Evidence of clinical efficacy of counterpulsation therapy methods.

Although heart transplantation remains the ultimate treatment for end-stage heart failure, its epidemiological impact is limited by donor organ availability. Surgical and device-based approaches have been introduced with the aim of increasing systemic perfusion and in some circumstances promoting left ventricular recovery by inducing reverse remodelling. Innovative counterpulsation devices based on the established principle of the intra-aortic balloon pump have been developed, and of these, the CardioVad and the C-Pulse System have been introduced in clinical practice with convincing evidence of haemodynamic efficacy. The evolution from pulsatile to continuous-flow left ventricular assist devices has been associated with improved survival rates during the first 2 years of support with the potential of matching heart transplantation outcomes. However, blood contact with the device remains a significant challenge despite the highly sophisticated technology currently available. Innovative extra-vascular counterpulsation devices have been shown to overcome the limitations of the intra-aortic balloon pump and rend the device suitable for prolonged support. Monitoring of the performance of these novel devices is essential, and carotid Doppler ultrasonography is of utility in assessing the haemodynamic performance of the devices in a clinical setting. Computational modelling has played a role in the simulation of these devices and should continue to assist with their optimisation and implementation in clinical practice.

Acute calcineurin inhibitor overdose: analysis of cases reported to a national poison center between 1995 and 2011.

Transplant recipients and other patients requiring immunosuppression with calcineurin inhibitors or their household contacts may be exposed to overdose. This study investigated the circumstances, pharmacokinetics and outcomes of overdose with cyclosporine and tacrolimus reported to the Swiss Toxicological Information Centre between 1995 and 2011. Of 145,396 reports by healthcare professionals, 28 (0.02%) concerned enteral or parenteral overdose with these calcineurin inhibitors. Thirteen (46%) were iatrogenic errors, 12 (43%) were with suicidal intent and 3 (11%) were accidental. Iatrogenic overdoses usually involved noncapsule drug formulations. Acute enteral overdoses caused symptoms in a dose-dependent fashion but were generally well tolerated; the mean multiple of patient's usual dose was 20.8 ± 28.8 for symptomatic versus 4.4 ± 3.4 for asymptomatic cases (p = 0.037). The most common symptoms were nausea, headache, somnolence, confusion, hypertension and renal impairment. In contrast, acute intravenous overdoses were often poorly tolerated and resulted in one fatality due to cerebral edema after a cyclosporine overdose. Enteral decontamination measures were performed in six cases involving oral ingestion and appeared to reduce drug absorption, as shown by pharmacokinetic calculations. In the one case where it was used, pharmacoenhancement appeared to accelerate tacrolimus clearance after intravenous overdose.

A clinical assay for the measurement of milrinone in plasma by HPLC mass spectrometry.

Milrinone is a bipyridine phosphodiesterase inhibitor with positive inotropic and vasodilatory effects. As interest in longer term use of intravenous therapy increases, it becomes essential to monitor its plasma concentration owing to a narrow therapeutic range, an increased half-life in renal failure and toxicity associated with high levels. A high-performance liquid chromatography (HPLC) method with mass (MS) detection using a triple quadrupole mass spectrometer is presented. The method was compared with the UV/HPLC method and validated according to current international guidelines. Coefficients of variation of less than 7.5% were obtained across the therapeutic range and 18.3% at 2.4 ng/mL, the lower limit of quantitation. Plasma from 13 cardiac surgery patients receiving standard intravenous doses of milrinone were measured. Eight patients achieved therapeutic milrinone levels within 3-4 h post start of infusion, one was borderline sub-therapeutic and four patients achieved levels that were above the upper limit of the therapeutic range and potentially toxic. This method offers high sensitivity, is rapid, easy to use and requires minimal amount of sample. We believe this method could become the reference procedure for clinical monitoring of milrinone and help to improve the safety of the use of this drug in patients with cardiac failure.

