Emergence of multiple cytomegalovirus strains in blood and lung of lung transplant recipients

BACKGROUND: Cytomegalovirus (CMV) is a major pathogen in lung transplant recipients (LTRs). The emergence of different CMV strains in lung and blood after transplantation has not yet been analyzed. METHODS: In total, 75 serum and 91 broncheoalveolar lavage (BAL) samples obtained from 25 LTRs in the follow-up after transplantation were tested for the presence of different CMV strains. The gB, gN, and gO genes of the CMV isolates were analyzed by subtype-specific PCR, restriction fragment length polymorphism (RFLP), sequencing, and phylogenetic analysis. RESULTS: Mixed CMV-strain populations were detected after cessation of antiviral prophylaxis in up to 80% and 90% of the patients' BAL and serum, respectively, and this was independent of the CMV serostatus of donor and recipient. In five patients, the same single CMV strain was consistently detectable over at least 1 year in lung and blood, although in two of these cases donor and recipient had both been CMV-seropositive. Most CMV strains were distributed in the lung and blood compartment. Symptomatic CMV infection within the first year after transplantation was observed only in patients with mixed CMV-strain populations (P<0.05). CONCLUSION: Most LTRs harbor more than one CMV strain in their lung and blood compartment after cessation of prophylaxis, but the CMV strain distribution within and between the compartments varies between individuals and is not associated with the donor/recipient serostatus. The data further show that compartmentalization of CMV strains in lung versus blood seems to be a rare event and that the presence of mixed CMV-strain infections within the first year after transplantation may be disadvantageous for LTRs.     

The use of sirolimus in ganciclovir-resistant cytomegalovirus infections in renal transplant recipients

BACKGROUND: The widespread use of prophylactic ganciclovir and anti-lymphocyte/thymocyte therapies are associated with increased induction of ganciclovir-resistant cytomegalovirus (CMV) strains. The use of sirolimus has been associated with a lower incidence of CMV infection in transplant recipients. We questioned whether it could also be effective as a therapeutic treatment of resistant CMV infection. METHODS: Patients with ganciclovir-resistant CMV infections determined clinically and by DNA sequencing analysis were enrolled. Antigenaemia and DNA sequencing were used to diagnosis and follow the mutations. RESULTS: Nine transplant patients were given sirolimus plus mycophenolate mofetil (n = 4) or a calcineurin inhibitor (n = 5). Seven out of nine recipients were CMV IgG negative before transplantation. We observed a rapid decrease in antigenaemia levels, reaching zero in eight out of nine (88.9%) patients within a median of 20.3 +/- 10.1 d. Graft function remained stable and no patient presented acute rejection or recurrence of the CMV infection. CONCLUSIONS: This suggests that the use of sirolimus plus ganciclovir therapy could be useful in ganciclovir-resistant CMV infections.     

Successful outcome of ganciclovir-resistant cytomegalovirus infection in organ transplant recipients after conversion to mTOR inhibitors

Ganciclovir-resistant (GanR) cytomegalovirus (CMV) infection after organ transplantation is emerging as a significant therapeutic challenge. We report two cases of GanR CMV infection successfully managed by switching immunosuppression from calcineurin inhibitors to an mTOR inhibitor-based regimen. This salvage therapy should be considered when other options are not available.     

Management of cytomegalovirus infection in lung transplant recipients: evidence-based recommendations

Cytomegalovirus (CMV) continues to cause significant morbidity and mortality in lung transplant recipients. This article presents recommendations based on available evidence for the optimal management of CMV in lung transplant recipients, which have been developed by an expert committee of transplant physicians-surgeons and infectious disease specialists.     

