肾移植受者HLA体液免疫致敏状态的监测及其临床意义

为探讨肾移植受者同种异体HLA抗原致敏后体液免疫状态与术后排斥反应及移植物存活率的相关性及其临床意义,应用One Lambda混合抗原板(LATM)通过ELISA筛查受者术前血清中的HLA-IgG抗体,对阳性血清进一步用抗原板(LAT1240和LAT1HDS)检测抗体阳性率及其特异性;并采用序列特异性引物聚合酶链反应(PCR-SSP)技术进行HLA基因分型。在1 297例肾移植受者中,HLA-IgG抗体阳性者165例,其中I类抗体阳性126例,II类抗体阳性90例,51例同时存在I类和II类HLA-IgG抗体,抗体阳性率>50%的高致敏受者94例。所有受者术后未发生超急性排斥反应,抗体阳性组受者的急性排斥发生率与阴性组受者比较,没有统计学差异。然而抗体阳性组受者移植物功能延迟恢复(DGF)的发生率显著高于阴性组受者(P<0.001)。抗体阳性组受者的1年、3年和5年移植肾存活率分别为95%、88%和80%;与抗体阴性组受者组比较无统计学差异。女性受者中抗体阳性率明显高于男性受者(P<0.001);再次移植受者中抗体阳性率显著高于初次移植受者(P<0.001)。抗体阳性组受者的供受者配型明显优于抗体阴性组受者。HLA-IgG抗体是反映受者体液免疫致敏状态的敏感指标,供受者间良好的HLA配型能显著降低排斥反应发生率和改善移植物存活。     

巨细胞病毒感染下调肾移植受者NK细胞CD226和CD16的表达

目的探讨肾移植术后巨细胞病毒(CMV)感染对自然杀伤(NK)细胞活化性受体CD226以及CD16表达的影响。方法采用流式细胞术分别检测肾移植术后CMV感染期和稳定期、肾移植术后稳定期受者和健康对照者NK细胞CD226和CD16的表达。结果肾移植受者发生CMV感染者与CMV感染恢复期、稳定受者组和健康对照组NK细胞占淋巴细胞比例均无明显差异。但CMV感染组外周血CD226~+NK细胞占NK细胞比例为(75.06±13.65)%,显著低于健康对照的(88.28±11.98)%和肾功能稳定组的(87.53±6.43)%;感染恢复期患者CD226~+NK细胞比例恢复至(88.37±8.91)%,与稳定受者组和健康对照组均无显著差异。CMV感染组的NK细胞CD226平均荧光强度(MFI)与稳定受者组和健康对照组均无显著差别,而CMV感染恢复期患者NK细胞CD226的MFI明显高于上述3组。CMV感染组CD16~+NK细胞占NK细胞比例下降为(75.06±13.65)%,显著低于稳定受者组的(88.28±11.98)%和健康对照的(90.35±10.07)%,而恢复期CD16~+NK细胞比例回升到(86.30±14.01)%,与稳定受者组和健康对照组无显著性差异。NK细胞CD16的MFI在感染期和恢复期与稳定受者组和对照组均未见显著性差异。结论 CMV感染可引起NK细胞CD226和CD16表达下调,而在感染恢复期CD226和CD16表达恢复,提示CD226和CD16参与肾移植受者NK细胞抗CMV感染的过程。     

CMV感染细胞核抗早期抗原抗体(PENA)的测定及临床评价

目的对目前国内各种广泛应用于婴、幼儿的CMV实验室检测方法进行初步评价.方法本研究建立了应用间接荧光免疫法测定CMV细胞核抗早期抗原抗体(PENA)的新方法,同时进行PCR检测和ELISA检测IgM、IgA、IgG实验,对491例临床可疑为CMV感染的患儿进行检测,同时进行PCR方法及ELISA-IgM、IgA、IgG方法的检测,观察结果,并与尿中寻找CMV包涵体方法结果相比较.结果PENA(1/20)阳性率54.99%,PENA(1/100)阳性率21.70%,PCR方法的阳性率55.80%,ELISA-IgM阳性率8.76%,ELISA-IgA阳性率5.50%,ELISA-IgG阳性率68.43%.结论PENA方法可以特异的检测出病人血清中的抗病毒早期抗原抗体的存在,并具有敏感、特异、简便的特点,是一种实验室检测CMV的新方法,可作为临床检测CMV感染的补充方法,尤其适用于婴儿.     