De novo donor HLA-specific antibodies after heart transplantation are an independent predictor of poor patient survival.

Preformed donor HLA-specific antibodies are a known indicator for poor patient survival after cardiac transplantation. The role of de novo donor-specific antibodies (DSA) formed after cardiac transplantation is less clear. Here we have retrospectively analyzed 243 cardiac transplant recipients, measuring HLA antibody production every year after transplantation up to 13 years post-transplant. Production of de novo DSA was analyzed in patients who had been negative for DSA prior to their transplant. DSA including transient antibodies were associated with poor patient survival (p = 0.0018, HR = 3.198). However, de novo and persistent DSA was strongly associated with poor patient survival (p = 0.0001 HR = 4.351). Although complement fixing persistent DSA correlated with poor patient survival, this was not increased compared to noncomplement fixing persistent DSA. Multivariable analysis indicated de novo persistent DSA to be an independent predictor of poor patient survival along with HLA-DR mismatch and donor age. Only increasing donor age was found to be an independent risk factor for earlier development of CAV. In conclusion, patients who are transplanted in the absence of pre-existing DSA make de novo DSA after transplantation which are associated with poor survival. Early and regular monitoring of post-transplant DSA is required to identify patients at risk of allograft failure.

Comparison of the incidence of malignancy in recipients of different types of organ: a UK Registry audit.

An increased incidence of malignancy is an established complication of organ transplantation and the associated immunosuppression. In this study on cancer incidence in solid organ transplant recipients in Britain, we describe the incidence of de novo cancers in the allograft recipient, and compare these incidences following the transplantation of different organs. Data in the UK Transplant Registry held by NHS Blood and Transplant (NHSBT) were linked with data made available by the cancer registries in England, Scotland and Wales. Incidence rates in the transplanted population were then compared with the general population, using standardized incidence ratios matched for age, gender and time period. The 10-year incidence of de novo cancer in transplant recipients is twice that of the general population, with the incidence of nonmelanoma skin cancer being 13 times greater. Nonmelanoma skin cancer, cancer of the lip, posttransplant lymphoproliferative disease and anal cancer have the largest standardized incidence ratios, but the incidence of different types of malignancy differs according to the organ transplanted. Patterns in standardized incidence ratios over time since transplantation are different for different types of transplant recipient, as well as for different malignancies. These results have implications for a national screening program.

De novo HLA sensitization and antibody mediated rejection following pregnancy in a heart transplant recipient.

Here we report a case wherein both donor-specific and third-party, paternal, HLA class II specific antibodies developed following a spontaneous miscarriage resulting in antibody-mediated rejection in a patient who had undergone an orthotopic cardiac transplant six years earlier.

Disease-specific survival benefit of lung transplantation in adults: a national cohort study.

The lung transplantation candidate population is heterogeneous and survival benefit has not been established for all patient groups. UK data from a cohort of 1997 adult (aged > or = 16), first lung transplant candidates (listed July 1995 to July 2006, follow-up to December 2007) were analyzed by diagnosis, to assess mortality relative to continued listing. Donor lungs were primarily allocated according to local criteria. Diagnosis groups studied were cystic fibrosis (430), bronchiectasis (123), pulmonary hypertension (74), diffuse parenchymal lung disease (564), chronic obstructive pulmonary disease (COPD, 647) and other (159). The proportion of patients in each group who died while listed varied significantly (respectively 37%, 48%, 41%, 49%, 19%, 38%). All groups had an increased risk of death at transplant, which fell below waiting list risk of death within 4.3 months. Thereafter, the hazard ratio for death relative to listing ranged from 0.34 for cystic fibrosis to 0.64 for COPD (p < 0.05 all groups except pulmonary hypertension). Mortality reduction was greater after bilateral lung transplantation in pulmonary fibrosis patients (p = 0.049), but not in COPD patients. Transplantation appeared to improve survival for all groups. Differential waiting list and posttransplant mortality by diagnosis suggest further use and development of algorithms to inform lung allocation.

