Perioperative Complications of Lung Transplantation in Patients With Emphysema and Fibrosis: Experience From 1992–2002

Role of Mesenchymal Stem Cells and Extracellular Vesicles in Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial fibrotic disease that leads to disability and death within 5 years of diagnosis. Pulmonary fibrosis is a disease with a multifactorial etiology. The concept of aberrant regeneration of the pulmonary epithelium reveals the pathogenesis of IPF, according to which repeated damage and death of alveolar epithelial cells is the main mechanism leading to the development of progressive IPF. Cell death provokes the migration, proliferation and activation of fibroblasts, which overproduce extracellular matrix, resulting in fibrotic deformity of the lung tissue. Mesenchymal stem cells (MSCs) and extracellular vesicles (EVs) are promising therapies for pulmonary fibrosis. MSCs, and EVs derived from MSCs, modulate the activity of immune cells, inhibit the expression of profibrotic genes, reduce collagen deposition and promote the repair of damaged lung tissue. This review considers the molecular mechanisms of the development of IPF and the multifaceted role of MSCs in the therapy of IPF. Currently, EVs-MSCs are regarded as a promising cell-free therapy tool, so in this review we discuss the results available to date of the use of EVs-MSCs for lung tissue repair.

Incidence and risk factors for respiratory tract bacterial colonization and infection in lung transplant recipients

To evaluate incidence of and risk factors for respiratory bacterial colonization and infections within 30 days from lung transplantation (LT). We retrospectively analyzed microbiological and clinical data from 94 patients transplanted for indications other than cystic fibrosis, focusing on the occurrence of bacterial respiratory colonization or infection during 1 month of follow-up after LT. Thirty-three percent of patients developed lower respiratory bacterial colonization. Bilateral LT and chronic heart diseases were independently associated to a higher risk of overall bacterial colonization. Peptic diseases conferred a higher risk of multi-drug resistant (MDR) colonization, while longer duration of aerosol prophylaxis was associated with a lower risk. Overall, 35% of lung recipients developed bacterial pneumonia. COPD (when compared to idiopathic pulmonary fibrosis, IPF) and higher BMI were associated to a lower risk of bacterial infection. A higher risk of MDR infection was observed in IPF and in patients with pre-transplant colonization and infections. The risk of post-LT respiratory infections could be stratified by considering several factors (indication for LT, type of LT, presence of certain comorbidities, and microbiologic assessment before LT). A wider use of early nebulized therapies could be useful to prevent MDR colonization, thus potentially lowering infectious risk.

[What the family doctor must know about lung transplantation. Complications, health promotion, and outcomes (Part 2)]

The lung transplantation is a therapeutic procedure indicated for lung diseases that are terminal and irreversible (except lung cancer) despite the best medical current treatment. It is an emergent procedure in medical care. In this review, an analyse is made of the most frequent complications of lung transplant related to the graft (rejection and chronic graft dysfunction), immunosuppression (infections, arterial hypertension, renal dysfunction, and diabetes), as well as others such as gastrointestinal complications, osteoporosis. The most advisable therapeutic options are also included. Specific mention is made of the reviews and follow-up for monitoring the graft and the patients, as well as the lifestyle recommended to improve the prognosis and quality of life. An analysis is also made on the outcomes in the Spanish and international registries, their historical evolution and the most frequent causes of death, in order to objectively analyse the usefulness of the transplant.

Pharmacokinetics and Toxicity of Tacrolimus Early After Heart and Lung Transplantation

Annually, about 8000 heart and lung transplantations are successfully performed worldwide. However, morbidity and mortality still pose a major concern. Renal failure in heart and lung transplant recipients is an essential adverse cause of morbidity and mortality, often originating in the early postoperative phase. At this time of clinical instability, the kidneys are exposed to numerous nephrotoxic stimuli. Among these, tacrolimus toxicity plays an important role, and its pharmacokinetics may be significantly altered in this critical phase by fluctuating drug absorption, changed protein metabolism, anemia and (multi-) organ failure. Limited understanding of tacrolimus pharmacokinetics in these circumstances is hampering daily practice. Tacrolimus dose adjustments are generally based on whole blood trough levels, which widely vary early after transplantation. Moreover, whole blood trough levels are difficult to predict and are poorly related to the area under the concentration-time curve. Even within the therapeutic range, toxicity may occur. These shortcomings of tacrolimus monitoring may not hold for the unbound tacrolimus plasma concentrations, which may better reflect tacrolimus toxicity. This review focuses on posttransplant tacrolimus pharmacokinetics, discusses relevant factors influencing the unbound tacrolimus concentrations and tacrolimus (nephro-) toxicity in heart and lung transplantation patients.

