Evaluation of heart-lung transplant recipients with prospective, serial transbronchial biopsies and pulmonary function studies

Airway Oscillometry Detects Spirometric-Silent Episodes of Acute Cellular Rejection

Rationale: Acute cellular rejection (ACR) is common during the initial 3 months after lung transplant. Patients are monitored with spirometry and routine surveillance transbronchial biopsies. However, many centers monitor patients with spirometry only because of the risks and insensitivity of transbronchial biopsy for detecting ACR. Airway oscillometry is a lung function test that detects peripheral airway inhomogeneity with greater sensitivity than spirometry. Little is known about the role of oscillometry in patient monitoring after a transplant.Objectives: To characterize oscillometry measurements in biopsy-proven clinically significant (grade ≥2 ACR) in the first 3 months after a transplant.Methods: We enrolled 156 of the 209 double lung transplant recipients between December 2017 and March 2019. Weekly outpatient oscillometry and spirometry and surveillance biopsies at Weeks 6 and 12 were conducted at our center.Measurements and Main Results: Of the 138 patients followed for 3 or more months, 15 patients had 16 episodes of grade 2 ACR (AR2) and 44 patients had 64 episodes of grade 0 ACR (AR0) rejection associated with stable and/or improving spirometry. In 15/16 episodes of AR2, spirometry was stable or improving in the weeks leading to transbronchial biopsy. However, oscillometry was markedly abnormal and significantly different from AR0 (P < 0.05), particularly in integrated area of reactance and the resistance between 5 and 19 Hz, the indices of peripheral airway obstruction. By 2 weeks after biopsy, after treatment for AR2, oscillometry in the AR2 group improved and was similar to the AR0 group.Conclusions: Oscillometry identified physiological changes associated with AR2 that were not discernible by spirometry and is useful for graft monitoring after a lung transplant.

Surveillance transbronchial biopsies in infant lung and heart-lung transplant recipients

There are limited published data on surveillance TBB for the identification of allograft rejection in infants after lung or heart-lung transplantation. We performed a retrospective review of children under one yr of age who underwent lung or heart-lung transplant at our institution. Since 2005, four infants were transplanted (three heart-lung and one lung). The mean age (±s.d.) at the time of transplant was 5.5 ± 2.4 (range 3-8) months. A total of 16 surveillance TBB procedures were completed in both inpatient and outpatient settings, with a range of 3-7 performed per patient. A minimum of five acceptable tissue pieces with expanded alveoli were obtained in 81% (13/16) of TBB procedures and a minimum of three pieces in 88% (14/16). There was no evidence of acute allograft rejection in 88% (14/16) of TBB procedures. One TBB procedure yielded two tissue specimens demonstrating A2 acute allograft rejection. One TBB procedure failed to yield tissue with sufficient alveoli. Additionally, B-grade assessment identified B0 in 50% (8/16), B1R in 12% (2/16), and BX (ungradeable or insufficient sample) in 38% (6/16) of biopsy procedures, respectively. In conclusion, TBB may be safely performed as an inpatient and outpatient procedure in infant lung and heart-lung transplant recipients and may provide adequate tissue for detecting acute allograft rejection and small airway inflammation.

Combined heart-lung transplantation: a perspective on the past and the future

During the last 20 years, there has been a shift away from combined heart-lung transplantation (HLT) in favor of bilateral lung transplantation. This paradigm shift allowed for the donor heart to be transplanted to another patient. However, HLT remains to be the definitive surgical treatment for certain congenital heart disorders and Eisenmenger's syndrome. With a growing population of adult patients with congenital heart disease, there remains a need for HLT. This article provides a perspective on the past and the future of HLT.

Single-institution study evaluating the utility of surveillance bronchoscopy after lung transplantation

BACKGROUND

Many lung transplant physicians advocate surveillance bronchoscopy with transbronchial lung biopsy and bronchoalveolar lavage (TBB/BAL) to monitor lung recipients despite limited evidence this strategy improves outcomes. This report compares rates of infection (INF), acute rejection (AR), bronchiolitis obliterans syndrome (BOS) and survival in lung allograft recipients managed with surveillance TBB/BAL (SB) versus those with clinically indicated TBB/BAL (CIB).

METHODS

We reviewed 47 consecutive recipients transplanted between March 2002 and August 2005. Of these recipients, 24 consented to a multi-center trial requiring SB and 23 were managed by our usual practice of CIB. Rates of freedom from INF, AR, BOS and survival were compared. BOS and AR were diagnosed according to published guidelines from the International Society for Heart and Lung Transplantation.

RESULTS

A total of 240 TBB/BALs were performed. CIB and SB groups underwent 84 (3.7 +/- 3.4/patient) and 156 (6.5 +/- 2.0/patient) TBB/BALs, respectively. In the SB group, 54 (2.2 +/- 1.6/patient) TBB/BALs were true surveillance procedures, whereas 102 (4.2 +/- 2.3/patient) were clinically indicated. No AR episode requiring treatment was detected by true surveillance. Freedom from respiratory INF, AR, BOS and survival in the SB and CIB groups showed no significant differences. Five patients in the CIB group remained stable without requiring TBB/BAL. In the SB group, 4 previously asymptomatic patients developed pneumonia within 2 weeks of surveillance TBB/BAL.