肾移植受者术前HLA特异性抗体筛查(附3 500例报告)

目的:预致敏的人白细胞抗原特异性抗体(HLA)是抗体介导排斥反应的主要危险因素.本研究对肾移植受者术前进行HLA特异性抗体检测和分析,以评价其致敏状态.方法:1998年至2007年于我院等待肾移植的受者共3 500名.2000年3月前694名受者采用补体依赖微量细胞毒性试验(CDC)进行群体反应性抗体(PRA)检测,之后2 806名受者改为用酶联免疫吸附实验(ELISA)检测.对致敏受者HLA抗体多样性和特异性,以及致敏相关因素进行分析.结果:CDC方法仅能检出抗HLAⅠ类IgG抗体,而ELISA可检出抗HLAⅠ类和Ⅱ类抗体.CDC方法所检出的病人血清PRA阳性率比ELISA方法检出的阳性率低.而且,ELISA能分别检出抗HLA-A、B、CW、DR和DQ抗原的抗体20种、37种、8种、14种和7种.抗HLA-A2、24、68、23、32;B27、56、57、7;DR7、4、9、13、17、12;CW1、2、6、4、8 等位基因产物的抗体频率较高.这些抗HLA抗体与华南地区人群HLA抗原分布不尽一致.不同性别PRA阳性率存在显著性差异,男性以输血致敏为主,女性以输血、妊娠致敏为主.结论:采用ELISA方法能较为准确地检出抗HLA特异性抗体.避免供受者间常见高频抗体相应的HLA位点的错配和减少输血是减少抗HLA抗体的产生,以提高移植物存活的有效手段.     

PENA-IgG荧光免疫法与ELISA法检测儿童人巨细胞病毒感染的比较

目的本研究介绍了一种敏感、稳定、快速、简便的实验室检测巨细胞包病毒(CMV)的方法,同时与ELISA检测IgM、IgA、IgG结果比较.方法建立了检测细胞核内抗早期抗原抗体的新方法,应用该方法,对452例临床可疑为CMV感染的患儿进行检测,同时进行ELISA-IgM、IgA、IgG方法的检测,观察结果,进行比较.结果 PENA(1/20)阳性率54.99%,ELISA-IgM阳性率8.76%,ELISA-IgA阳性率5.50%,ELISA-IgG阳性率68.43%.结论 PENA方法可以特异的检测出病人血清中的抗病毒早期抗原抗体的存在,并具有敏感、特异、简便的特点,是一种实验室检测CMV的新方法,可作为临床检测CMV感染的补充方法,尤其适用于婴儿.     

应用荧光免疫法检测PENA-IgG及PCR检测HCMV感染的比较

目的 建立应用间接荧光免疫法测定CMV抗早期核抗原抗体（PENA）的方法。同时进行PCR检测实验，对两种应用于幼儿的CMV实验室检测方法进行初步评价。方法 应用二种实验对552例临床可疑为CMV感染的患儿进行实验观察。结果 PENA（1/20）阳性率49.46%，可疑阳性率6.16%,PENA(1/100)阳性率15.49%，可疑阳性率4.89%;PCR阳性率41.30%。结论 PENA方法可以特异的检测出病人血清中的抗病毒早期抗原抗体的存在，并具有感染，特异，简便的特点，可为初筛CMV感染的检测方法之一。尤其适用于婴儿。     

肾移植围手术期检测CMV-PP65抗原的意义

目的 探讨肾移植围手术期检测CMV-PP65抗原的临床意义.方法 选取我院肾移植患者100例,调查统计全部患者围手术期CMV-PP65抗原及抗CMV-IgM抗体检测结果,比较两项检测指标的敏感性及特异性.结果 CMV-PP65抗原检测的敏感性明显高于抗CMV-IgM抗体检测,两者比较差异有统计学意义（P＜0.05）;两种检测方法的特异性无统计学意义（P＞0.05）,但是CMV-PP65抗原检测出现阳性结果的平均时间明显小于抗CMV-IgM抗体检测出现阳性结果的平均时间,两者比较差异有统计学意义（P＜0.05）.结论 肾移植患者围手术期检测CMV-PP65抗原对于早期诊断CMV病具有较高的敏感性,对肾移植术后CMV病的诊断和早期抗病毒治疗具有重要的临床意义,值得推广应用.     

