巨细胞病毒抗原检测对巨细胞病毒病预防的意义

目的：提高对肾移植术后巨细胞病毒（CMV）病的防治水平,方法：应用免疫组织化学方法（LSAB法）对1997年度肾移植患者进行CMV抗原检测,对检查阳性的患者采用丙氧鸟苷预防性治疗,并与1996年度未预防治疗组进行对照.结果：1997年预防性治疗后,CMV病发病率为3．1％（5／160）,病死率为20．0（1／5）,而1996年未预防治疗组,CMV病发病率为11．7％（16／136）,病死率为43．8％（7／16）,结论：对肾移植术后CMV抗原检测阳性患者预防性应用丙氧鸟式能显著降低CMV病的发生率和病死率。     

Comparison of quantitative PCR and antigenemia in cytomegalovirus infection in renal transplant recipients

Cytomegalovirus infection is a common complication of renal transplantation. Antigen pp65 levels serve as indicators of viral load, although the technique is difficult to perform and interpret. We sought to determine whether quantitative PCR had a higher sensitivity and predictive value in CMV infection. METHODS: The study included 100 renal transplant recipients who were screened for IgM and IgG at the time of admission. On days 7, 15, 30, 45, 60, 75, 90, 120, 180, and 360, antigenemia tests were performed on blood (pp65) and urine, and a quantitative PCR on blood. Among 59 patients recruited between November 2003 and August 2004 the mean age was 54.5 +/- 12.9 years. Two patients did not reach 90 days follow-up (3%); four patients have not surpassed 90 days (7%); 22, 120 days (37%); and 31, 180 days (53%). Ninety-three percent of patients showed anti-IgG CMV-positive titers with all being IgM CMV-negative at baseline. The patients at risk for infection were given valgancyclovir as prophylaxis throughout the study. RESULTS: At 474 visits, 8 samples (2.4%) were positive with urine; 5 (1.4%) with pp65, and 15 (4.7%) with PCR. Among the 15 positive samples, two (>100,000 and 3250 copies) revealed agreement of positive IgM and shellvial test on urine; two (15,100 and 5670 copies), antigen pp65 1+; one (17,400 copies) with pp65 2+ and shellvial urine; two (99,400 and 28,300 copies) with pp65 1+ and shellvial urine; and eight remaining determinations, 749, 2250, 686, 928, 2250, 26600, 777, and 2790 copies. The rest of the tests were negative. CONCLUSION: The preliminary results of this study demonstrated that quantitative PCR was a useful rapid tool for diagnosing and monitoring CMV infections.     

Real-time PCR assay compared with antigenemia assay for detecting cytomegalovirus infection in kidney transplant recipients

Human cytomegalovirus (CMV) infection is a major cause of morbidity and mortality among kidney transplant recipients. The CMVpp65 antigenemia assay has been used for preemptive therapy. Real-time polymerase chain reaction (PCR) technology for CMV DNA quantification in blood has demonstrated a good correlation with the currently employed CMV antigenemia assay. In this study, 90 renal transplant recipients were prospectively enrolled from July 2004 and May 2005. Monitoring of CMV infection was routinely performed with CMV antigenemia and real-time PCR assays. Real-time plasma PCR and CMV antigenemia assays were assessed on 797 samples. CMV antigenemia correlated with a positive CMV PCR (chi(2) = 78.05; P < .0001). Not only the positive rate but also the number of positive cells correlated with the number of PCR DNA copies (F = 26.07, r(2) = .25, P < .0001). To define an optimal cutoff value of CMV DNA load to initiate treatment in kidney transplant patients, we considered a CMV antigenemia titer of >50 positive cells per 400,000 leukocytes as the gold standard in our previous study. The optimal cutoff value for the quantitative real-time PCR assay was predicted to be 86 copies/microL. Thus, we observed that CMV real-time PCR assay would not completely replace antigenemia assay in kidney transplant recipients, but can be used complementarily to screen antigenemia and monitor preemptive therapy.     

Early diagnosis of CMV infection by detection of pp65 antigen in 91 renal transplant recipients

We evaluated how accurately a CMU antigenemia test correlated with classical CMU infection markers. We studied 91 kidney transplant recipients from February 1991 to June 1992. Antigenemia (pp65 antigen) was positive in 100% of cases of primary infection and in 70% of cases of reactivation and/or reinfection. Furthermore, antigenemia detected more infections (71%) than viremia (16%). The antigenemia test proved to be highly specific: it remained consistently negative in 22 seronegative patients, as well as in 19 of 20 seropositive recipients without recurrent infection. pp65 Antigen in the polymorphonuclear leukocytes was detected earlier than, or simultaneously with, virus culture in 78% of cases and became positive before serologic tests of primary and secondary infection in nearly 90% of cases. Most importantly, the antigenemia test detected all of the symptomatic cases.     