CONCLUSIONS

With no obvious advantage identified, surveillance bronchoscopy may pose a risk to stable lung transplant recipients. A multi-center, controlled trial is required to validate the utility and safety of surveillance bronchoscopy in lung transplantation.

Surveillance bronchoscopy in lung transplant recipients: risk versus benefit

BACKGROUND

Long-term survival of lung transplant (LT) recipients is limited by the development of the bronchiolitis obliterans syndrome (BOS). A number of risk factors for BOS have been identified, which can be detected using bronchoscopy with transbronchial biopsy (TBB). Many LT units perform routine surveillance bronchoscopy (SB) to detect problems such as: acute rejection (AR); infection, particularly with cytomegalovirus (CMV); and lymphocytic bronchiolitis. This study aimed to assess the safety and efficacy of surveillance bronchoscopy in lung transplant recipients (LTRs), including TBB and bronchoalveolar lavage (BAL).

METHODS

All bronchoscopy procedures, including SB and clinically indicated (CB) procedures performed on LTRs in one calendar year, were audited prospectively. Complications and clinical utility were recorded to determine the clinical utility both early (3 months and 3 to 12 months) and late (>12 months) post-LT.

RESULTS

In one calendar year, 353 procedures (232 SBs and 121 CBs) were performed on 124 LTRs, with 246 performed <1 year post-LT. The complication rates were similar to those reported previously, except for an increased rate of sedation-related complications, particularly up to 3 months post-LT. SBs showed high rates of acute rejection, particularly in the first year post-LT (p = 0.01). The rate of asymptomatic infection diagnosed on BAL remained high regardless of time post-transplant.

CONCLUSIONS

This study confirms that SB can frequently detect clinically significant infection and rejection with very low complication rates. The data support SB with TBB up to 12 months post-LT, and ongoing use of SB with BAL (only) to detect clinically silent infection beyond 1 year post-LT.

The use of multiple transbronchial biopsies as the standard approach to evaluate lung allograft rejection

Flexible bronchoscopy with transbronchial biopsy (TBB) is routinely performed in adult and pediatric lung transplant recipients. The clinical signs and symptoms of acute cellular rejection (ACR) are often identical to those of infection. TBB is a fairly sensitive and specific tool in which to diagnose ACR and can be performed safely in children of all ages. The utility of TBB is unquestioned during periods of worsening clinical symptoms. The utility of TBB for routine surveillance of the allograft remains unproven. The data suggests that during the first 4-6 months post-transplant there is a high incidence of clinically silent ACR. The significance of subclinical rejection in lung transplantation is unknown. Randomized, controlled trials are required to determine if multiple surveillance TBB, can impact the incidence of obliterative bronchiolitis.

What are the best pulmonary function test parameters for early detection of post-lung transplant bronchiolitis obliterans syndrome in children?

Post-lung transplant bronchiolitis obliterans syndrome (BOS) is defined as an unexplained fall in forced expiratory volume in 1 s (FEV1) >or=20% of baseline (B). There have been reports in adults that FEF25-75% (>30% decline from B) is more sensitive than FEV1 for the early diagnosis of BOS. Yet, it is not known if other pulmonary function test (PFT) parameters - forced expiratory flow rates at 25-75% of vital capacity (FEF25-75%) and maximal expiratory flow rate at 80% (Vmax80%), 70% (Vmax70%) and 60% (Vmax60%) - are more sensitive indicators for early diagnosis of BOS than FEV1 in post-lung transplant children. We reviewed serial PFTs of 18 patients (ages 14.1 +/- 3.7 yr, 50% female) who had lung transplantation at our institution from 1993 to 1999, and who met the criteria for BOS diagnosis. There was no significant difference in post-transplant days when decline in FEV1 >or=20% of B, FEF25-75% >30% of B, and Vmax80%, Vmax70% and Vmax60% from normal occurred (635 +/- 431, 551 +/- 422 and 454 +/- 287 days, respectively; p = 0.4). However, a decline in FEV1 was the first abnormality in only 39% of the patients, while a decline in FEF25-75% and Vmax at specific lung volume were the first abnormality in 78% and 56% of the patients, respectively. The earliest signs of BOS would be missed in 61% of patients if FEV1 was the primary parameter used for the diagnosis. In order to improve the sensitivity of the diagnosis of post-lung transplant BOS; we speculate that the diagnosis should be based on decreases in FEF25-75% rather than on FEV1.

Success of lung transplantation without surveillance bronchoscopy

BACKGROUND

No current evidence demonstrates improved survival or decreased rate of bronchiolitis obliterans syndrome (BOS) despite regularly scheduled fiberoptic bronchoscopy (FOB) with transbronchial biopsy and bronchoalveolar lavage (TBB/BAL) after lung transplantation. Reduced lung function detected with spirometry or oximetry in symptomatic and asymptomatic lung allograft recipients (LARs) may be a more appropriate indication for bronchoscopic sampling.

