Fungal infections in transplant recipients

Management of urinary tract infection in solid organ transplant recipients: Consensus statement of the Group for the Study of Infection in Transplant Recipients (GESITRA) of the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC) and the Spanish Network for Research in Infectious Diseases (REIPI)

BACKGROUND

Urinary tract infections (UTIs) are one of the most common infections in solid organ transplant (SOT) recipients.

METHODS

Experienced SOT researchers and clinicians have developed and implemented this consensus document in support of the optimal management of these patients. A systematic review was conducted, and evidence levels based on the available literature are given for each recommendation. This article was written in accordance with international recommendations on consensus statements and the recommendations of the Appraisal of Guidelines for Research and Evaluation II (AGREE II).

RESULTS

Recommendations are provided on the management of asymptomatic bacteriuria, and prophylaxis and treatment of UTI in SOT recipients. The diagnostic-therapeutic management of recurrent UTI and the role of infection in kidney graft rejection or dysfunction are reviewed. Finally, recommendations on antimicrobials and immunosuppressant interactions are also included.

CONCLUSIONS

The latest scientific information on UTI in SOT is incorporated in this consensus document.

Impact of previous invasive pulmonary aspergillosis on the outcome of allogeneic hematopoietic stem cell transplantation

Background

Invasive pulmonary aspergillosis (IPA) is one of the major complications encountered by patients receiving chemotherapy for hematologic malignancies. The prolonged period of intense immunosuppression following allogeneic hematopoietic stem cell transplantation (HSCT) may increase the risk of IPA recurrence in patients with a history of IPA. We evaluated the impact of a history of IPA on allogeneic HSCT outcome, and examined the incidence of IPA after HSCT.

Methods

This retrospective study included 22 patients with a history of IPA prior to receiving allogeneic HSCT at the Samsung Medical Center from 1995 to 2007. Diagnosis of IPA was defined as proven (N=5), probable (N=0), or possible (N=17).

Results

All 22 patients received amphotericin-based regimens to treat pre-transplant IPA. Secondary antifungal prophylaxis was administered to 10 patients during HSCT. The development of post-transplant IPA was observed in 2 patients. One of the patients died from septic shock within 2 days of the diagnosis of possible IPA. The other patient recovered from IPA, but eventually had a relapse of the primary disease. Of the 22 patients, the overall 2-year survival rate was 63% (95% confidence interval [CI]: 41-85), and the transplant-related mortality rate was 19% (95% CI: 0-38).

Conclusion

Our results suggest that a history of IPA prior to HSCT does not have an adverse impact on transplant outcomes, although the small number of cases was a limitation in this study. Future studies involving a larger number of cases are needed to further examine this issue.

Isolation of Aspergillus species from the airway of lung transplant recipients is associated with excess mortality

BACKGROUND

Aspergillus spp. are the leading cause of invasive fungal infection in lung transplant recipients. We investigated the relationship between the isolation of Aspergillus spp. from the respiratory tract of lung transplant recipients and their risk of mortality.

METHODS

A retrospective, observational cohort study of all patients who received lung allografts between January 1999 and May 2011 at a single UK centre was performed. The time from transplantation to death was analysed using Cox regression models. Isolation of Aspergillus spp. from the respiratory tract was included as a covariate in the Cox regression model.

RESULTS

Two hundred-thirteen patients were included. The median follow-up time was 5 years during which 102 patients (47.9%) died. Aspergillus was isolated from 74 (34.7%) patients. Twenty patients (27%) had Aspergillus isolated in the first 60 days post-transplant. Forty-one patients (55.4%) in the Aspergillus group and 61 patients (43.9%) in the non-Aspergillus group died during follow-up. A hazard ratio of 2.2 (95% CI 1.5-3.3; P < 0.001) for death following a positive Aspergillus sample was observed.

CONCLUSION

Isolation of Aspergillus spp. from patients following lung transplantation is associated with a significant increase in mortality. Novel preventative strategies are required to minimise the impact of Aspergillus in lung transplant recipients.

Prophylactic Antifungal Agents Used After Lung Transplantation

Objective:

To review the data supporting available antifungal agents and compare regimens utilized to prevent fungal infection in lung transplant recipients.

