Cohort Study between January 1986 and January 1991. All specimens were frozen and stored at -70 degrees C until analyzed in batch for human immunodeficiency virus type 1 ribonucleic acid by polymerase chain reaction. A multivariate longitudinal random effects model was developed to examine changes in human immunodeficiency virus type 1 ribonucleic acid levels over time. RESULTS: Overall, human immunodeficiency virus type 1 ribonucleic acid levels rose significantly during the study period, particularly during the second year post partum (mean, 0.09 log per year; 95% confidence interval, 0.03 to 0.15 logs per year; p = 0.005). However, the mean slope during pregnancy was not significantly different from zero (p = 0.65). CONCLUSION: Pregnancy had little immediate effect on human immunodeficiency virus type 1 viral load in most human immunodeficiency virus type 1-seropositive women.

Acquired Immunodeficiency Syndrome↗

PubMed2006

Quantitative detection of human immunodeficiency virus type 1 (HIV-1) viral load by real-time RT-PCR assay using self-quenched fluorogenic primers.

HIV-1 viral load is a basic marker to evaluate the severity of HIV-1 related diseases and to monitor the effectiveness of treatment. A method based on real-time RT-PCR technology has been developed to quantify HIV-1 RNA using self-quenched fluorogenic primers known as LUX primers. They were used in this study to recognize a low variable gag region of subtype E and B consensus sequences. Specificity was verified by amplicon melting temperatures. An external standard curve was constructed with 10 fold serial dilutions of synthetic HIV-gag RNA. A broad range linear relationship (10 to 10(6) copies/ml) was observed between the number of PCR cycles needed to detect a fluorescent signal and the number of RNA copies. The intra- and inter-assay coefficients of variation were 0.72 to 2.54% and 3.14 to 8.83%, respectively, thus indicating good reproducibility. Thirty out of fifty HIV-infected individual plasma samples were quantified by this method and compared with the AMPLICOR HIV-1 Monitor assay, which is widely considered the reference technique for HIV-RNA viral load measurement. The results indicate that the AMPLICOR HIV-1 Monitor assay and real-time RT-PCR using LUX primers are in good agreement (mean difference in log10 copies/ml+/-2 standard deviations = 0.21+/-1.34).

HIV Infections↗

PubMed2001

A preliminary open label dose comparison using an antioxidant regimen to determine the effect on viral load and oxidative stress in men with HIV/AIDS.

OBJECTIVE: To investigate the effect of antioxidant supplementation on viral load and the antioxidant/reactive oxygen species system in people with HIV. DESIGN: Single centre, prospective, dose comparison study. SETTING: Outpatient clinic specializing in HIV care. SUBJECTS: Sixty-six participants were sequentially recruited by advertisement, and 48 subjects completed the study. INTERVENTIONS: A recommended dose antioxidant regimen (5,450 IU vitamin A as beta-carotene, 250 mg vitamin C, 100 IU vitamin E, 100 microg selenium, 50 mg coenzyme Q10) or a high-dose antioxidant regimen (21,800 IU vitamin A as beta-carotene, 1,000 mg vitamin C, 400 IU vitamin E, 200 microg selenium, 200 mg coenzyme Q10) for a 12 week period. RESULTS: Using repeated measures analysis of variance, the changes over treatment time were significant for selenium, glutathione, glutathione peroxidase and lipid peroxides (P < 0.03). Changes in allantoin, uric acid and viral load were not significant (P > 0.05). The main effects for group and the interaction effects were not significant for any of the parameters measured (P > or = 0.05). CONCLUSION: Antioxidant supplementation significantly improved some measures of oxidative defence. There was no benefit in using a high-dose supplement in this study.

Adult↗

PubMed1998

Broadly reactive antibodies to hypervariable region 1 in hepatitis C virus-infected patient sera: relation to viral loads and response to interferon.