HYPOTHESIS

Clinically indicated TBB/BAL without routine invasive surveillance sampling of the transplanted lung does not decrease survival or increase the rate of BOS in LARs.

METHODS

We reviewed 91 consecutive LARs transplanted at Ochsner Clinic between January 1995 and December 1999. Clinical indications for FOB with TBB/BAL include 10% decline in forced expiratory volume in 1 second below baseline; 20% decrease in forced expiratory flow rate between 25% and 75% of the forced vital capacity; or unexplained respiratory symptoms, signs, or fever. Along with demographic and clinical data, 1-year and 3-year survival rates for these 91 LARs were compared with 5,430 LARs from the International Society for Heart and Lung Transplantation (ISHLT) Registry transplanted during the same 60-month period. Ten of the 91 patients did not survive to hospital discharge after transplantation. We divided the remaining 81 LARs into 2 subsets: Group A patients (n = 43) underwent zero to 1 TBB/BAL and Group B patients (n = 38) required more than 1 procedure. Demographic data, rejection, infection, and incidence of BOS were compared between groups.

RESULTS

The 1-year and 3-year survival rates in the Ochsner LAR cohort were 85% and 73%, respectively, vs 72% and 57% in the ISHLT cohort p < 0.01. The relative risks of death in the Ochsner group at 1- and 3-years were 0.56 (0.35-0.91) and 0.66 (0.48-0.92), respectively, p < 0.05. The median (range) follow-up was 910 days (60-1,886) for Group A and 961 days (105-1,883) for Group B, p = not significant. We observed twice as many patients with cystic fibrosis and twice as many pneumonia episodes in Group B. The rate of acute rejection in each group was not statistically different. The cumulative incidence of BOS was increased in Group B at 1 year and at 3 years (5% and 56%) when compared with Group A (3% and 13%), p < 0.01.

CONCLUSIONS

Based on the findings from this observational, single-institution study, clinically indicated TBB/BAL without routine surveillance sampling of the lung allograft is unlikely to pose greater risk than does regularly scheduled bronchoscopy after lung transplantation.

Aspects of Pulmonary Infections After Solid Organ Transplantation

The increasing number of solid organ transplant (SOT) recipients have high rates of pulmonary infections due to bacterial, fungal, and viral pathogens. These patients have unique sets of factors predisposing to infection. Lung and heart-lung transplants are associated with particularly high infection rates. The prominence of cytomegalovirus (CMV) as a pathogen in all subsets of SOT patients has led to new strategies for prophylaxis, detection, and treatment of CMV pneumonitis. Progress is similarly being made in managing fungal and bacterial infections. Advances in liver, kidney, heart, and lung transplantation are being discussed, with further attention to specific pathogens (ie, CMV, Aspergillus, Pneumocystis carinii, and Mycobacterium tuberculosis).

Pulmonary circulatory parameters as indices for the early detection of acute rejection after single lung transplantation

We investigated the relationship between the changes in the pulmonary blood flow and histology during acute rejection following single lung transplantation. In single lung transplantation using adult mongrel dogs, immunosuppression with cyclosporine and azathioprine was discontinued after postoperative day 14 to induce rejection. Doppler flow probes were placed adjacent to the ascending aorta and the left pulmonary artery to measure the blood flow on a daily basis. In addition, chest roentgenograms were also examined daily. The pulmonary pressure was measured using a Swan-Ganz catheter prior to and following the induction of rejection. Open lung biopsies were performed when the left pulmonary artery flow decreased to half of the prerejection value. The pulmonary artery flow decreased to 14.3% of the aortic flow 5 days after the discontinuation of immunosuppression. The graft pulmonary vascular resistance increased significantly compared to the prerejection values (P < 0.001). This was not accompanied by any abnormalities on chest roentgenography. The histology was consistent, with marked perivascular lymphocytic infiltration with little alveolar or interstitial changes. During rejection, the increased pulmonary vascular resistance in the graft was probably the result of perivascular inflammatory cell infiltration, which was seen prior to changes on chest roentgenography. Changes in the left pulmonary artery flow and histology thus appear to be closely correlated in the early stages of acute rejection.

Role of pulmonary function in the detection of allograft dysfunction after heart-lung transplantation

BACKGROUND

Lung function is altered by infection and rejection in patients who undergo heart-lung transplantation. The sensitivity, specificity, and positive/negative predictive values (PPV and NPV) of lung function for the detection of allograft dysfunction in these patients were measured.

METHODS

Thirty three patients who underwent heart-lung transplantation were followed for a mean period of 16.3 months. On 123 occasions functional measurements were obtained at the time a transbronchial biopsy specimen and/or bronchoalveolar lavage fluid was taken, which were used as gold standards. Optimal sensitivity (the value for which sensitivity equals specificity) was computed for each functional test from receiver-operator characteristic (ROC) curves.