Lack of effect of MICA antibodies on graft survival following heart transplantation.

Little is known about the effect of MICA antibodies (Abs) on cardiac allograft function and survival. Pretransplant and posttransplant serum from 491 and 196 adult cardiac allograft recipients, respectively, has been investigated for MICA Abs, donor specificity and the effect of MICA Abs on graft survival, acute rejection episodes (AR) and cardiac allograft vasculopathy (CAV). Patients with HLA Abs (11.6%) were excluded from the analysis. A total of 11.8% of patients had MICA Abs, without HLA Abs, before their transplant. Actuarial graft survival demonstrated slightly better survival of patients with donor-specific MICA Abs at 1 and 5 years (88.9% and 83.3%) than patients negative for MICA Abs (72% and 63.7%, p = 0.051). After transplantation, 15.8% of patients produced MICA Abs, and in 17 patients these were produced de novo. There was no effect of pretransplant or posttransplant production of MICA Abs on numbers of AR episodes in year 1, or CAV assessed at years 3 and 5. Immunocytochemistry of cardiac biopsies from 11 patients did not demonstrate a presence of MICA. Sera from only 4/69 patients with MICA Abs fixed complement prior to transplantation and from 7/38 patients following transplantation. In conclusion, this study suggests that MICA Abs do not adversely affect the outcome of cardiac transplantation.

Heart transplantation for homozygous familial transthyretin (TTR) V122I cardiac amyloidosis.

Heart failure is the usual cause of death in patients with amyloid cardiomyopathy. The commonest form of hereditary cardiac amyloidosis is associated with the Val122Ile variant of transthyretin (TTR), which is carried by 3-4% of the African American population. Here, we report the outcome of the first cardiac transplantation in a patient with TTR V122I. A 59-year-old Caribbean man presented with biventricular failure. Other than previous bilateral carpel tunnel syndrome, he had been well and had no evidence of extracardiac amyloidosis. An endomyocardial biopsy demonstrated amyloid of TTR type. Sequencing of TTR gene indicated homozygosity for V122I. He underwent cardiac transplantation and 3 years later, remains well with no evidence of allograft or systemic amyloid deposition.

Heat shock protein 27 is associated with freedom from graft vasculopathy after human cardiac transplantation.

Experimental studies have suggested that protective genes protect allografts from cardiac allograft vasculopathy (CAV), the major complication after cardiac transplantation. Here we have sought to confirm this hypothesis using long-term heart transplant recipients. Twenty-two patients that were 9 years or older after transplant were investigated; 11 of these were without angiographic evidence of CAV; 11 had developed early CAV at 1 to 3 years after transplant. To identify proteins that may act as protectors from CAV, a global proteomic approach was used comparing cardiac biopsies from 12 patients taken within the first 2 weeks after transplant and those taken after 9 years from the same patient. Proteins were separated by 2-D gel-electrophoresis, detected by silver staining, and analyzed using Progenesis software. A particular protein spot was found in 4/6 biopsies from patients without CAV, but absent from 5/6 biopsies from those with CAV (P=0.24); however, quantitative analysis of spot intensity showed a significant difference (0.061+/-0.05 versus 0.003+/-0.01, P=0.04). This spot was identified by mass spectrometry and a combination of techniques as a diphosphorylated form of HSP27. Immunohistochemistry of further biopsies not only validated that HSP27 was more abundantly expressed on biopsies without CAV but also showed it to be localized to blood vessels. In contrast, vessels from patients with CAV did not express HSP27 (P=0.028x10(-4)). Immunohistochemistry of 12 further early biopsies and nontransplanted heart showed HSP27 to be present in normal blood vessels. These findings suggest that expression of a specific diphosphorylated form of HSP27 is associated with healthy blood vessels; it appears to be lost from vessels of patients with graft vasculopathy.