To clarify the nature of serum anti-hypervariable region 1 (HVR1) antibodies in patients infected with hepatitis C virus (HCV), we assessed the reactivity of 21 patients' sera with 42 HVR1 proteins by Western blot. HVR1 was expressed as fusion proteins with glutathione S-transferase (GST). The patients' sera reacted with variable percentages of the HVR1 proteins, and always reacted with HVR1 proteins of the different genotype. In the genotype-1b-infected patients, the percentage of genotype-1b HVR1 proteins reactive with serum correlated significantly with viral loads; the sera reactive with the higher percentages of HVR1 proteins contained the larger viral loads. In addition, it was significantly lower in the responders of interferon (IFN) therapy than in nonresponders. The competition assays indicated that multiple fractions of anti-HVR1 antibodies with different specificity in a serum reacted with different HVR1 proteins, and that, additionally, a single fraction of antibodies often reacted with more than one HVR1 protein through a similar amino acid sequence. In conclusion, serum anti-HVR1 antibodies were broadly reactive by the mechanism of both the cross-reactivity of a single fraction of anti-HVR1 antibodies with more than one HVR1 protein and the presence of multiple fractions of anti-HVR1 antibodies with different specificity in a serum. In genotype-1b-infected patients, the broad reactivity of serum anti-HVR1 antibodies correlated with viral loads and response to IFN. Further studies are necessary to elucidate the correlation among the broad reactivity of sera with multiple HVR1 proteins and clinical features of chronic hepatitis C patients.

Adult↗

PubMed1999

Human immunodeficiency virus type 1-specific cytotoxic T lymphocyte activity is inversely correlated with HIV type 1 viral load in HIV type 1-infected long-term survivors.

HIV-1-specific cytotoxic T cell (CTL) activity has been suggested to correlate with protection from progression to AIDS. We have examined the relationship between HIV-specific CTL activity and maintenance of peripheral blood CD4+ T lymphocyte counts and control of viral load in 17 long-term survivors (LTSs) of HIV-1 infection. Longitudinal analysis indicated that the LTS cohort demonstrated a decreased rate of CD4+ T cell loss (18 cells/mm3/year) compared with typical normal progressors (approximately 60 cells/mm3/year). The majority of the LTSs had detectable, variable, and in some individuals, quite high (>10(4) RNA copies/ml) plasma viral load during the study period. In a cross-sectional analysis, HIV-specific CTL activity to HIV Gag, Pol, and Env proteins was detectable in all 17 LTSs. Simultaneous analysis of HIV-1 Gag-Pol, and Env-specific CTLs and virus load in protease inhibitor-naive individuals showed a significant inverse correlation between Pol-specific CTL activity and plasma HIV-1 RNA levels (p = 0.001). Furthermore, using a mixed linear effects model the combined effects of HIV-1 Pol- and Env-specific CTL activity on the viral load were significantly stronger than the effects of HIV-1 Pol-specific CTL activity alone on predicted virus load. These data suggest that the presence of HIV-1-specific CTL activity in HIV-1-infected long-term survivors is an important component in the effective control of HIV-1 replication.

CD4 Lymphocyte Count↗

PubMed2005

Correlation of histology, human papillomavirus, and viral load in laryngeal papillomas of childhood.

The purpose of this study was to analyze 47 laryngeal papillomas in children for human papillomavirus (HPV) DNA by in situ hybridization and RT in situ PCR and to correlate these results with the histologic findings. HPV DNA was detected by in situ hybridization in 29 of 47 (62%) of the cases; all positive cases contained HPVs 6 or 11. HPV DNA detection was associated with a statistically significant increase in the presence of keratohyaline granules, nonuniform perinuclear halos, and marked papillomatosis (P<0.02). The viral load was low, defined by less than 20 HPV-positive cells per tissue with a correspondingly weak signal, in 19 of 29 (65%) of the positive cases. In comparison, a high viral load was evident in 19 of 21 (90%) of vulvar condylomas. The laryngeal lesions negative for HPV by in situ hybridization were tested for HPV by RT in situ PCR using primers specific for HPVs 6 and 11. The detection rate of HPV increased to 38 of 47 (81%) after PCR amplification. It is concluded that laryngeal papillomas in childhood are characterized, in general, by a relatively low HPV viral load and that the cases with productive viral infection, as demonstrated by in situ hybridization, are associated with nonuniform keratohyaline granules, nonuniform perinuclear halos, and marked papillomatosis.