The impact of ganciclovir-resistant cytomegalovirus infection after lung transplantation

BACKGROUND: Cytomegalovirus (CMV) resistance to ganciclovir has become increasingly common in acquired immunodeficiency syndrome patients but has only rarely been reported in recipients of solid organ transplants. METHODS: A retrospective study of ganciclovir susceptibility testing of CMV isolates recovered from lung transplant recipients was performed. Patients with CMV isolates having partial (1 or =3 microg/ml) to ganciclovir determined by plaque reduction assay were included in a case-control study to identify risk factors for ganciclovir resistance. RESULTS: Between 2/91 and 5/98, 18 patients (5.2% of patients transplanted) were found to have CMV infections with some degree of ganciclovir resistance (4 partially, 14 fully resistant). More positive viral blood cultures (3.2+/-2.5 vs. 1.6+/-1.4 CMV positive cultures, P=0.02) and more episodes of CMV pneumonitis (0.24+/-0.23 vs. 0.10+/-0.17 episodes/bronchoscopy, P=0.02) occurring before the detection of resistance were seen among resistant patients than controls. Ganciclovir-resistant patients received more antithymocyte globulin during induction (70+/-44 vs. 45+/-39 mg/kg, P=0.03) and received ganciclovir for a greater number of days (79+/-52 vs. 64+/-53 days, P=0.005) before the detection of resistance than controls. Ganciclovir-resistant patients had a shorter survival and an earlier onset of bronchiolitis obliterans syndrome compared with patients in the transplant database at Washington University. CONCLUSIONS: Ganciclovir-resistant CMV infection is a serious complication of solid organ transplantation associated with more episodes of viremia, more frequent disease, earlier onset of bronchiolitis obliterans and shorter survival. The use of antithymocyte globulin and prolonged exposure to ganciclovir are risk factors for the development of ganciclovir resistance.     

Infection and reactivation with cytomegalovirus strains in lung transplant recipients.

Cytomegalovirus pneumonia is a major cause of morbidity and death following lung transplantation (LT) (1). The case fatality rate is highest in the CMV-seronegative recipients (R-) of organs from seropositive donors (D+), which suggests that transmission of CMV may occur with the graft (1), but in seropositive recipients (R+) the comparative importance of reactivation of endogenous virus and reinfection with donor virus is poorly understood.     

移植受者人巨细胞病毒感染研究进展

人巨细胞病毒（HCMV）是移植术后受者最易感染的机会性病毒之一。随着新型免疫抑制剂和抗病毒药物的研发,以及预防治疗和预先治疗的广泛应用,移植受者HCMV感染情况已经发生了显著变化。但HCMV感染仍然是引起移植受者近期和远期病变和死亡的重要因素。本文对HCMV感染基础研究、诊断技术和治疗的最新进展进行了综述。     

Association of cytomegalovirus DNA concentration in epithelial lining fluid and symptomatic cytomegalovirus infection in lung transplant recipients

BACKGROUND: The authors have investigated the effectiveness of virus detection from bronchoalveolar lavage (BAL) samples for the identification of symptomatic cytomegalovirus (CMV) infection in lung transplant recipients. METHODS: Thus, 275 BAL samples taken from 105 lung transplant recipients during follow-up were analyzed by quantitative polymerase chain reaction (PCR) and virus isolation. RESULTS: Quantitative PCR detected virus in all 24 BAL samples taken at onset of symptomatic disease, and virus culture in only 7 samples (29.2%). Twenty-three of 251 BAL samples (9.2%) were positive by PCR, although they were obtained in an asymptomatic phase. Quantitation of CMV DNA from BAL allowed no discrimination between symptomatic and asymptomatic infection in individual cases. However, when the urea dilution method was used to recalculate the CMV DNA concentration for the epithelial lining fluid (ELF) diluted in the BAL, a CMV DNA level of more than 10 copies/mL ELF was clearly associated with symptomatic disease. CONCLUSION: The CMV DNA level in ELF may be a marker for symptomatic CMV infection.     