Data Sources:

Literature retrieval was accessed through MEDLINE (1950 through October 2009) and United Network for Organ Sharing online database (available data through October 2009), using the terms lung transplantation, prophylaxis, and fungal infection. In addition, reference citations from publications identified were reviewed.

Study Selection And Data Extraction:

All articles or related abstracts in English identified from the data sources above were evaluated. Literature including adult lung transplant recipients who received systemic antifungal prophylaxis to prevent invasive fungal infections (IFIs) was included in the review.

Data Synthesis:

IFIs after lung transplantation remain a common postoperative problem and are associated with high mortality. The lung is the most vulnerable solid organ to be transplanted, as it is the main organ responsible for gas exchange and therefore the high risk for pulmonary-related IFIs. It is most susceptible to developing an IFI, as it serves as a medium for organisms traveling from air to human tissue, potentially causing life-threatening infections. Such infections typically involve Candida and Aspergillus spp. and tend to occur within the first 12 months after transplant. Although there has been an increase in lung transplants performed over the past decade, no standard antifungal prophylactic regimen exists. Literature describing antifungals used to prevent IFI after transplant is scarce, which may be due to a lack of consistency in regimens used between transplant centers. Several regimens have been described utilizing different antifungal agents as both monotherapy and combination therapy. The majority of the literature reviewed here describes aerosolized amphotericin B formulations and azole antifungals demonstrating an overall decreased risk of fungal infection after lung transplantation. It has become the standard of practice to initiate some form of antifungal prophylaxis in these patients.

Conclusions:

The risk of fungal infection after lung transplant is multifactorial and optimal prophylactic regimens should include agents with adequate activity against the most pathogenic fungi.

Eight years of lung transplantation: experience of the National Research Institute of Tuberculosis and Lung Diseases

BACKGROUND

Lung transplantation has evolved from an experimental procedure to a viable therapeutic option in many countries. In Iran, the first single-lung transplantation was performed in the year 2000, more than 3 decades after the first successful procedure in the world, and the first double-lung transplantation was performed in the year 2006.

OBJECTIVE

To describe our 8-year experience in lung transplantation.

PATIENTS AND METHODS

During 8 years, we performed 24 lung transplantation procedures. Underlying lung diseases were pulmonary fibrosis in 16 patients (66.6%); chronic obstructive pulmonary disease in 2 (8.3%); bronchiectasis in 5, including 2 patients with cystic fibrosis (20.8%), and alveolar microlithiasis in 1 (4.16%). Data for all patients were collected and analyzed. Procedures were carried out using standardized methods. The induction suppression regimen consisted of cyclosporine and methylprednisolone. Maintenance immunosuppression drugs were cyclosporine and mycophenolate mofetil, and tapering dosage of prednisolone. Patients were followed up with physical examinations, 3 times a week, as well as and cycle ergometry 3 times a week and spirometry and laboratory tests once a week and chest radiography per needed for up to 3 months posttransplantation.

RESULTS

The longest survival time was 7.2 years, in a 60-year-old patient with idiopathic pulmonary fibrosis. Fourteen patients died, 8 as a result of hemodynamic instability and/or hemorrhage, 1 as a result of bone and fat emboli, 3 after cessation of drug and 2 of them after infection.

CONCLUSION

Although lung transplantation is a complex procedure it can be performed in developing countries such as Iran.

Candida and the paediatric lung

Although systemic candidosis is common in hospitalised children, Candida involvement of lung parenchyma is rare and usually perceived only at autopsy. The purpose of this article was to review the evidence regarding lung involvement in Candida infections, with special attention to paediatric patients. Primary Candida pneumonia is rare and usually associated with aspiration of oropharyngeal contents. The majority of cases of Candida pneumonia are secondary to haematological dissemination of Candida organisms from a distant site, usually the gastrointestinal tract or the skin. The diagnosis of pulmonary candidosis is difficult because there is no specific clinical or radiological presentation. In addition, the presence of Candida in sputum or other respiratory specimens mostly represents contamination. A definitive diagnosis of Candida pneumonia requires histopathologic proof of lung invasion in association with inflammation. Children can also be affected by pulmonary allergic reactions caused by Candida species. Treatment of Candida pneumonia is essentially the same as for candidaemia. Preliminary evidence suggests that patients with severe asthma sensitised to Candida species may also benefit from antifungal drugs.