Child↗

PubMed2000

[The prognostic markers of survival and progression in HIV-1 infection. A study of CD4+ lymphocytes, antigen p24 and viral load during 3 years in a cohort of 251 patients].

BACKGROUND: Prospective study of survival and AIDS or death progression in a cohort of 251 HIV infected patients whose seroconversion time is unknown, with 1 main objective: To analyse CD4+ lymphocytes count, p24 antigen plasmatic levels and viral load as surrogate markers. PATIENTS AND METHODS: 251 patients were included, most of them undergoing antiretroviral therapy, followed consecutively in the HIV/AIDS Unity of Internal Medicine Service of the Hospital Universitario Arnau de Vilanova in Lleida. We made clinical and analytical baseline studies and every 3 months thereafter. In relation to CD4+ lymphocytes, 3 groups were established: group I, 500 or more cells/mL; group II, 200-499 cells/mL and group III, < 200 cells/mL. In the same way, with p24 antigen we established 3 group: group I, < 20 pg/mL, group II, 20-39 pg/mL, group III 40 or more pg/mL. We studied survival in relation to baseline levels and stability, the latter being understood as persistent levels in the initial group, or better, over 3 year period. Survival analysis was made by Kaplan-Meier estimation. Relative risk was calculated by Cox's proportional hazards model. RESULTS: During the 36 months of follow-up 53 patients died. AIDS progression risk or death was 4.8 times higher for the p24 antigen > = 40 pg/mL group than for the p24 antigen < 20 pg/mL one; patients with p24 antigen between 20-39 pg/mL relative risk was 2.5 times higher than those included in p24 antigen < 20 pg/mL group. These results emphasize that if we take into account the p24 antigen stability during these 36 months. In relation to progression study, 36 patients progressed. AIDS progression risk or death for p24 antigen > = 40 pg/mL group was 7.69 times higher in relation to that with p24 antigen levels between 20-39 pg/mL. The bivariable study shows that CD4 lymphocytes counts and p24 antigen level have quite an independent value. The comparison with viral load by PCR determination makes manifest discrepancy, difficult to explain. CONCLUSIONS: p24 antigen plasma level is a good survival and AIDS progress or death surrogate markers in HIV infected patients, and it is useful for 3 years or more. An isolated value < 20 pg/mL and, furthermore, the stability in successive controls under this concentration is a sign of good prognosis. Its value is emphasized with CD4+ lymphocytes count. It seem necessary that more comparative studies with viral load are required.

Adult↗

PubMed2005

Kinetics of sedimentation rate, viral load and TNF-alpha in relation to HIV co-infection in tuberculosis.

The kinetics of potential surrogate markers in HIV-positive (HIV+) and HIV-negative (HIV-), smear-positive tuberculosis (Tb+) patients in Gondar, Ethiopia (n = 60) was investigated. Clinical symptoms, sputum conversion, sedimentation rate (SR), HIV viral load and serum levels of TNF-alpha were determined before and 8 weeks after treatment initiation. The co-infection rate of HIV was 45%. There were significantly higher initial levels of SR and TNF-alpha in HIV+/Tb+ patients (79 +/- 29 mm/h and 13.5 +/- 7.6 pg/ml), than in HIV-/Tb+ patients (60 +/- 23 mm/h and 6.8 +/- 5.9 pg/ml, P<0.001). In HIV-/Tb+ patients, there was a marked decrease in SR compared with co-infected patients (46% [33 +/- 24 mm/h at week 8] vs. 24% [61 +/- 27 mm/h at week 8]). The HIV viral load (4.99 [range 3.70-5.92] to 4.90 [range 3.96-5.78] log10 copies/ml from week 0 to 8) and TNF-alpha (13.5 +/- 7.6 to 12.0 +/- 6.0 pg/ml) remained high in HIV+/Tb+ patients. In Tb patients, SR was significantly increased in HIV+ compared with HIV- patients. Additionally, TNF-alpha and HIV viral load remained elevated in HIV+/Tb+ patients following treatment despite clinical improvement comparable to HIV-/Tb+ patients.