Letermovir in lung transplant recipients with cytomegalovirus infection: A retrospective observational study

Letermovir is a new antiviral drug approved for the prophylaxis of CMV infection in allogeneic stem cell transplants. The aim of the study was to assess the therapeutic efficacy of letermovir in difficult to treat CMV infections in lung transplant recipients. All lung transplant recipients between March 2018 and August 2020, who have been treated with letermovir for ganciclovir-resistant or refractory CMV infection were included in the study and analysed retrospectively. In total, 28 patients were identified. CMV disease was present in 15 patients (53.6%). In 23 patients (82.1%), rapid response was noticed, and CMV-viral load could be significantly decreased (>1 log₁₀) after a median of 17 [14–27] days and cleared subsequently in all of these patients. Five patients (17.9%) were classified as non-responder. Thereof, development of a mutation of the CMV UL56 terminase (UL-56-Gen: C325Y) conferring letermovir resistance could be observed in three patients (60%). Common side effects were mild and mostly of gastrointestinal nature. Mild adjustments of the immunosuppressive drugs were mandatory upon treatment initiation with letermovir. In addition to other interventions, letermovir was effective in difficult to treat CMV infections in lung transplant recipients. However, in patients with treatment failure mutation conferring letermovir, resistance should be taken into account.     

Relationship of cytomegalovirus viral load in blood to pneumonitis in lung transplant recipients.

We developed a multiplex, quantitative, real-time, polymerase chain reaction assay for cytomegalovirus (CMV) and used it to measure the CMV viral load in weekly blood specimens from 43 lung transplant recipients. The median viral load in blood samples immediately preceding bronchoscopy was 1150 copies/microg human DNA for 12 subjects with pneumonitis compared to 91 copies for 31 subjects without (P=0.02, Mann-Whitney U test). Each log10 increase in CMV viral load resulted in an increase of 1.92 in the odds ratio for CMV pneumonitis (95% confidence interval 1.03-3.56). CMV viral load was elevated (>100 copies/microg human DNA) for a median of 21 days before bronchoscopy in those subjects with pneumonitis versus 0 days in those without (P=0.004). We conclude that the risk of CMV pneumonitis after lung transplantation is related to the level of CMV DNA in blood. Quantitative PCR should be evaluated prospectively for the preemptive management of CMV in lung transplant recipients.     

Pregnancy in lung transplant recipients

Eight female lung transplant recipients, all of whom became pregnant after transplant, were reported to the National Transplantation Pregnancy Registry from US transplant centers. Outcomes of the 8 pregnancies were 4 live births, 3 therapeutic abortions, and 1 spontaneous abortion. Three of the 4 newborns were premature, with low birth weight (< 2500 grams). Rejection during pregnancy occurred in 3 pregnancies (38%). All 8 transplant recipients reported at least 1 complication during pregnancy, including shortness of breath, rejection, and infection. Two of the 4 deliveries were by cesarean section. At follow-up, all children were developing well with no residual problems. Female lung transplant recipients may face higher risks during pregnancy than other solid organ transplant recipients.     

Tuberculosis in lung transplant recipients

BACKGROUND: Post-lung transplant infection is one of the leading causes of morbidity and mortality. The cause and incidence are similar in many series; however, infections such as Mycobacterium tuberculosis are influenced by the epidemiologic situation. The authors present a prospective and observational study to define the incidence, clinical presentation, and course of tuberculosis in a cohort of lung transplant patients at a single center in Spain. METHODS: Between 1990 and 2002, cutaneous delayed-type hypersensitivity testing and pathologic and microbiologic study of explanted lungs were conducted in 187 lung transplant patients. Serial bronchoscopies with transbronchial biopsy and bronchioalveolar lavage were performed during follow-up. The diagnosis of tuberculosis was established only when M. tuberculosis was identified in any sample or when histopathologic study was conclusive. RESULTS: Forty-eight patients were classified as anergic (25.6%) and 61 (32.6%) were classified as having a positive tuberculin skin test. Of the 109 patients, 95 received latent tuberculosis infection prophylaxis. Tuberculosis was diagnosed in 12 patients (6.41%); in six of them, diagnosis was determined from the explanted lungs. The remainder were diagnosed during follow-up. Fever and dyspnea were the most common symptoms. Chest radiographic findings presented an alveolar pattern. All patients responded well to antituberculous therapy; no deaths were attributable to tuberculosis. CONCLUSIONS: In the authors' experience, tuberculosis is not rare in lung transplant patients and can be managed successfully with antituberculous therapy without rifampin. A systematic protocol for diagnosing tuberculosis of the explanted lung is useful for reducing tuberculous complications of the implanted lung.     