RESULTS

Acute rejection was present on 31 occasions and infection on 36 occasions; 56 samples were normal. Infection and rejection were accompanied by airflow obstruction, a rise in the slopes of the alveolar plateaus for nitrogen, hexafluoride sulphur and helium (SN2, SSF6, and SHe), and a decrease in the difference between SSF6 and SHe (delta S), total lung capacity (TLC), and lung transfer factor (TLCO). Optimal sensitivities for SHe, mid forced expiratory flow (FEF25-75), TLC, and forced expiratory volume in one second (FEV1) were 68%, 67%, 66%, and 60%, respectively; they were not different for infection and rejection and did not change over the study period. For infection and rejection together, PPV ranged from 72% to 88% and NPV from 27% to 52% according to the functional test and the postoperative period considered.

CONCLUSIONS

Indices of ventilation distribution, FEF25-75, and TLC have the best optimal sensitivity for the diagnosis of infection and rejection after heart-lung transplantation. The high PPV of pulmonary function in detecting allograft dysfunction observed in this study suggests that a diagnostic procedure should be performed whenever one or more functional tests deteriorate; conversely, the low NPV indicates that a stable pulmonary function does not rule out allograft dysfunction.

Acute pulmonary allograft rejection. Mechanisms, diagnosis, and management

Rejection is a common complication following lung transplantation, and can lead to considerable short- and long-term morbidity. As numbers and survival rates of lung transplant recipients increase, it is apparent that acute rejection can occur months or years after transplantation, and may be resistant to standard therapies. Mechanisms of acute rejection have been well studied in other solid organ transplant recipients, and are beginning to be addressed in the lung recipient. This article addresses some of the common issues of diagnosis and management of acute rejection which arise frequently during the care of lung transplant recipients.

Surveillance bronchoscopy in lung transplant recipients

STUDY OBJECTIVES

To establish whether a consensus exists among active transplant centers regarding the use and interpretation of information obtained by surveillance bronchoscopic lung biopsy (SBLB).

DESIGN

Prospective standardized questionnaire answered via mail and telephone communications.

PARTICIPANTS

A five page, 18-question survey was sent to all lung transplant programs listed by the United Network of Organ Sharing in North America, as well as eight selected international programs. Ninety-one surveys were sent to 83 North American and eight international programs. Seventy-four programs (81%) responded. Seventeen programs (19%) were excluded secondary to inactivity. The remaining 57 programs (63%) were included in final data analysis.

INTERVENTIONS

None.

RESULTS

Sixty-eight percent (39/57) of the responding programs perform SBLBs. Ninety-two percent of the programs performing SBLBs do so within the first month, and 69% continue to do so on a regular basis. Sixty-nine percent (27/39) of programs performing SBLBs continue to do so after 1 year. Eighty-six percent (32/37) of respondents believe that SBLB impacts on patient management at least 10% of the time. Technically, 90% (35/39) take biopsy specimens from more than one lobe per SBLB session. Fifty-nine percent (23/39) took 6 to 10 biopsy specimens per session, 33% (13/39) took three to five biopsy specimens, and 7% (4/39) took > 10 biopsy specimens per session. Eighty-six percent (32/37) of the responding centers reported treating asymptomatic rejection at grade 2A, while 14% (5/37) waited until histologic grade 3A before beginning treatment. Complications from SBLB were minimal with < 5% rates of pneumothorax, requirement for chest tube placements, or significant bleeding during SBLB reported by > 95% of the programs performing SBLB.

CONCLUSIONS

Most active lung transplant centers perform SBLBs and do so on a regular basis. However, a wide range of opinion exists over the utility and technique of SBLB and the impact of its results influencing outcome in the lung transplant recipient. To answer these questions, a randomized multicentered trial or registry to determine the effect of SBLB on lung transplant recipient morbidity and mortality is required.

Acute rejection diagnosed with computed tomography in a porcine experimental lung transplantation model

The role of computed tomography (CT) in the diagnosis of acute rejection was studied in an experimental lung transplantation model, with 15 left lung allotransplantations and six autotransplantations performed on piglets weighing 16-24 kg. There were 31 episodes of acute rejection. In the allotransplantation group the development of acute rejection was monitored 115 times with CT, transbronchial biopsy (TBB) and bronchoalveolar lavage (BAL). The stages of acute rejection were 1) ill-defined centrilobular micronodules or minimal patchy ground-glass opacities. 2) dense, small-nodular infiltration or extensive ground-glass opacities, and bronchial wall thickening. 3) lung volume loss and dense, patchy ground-glass opacities and 4) consolidation of the lung. In the autotransplantation group monitoring was done 42 times. After allotransplantation, TBB and BAL suggested rejection 60 times and infection 23 times. CT had 86.7% sensitivity and 85.6% specificity. During the first month these figures were, respectively, 71.4% and 84.2%. Rising histologic grade was associated with increasing stage of acute rejection on CT, which thus proved to be a sensitive and specific method for diagnosing acute rejection of lung transplant.

Living-donor lobar lung transplantation experience: intermediate results

OBJECTIVE

Living-donor lobar lung transplantation offers an alternative for patients with a life expectancy of less than a few months. We report on our intermediate results with respect to recipient survival, complications, pulmonary function, and hemodynamic reserve.

