Quantitation of cytomegalovirus (CMV) DNA by real-time PCR for occurrence of CMV disease in HIV-infected patients receiving highly active antiretroviral therapy

Comparison of prophylaxis and preemptive strategy as cytomegalovirus prevention in liver transplant recipients

OBJECTIVES

Prophylaxis (P) or pre-emptive strategy (PS) in high-risk liver transplant recipients (LTRs) are either recommended. We compared the results of each strategy.

METHODS

Two groups of LTR transplanted during two consecutive periods were compared. Only cytomegalovirus (CMV)-mismatched LTR (Donor +/ Recipient -) were included. The primary endpoints were: the onset of polymerase chain reaction-based DNAemia and the proportion of patients with CMV disease. A number of episodes of CMV infection, antiviral therapy, ganciclovir resistance, infectious or immunological complications, cost of both strategies, and survival (1, 5, and 10 years) were also compared.

RESULTS

Forty-eight and 60 patients were respectively included in the P and PS groups. Eighteen (38%) in the P group and 56 (93%) in the PS group had CMV DNAemia (p <.0001) with a similar CMV disease rate (16.7% and 15%). Duration of curative therapy was longer in the PS group: 91 days versus 16 (p <.0001). Acute rejection was less frequent (p = .04) and more patients experienced a ganciclovir-resistant CMV infection in the PS group (10% vs. 0, p = .03). The drug-associated cost of PS was higher (10 004 vs. 4804€) and the median number of rehospitalization days tended to be higher (6 vs. 4, p = .06). Survival at any time was similar.

CONCLUSION

We reported more CMV DNAemias and ganciclovir-resistant CMV events with PS. The cost of the PS strategy was higher.

Diagnostic utility of quantitative plasma cytomegalovirus DNA PCR for cytomegalovirus end-organ diseases in patients with HIV-1 infection

OBJECTIVE

To investigate the diagnostic value of quantitative plasma cytomegalovirus (CMV)-DNA polymerase chain reaction (PCR) for CMV end-organ diseases (CMV-EOD) in patients with HIV-1 infection.

DESIGN

Single-center cross-sectional study.

METHODS

The study subjects were HIV-1-infected patients with CD4 ≤200 per microliter, who had undergone ophthalmologic examination with plasma CMV-DNA PCR measured within 7 days. CMV retinitis and other CMV-EOD were diagnosed according to the ACTG criteria. PCR value was converted into the WHO international standard.

RESULTS

CMV retinitis and all CMV-EOD were diagnosed in 23 (5%) and 37 (8%) of the 461 study patients, respectively. CMV-DNA was undetectable (<185 IU/mL) in 2 patients with CMV retinitis and 1 with encephalitis. The area under the receiver operating characteristic curve of CMV-DNA for CMV retinitis and all CMV-EOD were 0.80 [95% confidence interval (CI): 0.71 to 0.89] and 0.82 (0.75 to 0.89), respectively. The sensitivity, specificity, positive predictive value, and negative predictive value for each cutoff value of CMV-DNA were as follows: for CMV retinitis, ≥10,086 IU/mL: 26.1%, 94.1%, 18.8%, 96%; ≥2946 IU/mL; 56.5%, 86.8%, 18.3%, 97.4%; ≥959 IU/mL; 60.9%, 78.1%, 12.7%, 97.4%; detectable CMV-DNA (≥185 IU/mL): 91.3%, 48.2%, 8.5%, 99.1%; for all CMV-EOD: ≥10,086 IU/mL: 32.4%, 95.3%, 37.5%, 94.2%; ≥2946 IU/mL; 54.1%, 88%, 28.2%, 95.6%; ≥959 IU/mL; 62.2%, 79.5%, 20.9%, 96%; detectable CMV-DNA; 91.9%, 49.5%, 13.7%, 98.6%.

CONCLUSIONS

Plasma CMV-DNA PCR has a high diagnostic value for both CMV retinitis and all CMV-EOD in patients with advanced HIV-1 infection. A cutoff value of CMV-DNA ≥10,086 IU/mL and ≥2946 IU/mL yields high specificity, whereas undetectable CMV-DNA load (<185 IU/mL) likely rules out CMV-EOD.