A review on the clinical use of inhaled amphotericin B

BACKGROUND

Despite the systemic toxicity of amphotericin B (AMB), it still has a place in treatment or prophylactic regimes of fungal infections.

METHODS

A strategy for minimizing the potential of systemic side effects is to bring it in direct contact with the body site most likely to be infected, such as the administration of AMB as an aerosol. Nebulized amphotericin has been used in humans since 1959. However, due to a lack of sufficient data regarding efficacy, its use is still not established. Little is known about the optimal dose, frequency, duration of administration, and the pharmacokinetics of inhaled AMB in humans.

RESULTS AND CONCLUSIONS

In this review, published data regarding inhaled AMB are summarized, including available descriptions regarding preparation, dose, efficacy, and toxicity, and its place in therapy is discussed. The results from the studies that were reviewed in this article indicate that inhaled AMB may have a place in the prophylactic regimens of patients with prolonged neutropenia and in lung transplant recipients. Furthermore, nebulized (liposomal) AMB may have a place in the treatment of allergic bronchopulmonary aspergillosis (ABPA) in patients with corticosteroid-dependent ABPA.

Pulmonary fungal infections in kidney transplant recipients: an 8-year study

Invasive fungal infections are among the most important causes of mortality among transplant patients. One of the most common manifestations of these infections is pulmonary fungal infection (PFI). The present study sought to evaluate the rate of PFI in kidney transplant patients.

MATERIALS AND METHODS

We retrospectively analyzed the data of 595 patients who underwent kidney transplantation from February 1999 to February 2007. Bronchoalveolar lavage (BAL) culture and tissue biopsy were used to confirm PFI.

RESULTS

Thirteen of 595 patients (2.2%) experienced PFI. The most common pathogen (8/13, 41.5%) was Aspergillus, with 5 (38.5%) infected with Aspergillus only, 2 (15.4%) with both Aspergillus and Candida, and 1 (7.7%) with Aspergillus and mucormycosis. Seven of 13 (53.8%) died and 4 (30.7%) lost the transplanted kidney. Immunosuppressive therapy following rejection and prescription of broad spectrum antibiotics were the most important risk factors for fungal infections in these patients.

CONCLUSIONS

Fungal infections are among the most important causes of mortality among transplant patients, of which the most common manifestation is pulmonary. Immunosuppressive therapy and broad spectrum antibiotics are important risk factors, and Aspergillus is the most common pathogen responsible for fungal infections.

Fungal infections after lung transplantation

PURPOSE OF REVIEW

Lung transplant's Achilles heel is chronic rejection. This is the reason why high immunosuppression is used, which leads to the development of infections. Fungal infections are a great obstacle in lung transplant patients' progress, not only because of their impact on patient survival, but also because fungal infections indirectly have an influence on the graft's progress. This review highlights the changing spectrum of invasive fungal infections as well as the most recent developments in diagnosis, prophylaxis, treatment and monitoring of lung transplantation.

RECENT FINDINGS

Fungal infections have a bimodal presentation: early onset, in relation to difficult postsurgeries and prior colonizations, and late onset, primarily in relation to chronic rejection and terminal renal insufficiency. The clinical impact of non-Aspergillus moulds is still unknown. Recent efforts have focused on nonculture-based methods to establish a rapid diagnosis. However, multicentre studies are needed to establish the diagnostic value of galactomannan antigen assay in invasive aspergillosis in lung transplantation. In addition, studies of the sensitivity and specificity of PCR assays are required to establish their diagnostic value. Unfortunately, only some advances in the diagnosis of aspergillosis have been achieved.

SUMMARY

Prophylaxis should be tailored according to the different individual patient's risk status. Combined treatments, including surgical therapy, may be useful in some patients.