METHODS

Thirty-eight living-donor lobar lung transplants were performed in 27 adult and 10 pediatric patients for cystic fibrosis (32), pulmonary hypertension (two), pulmonary fibrosis (one), viral bronchiolitis (one), bronchopulmonary dysplasia (one), and posttransplantation obliterative bronchiolitis (one). Seventy-six donors underwent donor lobectomies.

RESULTS

There were 14 deaths among the 37 patients, with an average follow-up of 14 months. Predominant cause of death was infection, consistent with the large percentage of patients with cystic fibrosis in our population. The overall incidence of rejection was 0.07 episodes/patient-month, representing 0.8 episodes/patient. Postoperative pulmonary function testing generally showed a steady improvement that plateaued by postoperative months 9 to 12. Fourteen patients who were followed up for at least 1 year underwent right heart catheterization; pressures and pulmonary vascular resistances were within normal ranges. Bronchiolitis obliterans was definitively diagnosed in three patients. Among the 76 donors, complications in the postoperative period included postpericardiotomy syndrome (three), atrial fibrillation (one), and surgical reexploration (three).

CONCLUSIONS

We believe that these data support an expanded role for living-donor lobar lung transplantation. Our intermediate data are encouraging with respect to the functional outcome and survival of these critically ill patients, who would have died without this option.

Total lymphoid irradiation for refractory acute rejection in heart-lung and lung allografts

Persistent or recurrent acute allograft rejection (AR) refractory to high-dose steroid therapy can adversely affect long-term outcomes of heart-lung (HLT), bilateral-lung (BLT), and single-lung (SLT) transplantations. The use of total lymphoid irradiation (TLI) for the management of refractory acute AR in six transplant recipients (two men, four women; mean age, 29.8 +/- 3.8 years) is detailed. There are two HLT (primary pulmonary hypertension [PPH], cystic fibrosis [CF]), 1 BLT (pulmonary hypertension postventricular septal defect repair), and 3 SLT (sarcoid, PPH, congenital heart disease with atrial septal defect) recipients. Refractory AR is defined as persistent rejection unresponsive to high-dose steroid therapy in all cases. The BLT and SLT recipients had at least two moderate and one mild AR events per patient. The HLT recipients had at least two moderate acute heart and one severe and one mild asynchronous acute lung rejection events per patient. A total of 800 cGy of total lymphoid irradiation (TLI) was administered over a 5-week period. Mild and transient leukopenia was the only observed side effect. The patient with PPH received TLI 313 days after HLT for recurrent AR at another institution and died of ARDS 4 weeks after completing TLI. The patient with CF received TLI 707 days after HLT and died 457 days after TLI of severe obliterative bronchiolitis (OB) with multiorgan failure. The patient with BLT received TLI 176 days after transplant and died 372 days after TLI of respiratory failure related to severe rejection. One patient with SLT received TLI 78 days after transplant and died 679 days after TLI of severe acute AR. The two remaining patients with SLTs have been free from acute AR for more than 4 years. The patient with sarcoidosis received TLI 37 days after SLT following a clinical rejection event and two severe acute AR events. He is alive with normal lung function 5 years later. The patient with PPH received TLI 108 days after SLT following three moderate acute AR events and is alive with stable OB 4 years later. These limited preliminary results suggest that TLI has merit for the treatment of intractable acute AR following HLT and lung transplantation.

Selective assessment of single-lung graft function with 133Xe radiospirometry in acute rejection and infection

In single-lung transplant recipients, the usefulness of spirometric indexes in detecting acute events involving the lung graft is limited due to the bias caused by the native lung. Selective functional monitoring is needed for the proper evaluation of complications after transplantation, but thus far, to our knowledge, no clinically feasible methods for selective graft-function assessment have been presented. In ten single-lung recipients, of whom six had a parenchymal lung disease and four had pulmonary hypertension, the relative ventilation (Vtx), perfusion (Qtx), and ventilation/perfusion ratio of the transplanted lung (V/Qtx) were determined with multidetector 133Xe radiospirometry. Additionally, the fractions of FEV1, FVC, and diffusing capacity for carbon monoxide (Dco) of the transplant (FEV1tx, FVCtx, Dcotx, respectively) were determined by using corresponding radiospirometric parameters for the calculation of their distribution between the lungs. The analysis included seven episodes of acute rejection and nine episodes of infection. The Qtx decreased during acute rejection but did not change during infection (p=0.001). Compared with the figures during infection, the V/Qtx increased during acute rejection significantly (p<0.05) in patients with underlying fibrosis or emphysema, but not in those with pulmonary hypertension. In detection of acute events, the sensitivity of the selective parameters, ie, FEV1tx (86%) and FVCtx (73%), was higher than that of the sum-function parameters, FEV1 (66%) and FVC (40%). Moreover, the sensitivity of Dcotx (80%) was higher than that of Dco (60%) in detecting acute rejection. The findings indicate that, in single-lung recipients with a parenchymal lung disease, the assessment of Qtx, V/Qtx, and Dcotx with a radioactive tracer can help to distinguish acute rejection from infection. The graft-selective parameters, ie, FEV1tx, FVCtx, and Dcotx, tended to be more sensitive than the corresponding sum-function parameters in detecting acute events, thus providing a more accurate functional profile of the single-lung graft.