Hypogammaglobulinemia in lung transplant recipients

BACKGROUND: Infectious complications continue to represent a significant source of morbidity and mortality in lung transplant recipients. Identifying specific, remediable immune defects is of potential value. After one lung transplant patient with recurrent infections was noted to be severely hypogammaglobulinemic, a screening program for humoral immune defects was instituted. The objectives were to define the prevalence of hypogammaglobulinemia in lung transplant recipients, assess levels of antibody to specific pathogens, and correlate infectious disease outcomes and survival with immunoglobulin levels. METHODS: All lung transplant recipients followed at a single center between October 1996 and June 1999 underwent a posttransplant humoral immune status survey as part of routine posttransplant follow-up. This survey consists of total immunoglobulin levels (IgG, IgM, IgA), IgG subclasses (IgG1-4), and antibody titers to Pneumococcus, diphtheria, and tetanus. Since February 1997, this survey has been incorporated into the pretransplant evaluation as well. Humoral survey results for October 1996 through July 1999 were recorded, and clinical information on major infectious disease outcomes was obtained from chart reviews, discharge summaries, the Cleveland Clinic Unified Transplant Database, and review of all microbiological studies and pathology results for each patient. RESULTS: Of 67 patients with humoral immune surveys drawn posttransplant, 47 (70%) had IgG levels less than 600 mg/dl (normal 717-1410 mg/dl), of which 25 (37%) had IgG levels less than 400 mg/dl ("lowest IgG group") and 22 (33%) had IgG levels between 400 and 600 mg/dl ("moderately low IgG group"). A total of 20 patients (30%) had IgG levels of more than 600 mg/dl ("normal IgG group"). Infections that were significantly more common in the lowest IgG group, and more common in the moderately low IgG group than the normal IgG group, included: number of pneumonias (P=0.0006), bacteremias (P=0.02), total bacterial infections (P=0.002), tissue-invasive cytomegalovirus (P=0.01), invasive aspergillosis (P=0.001), total fungal infections (P=0.001), and total infections (P=0.006). Median hospital days per posttransplant year was significantly different in the three groups (11.0 vs. 7.4 vs. 2.8 days, P=0.0003.) Invasive aspergillosis occurred in 44% of the lowest IgG group, 9% of the moderately low IgG group, and 0% of the normal IgG group (P<0.001). Survival was poorest in the lowest IgG group and intermediate in the moderately low IgG group. IgG subclass deficiencies occurred in a variety of patterns. Hypogammaglobulinemic patients lacked protective responses to Pneumococcus in 14/47 (30%), diphtheria in 15%, and tetanus in 19%. In a group of 48 patients screened pretransplant, 90% had normal immunoglobulin levels. CONCLUSIONS: Hypogammaglobulinemia in lung transplant recipients is more common than has been previously recognized. An IgG level of less than 400 mg/dl identifies a group at extremely high risk of bacterial and fungal infections, tissue-invasive cytomegalovirus, and poorer survival. Immunoglobulin monitoring may offer an opportunity for intensive surveillance, tapering of immunosuppression, and preemptive therapy for infection.     

Intravenous ganciclovir prophylaxis for cytomegalovirus in heart, heart-lung, and lung transplant recipients

