Pleural effusion from acute lung rejection

Alterations in Pulmonary Physiology with Lung Transplantation

Lung transplant is a treatment option for patients with end-stage lung diseases; however, survival outcomes continue to be inferior when compared to other solid organs. We review the several anatomic and physiologic changes that result from lung transplantation surgery, and their role in the pathophysiology of common complications encountered by lung recipients. The loss of bronchial circulation into the allograft after transplant surgery results in ischemia-related changes in the bronchial artery territory of the allograft. We discuss the role of bronchopulmonary anastomosis in blood circulation in the allograft posttransplant. We review commonly encountered complications related to loss of bronchial circulation such as allograft airway ischemia, necrosis, anastomotic dehiscence, mucociliary dysfunction, and bronchial stenosis. Loss of dual circulation to the lung also increases the risk of pulmonary infarction with acute pulmonary embolism. The loss of lymphatic drainage during transplant surgery also impairs the management of allograft interstitial fluid, resulting in pulmonary edema and early pleural effusion. We discuss the role of lymphatic drainage in primary graft dysfunction. Besides, we review the association of late posttransplant pleural effusion with complications such as acute rejection. We then review the impact of loss of afferent and efferent innervation from the allograft on control of breathing, as well as lung protective reflexes. We conclude with discussion about pulmonary function testing, allograft monitoring with spirometry, and classification of chronic lung allograft dysfunction phenotypes based on total lung capacity measurements. We also review factors limiting physical exercise capacity after lung transplantation, especially impairment of muscle metabolism. © 2023 American Physiological Society. Compr Physiol 13:4269-4293, 2023.

Surgical Complications of Lung Transplantation

Lung transplantation is a life-saving intervention and the most effective therapy for select patients with irreversible lung disease. Despite the effectiveness of lung transplantation, it is a major operation with several opportunities for complications. For example, recipient and donor factors, technical issues, early postoperative events, and immunology can all contribute to potential complications. This article highlights some of the key surgery-related complications that can undermine a successful lung transplantation. The authors offer their expert opinion and experience to help practitioners avoid such complications and recognize and treat them early should they occur.

Emergency Department Visits Among Lung Transplant Patients: A 4-Year Experience

BACKGROUND

Emergency department (ED) visits by lung transplant (LT) patients have not been well documented in the literature.

OBJECTIVES

To analyze outcomes among LT recipients with ED visits, to better inform clinicians regarding evaluation and treatment.

METHODS

This was a retrospective cohort study of LT patients at our ED (2015-2018). Demographics, transplant indication, laboratory studies, ED interventions, disposition, death, and revisit data were collected. Logistic regression models were used to identify univariable and multivariable predictors of ED revisit, intensive care unit (ICU) admission, or death.

RESULTS

For 505 ED visits among 160 LT recipients, respiratory-related concerns were most frequent (n = 152, 30.1%). Infection was the most common ED diagnosis (n = 101, 20.0%). Many patients were sent home from the ED (n = 235, 46.5%), and 31.3% (n = 158) returned to the ED within 30 days. Fourteen patients (2.8%) needed advanced airway measures. One patient died in the ED, and 18 died in the hospital. On multivariable analysis, more previous ED visits significantly increased the probability of 30-day ED revisit. Heart rate faster than 100 beats/min and systolic blood pressure < 90 mm Hg were significantly associated with ICU admission or death.

CONCLUSION

Infection should be prominent on the differential diagnosis for LT patients in the ED. A large proportion of patients were discharged from the ED, but a higher number of previous ED visits was most predictive of ED revisit within 30 days. Mortality rate was low in our study, but higher heart rate and lower systolic blood pressure were associated with ICU admission or death.