Prognostic factors in lung transplantation: the Santa Casa de Porto Alegre experience

BACKGROUND

Lung transplantation (LT) has been established as a current therapy for selected patients with end-stage lung disease. Different prognostic factors have been reported by transplant centers. The objective of this study is to report our recent results with LT and to search for prognostic factors.

METHODS

We performed a retrospective analysis of 130 patients who underwent LT at our institution from January 2004 to July 2009. Donor, recipient, intraoperative, and postoperative variables were collected.

RESULTS

The mean age was 53.14 years (ranging from 8 to 72 years) and 80 (61.5%) were male. The main causes of end-stage respiratory disease were pulmonary fibrosis 53 (40.7%) and chronic obstructive pulmonary disease 52 (40%). The actuarial 1-year survival was 67.7%. Variables correlated with survival were age (P=0.004), distance in the 6-min walk test (P=0.007), coronary heart disease (P=0.001), cardiopulmonary bypass (P=0.02), intraoperative transfusion of red blood cells (P=0.016), increasing central venous pressure at 24th postoperative hour (P=0.001), increasing pulmonary capillary wedge pressure at 24th postoperative hour (P=0.01); length of intubation (P<0.01), reintubation (P=0.001), length of intensive care unit stay (P<0.001), abdominal complication (P=0.003), acute renal failure requiring dialysis (P<0.001), native lung hyperinflation (P=0.02), and acute rejection in the first month (P=0.03). In multivariate analysis, only dialysis (P=0.004, hazards ratio [HR] 2.68), length of intubation (P=0.004, HR 1.002 for each hour), and reintubation (P=0.003, HR 2.88) proved to be independent predictors.

CONCLUSION

Analysis of variables in our cohort highlighted dialysis, longer mechanical ventilation requirement, and reintubation as independent prognostic factors in LT.

Review Article: Anemia post—lung transplantation: mechanisms and approach to diagnosis

Anemia is a common complication in post-lung transplant recipients. Although its mechanism is often multifactorial, clinicians should investigate an eventual underlying explanation to provide the best care. Among the reasons for anemia in lung transplant recipients, blood loss should be thought within the first few days after surgery. Later on, immune-mediated mechanisms, microangiopathic hemolytic anemia and reduction in red blood cell production mediated by viruses, drugs and infiltrative disorders prevail. This article reviews the mechanisms of anemia in post—lung transplant patients and provides an algorithm towards its approach.

Single versus double lung transplantation in pulmonary fibrosis: a debated topic

Idiopathic pulmonary fibrosis (IPF) represents the second most frequent indication for lung transplantation after chronic obstructive pulmonary disease. Survival rate after transplantation is poorer compared with other lung diseases for reasons that are not completely clear. Medical therapy with anti-inflammatory drugs may improve symptoms and quality of life, but it does not influence the survival rate. Lung transplantation is the best therapy for end-stage IPF. The debate regarding the superiority of double lung transplantation (DLT) compared with single lung transplantation (SLT) is still ongoing. Until some years ago, SLT was almost uniformly utilized for this indication. In the most recent years, a larger application of DLT has been observed worldwide, probably related to higher 1-year and 5-year survivals. The unanswered question is whether it is ethical to use two lungs for the same patient, considering the donor shortage, when a single lung would suffice. Many reports have demonstrated that SLT offers acceptable pulmonary function and satisfactory early and intermediate survival. Probably DLT should be reserved for younger recipients, for those with concomitant or possible chronic infection of the contralateral lung, or cases of marginal donors. Further studies will be needed to formulate recommendations regarding the preferred surgical approach in IPF.