Antigenemia,immunoblotting, and enzyme immunoassay for early diagnosis of cytomegalovirus infection in renal transplant patients

Timely and rapid diagnosis of cytomegalovirus (CMV) infection is important for the management of transplant patients. We compared three serological assays, IgM immunoblot and IgG/IgM enzyme immunoassay (EIA), as well as the detection of CMV antigens in polymorphonuclear blood leukocytes (antigenemia), for their value in the early diagnosis of CMV infection. Thirty-one patients were monitored longitudinally for 3 months after renal transplantation. Laboratory documented CMV infection occurred in 20 patients. All of these cases showed a positive IgM immunoblot result that was confirmed by at least one of the other test assays (IgG EIA 19/20, antigenemia assay 13/20, and IgM EIA 12/20). All of the ten patients whose clinical picture was compatible with symptomatic CMV disease were positive for CMV infection according to IgM immunoblot and IgG EIA, nine were positive according to the antigenemia assay, and seven were positive according to IgM EIA. With reference to the temporal pattern, the antigenemia assay indicated CMV infection significantly earlier than the serological tests (P0.05). In symptomatic patients CMV antigen-positive leukocytes were, on the average, detected on the day of onset of symptoms, whereas detection by IgM immunoblot, IgG EIA, and IgM EIA followed 8, 13, and 14 days later, respectively. These results show that: (1) the CMV antigenemia assay is very useful for the early diagnosis of symptomatic CMV infections; (2) CMV antibodies, as an indicator of CMV infection, are detectable earlier and more frequently by IgM immunoblot than by IgG/IgM EIA; (3) compared to CMV anti-genemia, the IgM immunoblot indicated CMV infection more often but significantly later; and (4) only a combination of several diagnostic methods allows optimal detection of CMV infections in renal transplant patients.     

肾移植术后多瘤病毒感染的临床诊断和治疗

目的 探讨肾移植术后多瘤病毒（BKV）感染的诊断方法、监测指标及初步治疗方法。方法 采集64例肾移植受者的血、尿样本，行BKV细胞学与聚合酶链反应（PCR）检测。对肾移植术后BKV感染的流行病学以及相关因素进行分析，并对BKV感染的受者进行试验性治疗。结果 64例受者的尿Decoy细胞、多瘤病毒尿症与多瘤病毒血症的阳性率分别为28．7％、17．2％和6．3％。血肌酐（Cr）升高的受者尿Decoy细胞阳性率高于血Cr稳定的受者（P=0．04）。受者的性别、年龄、诱导治疗方案、是否发生急性排斥反应以及术后肾功能恢复情况等临床因素与尿Decoy细胞、多瘤病毒尿症及多瘤病毒血症的出现无明显相关性。应用更昔洛韦试验性治疗4例BKV感染的受者，治疗2～3周后，受者的尿Decoy细胞以及血、尿BKV DNA均转为阴性。结论 血肌酐水平升高的肾移植受者易发生BKV再活化。可通过检测血BKV DNA筛查BKV相关的移植肾肾病。更昔洛韦治疗BKV具有良好的疗效，但需进一步验证。     

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.     

Cryptosporidium infection in renal transplant patients

Cryptosporidium parvum, an intracellular protozoan parasite, is a significant cause of gastrointestinal disease worldwide. Transmission can occur from an infected person, animal or fecally contaminated environment. The clinical manifestations of cryptosporidiosis are dependent on the immunologic state of the host. Infection among immunocompetent hosts results in diarrhea that is typically self-limited. In immunocompromised hosts, however, the infection may be protracted and life-threatening with no reliable antimicrobial therapy. In transplant patients, a course of antimicrobial therapy along with concurrent reduction in immunosuppression optimize immunologic status and may potentially lead to resolution of the infection.     

Serial beta-2 microglobulin measurement as an auxilliary method in the early diagnosis of cytomegalovirus infection in renal transplant patients

Infection by cytomegalovirus is one of the most important causes of morbidity and mortality after renal transplant. During episodes of acute rejection serum levels of beta-2 microglobulin (B2M) are elevated due to decreased excretion and/or increased production from T-cell proliferation. Sequential measurement of B2M in the first months after transplantation may detect patients at increased risk of rejection. This study assesses the usefulness of serum B2M for early detection of patients with increased risk of cytomegalovirus disease. Among 16 of 18 cases of CMV infection, there was an increase in serum B2M levels before CMV diagnosis. In all cases, B2M serum levels increased at an average of 10.8 days before the symptoms or the positive antigenemia. From a mean baseline B2M value of 5.0 mg/L, the mean value at the time of diagnosis was 7.7 mg/L before any clinical or laboratory evidence of CMV infection. These findings suggest that B2M serum levels can be used as a marker for early diagnosis of cytomegalovirus infection.     

Fibrosing cholestatic hepatitis in renal transplant recipient with CMV infection: A case report

Fibrosing cholestatic hepatitis (FCH) is an uncommon complication of renal transplantation. It is usually associated with hepatitis B and C viral infection. It is further rare in renal transplantation in absence of HBV and HCV infection. To the best of our knowledge, only three cases of FCH in renal transplantation, which were both HBV and HCV negative, have been reported to date. Out of these, two cases were diagnosed to have CMV infection and the third was attributed to azathioprin. We are presenting another case of FCH in a renal transplant recipient with CMV infection.