Invasive fungal infections and antifungal therapies in solid organ transplant recipients

This manuscript will review the risk factors, prevalence, clinical presentation, and management of invasive fungal infections (IFIs) in solid organ transplant (SOT) recipients. Primary literature was obtained via MEDLINE (1966-April 2007) and EMBASE. Abstracts were obtained from scientific meetings or pharmaceutical manufacturers and included in the analysis. All studies and abstracts evaluating IFIs and/or antifungal therapies, with a primary focus on solid organ transplantation, were considered for inclusion. English-language literature was selected for inclusion, but was limited to those consisting of human subjects. Infectious complications following SOT are common. IFIs are associated with high morbidity and mortality rates in this patient population. Determining the best course of therapy is difficult due to the limited availability of data in SOT recipients. Well-designed clinical studies are infrequent and much of the available information is often based on case-reports or retrospective analyses. Transplant practitioners must remain aware of their therapeutic options and the advantages and disadvantages associated with the available treatment alternatives.

Radiología de las infecciones fúngicas invasoras del aparato respiratorio

Invasive fungal infections of the respiratory tract are a major cause of serious morbidity and mortality especially in immunocompromised patients due to neutropenia, corticosteroids, or hematologic malignancy. The role of imaging is very important in the management of patients with fungal infections and chest x-ray is still the most used exploration. Nevertheless, new approaches recommend the systematic use of computed tomography scan for early documentation of invasive fungal infection. Combination of clinical setting with recognition of radiological pattern is the best approach to pulmonary fungal diseases. The following is a review of the imaging features of different invasive fungal infections we can face in our daily practice.

Long-term CT follow-up in 40 non-HIV immunocompromised patients with invasive pulmonary aspergillosis: kinetics of CT morphology and correlation with clinical findings and outcome

OBJECTIVE

The aim of this study was to assess CT signs of invasive pulmonary aspergillosis (IPA) and their long-term kinetics in correlation with clinical findings and outcome.

MATERIALS AND METHODS

Three hundred ten serial CT scans (mean, 7.7) in 40 consecutive patients were reviewed retrospectively over a median follow-up of 112 days (range, 5-841 days). Along with underlying disease, hematopoietic stem cell transplantation, neutropenia, graft-versus-host disease or antifungal treatment, signs of IPA, and number or size of lesions were evaluated regarding outcome and radiologic dynamics.

RESULTS

On the day of IPA diagnosis, median lesion number and size were 3 or 3.1 cm(2), respectively. Irrespective of antifungal therapy, 90% of patients showed an increase in lesion size and number until day 9 (median and mean). Lesion size subsequently showed a median plateau phase of 3.5 days (mean, 7), during which median lesion numbers dropped by 17%. Consequently, 42.5% of patients showed a complete radiologic remission within a median 80 days. Of all parameters, formation of cavitation most strongly predicted time until radiologic remission, which was 2.5 times as long in patients with cavitary lesions. Likewise, cavitations were strong precursors of beneficial outcome (odds ratio, 8.4; confidence interval [CI], 1.07-176).

CONCLUSION

The kinetics of radiologic signs of IPA adheres to a distinctive pattern with initial rise in number and size, followed by a plateau phase of size and gradual reduction. Both time until complete radiologic remission and outcome are independent of initial or maximum lesion size and number yet strongly influenced by cavitation.

Transplant-related immunosuppression: a review of immunosuppression and pulmonary infections

Solid organ and hematopoietic stem cell transplantation are definitive therapies for a variety of end-stage diseases. Immunosuppression has improved graft survival but leaves the patient susceptible to infectious complications. Of these, pulmonary infections are the leading cause of morbidity and mortality in the transplant recipient. Allograft rejection is mediated primarily by T cells, with B cells playing a role via antibody production. Depending on the transplant type, rejection can be hyperacute, acute, or chronic. Hyperacute rejection occurs as an immediate response to preformed antibodies to donor human leukocyte antigens. Acute cellular rejection involves recipient T-cell recognition of human leukocyte antigen molecules expressed on donor-derived, antigen-presenting cells (direct allorecognition) or presentation of donor-derived peptides by recipient antigen-presenting cells to recipient T cells (indirect allorecognition). Once the alloantigens are recognized as foreign, the activation, proliferation, and production of cytokines by T lymphocytes and other immune cells lead to the amplification of the alloimmune response. This complex process involves the generation of effector T cells, antibody production by activated B cells, and macrophage activation. Alloimmunity is facilitated by the production of many cytokines, chemokines, and other effector molecules, such as complement. The immunosuppressants involve many classes of drugs, including antibody therapies that eliminate specific groups of cells or alter signaling pathways used by effector cells. The article reviews the agents and associated infections.