PENA-IgG荧光免疫检测方法与ELISA法检测婴儿HCMV感染的比较

目的 本研究介绍了一种敏感、稳定、快速、简便的实验室检测CMV的方法,同时与ELISA检测IgM、IgA、IgG结果比较.方法 建立了检测细胞核内抗早期抗原抗体的新方法,应用该方法,对491例临床可疑为CMV感染的患儿进行检测,同时进行ELISA-IgM、IgA、IgG方法的检测,观察结果,进行比较.结果 PENA(1/20)阳性率54.99%,PENA(1/100)阳性率21.70%,ELISA-IgM阳性率8.76%,ELISA-IgA阳性率5.50%,ELISA-IgG阳性率68.43%.结论 PENA方法可以特异的检测出病人血清中的抗病毒早期抗原抗体的存在,并具有敏感、特异、简便的特点,是一种实验室检测CMV的新方法,可作为临床检测CMV感染的补充方法,尤其适用于婴儿.     

肾移植术后巨细胞病毒抗体IgM/IgA的动态观察及临床意义

应用BSA-ELISA检测45例肾移植患者手术前后的抗CMV IgM/IgA.结果表明:术前患者抗CMV IgM和IgA的阳性率分别为42.2%和24.4%,术后随着移植时间的延长其阳性率递增,在术后8周分别达95.6%和88.9%,但其发病率仅占13.9%,分析证明CMV感染的发病与排斥反应有关.     

肾移植群体反应性抗体的检测及其临床应用

目的 :探讨人类白细胞抗原 (HLA)群体反应性抗体 (PRA)对肾移植效果的影响。方法 :采用酶联免疫吸附法 (ELISA)对 2 0 6例肾移植受者的血清PRA进行检测。同时对 14 0份血清分成四组包括首次移植术前及术后 1个月 ,半年至 1年肾功能稳定期病人 ,第一次尸肾移植失功恢复血透病人进行PRA检测。结果 :PRA阴性组受者移植术后排斥发生率为 11 85 % ,阳性组受者平均PRA高达 4 6 5 % ,两组比较差异显著 (P <0 0 0 1)。首次移植术前A组PRA阳性率 17 1% ,术后B组PRA阳性率 31 4 % ,肾功能稳定组 (C组 )PRA阳性率 14 3%。而移植失功恢复血透者 (D组 )PRA阳性率达 77 1%。结论 :PRA的检测是肾脏移植术前筛选致敏受者的重要指标 ,对肾脏移植后排斥反应和移植物存活率关系密切。     

Monitoring of cytomegalovirus infection in solid-organ transplant recipients by an ultrasensitive plasma PCR assay

Early and accurate monitoring of cytomegalovirus (CMV) infection in solid-organ transplant recipients is of major importance. We have assessed the potential benefit of an ultrasensitive plasma-based PCR assay for renal transplant recipients. The pp65 CMV antigen (pp65 Ag) assay using leukocytes was employed as a routine test for the monitoring of CMV in 23 transplant recipients. We compared the pp65 antigenemia with the CMV load quantified by an ultrasensitive PCR (US-PCR) with a limit of detection of 20 CMV DNA copies/ml of plasma. CMV infection was detected in 215 (67%) of 321 plasma samples by the US-PCR compared with 124 (39%) of 321 samples by the pp65 Ag assay. The US-PCR assay permitted the detection of CMV infection episodes following transplantation a median of 12 days earlier than the pp65 Ag assay. Moreover, during CMV infection episodes, DNA detection by the US-PCR was consistently positive, whereas false negative results were frequently observed with the pp65 Ag assay. We found a good correlation between the two assays, and the peak viral loads were significantly higher in patients with CMV-related complications (median, 5000 DNA copies/ml) than in those without symptoms (1160 DNA copies/ml) (P = 0.048). In addition, patients that did not require preemptive therapy based on the results of the pp65 assay had CMV loads significantly lower (median, 36 DNA copies/ml) than those that needed treatment (median, 4703 DNA copies/ml) (P < 0.001). These observations provided cutoff levels that could be applied in clinical practice. The ultrasensitive plasma-based PCR detected CMV infection episodes earlier and provided more consistent results than the pp65 Ag assay. This test could improve the monitoring of CMV infection or reactivation in renal transplant recipients.     

Cytomegalovirus diagnosis in renal and bone marrow transplant recipients: the impact of molecular assays.