Detection, classification, and management of rejection after lung transplantation

Rejection is a major complication following lung transplantation. Acute cellular rejection, lymphocytic bronchiolitis, and antibody-mediated rejection (AMR) are all risk factors for the subsequent development of chronic lung allograft dysfunction (CLAD). Acute cellular rejection and lymphocytic bronchiolitis have well defined histopathologic diagnostic criteria and grading. Diagnosis of AMR requires a multidisciplinary approach. CLAD is the major barrier to long-term survival following lung transplantation. The most common phenotype of CLAD is bronchiolitis obliterans syndrome (BOS) which is defined by a persistent obstructive decline in lung function. Restrictive allograft dysfunction (RAS) is a second phenotype of CLAD and is associated with a worse prognosis. This article will review the diagnosis, staging, clinical presentation, and treatment of acute rejection, AMR, and CLAD following lung transplantation.

Medical Course and Complications After Lung Transplantation

Lung transplant prolongs life and improves quality of life in patients with end-stage lung disease. However, survival of lung transplant recipients is shorter compared to patients with other solid organ transplants, due to many unique features of the lung allograft. Patients can develop a multitude of noninfectious (e.g., primary graft dysfunction, pulmonary embolism, rejection, acute and chronic, renal insufficiency, malignancies) and infectious (i.e., bacterial, fungal, and viral) complications and require complex multidisciplinary care. This chapter discusses medical course and complications that patients might experience after lung transplantation.

Recommendations of diagnosis and treatment of pleural effusion. Update

Although during the last few years there have been several important changes in the diagnostic or therapeutic methods, pleural effusion is still one of the diseases that the respiratory specialist have to evaluate frequently. The aim of this paper is to update the knowledge about pleural effusions, rather than to review the causes of pleural diseases exhaustively. These recommendations have a longer extension for the subjects with a direct clinical usefulness, but a slight update of other pleural diseases has been also included. Among the main scientific advantages are included the thoracic ultrasonography, the intrapleural fibrinolytics, the pleurodesis agents, or the new pleural drainages techniques.

Acute rejection and humoral sensitization in lung transplant recipients

Despite the recent introduction of many improved immunosuppressive agents for use in transplantation, acute rejection affects up to 55% of lung transplant recipients within the first year after transplant. Acute lung allograft rejection is defined as perivascular or peribronchiolar mononuclear inflammation. Although histopathologic signs of rejection often resolve with treatment, the frequency and severity of acute rejections represent the most important risk factor for the subsequent development of bronchiolitis obliterans syndrome (BOS), a condition of progressive airflow obstruction that limits survival to only 50% at 5 years after lung transplantation. Recent evidence demonstrates that peribronchiolar mononuclear inflammation (also known as lymphocytic bronchiolitis) or even a single episode of minimal perivascular inflammation significantly increase the risk for BOS. We comprehensively review the clinical presentation, diagnosis, histopathologic features, and mechanisms of acute cellular lung rejection. In addition, we consider emerging evidence that humoral rejection occurs in lung transplantation, characterized by local complement activation or the presence of antibody to donor human leukocyte antigens (HLA). We discuss in detail methods for HLA antibody detection as well as the clinical relevance, the mechanisms, and the pathologic hallmarks of humoral injury. Treatment options for cellular rejection include high-dose methylprednisolone, antithymocyte globulin, or alemtuzumab. Treatment options for humoral rejection include intravenous immunoglobulin, plasmapheresis, or rituximab. A greater mechanistic understanding of cellular and humoral forms of rejection and their role in the pathogenesis of BOS is critical in developing therapies that extend long-term survival after lung transplantation.

Lung

Experiments with animals in the 1940 and 1950s demonstrated that lung transplantation was technically possible [33]. In 1963, Dr. James Hardy performed the first human lung transplantation. The recipient survived 18 days, ultimately succumbing to renal failure and malnutrition [58]. From 1963 through 1978, multiple attempts at lung transplantation failed because of rejection and complications at the bronchial anastomosis. In the 1980s, improvements in immunosuppression, especially the introduction of cyclosporin A, and enhanced surgical techniques led to renewed interest in organ transplantation. In 1981, a 45-year-old-woman received the first successful heart–lung transplantation for idiopathic pulmonary arterial hypertension (IPAH) [106]. She survived 5 years after the procedure. Two years later the first successful single lung transplantation for idiopathic pulmonary fibrosis (IPF) [128] was reported, and in 1986 the first double lung transplantation for emphysema [25] was performed.