Significance of clinically silent untreated mild acute cellular rejection in lung allograft recipients

Although acute rejection is a frequent occurrence after transplantation, the clinical behavior and pathological manifestations of untreated mild acute cellular rejection in clinically stable lung allograft recipients is poorly defined. Sixteen patients were identified who had asymptomatic mild acute rejection that was untreated but followed by subsequent pulmonary function tests and repeat transbronchial biopsy. Six patients had spontaneous resolution of their infiltrates; the condition of 10 patients worsened as observed from their biopsies or function studies. Those who worsened had more episodes of acute rejection per patient before the A2 biopsy (2.0 vs 1.3), and 50% developed bronchiolitis obliterans compared with 16% in the spontaneously regressing group. Pathological evaluation showed that patients with persistent or worsening untreated A2 rejection tended to have more large and small airway inflammation, larger numbers of eosinophils and plasma cells in their biopsies, and airway and airspace granulation tissue. These variables may be used to help determine which low grade lung rejection episodes should receive adjunctive immunosuppressive therapy.

Bronchiolitis obliterans in recipients of single, double, and heart-lung transplantation

Thirty-two recipients of single, double, or heart-lung transplantation followed-up for at least 3 months posttransplant were retrospectively reviewed to assess the frequency, predictors, and risk factors associated with the development of bronchiolitis obliterans (BO). A clinical definition for the diagnosis of BO was made using the following criteria: persistent and progressive decline in FEF25-75, associated with normal results of cytologic and microbiologic studies for significant pathogens in bronchoalveolar lavage fluid, with a normal chest radiograph. This was correlated with histologic diagnosis and patient outcome. Sixteen (50%) of the patients developed BO, and this was associated with a 56% mortality. All but 1 patient with histologic BO had a clinical diagnosis of BO made (often months) prior to diagnostic biopsy. No patients with normal histologic findings had a clinical diagnosis of BO. More than 3 episodes of histologically documented acute rejections in any 12-month period were eventually associated with a 100% incidence of BO. Cytomegalovirus occurred with greater frequency in patients with BO, and in most cases, preceded or occurred concomitantly with the diagnosis of acute rejection or BO.

Analysis of bronchoalveolar lavage from human lung transplant recipients by flow cytometry

Bronchoalveolar lavage (BAL) cells and peripheral blood leucocytes (PBL) from 24 lung transplant recipients were analysed for leucocyte subsets and expression of cell surface antigens. Total and differential white cell counts were performed on BAL, and lymphocyte subsets were evaluated in both BAL and peripheral blood. Measurement of immunofluorescence by flow cytometry was used to assess the percentage of: T cells (CD3+); T-helper cells (CD4+); T-cytotoxic/suppressor cells (CD8+); and activated lymphocytes (HLA-DR+). Lymphocyte subsets in BAL demonstrated marked differences to those in blood. A lower percentage of CD3+ and CD4+ lymphocytes were found in BAL, whereas CD8+ cells were more prevalent in BAL than in PBL. The mean CD4:CD8 ratio was significantly lower in BAL (1:1) than in blood (2.1:1). In the absence of pulmonary infection, there was a trend for a lower CD4:CD8 ratio in BAL associated with acute rejection (1.1:1) and obliterative bronchiolitis (1:1), when compared to the group with no evidence of rejection (1.4:1). In the absence of pulmonary rejection, pulmonary infection was associated with a marginally lower CD4:CD8 ratio in BAL (0.7:1), than when infection was absent (1.4:1). This difference was more evident in cases of cytomegalovirus (CMV) infection with a mean CD4:CD8 ratio of 0.3:1, compared to 1.5:1 in the absence of CMV disease (P < 0.05).

Early diagnosis of acute rejection by pulmonary hemodynamics after single-lung transplantation

The aim of this study was to facilitate the early diagnosis of acute rejection after single-lung transplantation based on pulmonary hemodynamic findings. A Doppler flowmeter was placed in the ascending aorta and the pulmonary artery of adult mongrel dogs after single-lung transplantation. The pulmonary hemodynamics of the lung graft were then evaluated during the early postoperative period and during subsequent rejection. Twenty dogs were divided into three groups. Group 1 consisted of 6 dogs that underwent autotransplantation of the left lung. Group 2 was made up of 6 dogs that underwent allotransplantation of the left lung without immunosuppressant therapy. Group 3 consisted of 8 dogs that underwent allotransplantation of the left lung and were treated with 10 mg/kg of cyclosporine and 4 mg/kg of azathioprine. Pulmonary hemodynamics and chest roentgenograms were studied for more than 2 weeks postoperatively. Open lung biopsy was performed in some dogs to obtain graft specimens for histologic examination. The left pulmonary artery flow rate (percentage of pulmonary graft blood flow to cardiac output) decreased slightly after operation in group 1, and decreased to 14.4% after 1 week and to zero on postoperative day 10 in group 2. The pulmonary vascular resistance of the grafts in group 2 also increased exponentially. In contrast, the left pulmonary artery flow rates decreased to 29.1% on the day after operation in group 3, but recovered to 38.5% on postoperative day 14. Within a mean of 3.7 days of immunosuppressant discontinuation, the left pulmonary artery flow rates decreased to less than 12.7%, with a marked increase in pulmonary resistance.(ABSTRACT TRUNCATED AT 250 WORDS)