Adolescent↗

PubMed2003

Impact of acute vivax malaria on the immune system and viral load of HIV-positive subjects.

OBJECTIVE: To explore the mechanisms of malariotherapy for human immunodeficiency virus (HIV)-infected patients and to identify which stage(s) of HIV infection is suitable for the treatment of malariotherapy. METHODS: Therapeutic acute vivax malaria was induced and terminated after 10 fever episodes in 12 HIV-1-infected subjects: Group 1 (G1) had 5 patients with CD(4) T-cell counts >or=500/ micro l at baseline, Group 2 (G2) had 5 patients with CD4 at 499 - 200/ micro l and Group 3 had 2 patients with CD(4) < 200/ micro l (not included in statistical analysis). Enzyme-Linked-Immuno-Sorbent Assay (ELISA) was used to measure plasma levels of cytokines and soluble activation markers. Flow cytometry was used to measure levels of lymphocyte subsets and phenotypes and CD(4) cell apoptosis. Bayer bDNA assay was used to test plasma levels of HIV-1 RNA (viral load). Samples were taken and tested twice before malaria (baselines), three times during malaria and seven times after termination of malaria (at day 10 and 1, 3, 6, 12, 18 and 24 months). RESULTS: Levels of plasma tumor necrosis factor-alpha (TNF-alpha), soluble TNF-alpha receptor-2 (sTNF-RII), neopterin (NPT) and soluble IL-2 receptor (sIL-2R) significantly increased during malaria and sharply reduced to baselines post malaria in all groups. Stronger responses of the aforementioned factors were seen in G2 than in G1 during malaria (P = 0.081, 0.001, 0.013, 0.020). CD4 count and percentage; CD(4)/CD(8) ratio and CD(25)(+) and CD(4)(+)CD(25)(+) percentages increased but HLA-DR+ percentage decreased either during or post malaria in G2. Most G2 patients experienced sustained increase but most G1 patients underwent natural history decline of CD(4) counts and percentages during 2-year follow-up. Percentage of apoptotic CD(4) cells decreased post malaria in all groups. G3 patients had weaker immune responses, however, one advanced AIDS patient in this group experienced clinical improvement after malariotherapy. Most of the 12 patients experienced increase of HIV viral load during malaria but the viral load returned to baseline levels 1 - 3 months after cure of malaria and remained near baseline levels for up to two years. CONCLUSIONS: Part of the mechanisms of malariotherapy is to induce high levels of cytokine activities and subsequently the changes of T-lymphocyte subsets and phenotypes in HIV-infected patients. These findings suggest that malariotherapy may treat HIV-1-infected patients whose CD4 baselines are in the range of 500 - 200/ micro l.

Acute Disease↗

PubMed1999

Effect of potentially interfering substances on the measurement of HIV-1 viral load by the bDNA assay.

As high heterogeneity of plasma composition may be responsible for interference with HIV-1 viral load determination by the bDNA assay, the potential interference caused by a number of plasma components was examined. Among the biochemical substances assayed, cholesterol, bilirubin, and triglycerides did not affect viral load quantification. Hemoglobin did not interfere with the assay at concentrations lower than or equal to 14 g/dl. Above this concentration, measurements decreased by up to 0.78 log, but these hemoglobin levels do not usually occur in the clinical setting. None of the antiretroviral drugs assayed (AZT, dDC, d4T, 3TC and Indinavir) interfered with the measurement. HIV bDNA is a robust assay even in those frequent circumstances in which plasma composition differs notably from normal.

Anti-HIV Agents↗

PubMed2004

Clinical utility of cytomegalovirus viral load testing for predicting CMV disease in D+/R- solid organ transplant recipients.