Clinical recovery from end-stage heart failure using left-ventricular assist device and pharmacological therapy correlates with increased sarcoplasmic reticulum calcium content but not with regression of cellular hypertrophy.

BACKGROUND: Left ventricular assist device (LVAD) treatment is known to lead to structural and functional cellular modifications in the heart. The relevance of these changes for clinical recovery is unknown. METHODS AND RESULTS: We compared properties of cardiomyocytes obtained from tissue taken at explantation of the LVAD in patients with clinical recovery with those obtained from hearts of patients who did not show clinical recovery, thus requiring transplantation. Compared with myocytes taken at implantation, both the recovery and nonrecovery groups showed approximately 50% reduction in cell capacitance, an index of cell size. However, action potential duration shortened, L-type Ca2+ current fast inactivation was more rapid, and sarcoplasmic reticulum Ca2+ content was increased in the recovery compared with the nonrecovery group. CONCLUSIONS: These results show that specific changes in excitation-contraction coupling, and not regression of cellular hypertrophy, are specifically associated with clinical recovery after LVAD and further identify sarcoplasmic reticulum Ca2+ handling as a key functional determinant in patients with heart failure.

Tumor necrosis factor-alpha is expressed in donor heart and predicts right ventricular failure after human heart transplantation.

BACKGROUND-Myocardial failure is an important problem after heart transplantation. Right ventricular (RV) failure is most common, although its mechanisms remain poorly understood. Inflammatory cytokines play an important role in heart failure. We studied the expression of tumor necrosis factor (TNF)-alpha and other cytokines in donor myocardium and their relationship to the subsequent development of RV failure early after transplantation. METHODS AND RESULTS-Clinical details were obtained, and ventricular function was assessed by transesophageal echocardiography in 26 donors before heart retrieval. A donor RV biopsy was obtained immediately before transplantation, and each recipient was followed for the development of RV failure. Reverse transcriptase-polymerase chain reaction was performed to detect TNF-alpha, interleukin-2, interferon-gamma, and inducible nitric oxide synthase expression. Eight of 26 recipients (30.8%) developed RV failure. Seven of these 8 (87.5%) expressed TNF-alpha, but only 4 of the 18 (22.2%) who did not develop RV failure expressed TNF-alpha (P<0.005). As a predictor of RV failure, TNF-alpha mRNA had a sensitivity of 87.5%, a specificity of 83.3%, a positive predictive value of 70%, and a negative predictive value of 93.7%. Western blotting demonstrated more TNF-alpha protein in the myocardium of donor hearts that developed RV failure (658+/-60 versus 470+/-57 optical density units, P<0.05). Immunocytochemistry localized TNF-alpha expression to cardiac myocytes. Reverse transcriptase-polymerase chain reaction detected interferon-gamma in 2 (7.7%), interleukin-2 in 1 (3.8%), and inducible nitric oxide synthase mRNA in 1 (3.8%) of the 26 donor hearts, none of which developed RV failure. CONCLUSIONS-TNF-alpha expression in donor heart cardiac myocytes seems to predict the development of RV failure in patients early after heart transplantation.

Elevated tumor necrosis factor-alpha and interleukin-6 in myocardium and serum of malfunctioning donor hearts.

