Standardization of antigenemia and qpcr cut-off values in whole blood for the detection of cytomegalovirus disease in hiv patients

Abstract INTRODUCTION: We defined the cut-off values of the antigenemia and cytomegalovirus (CMV) DNA tests in HIV/AIDS patients to identify CMV disease. METHODS: A total of 97 samples from 68 patients with and without CMV disease were analyzed by viral DNA detection and antigenemia assay. RESULTS: Qualitative and quantitative results significantly differed between assays. The cut-off values for the antigenemia and qPCR assays were 1.5 positive cells/200,000 leukocytes and 3.715 log/mL, respectively. CONCLUSIONS: Antigenemia and qPCR are suitable for monitoring CMV disease in HIV patients, however, the threshold values should be determined within the centers where the patients are monitored.

Clinical correlates of pp65 antigenemia monitoring in the first months of post kidney transplant in patients undergoing universal prophylaxis or preemptive therapy

Abstract Introduction: Human cytomegalovirus is a major cause of morbidity in kidney transplant patients. Objectives: We aimed to study viral replication and serological response in the first months post kidney transplant in patients undergoing universal prophylaxis or preemptive therapy and correlate the findings with the clinical course of Human cytomegalovirus infection. Patients and methods: Independent from the clinical strategy adopted for managing Human cytomegalovirus infection, prophylaxis versus preemptive therapy, the pp65 antigenemia assay and serological response were assessed on the day of transplantation, and then weekly during the first three months of post-transplant. Results: From the 32 transplant recipients, 16 were positive for pp65 antigenemia, with a similar incidence rate in each group. There were no positive results in the first three weeks of monitoring; the positivity rate peaked at week eight. There was a trend for a higher and earlier frequency of positivity in the universal prophylaxis group in which the course of the Human cytomegalovirus infection was also more severe. Despite the differences in clinical picture and in the initial immunosuppressant schedule, the serological response was similar in both groups. Conclusion: Routine monitoring during the first three post-transplant months has a positive impact on the early detection of Human cytomegalovirus viral replication allowing for timely treatment in order to reduce morbidity of the disease. The strategy of universal therapy employing intravenous ganciclovir was associated to a worse clinical course of the Human cytomegalovirus infection suggesting that the use of >10 cells/2 × 105 leukocytes as a cut-off in this setting may be inappropriate.

Fluorescence quantitative PCR in diagnosing and treating infantile cytomegalovirus infection / 国际儿科学杂志

Fluorescence quantitative PCR (FQ-PCR) is a more sensitive and specific method to diagnose and monitor cytomegalovirus(CMV) infection, and it is closely correlated with pp65 antigenemia levels. Measuring the CMV-DNA levels in infant urine and blood can be helpful to regulate the treatment and monitor the effects of the antivirus therapy.

Comparison of Real-time PCR Methods and pp65 Antigenemia Assay to Detect Cytomegalovirus Reactivation in Hematopoietic Stem Cell Transplantation / 감염과화학요법

Human cytomegalovirus (HCMV) is a common human pathogen that causes morbidity and mortality in hematopoietic stem cell transplantation (HSCT) recipients. Early diagnosis of HCMV infection or reactivation, and setting threshold values for effective pre-emptive therapies, are required for appropriate HCMV disease prevention in HSCT recipients. We compared the HCMV infections detected by the two methods, LightCycler-based PCR (LC PCR) and in-house immediate early protein PCR (in-house IE PCR) with the results of a pp65 antigenemia assay as the reference. The sensitivity and specificity for the in-house IE PCR were 79.3% and 72.7%, respectively, and 82.9% and 40.7%, respectively, for the LC PCR. The correlation between the HCMV viral load and pp65 antigenemia in HSCT recipients was r=0.603 with in-house IE PCR and r=0.525 with LC PCR. The discordant results between methods and relatively low (r) values suggest that we need more study to set threshold values according to the using methods with clinical outcome.