Trasplante pulmonar en la fibrosis quística: complicaciones infecciosas

BACKGROUND AND OBJECTIVE

Lung transplantation is the only treatment for end-stage lung disease in patients with cystic fibrosis (CF). The presence of pathogens in the airways prior to transplantation is a risk factor for infections in the post-transplantation period; in fact, infections account for 80% of deaths within the first year. Our goal was to analyze the incidence of infectious complications in patients who underwent a lung transplantation due to cystic fibrosis.

PATIENTS AND METHOD

Descriptive transversal study of CF transplanted lung patients since the beginning of the transplantation programme (1991 to September 2004). We evaluated data regarding opportunistic infections, demographical information, lung function, mortality causes and survival. We used descriptive statistics and Kaplan Meier for survival.

RESULTS

267 lung transplants were done, 57 were due to CF, 30 men and 27 women, with an average age of 21 years (7.8 years. The average time on waiting list was 96 days (range 1-407). 57 bilateral lung transplants, 3 heart-lung transplants and one combined liver-lung transplant were performed. All patients received triple immunosuppression (tacrolimus/cyclosporine, azathioprine and prednisone). 16 patients (28%) died: 4 in early postoperative period (7%), 5 at 6 months after transplantation, and the remaining 7 patients died several years post transplantation. Survival was 82% at one year, 76% at three years, and 65% at five years; 75% of our patients survived a mean of 3.56 years. Cytomegalovirus (CMV) infections occurred in 26% of patients and were associated with chronic rejection (p < 0.05). Purulent bronchitis was the most frequent bacterial infection: 59% of cases were caused by multiresistant pathogens. There was a 8.77% cases of B cepacia infection with 2 patients dying because of it. There were 7 cases of airway infection due to Aspergillus fumigatus, and 5 fungal invasive forms that were associated with chronic rejection (p < 0.05). Two cases of tuberculosis (Mycobacterium tuberculosis) were registered, 1 case of M. abcessus lung disease and 1 case of visceral leishmaniosis. Infectious diseases accounted for 19% of early and 12% of late mortality.

CONCLUSIONS

Although serious infections were seen after transplantation in our series, infectious events did not represent a high risk of postoperative mortality rate. Fungal disease was the only late relevant infectious complication, mainly associated with chronic rejections. Close CMV monitoring, and even pre-emptive antifungal therapy, are recommended for patients with chronic rejection.

Enzymatic Variability of Candida krusei Isolates in a Course of Fungal Infection in a Liver Transplant Recipient

Transplant recipients are at high risk of fungal infections. The main site of fungal infections in patients undergoing liver transplantation is the abdominal cavity. One factor determining the pathogenicity of fungi is their ability to secrete hydrolytic enzymes. The aim of this study was to assess the enzymatic activity of Candida krusei, which caused an infection in a liver transplant recipient. The clinical specimens included swabs of throat, nose, and two drains, as well as bile, stool, and abdominal cavity aspirate. The yeast-like fungi isolated were identified by an ID 32 C test (bioMérieux) and their enzymatic activity assayed with the use of an API-ZYM test. Two biotypes of C. krusei were identified, depending on the source of the clinical specimen. The C. krusei isolates cultured from a throat swab, a nasal swab, and one of the drains secreted esterase lipase C8 (enzyme IV) and valine arylamidase (enzyme VII), in contrast to those isolated from the bile, abdominal cavity fluid, another drain, and stool. Characterization of two biotypes of C. krusei isolates cultured from different clinical samples from several infection sites indicated an ability of C. krusei to adapt to variable environmental conditions.