BACKGROUND: Myocardial dysfunction is a common and important problem in donor hearts. The mechanisms responsible remain unclear. We have studied the cytokines tumor necrosis factor (TNF)-alpha and interleukin-6 (IL-6) in the myocardium and serum from donors with myocardial dysfunction (unused donors) and compared them with donors with good ventricular function (used donors) and patients with advanced heart failure (HF). METHODS AND RESULTS: Clinical details and ventricular function were assessed in 46 donors (31 used, 15 unused). Real-time reverse transcription-polymerase chain reaction, Western blotting, and immunocytochemistry were performed on myocardium and immunoassays on serum. TNF-alpha mRNA was 1.6-fold higher in unused than in used donors (P:<0.005) and 1.74-fold higher than in 36 patients with HF. IL-6 mRNA was 2.4-fold higher in unused than in used donors (P:<0.0001) and 4.67-fold higher than in HF (P:<0.0001). Western blotting showed higher TNF-alpha in unused (218. 3+/-6.4, n=4 versus 187.3+/-5.4, n=3 OD units) than used donors (P:<0.05). TNF-alpha expression was localized to cardiac myocytes. Serum TNF-alpha was higher in unused (8.72+/-1.3 pg/mL, n=13) than in used (6.12+/-0.8 pg/mL, n=25, P:<0.05) donors and HF (4.0+/-0.4 pg/mL, n=17, P:<0.005). Serum TNF-alpha receptors did not differ between unused (4.3+/-0.8 and 8.6+/-1.6 ng/mL, n=10) and used (3. 5+/-0.4 and 6.5+/-1.1 ng/mL, n=24) donors. There was a trend for higher serum IL-6 in unused (16.5+/-2.9 pg/mL, n=9) compared with used (13.9+/-1.6 pg/mL, n=26, P:=NS) donors. CONCLUSIONS: This study documented an increase in the expression of TNF-alpha and IL-6 in the myocardium of all donor hearts that was more marked in the dysfunctional (unused) donor hearts. This was accompanied by similar changes in the serum. This might have important therapeutic implications.

Quantitative myocardial cytokine expression and activation of the apoptotic pathway in patients who require left ventricular assist devices.

BACKGROUND: Molecular mechanisms underlying the deterioration of patients undergoing LV assist device (LVAD) implantation remain poorly understood. We studied the cytokines tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta and IL-6 and the terminal stage of the apoptotic pathway in patients with decompensating heart failure who required LVAD support and compared them with patients with less severe heart failure undergoing elective heart transplantation. METHODS AND RESULTS: Myocardial and serum samples from 23 patients undergoing LVAD implantation were compared with those from 36 patients undergoing elective heart transplantation. Myocardial TNF-alpha mRNA (1.71-fold; P<0.05) and protein (3.43+/-0.19 versus 2.95+/-0.10 pg/mg protein; P<0.05) were elevated in the LVAD patients. Immunocytochemistry demonstrated TNF expression in the myocytes. Serum TNF-alpha was also elevated (12.5+/-1.9 versus 4.0+/-0.4 pg/mL; P<0.0001) in the LVAD patients. IL-6 mRNA (2.57-fold higher; P<0.005) and protein (27.83+/-9.35 versus 4.26+/-1.24 pg/mg protein; P<0.001) were higher in the LVAD candidates, as was serum IL-6 (79.3+/-23.6 versus 7.1+/-1.6 pg/mL; P<0.0001). Interleukin-1beta mRNA expression was 9.78-fold higher in the LVAD patients (P<0.001). iNOS mRNA expression was similar to that in advanced heart failure patients and was not further elevated in the LVAD patients. Levels of procaspase-9 (8.02+/-0.91 versus 6.16+/-0.43 oligodeoxynucleotide [OD] units; P<0.01), cleaved caspase-9 (10.02+/-1.0 versus 7.34+/-0.40 OD units; P<0.05), intact and spliced DFF-45 (4.58+/-0.75 versus 2.84+/-0.23 OD units; P<0.05) were raised in LVAD patients, but caspase-3 and human nuclease CPAN were not. CONCLUSIONS: Elevated TNF-alpha, IL-1beta, and IL-6 and alterations in the apoptotic pathway were found in the myocardium and elevated TNF-alpha and IL-6 in serum of deteriorating patients who required LVAD support. These occurrences may have therapeutic implications and influence the timing of LVAD insertion.

Altered sympathoadrenal response to dynamic exercise in cardiac transplant recipients.