Comparison of Real-time PCR Methods and pp65 Antigenemia Assay to Detect Cytomegalovirus Reactivation in Hematopoietic Stem Cell Transplantation / 감염과화학요법

Human cytomegalovirus (HCMV) is a common human pathogen that causes morbidity and mortality in hematopoietic stem cell transplantation (HSCT) recipients. Early diagnosis of HCMV infection or reactivation, and setting threshold values for effective pre-emptive therapies, are required for appropriate HCMV disease prevention in HSCT recipients. We compared the HCMV infections detected by the two methods, LightCycler-based PCR (LC PCR) and in-house immediate early protein PCR (in-house IE PCR) with the results of a pp65 antigenemia assay as the reference. The sensitivity and specificity for the in-house IE PCR were 79.3% and 72.7%, respectively, and 82.9% and 40.7%, respectively, for the LC PCR. The correlation between the HCMV viral load and pp65 antigenemia in HSCT recipients was r=0.603 with in-house IE PCR and r=0.525 with LC PCR. The discordant results between methods and relatively low (r) values suggest that we need more study to set threshold values according to the using methods with clinical outcome.

Evaluation of BiosewoomTM Real-Q Cytomegalovirus Quantification kit for Cytomegalovirus Viral Load Measure / 대한진단검사의학회지

BACKGROUND: Rapid and accurate laboratory tests are essential to detect cytomegalovirus (CMV) infections in solid organs and haematopoietic stem cell transplant recipients. We assessed the realtime quantitative PCR (RQ-PCR) technology for its usefulness in detecting CMV DNA. METHODS: We evaluated the analytical performance of CMV RQ-PCR using Real-Q Cytomegalovirus Quantification kit (BioSewoom Inc., Korea). To evaluate its clinical utility, we also compared it to pp65 antigenemia test, an immunostaining method, on 343 samples of total 84 patients, including 63 transplant recipients. RESULTS: The detection limit of RQ-PCR was 63 copies/mL and none of hepatitis B virus, hepatitis C virus, or human immunodeficiency virus showed a cross-reactivity with CMV. Total coefficient of variation (CV) was 10.4-19.5%. It detected CMV DNA in a linear range from 1 x 10(2) to 5 x 10(11) copies/mL (P<10(-13), R2=0.9994). The qualitative positive rates of pp65 antigenemia test and RQ-PCR were 4.7%, 16.3%, respectively and concordance rate between the two tests was 84.8% (K=0.221, P<10(-6)). In comparison of quantitative results, the correlation between two tests was significant (r=0.45, P<10(-17)). In comparison among three groups by pp65 antigen level, CMV DNA level obtained with RQ-PCR increased significantly (P<10(-3) and P<10(-7), respectively). CONCLUSIONS: The RQ-PCR is easier to perform than the immunostaining method, has good analytical performance and reflects the blood level of viral DNA well. It may be a new method substituting the pp65 antigenemia test. Further studies determining RQ-PCR value starting pre-emptive therapy will be required.

Evaluation of BiosewoomTM Real-Q Cytomegalovirus Quantification kit for Cytomegalovirus Viral Load Measure / 대한진단검사의학회지