Cytomegalovirus (CMV) disease has had a significant clinical impact on the heart, heart-lung and lung transplant recipients in our centre. CMV disease has been so severe with CMV antibody-negative heart-lung transplant patients receiving organs from CMV antibody-positive donors (CMV-mismatched patients) that in 1986 we adopted the policy of not transplanting CMV-positive organs into CMV-negative heart-lung or lung recipients. In December 1992, we instituted a policy of providing intravenous ganciclovir (5 mg/kg twice a day for 28 days) during the immediate postoperative period for CMV-mismatched heart recipients and CMV antibody-positive heart-lung and lung patients, who have been the patients at greatest risk of severe CMV disease in our centre. A placebo group was not employed because of ethical considerations, ganciclovir having been shown to be effective for the treatment of CMV infections among transplant patients. Compared with a historical control group of patients receiving no prophylaxis, prophylactic ganciclovir reduced the incidence of CMV infection (39 % vs 91 %, P = 0.0006) and CMV disease (17 % vs 74 %, P = 0.0004) among CMV antibody-positive heart-lung recipients. Prophylactic ganciclovir did not significantly reduce the incidence of CMV infection or disease among heart or isolated lung recipients. Ganciclovir was well tolerated, with few adverse reactions. In the case of heart-lung transplant patients, one month of intravenous prophylactic ganciclovir significantly reduced the incidence of both CMV infection and disease when compared with patients who received no prophylaxis. With the lung transplant and heart transplant patients, there were no significant differences between the prophylaxis and nonprophylaxis groups, although there was a consistent trend towards less infection and disease in the prophylaxis groups. Received: 14 April 1998 Received after revision: 24 September 1998 Accepted: 18 December 1998     

Preemptive therapy with intravenous ganciclovir for the prevention of cytomegalovirus disease in lung transplant recipients

The most effective strategy for the prevention of cytomegalovirus (CMV) disease in lung transplantation has not been conclusively established. The aim of this study was to determine the efficacy of preemptive ganciclovir therapy for this purpose. Twenty-five consecutive adult patients positive for CMV before transplantation and surviving more than 30 days after the procedure were studied. Mean follow-up was 732.2 days (range, 210-1125). All patients received intravenous (IV) ganciclovir prophylaxis for the first 21 days and subsequently underwent frequent CMV antigenemia monitoring: weekly for the first 3 months, every 15 days between 3 and 6 months, and monthly thereafter. IV ganciclovir was given when antigenemia results were greater than 10 infected cells per 100,000 polymorphonuclears. The study group was compared with a historical group of 30 consecutive patients who had received IV ganciclovir prophylaxis and continued on oral ganciclovir up to day 120 posttransplantation. Eighteen of the 25 patients (72.0%) presented episodes of CMV infection. Six of the 25 patients (24.0%) had CMV disease, including 3 viral syndromes and 3 cases of pneumonitis. Four patients debuted with CMV disease, 1 of them with pneumonitis. CMV resistance to ganciclovir was observed in 2 patients. The incidence of infection was higher than in the historical group (72.0% vs 46.7%; P < .05), but there were no significant differences in the incidence of CMV disease (24.0% vs 40.0%; P = not significant [NS]). Mean time before onset of the first episode of disease was lower in the preemptive therapy group than in the comparison patients (82.8 days; range, 42-240 vs 175 days; range, 90-243; P < .05). In conclusion, preemptive therapy for CMV disease is as effective a prevention strategy as oral ganciclovir prophylaxis. However, the early appearance of CMV disease with preemptive therapy can make this approach inadvisable.     

肾移植患者巨细胞病毒感染的检测

目的建立一种诊断。肾移植受者巨细胞病毒（CMV）活动性感染的简便方法，并探讨其指导临床抗病毒治疗的价值。方法运用免疫组织化学的催化信号扩增法检测肾移植患者外周血白细胞中的巨细胞病毒磷蛋白（CMV pp65）。结果100例。肾移植受者中，44例CMV pp65抗原阳性，其中29例表现出CMV病的症状，其CMV抗原指数为（72±45）／2×10^5，而15例无症状CMV pp65抗原阳性者的CMV抗原指数为（46±25）／2×10^5，二者比较，差异有统计学意义（P〈0．05）。29例CMV病患者中，27例接受抗病毒治疗，其中26例治疗后CMV pp65抗原阳性细胞减少，症状消失，另1例CMV pp65抗原阳性细胞持续不降，患者因肺部感染死亡；未经抗病毒治疗的2例患者均死亡。结论催化信号扩增法检测外周血白细胞中的CMV pp65用于诊断。肾移植术后CMV活动性感染简便、敏感，并可指导抗病毒治疗。