Detection of cytomegalovirus infection by quantitative polymerase chain reaction

Human cytomegalovirus (CMV), also known as human herpes virus-5 (HHV-5), is a common human pathogen acquired early in life in the majority of immunocompetent individuals. Primary infection establishes a state of latency and the virus can be reactivated during immunosuppression. CMV is a significant cause of morbidity and mortality in newborns and patients with impaired immune system. Prenatal infection can result in intrauterine growth retardation, hepatitis, myocarditis, pneumonitis, and neurologic abnormalities. Individuals with congenital or acquired immunosuppression can develop a primary CMV infection, infection with another CMV strain or experience reactivation of the latent virus. The hematopoietic stem cell and solid organ transplant recipients are at high risk of developing CMV infection, especially early in a post-transplant period. The definition of CMV disease includes the evidence of end-organ involvement in the presence of CMV detected by a validated laboratory assay. The selection of a laboratory method is highly dependent on the type of sample to be tested and the clinical presentation. In the clinical practice, the quantitative PCR-based assays are most helpful, since they can measure the level of CMV DNA in whole blood, plasma, cerebrospinal fluid, amniotic fluid, tissue, and urine, and follow the kinetics of infection. In this chapter we describe the PCR assay designed to quantify CMV DNA in human plasma by amplifying a 105 base-pair (bp) fragment of the CMV immediate-early DNA polymerase gene.

Evaluation of glycoprotein B genotypes and load of CMV infecting blood leukocytes on prognosis of AIDS patients

BACKGROUND

Cytomegalovirus (CMV) remains an important pathogen to immunocompromised patients even in the era of HAART. The present study aimed at evaluating the influence of CMV viral load and its gB genotypes on AIDS patients' outcome.

METHODS

Blood samples of 101 AIDS patients were collected and tested for HIV load, CD4 - cell count and opportunistic pathogens, including CMV. Semi-nested PCRs were run to detect CMV genome and in the positive samples, gB genotyping and CMV load were established using enzymatic restriction and real time PCR, respectively. All patients were clinically followed for four years.

RESULTS

In thirty patients (31%) CMV was detected and all fatal cases (n = 5) occurred in this group of patients (p = 0.007), but only two patients had CMV disease (1.9%). However, viral load was not statistically associated with any analyzed parameter. The most frequently observed CMV genotype was gB2 (45.16%) followed by gB3 (35.48%). gB2 genotype was more frequently found in patients with CD4-cell counts under 200 cells/mm³ (p = 0.0017), and almost all fatal cases (80%) had gB2 genotype.

CONCLUSIONS

Our study suggests that CMV and its polymorphisms in biologically relevant genes, such as the gB encoding ORF, may still influence the prognosis and outcome of AIDS patients. The gB2 genotype was associated to patient's bad outcome.

[Evaluation of cytomegalovirus quantification in blood by the R-gene real-time PCR test]

AIM OF THE STUDY

Diagnosing the presence of cytomegalovirus (CMV) in the blood of immunodepressed patients is often done by quantitative polymerase chain reaction (Q-PCR) even though the reference method remains the antigenemia pp65 (Ag-pp65) test.

OBJECTIVES

To define the predictive value of the Q-PCR in the diagnosis of CMV disease and assess treatment efficacy using the CMV R-gene test. To compare the Q-PCR results and feasibility with those of the Ag-pp65 test.

PATIENTS AND METHODS

The Q-PCR was performed in 34 whole blood samples (frozen at -80 degrees C until use) from five patients diagnosed with CMV disease, defined as the presence of clinical signs and Ag-pp65 in the nuclei of more than two cells. After extraction, viral DNA was quantified in each sample using the Q-PCR CMV R-gene kit according to the manufacturer's instructions. Immediately after blood was drawn, the Ag-pp65 test had been performed in 32 samples using CINAkit (Argene).

RESULTS

The 16 samples positive by the Ag-pp65 test were also positive by PCR; six samples negative by the Ag-pp65 test were positive by PCR; and the remaining 10 samples were negative by both techniques. During treatment, the two markers' kinetics were similar.

CONCLUSION

The CMV R-gene test has a predictive value as good as that of the Ag-pp65 test but is fast and easier to use. A prospective study with a greater number of patients is needed to define the prediction threshold for CMV disease.