BACKGROUND: Cytomegalovirus (CMV) infections are a major threat in transplant recipients. In recent years, new assays for routine CMV diagnosis, based on molecular techniques, have become available. OBJECTIVE: The impact of molecular assays for CMV diagnosis in transplant recipient was evaluated. STUDY DESIGN: A total of 51 transplant recipients were screened for CMV infection. Serological (AxSYM CMV IgG and recombinant CMV IgM assays), antigenemia, CMV DNA (qualitative in house PCR and the quantitative COBAS AMPLICOR CMV MONITOR Test), and CMV mRNA (NucliSens CMV pp67 Test) tests were compared. RESULTS: In 11/20 bone marrow transplant (BMT) recipients and 10/31 renal transplant (RTX) recipients there was no evidence of active CMV infection. Ten RTX recipients and one BMT recipient were antigenemia positive, 21 RTX and seven BMT recipients were PCR positive (qualitative CMV PCR). There were more BMT recipients CMV DNA positive in serum (7/21) than antigenemia positive (1/21). CMV mRNA was found positive in two BMT recipients (one case with no other evidence of CMV infection, the other one CMV DNA positive and antigenemia negative). The only antigenemia positive BMT recipient was found negative for CMV mRNA, but positive in all other tests. Eight RTX recipients were found positive for CMV mRNA. Six of them were also antigenemia positive and five of those were also found positive for CMV IgM. One CMV mRNA positive RTX recipient was CMV IgM positive but antigenemia negative and the other one CMV mRNA positive RTX recipient was found negative in all other tests. Two antigenemia positive RTX recipients were found negative for mRNA and CMV IgM. CONCLUSION: Antigenemia was found to be a good screening test for CMV infection in RTX recipients. In BMT recipients, tests based on molecular techniques appeared to be superior compared to antigenemia.     

Primary cytomegalovirus infection after combined cadaveric transplantation of the liver and kidney

Seronegative transplant recipients are at a high risk of developing primary cytomegalovirus (CMV) infection. The D+/R--constellation produces a 60%-80% probability of CMV disease. In such cases CMV prophylaxis is justified. Presentation of a 12-year old boy who developed a primary CMV infection following A combined liver-kidney transplantation; evaluation of prophylactic options and review of some difficulties in the diagnosis of CMV infection. A cadaveric liver-kidney transplantation (Tx) was done in a 12-year old boy with ESRD due to type I primary hyperoxaluria. CMV status: D+, R-; number of mismatches: 5. PRA 0; kidney cold ischemia time (CIT): 13.54 h; liver CIT: 10.10 h; immediate diuresis; Immunosuppression protocol: anti IL-2 receptor antibodies, steroids, mycophenolate mofetil (MMF); cyclosporine introduced on day 6. Over the first week, daily hemodialyses were done in order to remove oxalate deposits. Kidney and liver biopsies: no ACR, no oxalate deposits. CMV prophylaxis with ganciclovir started on day 0. Routine serology and PCR for CMV follow-up showed: pp 65, IgM and IgG, CMV. DNA (Murex CMV. DNA Hybrid Capture test 2.0): negative over the first 3 months. Day 98: CMV pp 65 positive, IgM neg, DNA neg. Day 108: pp 65 neg, IgM positive, IgG neg. CMV. DNA positive (15 x 105 copies/ml). Clinical status: except for mild Cushing, liver tests and kidney function were normal. Ganciclovir was administered intravenously (i.v.) and after 14 days continued perorally. A few days later, leukopenia with severe neutropenia (neutrophil count: 400) and right otitis media developed. MMF and ganciclovir were withdrawn for a few days and reintroduced after WBC count reconstitution. We had no possibility to monitor MMF. Day 150 pp 65 neg, IgM still positive, IgG neg. No clinical signs of infection. Liver and kidney functions normal. After liver-kidney transplantation in a CMV high-risk pediatric patient (D+/R-), asymptomatic CMV primary infection developed. Although ganciclovir prophylaxis could not prevent the infection, it was mild and delayed. Due to bone marrow suppression, discontinuation of MMF and ganciclovir was necessary. Antigenemia assay pp 65 did not correlate very well with CMV viremia so it could not be recommended as a routine test. It should be used in combination with other CMV tests.     

Detection of cytomegalovirus (CMV) in granulocytes by polymerase chain reaction compared with the CMV antigen test.