Diagnosis and outcome of early pleural space infection following lung transplantation

BACKGROUND

Despite the frequent occurrence of pleural effusions in lung transplant recipients, little is known about early posttransplant pleural space infections. We sought to determine the predictors and clinical significance of pleural infection in this population.

METHODS

We analyzed 455 consecutive lung transplant recipients and identified patients who had undergone sampling of pleural fluid within 90 days posttransplant. A case-control analysis was performed to determine the characteristics that predict infection and the impact of infection on posttransplant survival.

RESULTS

Pleural effusions undergoing drainage occurred in 27% of recipients (124 of 455 recipients). Ninety-six percent of effusions were exudative. Pleural space infection occurred in 27% of patients (34 of 124 patients) with effusions. The incidence of infection did not differ significantly by native lung disease or type of transplant operation. Fungal pathogens accounted for > 60% of the infections; Candida albicans was the predominant organism found. Bacterial etiologies were present in 25% of cases. Infected pleural effusions had elevated lactate dehydrogenase levels (p = 0.036) and markedly increased neutrophil levels in the pleural space (p < 0.0001) compared to noninfected effusions. A pleural neutrophil percentage of > 21% provides a sensitivity of 70% and a specificity of 79% for correctly identifying an infection. Patients with pleural space infection had a diminished 1-year survival rate compared to those without infection (67% vs 87%, respectively; p = 0.002).

CONCLUSION

Pleural infection with fungal or bacterial pathogens commonly complicates lung transplantation, and an elevated neutrophil level in the pleural fluid is the most sensitive and specific indicator of infection.

Noninfectious Pulmonary Complications After Lung Transplantation

This article reviews several important noninfectious pulmonary complications that threaten survival, pulmonary function, and quality of life after lung transplantation. Topics reviewed include primary graft dysfunction (PGD), native lung hyperinflation, anastomotic complications, phrenic nerve injury, pleural complications, lung cancer, pulmonary toxicity associated with immunosuppressive medications, and exercise limitation.

Late postoperative pleural effusion following lung transplantation: characteristics and clinical implications

OBJECTIVE

Pleural effusions are extremely common in the early postoperative period after lung transplantation (LTX). It occurs in all transplant recipients, and like pleural fluid following other cardiothoracic surgery is bloody, exudative and neutrophil predominant. There was no information, however, on the characteristics of the late (14-45 days) postoperative pleural fluid after LTX. The purpose of this study was to describe the characteristics and the clinical implications of late postoperative pleural effusion after LTX.

METHODS

Thirty-five patients underwent TX between May 1997 and May 2001. Seven patients (20%) developed late postoperative pleural effusion. Thoracentesis were performed in these patients and the white blood cell counts, cell differential as well as biochemical parameters were determined.

RESULTS

The median time for late pleural effusion appearance was 23 days (range, 14-34 days) after TX. The pleural effusions were medium in size (700 ml, range, 100-1300), exudative in all the patients and had lymphocyte predominance. No evidence of fluid recurrence or clinical deterioration was noted in these patients.

CONCLUSION

Late-onset exudative lymphocytic pleural effusion after LTX is not uncommon. When there is no evidence of rejection or infection, it usually has a benign, favorable outcome.

Bullous sarcoidosis: a report of three cases

Three cases of pulmonary sarcoidosis presented as bullous emphysema with severe airflow obstruction, and the diagnosis of sarcoidosis was unsuspected for at least 2 years. Potential mechanisms of bullous emphysema from sarcoidosis are discussed. The physician should suspect sarcoidosis as the cause of bullous emphysema when young patients who have smoked relatively few pack-years present with emphysema or severe airflow obstruction. Additional clues are the presence of mediastinal adenopathy on a chest radiograph or a CT scan and a history consistent with extrapulmonary sarcoidosis.