Monitoring of human cytomegalovirus infection in immunosuppressed patients using real-time PCR on whole blood

BACKGROUND

Quantitative monitoring of human cytomegalovirus (HCMV) is currently used in the follow-up of immunosuppressed patients.

OBJECTIVE

To investigate whether real-time PCR quantification (QPCR) of HCMV DNA could replace pp65 antigenemia.

STUDY DESIGN

We compared HCMV QPCR on whole blood (WB) and on plasma with a pp65-antigenemia assay on 192 samples. Afterwards, we tested 1310 samples from 308 immunosuppressed patients both by antigenemia assay and QPCR on WB.

RESULTS

The first study comparison showed that QPCR results on WB and plasma were significantly correlated with antigenemia. QPCR on WB was more sensitive than QPCR on plasma or antigenemia, detecting 31 and 49 additional positive samples, respectively. During the second comparison, QPCR on WB and antigenemia were again correlated (r=0.70; p<0.0001), but QPCR detected 244 additional positive samples. HCMV DNA was detected earlier than pp65 antigen (median difference: 14 days; range: 7-30). One, 5, 10, 50 and 100 pp65-positive cells/200,000 leukocytes corresponded to 439, 1531, 2623, 9150 and 15,671 HCMV DNA copies/mL of WB, respectively, but this equivalence differed according to the sub-group of patients considered.

CONCLUSION

QPCR on WB is the most sensitive method for the monitoring of HCMV infection in immunosuppressed patients.

Quantification of hepatitis delta virus RNA in serum by consensus real-time PCR indicates different patterns of virological response to interferon therapy in chronically infected patients

Hepatitis delta virus (HDV), in association with hepatitis B virus, is responsible for severe acute and chronic hepatitis. Treatment of the infection relies on the long-term administration of high doses of alpha interferon (IFN), and the treatment efficiency is monitored by the detection of anti-HDV immunoglobulin M and HDV genome in serum. Like the case for other chronic viral infections, HDV genome quantification in serum should be useful for the follow-up of infected patients. The aims of this study were to develop a quantitative assay for the detection of any type of HDV in serum and to evaluate the benefit of HDV RNA quantification for the follow-up of chronically infected patients receiving IFN. A real-time reverse transcription-PCR assay was developed to quantify the HDV RNA load in serum. Its efficacy was evaluated with 160 serum samples, 76 of which were collected from 11 chronically infected patients who were treated with pegylated IFN. The assay was sensitive (100 copies/ml of serum) and efficient for all HDV types, including type 3 and the recently described types 5, 6, and 7. The viral load determinations for treated patients allowed us to identify different profiles of virological responses to IFN therapy with more accuracy than that attainable with the qualitative approach. In conclusion, we have developed a quantitative HDV RNA assay for serum which is adapted to the follow-up of antiviral treatment for patients infected with any HDV type. The assay will help us to understand the natural history of HDV infection and to define guidelines for the management of chronic delta hepatitis.

Monitoring low cytomegalovirus viremia in transplanted patients by a real-time PCR on plasma

Until recently, human cytomegalovirus (hCMV) infection and anti-CMV treatment in transplanted patients have been monitored essentially by pp65 antigenemia, which is time-consuming and requires experienced operators. For the last two years, pp65 antigenemia levels have tended to be lower than previously in our laboratory, which could be due to better monitoring of CMV-related risk. Results obtained by real-time PCR with a LightCycler instrument or by pp65 antigen assay were compared on 145 serial samples from bone marrow or kidney transplant recipients under the usual conditions of our laboratory. CMV DNA was extracted from plasma and quantified by using primers and probes directed to HXFL4 gene. The plasma CMV DNA load was measured by using a standard curve constructed with a commercially available quantified CMV DNA suspension. Among the 145 samples, 139 showed a pp65 antigen which was negative or lower than 20 positively stained cells per 200,000 leukocytes. In the patients with positive pp65 antigenemia, the corresponding values of CMV DNA copy number/ml were significantly higher than those observed in patients without antigenemia (P < 0.001). CMV DNA was detected from 4 up to 52 days before pp65 antigen. Elsewhere, between two dates at which pp65 antigen was positive, intermediate PCR results could be positive while the pp65 antigen was negative. This real-time quantitative PCR assay is a rapid technique adapted to monitor plasma CMV DNA in transplant setting, even for low viremia.