Lung transplantation

Solid-organ transplantation has flourished during the last decade, with transplantation of heart and lungs becoming available to patients with end-stage cardiac or pulmonary diseases. The first lung transplant was performed in 1963 on a 58-year-old man with bronchogenic carcinoma. He survived for 18 days. During the next two decades, approximately 40 lung transplant procedures were attempted without success. These early attempts at lung transplantation were unsuccessful because of the development of lung rejection, anastomotic complications, or infection in the transplant recipients. In the early 1980s, human heart-lung transplantation was successfully performed for the treatment of pulmonary vascular disease. After this procedure, single-lung transplantation for the treatment of end-stage interstitial lung disease and obstructive lung disease was developed. More recently, the technique of double-lung transplantation has come into existence. This article reviews various aspects of lung transplantation, including immunosuppression, lung graft preservation, the various surgical techniques and types of lung transplant procedures available, recipient and donor selection criteria, and postoperative care of the transplant recipient. In addition, infectious and noninfectious complications seen in this particular patient population, including acute and chronic rejection, will be discussed.

Single lung transplantation. Morphological surveillance by transbronchial biopsy

Seven cases of single lung transplantation are reported. The recipients were all below 60 years of age and severely disabled with end-stage lung disease. Transplantation was performed according to ABO blood group compatibility and negative lymphocytotoxic cross-match between donor and recipient irrespective of HLA mismatch. Recipients' diagnoses were sarcoidosis (3), alfa-1 antitrypsin deficiency (3), and idiopathic emphysema (1). Mean recipient age was 48 +/- 2.4 years (range 45-52). Donor age was 29.7 +/- 5.6 years (range 16-49). The immunosuppressive regimen included cyclosporin A, azathioprine, steroids and rabbit antithymocyte globulin. Excellent graft function was achieved. Six patients survived the postoperative period and are alive 4-18 months posttransplant. One patient died after the operation due to pneumonia with respiratory distress syndrome. Graft function was also monitored by transbronchial biopsy, and 57 biopsy procedures were performed without fatal complications. Acute cellular rejection was seen in 16 biopsy specimens from 5 recipients (grade 1 and 2 rejection in 14, grade 3 rejection in 2). Neither severe rejection with septal necrosis (grade 4) nor obliterative bronchiolitis was seen. The rejection rate was 0.03 episodes per patient/month. In contrast to other reports, episodes of cellular rejection occurred throughout the observation period, and were not mainly limited to the first 4 months posttransplant. Graft vascular occlusive disease or chronic vascular rejection was found in 6 biopsy specimens from one recipient. Five patients experienced 7 episodes of cytomegalovirus infection. The cytomegalovirus infection rate was 0.01 episodes per patient/month. The incidence of infection was significantly lower compared to previous studies of rejection in other lung graft combinations. Both infections and rejection episodes may contribute to the development of obliterative bronchiolitis. Almost one third of the specimens (30%) showed lymphocytic bronchitis without perivascular inflammation. The absence of perivascular infiltrates and exclusion of infectious agents leaves in question the aetiology of this inflammation. The lymphocytic bronchitis could be ischaemic, related to aspiration, or represent recurrent sarcoidosis, or, in fact, express bronchial rejection. All biopsy specimens regarded as rejection with cellular infiltrates in the lung parenchyma also showed a lymphocytic bronchitis. The impact of HLA mismatch on cellular and vascular rejection is unclear. Transbronchial biopsy is a reasonably safe and reliable method in the diagnosis of rejection and infection in single lung transplantation.

Management of lung transplant rejection

Using current immunosuppressive protocols, rejection is common after lung transplantation. Most recipients have at least one episode of acute rejection, and approximately 25 percent of recent long-term survivors have developed chronic rejection. Acute rejection has usually been reversible with treatment, but chronic rejection has responded poorly, relapsed frequently, and been one of the leading causes of late morbidity and mortality. Appropriate management of rejection is predicated on timely, accurate diagnosis. Clinical criteria for the diagnosis of acute rejection are useful but nonspecific, and TBB has emerged as the procedure of choice for diagnosing acute rejection and infection. Chronic rejection is manifested by OB and is characterized physiologically by the development of airflow obstruction. Although histologic confirmation is preferable, the sensitivity of TBB for the detection of OB has been inconsistent, and the specificity has been low. Lung transplantation has indeed come of age, but understanding the immunopathogenesis and improving the clinical management of rejection remain major challenges for the next decade.