To compare the sensitivity and suitability of detection of active cytomegalovirus (CMV) infection by using monoclonal antibodies against CMV antigen (antigen test to detect antigenemia) and the polymerase chain reaction (PCR; to detect viral DNA) in granulocytes, 19 heart and 2 lung transplant recipients were closely monitored by these tests for at least 3 months after transplantation. All patients were CMV seropositive or had a seropositive donor. In total, 201 samples were tested; 46 were positive by both tests, 9 samples showed only antigenemia, 54 samples were positive by PCR only, and 102 samples were negative by both tests. PCR was positive earlier after transplantation in eight patients, whereas antigenemia was positive earlier after transplantation in one patient. In another four patients, both tests were positive at the same time. PCR was, on average, positive for a longer period of time. Discordant results showing a positive antigen test and a negative PCR were partly due to sampling error; some were positive by PCR on retesting. Samples which were negative by the antigen test and positive by PCR were taken at the beginning or at the end of an active CMV infection. In two patients, no active CMV infection was detected by the antigen test, cultures of urine and saliva, or serology, although PCR was positive for a long period of time in the two patients.     

Antibodies to cytomegalovirus in renal allograft recipients: correlation with isolation of virus.

A cohort of 47 renal transplant recipients was studied prospectively for up to one year after transplantation. Cytomegalovirus (CMV) was isolated from 21 of the patients. The first time the virus was isolated seven patients were IgM positive, nine showed a significant rise in IgG titres, and 12 had a four-fold or greater rise in complement fixation titre. There was no significant difference in the time at which virus was first detected following transplantation between patients with primary CMV infection and those with reinfection or recurrent infection. In general, patients with primary infection shed virus consistently over long periods. Those with reinfection or recurrent infection shed virus intermittently or not at all. There were considerable differences between individual patients in the timing and pattern of the immune response. Taken overall, a four-fold rise detected by the complement fixation test correlated best with the onset of CMV shedding in primary infection. There was more variation in the pattern of antibody response in cases of reinfection or recurrent infection, with no single serological test correlating better than the others. It is concluded that serology is of limited value in the detection of active CMV infection after renal transplantation.     

Different profiles of cytomegalovirus RNA transcripts and anti-cytomegalovirus IgM antibodies in renal transplant recipients.

BACKGROUND: A difference in anti-cytomegalovirus IgM antibody profile has been found between sera from acutely cytomegalovirus (CMV)-infected patients and sera from CMV-infected patients with subclinical infection. OBJECTIVES: The aim of this study is to investigate whether such different IgM antibody responses are correlated with differences in the expression of CMV immediate early and late mRNAs. STUDY DESIGN: We have investigated the anti-CMV IgM response in 46 renal transplant recipients by employing two commercially available IgM kits (AxSYM and IMX) as well as two novel enzyme-linked immunosorbent assays (ELISAs), which were developed using recombinant ppUL32 (pp150) and pUL80a (p38), respectively. The results were compared with four direct CMV diagnostic tests: pp65 antigenemia, viral culture and nucleic acid sequence-based amplification (NASBA), detecting either CMV immediate early 1 (IE1) mRNA (IE1-NASBA), or CMV pp67 (late) mRNA (pp67-NASBA). RESULTS: Analysis of all CMV-infected recipients (n=28) showed that in 16 recipients (group I) more than one direct test became positive after transplantation, while in the other 12 recipients (group II), IE1-NASBA was the only direct test to become positive. In group I, 100, 81, 100 and 50% of the recipients were IgM-positive with AxSYM, IMX, p38 and pp150, respectively. In group II, 100, 83, 17 and 83% of the recipients were IgM-positive with AxSYM, IMX, p38 and pp150, respectively. CONCLUSIONS: Our data indicate that the IgM-response against p38 and pp150 differs significantly (P<0.01) between group I recipients with productive CMV infection, and group II recipients with a non-productive CMV infection which may be of diagnostic and prognostic relevance.     