The cardiac denervation produced by heart transplantation modifies the physiological response to exercise. The cardiorespiratory and sympathoadrenal response of seven "healthy" orthotopic heart transplant recipients was compared to seven age matched normal subjects during progressive dynamic exercise. The initial venous noradrenaline concentration tended to be higher in the transplant group, at 3.6 (SEM 0.6) v 2.9(0.2) nmol-litre-1 (NS). Noradrenaline concentrations were significantly higher in the transplant group during exercise (p less than 0.05, by analysis of variance). The transplant recipients reached a lower maximum workload than the normal subjects, at 102(8) v 170(10) watts (p less than 0.01) and the peak noradrenaline concentrations were similar in the two groups. The fall in noradrenaline concentrations after exercise was similar in the two groups. This showed that noradrenaline clearance was normal in the transplant recipients and the higher noradrenaline level reflected increased sympathetic activity. Despite the normal peak noradrenaline concentration, the transplant recipients achieved lower maximum heart rates than the normal subjects, at 142(3) v 181(5) beats min-1 (p less than 0.01). Adrenaline concentrations were similar in the two groups during submaximal exercise and tended to be lower in the transplant recipients at maximal exercise. The increased sympathetic activity may be a response to altered cardiac performance because of efferent cardiac denervation or to loss of tonic inhibition of sympathetic activity by cardiac receptors due to afferent denervation. Both circulating noradrenaline and adrenaline appear to play a significant role in the heart rate response to exercise after cardiac transplantation.

Neutrophil dysplasia caused by mycophenolate mofetil.

Two transplant recipients developed striking morphological abnormalities in their circulating neutrophils while receiving mycophenolate. The changes included nuclear hypolobulation and abnormal clumping of nuclear chromatin and were presumably related to inhibition of guanosine nucleoside synthesis. In both cases the neutrophil abnormalities preceded the development of neutropenia and were thus a sign of impending hematological toxicity. The hematological changes resolved after the drug was discontinued.

Cardiac myosin autoantibodies and acute rejection after heart transplantation in patients with dilated cardiomyopathy.

OBJECTIVES: To determine whether humoral autoimmune responses associated with dilated cardiomyopathy (DCM) influence the postoperative clinical course following cardiac transplantation. METHODS: ELISA levels of preformed cardiac myosin (CM) autoantibodies (Abs) in patients with a pretransplant diagnosis of dilated cardiomyopathy (DCM) (n=64) and ischemic heart disease (IHD, n=53) were correlated with cardiac rejection, immunosuppression, and the incidence of endocardial infiltrates after transplantation. RESULTS: Alpha- and beta-CM autoantibody (IgG and IgM) levels were similar in DCM and IHD patients but were statistically higher than in controls. Distribution of preformed (beta-CM) IgM-Abs in patients with and without rejection in the first postoperative year differed in the two groups. DCM patients rejected earlier P=0.006, and the frequency of rejection at 3 months was statistically higher than in IHD patients. Frequency and reactivity of IgM-Abs in DCM patients with rejection [International Society for Heart and Lung Transplant (ISHLT) grade I and above] was 28% compared with 7% in rejection-free patients, P<0.05. IgM-positive patients had a greater frequency and severity of rejection episodes and required more immunosuppression. These patients had rejection earlier than Ab-negative patients, P<0.009. There was no correlation between antibody status and rejection in IHD patients or with IgG in either group. Distribution of IgG subclass differed in the two diseases. DCM patients had significantly higher IgG3 reactivity; 70% of this activity was present in patients who developed moderate rejection. IgG3-positive patients experienced more frequent rejections, as well as a greater incidence of grade 3A/B rejection as the first episode, than did Ab-negative patients (50% vs. 15%), P<0.05. Frequency of endocardial infiltrates was statistically higher in IgG3-positive patients. CONCLUSION: Proinflammatory characteristics of preformed IgG3 and IgM antibodies in DCM patients may influence the frequency and severity of cardiac rejection after transplantation.

Activation of apoptotic and inflammatory pathways in dysfunctional donor hearts.