Despite prophylaxis, cytomegalovirus (CMV) disease is common in donor seropositive (D+)/recipient seronegative (R-) transplant patients after cessation of prophylaxis. Early detection of CMV may allow for pre-emptive therapy to prevent active disease. The clinical utility of quantitative plasma viral load measurements for predicting CMV disease was determined in 364 D+/R- organ transplant patients receiving prophylaxis (100 d of valganciclovir or oral ganciclovir). Measurements were performed every 2 weeks until day 100 and at months 4, 4.5, 5, 6, 8 and 12 post-transplant. CMV disease occurred in 64 (17.6%) patients by 12 months. Using a positive cut-off value of >400 copies/mL, sensitivity was 38%, specificity 60%, positive predictive value 17%, and negative predictive value 82% for prediction of CMV disease. Therefore, routine monitoring would have predicted disease in only 24/64 (38%) patients. The test characteristics were not improved by changing the viral load cut-off point for defining a positive result. Similarly, single time point measures at the end of prophylaxis or month 4 had low sensitivity for disease prediction. Overall, regular CMV plasma viral load measurements were only of modest value in predicting CMV disease.

Administration, Oral↗

PubMed2005

Chemiluminescence enzyme immunoassay for monitoring hepatitis C virus core protein during interferon-alpha2b and ribavirin therapy in patients with genotype 1 and high viral loads.

This study evaluated an updated chemiluminescence enzyme immunoassay (CLEIA) for hepatitis C virus (HCV) core protein for monitoring viral kinetics during treatment with interferon (IFN)-alpha and ribavirin. Using the CLEIA, serum levels of HCV core protein were measured in 17 patients with genotype 1 and high baseline viral loads during the first 4 weeks of combination therapy. HCV RNA was measured by the Amplicor Monitor test for comparison. At the start of therapy, the median HCV level (interquartile range) was 700 (540-940) kIU/ml of viral RNA and 11,310 (5,528-14,238) fmol/L of core protein. HCV RNA was above the upper limit of the linear range of the Amplicor Monitor test in 13 of the 17 patients, while the core protein level was within the linear range of the CLEIA in all patients. During therapy, the proportion of patients with HCV levels below the cutoff values at each time point was less with the Amplicor Monitor test than with CLEIA. Serum HCV core protein level decreased rapidly during the first 24 hr of therapy and more slowly thereafter, with median exponential decays of 1.08 and 0.046 log10/day, respectively. In the second phase, between day 1 and 28, the median decrease in HCV core protein level was higher in four patients with sustained virologic response (0.13 log10/day) than in 13 patients with no response (0.028 log10/day, P = 0.042). The wide linear range of the HCV core protein assay is appropriate for measuring viral loads during therapy with IFN-alpha and ribavirin.

Antiviral Agents↗

PubMed2006

Viral load, E2 gene disruption status, and lineage of human papillomavirus type 16 infection in cervical neoplasia.

The clinical utility of human papillomavirus (HPV) load and integration status remains unclear. We applied refined methods to delineate the viral load, integration status, and lineage of 104 women with HPV-16 monotype infection, including 19 with normal cervices, 9 with histologically proven cervical intraepithelial neoplasia (CIN) 1, 24 with CIN 2, 27 with CIN 3, and 25 with squamous cell carcinoma (SCC). Higher crude viral load, as determined by real-time polymerase chain reaction (PCR) targeting the E7 gene, was observed for SCC but became insignificant after normalization for cell content. Integration was located and quantified by real-time PCRs targeting, respectively, the carboxyl, amino, and hinge domains of the E2 gene. Pure episomal, integrated, and mixed forms were observed in all disease groups. Most E2 gene disruptions involved the amino-terminal, but sparing the hinge region that has been frequently used as a surrogate marker of integration. Large-fragment disruption involving all 3 E2 regions was observed only in the CIN 3 and SCC groups. Altogether, 33.3% of the CIN 3 group and 28.0% of the SCC group harbored pure episomal genomes. The Asian lineage was associated with a higher risk for CIN 3/SCC than the European lineage, and 6 of the 7 large-fragment E2 disruptions were from Asian lineage. The link between viral lineage, integration pattern, and oncogenesis deserves further study.

Adolescent↗