Cytomegalovirus-specific antibody responses in renal transplant patients with primary and recurrent CMV infections

Cytomegalovirus (CMV) specific immunoglobulin G (IgG) and immunoglobulin M (IgM) antibody responses were measured before and after renal transplantation in 20 patients with primary CMV infection and in 16 patients with recurrent CMV infection. In primary CMV infection IgG antibody titres to late antigen (IgG-LA) measured by indirect fluorescence (IFA) were approximately seven times higher than those obtained by the complement fixation test (CFT). In contrast, in recurrent CMV infection this difference was found to be about twofold. Virus-specific IgM antibody to late antigen (IgM-LA) was detected in 100 percent of patients with primary CMV infection and in only 50 percent of patients with recurrent CMV infection. The IgM-LA titres were highest in primary CMV infection and reached peak levels at approximately 10 weeks post transplantation, whereas in recurrent CMV infection the IgM-LA titres were lower and reached peak levels at three months post transplantation. Moreover, IgM-LA was found to persist in patients from both groups at nine months post transplantation. IgM antibody to early antigen (IgM-EA) was not detected in any patient in this study. However, significant fourfold titre rises in IgG antibody to EA (IgG-EA) were detected in 100 percent of patients with recurrent CMV infection and in 50 percent of patients with primary CMV infection. These results clearly show the difference in antibody responses to the various antigens of CMV in patients with primary and recurrent CMV infection.     

Detection of cytomegalovirus using PCR in serum from renal transplant recipients.

AIMS--To develop a polymerase chain reaction (PCR) assay for the detection of cytomegalovirus (CMV) DNA in serum and leucocytes of renal transplant recipients and compare this assay with CMV culture and serodiagnosis. METHODS--Monthly specimens were obtained from 12 patients starting immediately before transplant. CMV infection was monitored by IgM enzyme linked immunosorbent assay, virus culture and PCR on serum and leucocytes. RESULTS--Two of four IgG positive patients had reactivation of CMV disease confirmed by culture, three of eight seronegative patients had a primary infection, one confirmed by serology and two by culture. PCR was positive earlier than conventional methods in three cases and concurrently in two. No positive PCR reactions occurred in the seven patients who remained negative by culture and serology. CONCLUSIONS--CMV DNA is detectable in serum; serum may be positive before virus is detectable by buffy coat culture; and PCR may be useful as an early indication of potential CMV disease in renal transplant recipients.     

Use of recombinant nucleocapsid proteins of the hantaan and nephropathia epidemica serotypes of Hantaviruses as immunodiagnostic antigens

Cytomegalovirus-specific in vitro antibody production (CMV-IVAP) by peripheral blood lymphocytes (PBL) was investigated in 12 renal transplant recipients. CMV-IVAP, CMV-serology, and viral cultures were carried out weekly during at least 8 weeks after transplantation. Nine episodes of CMV infection occurred in eight patients. CMV-IVAP was positive in eight episodes; IgG and/or IgA and/or IgM antibodies reacting with several CMV polypeptides were secreted by PBL. In two patients with primary CMV infection, only IgA antibodies were detected. Cytomegalovirus cultures were positive in eight episodes and serological evidence of CMV infection was obtained in five episodes. In one case, CMV-IVAP was observed before CMV isolation and in another case, before serological evidence of CMV infection. Our study indicates that CMV-IVAP could represent an additional tool for the diagnosis of CMV infection. Our study indicates that CMV-IVAP could represent an additional tool for the diagnosis of CMV infection in renal transplant recipients. © 1993 Wiley-Liss, Inc.     

Cytomegalovirus DNA concentration in plasma predicts development of cytomegalovirus disease in kidney transplant recipients

The clinical significance of cytomegalovirus (CMV) DNA detection in post-kidney transplantation infection surveillance was examined by comparing the performance of three assays for detection of CMV in blood: the test for CMV-pp65-antigen in leukocytes, which is routinely employed in our laboratory, the quantitative plasma CMV-DNA-polymerase chain reaction (PCR; Cobas Amplicor CMV Monitor test^®) and the qualitative plasma CMV-DNA-PCR (Amplicor CMV test^®). Thirteen kidney transplant recipients were monitored with serial samples taken over a period of 3 months following transplantation. The quantitative CMV-PCR was the test with highest sensitivity, 95.9%, vs. 88.9% and 76.9% for the CMV-pp65 antigen assay and qualitative CMV-PCR, respectively. The virus load in the first positive specimens, assessed as DNA-copies/mL, was significantly associated with CMV disease because five of the six patients who developed disease, but only one of the seven who did not develop disease, had more than 3000 CMV-DNA-copies/mL. The number of CMV-pp65 antigen-positive cells in the first positive specimens did not have predictive value for development of CMV disease. Assessment of CMV in plasma by the quantitative CMV-PCR is especially useful since it has a high sensitivity and the amount of CMV DNA in plasma is a good predictor of CMV disease.