BACKGROUND: Rapid and accurate laboratory tests are essential to detect cytomegalovirus (CMV) infections in solid organs and haematopoietic stem cell transplant recipients. We assessed the realtime quantitative PCR (RQ-PCR) technology for its usefulness in detecting CMV DNA. METHODS: We evaluated the analytical performance of CMV RQ-PCR using Real-Q Cytomegalovirus Quantification kit (BioSewoom Inc., Korea). To evaluate its clinical utility, we also compared it to pp65 antigenemia test, an immunostaining method, on 343 samples of total 84 patients, including 63 transplant recipients. RESULTS: The detection limit of RQ-PCR was 63 copies/mL and none of hepatitis B virus, hepatitis C virus, or human immunodeficiency virus showed a cross-reactivity with CMV. Total coefficient of variation (CV) was 10.4-19.5%. It detected CMV DNA in a linear range from 1 x 10(2) to 5 x 10(11) copies/mL (P<10(-13), R2=0.9994). The qualitative positive rates of pp65 antigenemia test and RQ-PCR were 4.7%, 16.3%, respectively and concordance rate between the two tests was 84.8% (K=0.221, P<10(-6)). In comparison of quantitative results, the correlation between two tests was significant (r=0.45, P<10(-17)). In comparison among three groups by pp65 antigen level, CMV DNA level obtained with RQ-PCR increased significantly (P<10(-3) and P<10(-7), respectively). CONCLUSIONS: The RQ-PCR is easier to perform than the immunostaining method, has good analytical performance and reflects the blood level of viral DNA well. It may be a new method substituting the pp65 antigenemia test. Further studies determining RQ-PCR value starting pre-emptive therapy will be required.

Diagnosis value of PP65 antigenemia assay in febrile children with cytomegalovirus infection / 中国医师进修杂志

Objective To evaluate diagnosis value of PP65 antigenaemia assay(AA) on cytomegalovirus(CMV) infection in febrile children.Method One hundred and twenty-eight febrile children with febrile duration between one to two weeks,their blood preparations and urine aliquots were screened,indirect IF staining(antigen PP65),ELISA(CMV-IgM) and light microscope(urinary cytomegalic inclusion).Three methods above mentioned were used in all patients.Result The positive rate of PP65 antigenaemia,CMV-IgM and urinary cytomegalic inclusion was 17.2%,8.6%,6.3%,respectively.The positive coincidence rate of PP65 antigen with CMV-IgM and PP65 antigen with urinary cytomegalic inclusion was 50%(11/22),36%(8/22),respectively.Nineteen childrens antigenaemia PP65 became negative with patient′s condition improved.Three children′s PP65 antigenaemia remained positive,when they were clinic cured.Two of them became negative after two weeks and one after three weeks.Conclusion Antigenaemia PP65 is effective in early diagnosis of active CMV infection,predicting patient′s condition and providing early intervention and treatment.

Congenital Asymptomatic Cytomegalovirus Infection: A Comparison of Specific IgM Antibody Test and pp65 Antigenemia Assay

PURPOSE: It is increasingly important to diagnosis asymptomatic infections which make up a majority (90%) of congenital cytomegalovirus (CMV) infections and that they may have sequeles such as sensorineural hearing loss and mental retardation. Recently antigenemia assay has been developed by using monoclonal antibodies against early structural protein pp65 of CMV. This CMV antigenemia assay seems to be more quicker to diagnosis than conventional viral culture or other tests. In this study, we evaluated the CMV antigenemia assay in neonatal congenital asymptomatic CMV infections comparing it to the CMV specific IgM test that uses enzyme immunoassay. METHODS: From October 1995 to May 1996, 231 normal term newborns delivered with asymptomatic in St. Holy Hospital of Catholic University were included. The CMV antigenemia assay was performed with CMV-vueTM Kit by immunocytochemical staining and the CMV specific IgM test was performed with Enzygnost Anti-CMV/IgM by using an enzyme immunoassay. RESULTS: Three cases (male 2, female 1) were CMV pp65 antigenemia assay positive, but none of them were CMV specific IgM antibody test positive. The CMV pp65 antigenemia assay was more sensitive than CMV specific IgM antibody test for detection of congenital asymptomatic CMV infections by 1.3% and 0%, respectively. CONCLUSION: According to previous results, we suggest that the rate of congenital CMV infections using only CMV specific IgM tests have been underestimated. We recommend the CMV antigenemia assay as the preferred method for more rapid and accurate diagnosis of CMV infections. And congenital asymptomatic CMV infections should be diagnosed and followed up because of possible future sequeles.