Aerosolised antibiotics: a critical appraisal of their use

Aerosolised antimicrobial agents have been used in clinical practice since the 1950s. The main advantage of this route of administration is the targeted drug delivery to the site of infection in the lung. Exploitation of this targeted delivery can yield high concentrations at the site of infection/colonisation while minimising systemic toxicities. It is important to note that the ability of a drug to reach the target area in the lung effectively is dependent on a number of variables, including the nebuliser, patient technique, host anatomy and disease-specific factors. The most convincing data to support the use of aerosolised antimicrobials has been generated with tobramycin solution for inhalation (TOBI, Chiron Corp.) for maintenance treatment in patients with cystic fibrosis. In addition to cystic fibrosis, the use of aerosolised antimicrobials has also been studied for the treatment or prevention of a number of additional disease states including non-cystic fibrosis bronchiectasis, ventilator-associated pneumonia and prophylaxis against pulmonary fungal infections. Key studies evaluating the benefits and shortcomings of aerosolised antimicrobial agents in these areas are reviewed. Although the theory behind aerosolised administration of antibiotics seems to be sound, there are limited data available to support the routine use of this modality. Owing to the gaps still existing in our knowledge base regarding the routine use of aerosolised antibiotics, caution should be exercised when attempting to administer antimicrobials via this route in situations falling outside clearly established indications such as the treatment of patients with cystic fibrosis or Pneumocystis pneumonia.

Aspergillus infections in lung transplant recipients: risk factors and outcome

This retrospective study of 251 lung transplant patients aimed to determine the prevalence, clinical presentation and mortality of Aspergillus infection in order to define specific risk factors and to compare survival in patients with and without infection. Aspergillus was isolated from 86 (33%) cases, which involved colonisation (n = 50), tracheobronchial lesions (n = 17) or invasive aspergillosis (n = 19). Overall, aspergillosis had an impact on survival (p < 0.05); in fact the 5-year mortality rate was substantially higher in single lung transplant recipients with bronchial anastomotic infection, and in those with late-onset infections and chronic rejection. A significant association (p < 0.05) was found between acute rejection and the time at which fungal infection was diagnosed. Aspergillus infection was not related to cytomegalovirus infection or treatment with corticosteroids. The mortality rate for invasive infections was 78% and was related to survival (p < 0.0001); invasive aspergillosis was also associated with chronic rejection (p < 0.05), but not with high corticosteroid doses (p 0.49) or use of tacrolimus (p 0.73). In conclusion, Aspergillus infection was associated with a reduction in the 5-year survival rate of lung transplant recipients, and this was particularly true for patients infected with the invasive forms and for patients with single lung transplants, bronchial anastomotic infection and chronic rejection. Isolation of Aspergillus spp. from respiratory samples preceded acute rejection, and may be a marker of graft dysfunction and/or airway inflammation. Close monitoring, or even pre-emptive antifungal therapy, is recommended for patients with chronic rejection or bronchial airway mechanical abnormalities and persistent Aspergillus colonisation.

Pulmonary complications of solid organ and hematopoietic stem cell transplantation

The ability to successfully transplant solid organs and hematopoietic stem cells represents one of the landmark medical achievements of the twentieth century. Solid organ transplantation has emerged as the standard of care for select patients with severe vital organ dysfunction and hematopoietic stem cell transplantation has become an important treatment option for patients with a wide spectrum of nonmalignant and malignant hematologic disorders, genetic disorders, and solid tumors. Although advances in surgical techniques, immunosuppressive management, and prophylaxis and treatment of infectious diseases have made long-term survival an achievable goal, transplant recipients remain at high risk for developing a myriad of serious and often life-threatening complications. Paramount among these are pulmonary complications, which arise as a consequence of the immunosuppressed status of the recipient as well as from such factors as the initial surgical insult of organ transplantation, the chemotherapy and radiation conditioning regimens that precede hematopoietic stem cell transplantation, and alloimmune mechanisms mediating host-versus-graft and graft-versus-host responses. As the population of transplant recipients continues to grow and as their care progressively shifts from the university hospital to the community setting, knowledge of the pulmonary complications of transplantation is increasingly germane to the contemporary practice of pulmonary medicine.