BACKGROUND: Myocardial dysfunction is common after brain death, but the mechanisms remain unclear. Apoptosis is tightly regulated by enzymes termed the caspases. We have investigated the caspases involved in the terminal part of the apoptotic pathway in dysfunctional (nontransplanted) donor hearts and their relation to inflammatory markers and compared them to hearts with good ventricular function (transplanted donors). METHODS: Thirty-one donor hearts assessed for transplantation were examined. Western blotting was used to measure pro-caspase-9, caspase-3, DFF45, the activated nuclease CPAN and poly (ADP-ribose) polymerase, a DNA repair enzyme inactivated by caspase-3. Caspase-3 activity was also measured. Histologic and immunocytochemical analysis for HLA Class II and Real Time polymerase chain reaction for tumor necrosis factor-alpha and interleukin 6 were performed to detect inflammatory activation. RESULTS: Cleaved caspase-9 was higher (5.53+/-0.6 vs. 3.64+/-0.4 O.D. units, P<0.01) in nontransplanted compared with transplanted donors and there was a trend for higher pro-caspase-9 (5.20+/-1.0 vs. 4.22+/-0.4 O.D. units, P=NS). Levels of pro-caspase-3 were higher in nontransplanted (9.66+/-0.5 vs. 5.15+/-0.5 O.D. units, P<0.00001) donors and cleavage products of caspase-3 were elevated in 14 of 14 nontransplanted and 2 of 17 transplanted donors. Intact DFF-45 (8.94+/-0.36 vs. 6.14+/-0.30 O.D. units, P<0.000005), its spliced product (2.38+/-0.35 vs. 0.4+/-0.21 O.D. units, P=0.0001) and the nuclease caspase-activated nuclease (2.01+/-0.3 vs. 0.66+/-0.16 OD units, P=0.001) were higher in nontransplanted donors. The caspase-3 substrate poly (ADP-ribose) polymerase was higher in nontransplanted (1.16+/-0.13 vs. 0.61+/-0.22 O.D. units, P=0.57) donors. CONCLUSIONS: The caspases are elevated in dysfunctional donor hearts compared with hearts with good ventricular function with a possible link to inflammatory activation supporting the concept that brain death causes inflammatory activation which can lead to apoptosis with a possible important effect on function.

Evaluation of human cytomegalovirus gene expression in thoracic organ transplant recipients using nucleic acid sequence-based amplification.

BACKGROUND: Human cytomegalovirus (CMV) infection is a major cause of morbidity in transplant patients. Early diagnosis and treatment have been shown to improve outcome. We evaluated the suitability of CMV immediate early, early, and late gene expression detected by nucleic acid sequence-based amplification (NASBA) as markers of CMV infection. METHODS: Blood samples were taken immediately before transplant and every one to two weeks after transplantation for 12 weeks from 50 patients undergoing thoracic organ transplantation. CMV-NASBA was performed and results compared with serology, CMV pp65 antigenaemia (CMV-AG) and the development of clinical CMV infection. Patients received "preemptive" anti-CMV therapy with ganciclovir based on the CMV-AG results. RESULTS: CMV immediate early and early gene expression were detected in 87 and 47%, respectively, of patients without other evidence of CMV infection. CMV late gene expression had a sensitivity of 97% for infection (compared with 83% for CMV-AG P=0.06) and a specificity of 93% (compared with 100% P=NS). Late gene expression occurred at the same time as CMV antigenaemia but 1.1 weeks earlier than the threshold of antigenaemia (CMV-AG>10) used to initiate preemptive therapy. CONCLUSION: NASBA provided a standardized tool for the detection of CMV transcripts with a greater sensitivity than the standard antigenemia test. Detection of immediate early and early gene transcripts was not specific for subsequent infection. CMV late gene expression determined by NASBA was an accurate and early marker of CMV infection. Detection of CMV late gene expression could be used to trigger "preemptive" anti-CMV therapy.