The role of transbronchial lung biopsy in the treatment of lung transplant recipients. An analysis of 200 consecutive procedures

STUDY OBJECTIVE

The purposes of this study were as follows: (1) to establish the positivity rate and complication rate of transbronchial lung biopsies in the treatment of lung transplant recipients; (2) to determine the sensitivity of transbronchial lung biopsy specimens for the diagnosis of clinically suspected acute rejection and cytomegalovirus pneumonia; and (3) to examine the results of surveillance transbronchial lung biopsies in clinically and physiologically stable recipients.

DESIGN

Retrospective review and analysis of 203 consecutive procedures.

SETTING

Washington University Lung Transplantation Program, Washington University School of Medicine and Barnes Hospital, St. Louis, Mo.

PATIENTS

Fifty-five lung transplant recipients.

INTERVENTIONS

Biopsies were done with 2-mm fenestrated forceps using fluoroscopic guidance. Two hundred three bronchoscopies with transbronchial lung biopsy were performed for clinical indications (n = 88), routine surveillance (n = 90), or follow-up of a previous biopsy (n = 25). Biopsy specimens showing acute allograft rejection were classified according to the scheme recommended by the Lung Rejection Study Group.

MEASUREMENTS AND RESULTS

The positivity rate and complication rate were determined for the procedures. In procedures performed for clinical indications, the sensitivity for the diagnosis of acute rejection and cytomegalovirus pneumonia was calculated by a decision-to-treat analysis. A specific histologic diagnosis was detected in 69 percent of the clinical procedures, 57 percent of the surveillance procedures, and 64 percent of the follow-up procedures. For clinical indications, the sensitivity of transbronchial lung biopsy was 72 percent for the diagnosis of acute rejection and 91 percent for the diagnosis of cytomegalovirus pneumonia. Surveillance biopsy specimens often showed clinically inapparent rejection or cytomegalovirus pneumonia. The overall complication rate was 8.9 percent; none of the complications were life threatening.

CONCLUSIONS

Transbronchial lung biopsy is a useful and safe procedure in the treatment of lung transplant recipients. When performed for clinical indications, the procedure proved to be sensitive for the diagnosis of acute rejection and cytomegalovirus pneumonia. When performed for surveillance in clinically and physiologically stable recipients, the incidence of rejection and cytomegalovirus pneumonia was unexpectedly high; the potential clinical implications of these findings will require further study.

Evaluation of lung function during pulmonary rejection and infection in heart-lung transplant patients. Hannover Lung Transplant Group

Pulmonary rejection and infection are the most important complications after lung transplantation. To evaluate the diagnostic value of pulmonary function testing for early detection and discrimination of these complications, seven heart-lung recipients were examined. The diagnosis of each complication was confirmed by clinical and laboratory findings including transbronchial biopsies and bronchoalveolar lavage. Eight episodes of rejection, ten episodes of viral infection and six episodes of bacterial pneumonia were analyzed. Pulmonary rejection was associated with a significant fall in the FEV1/IVC% and the FEF50%. In viral infection, the most impressive finding was a reduction in the DCO, whereas no obstructive or restrictive airway dynamics were observed. During bacterial pneumonia, pulmonary function measurement revealed a decrease in IVC without signs of obstructive airway dynamics. Adequate treatment resulted in reconstitution of pretreatment values. Assessment of lung function provides valuable information for the diagnosis of pulmonary complications following HLTx.

Single lung transplantation. Surgical experiences with the first seven patients

Seven single lung transplants are reported. The patients were severely disabled and oxygen dependent below sixty years of age with a poor prognosis. Diagnosis were alfa 1-antitrypsin deficiency (3), sarcoidosis (3) and idiopathic emphysema (1). Multiorgan-harvesting including six hearts, was performed in local or distant hospitals (3). Partial cardiopulmonary bypass simplified transplantation. The surgical procedure was modified with a direct transpericardial approach. Soft tissue wrapping by a vascularized pedicle secured the bronchial anastomosis. The four drug immunosuppressive regimen included cyclosporin A, azathioprine, steroids and antithymocyte globulin. Primary graft function was excellent. Six patients survived the postoperative period and are alive 5-19 months post transplant. Transbronchial biopsies and lung function studies have been helpful in detecting pulmonary rejections. Patient rehabilitation is satisfactory in most patients with improvement in physiologic parameters.

[Lung transplantation]

Lung transplantation began to expand in 1983, after the advent of cyclosporin and the publication of the Toronto lung transplant group study. Single lung transplantation was first performed in patients with interstitial pneumopathy to be extended later to pulmonary emphysema, then to primary or secondary pulmonary arterial hypertension. Double lung transplantation provides patients suffering from chronic lung infection (e.g. cystic fibrosis) with a useful alternative to their ordinary treatment. The experience acquired throughout these years has resulted in wider criteria for patients' inclusion. More than acute rejection, bacterial infections directly condition the immediate prognosis. The frequency and severity of cytomegalovirus lung diseases lead to a discussion on the possibility of prophylactic and curative antiviral therapy. The occurrence of obliterative broncholitis, which reflects chronic lung rejection, jeopardizes the long-term results of transplantation. The functional results of the various types of lung grafting are analysed, and the position of lung transplantation in thoracic surgery is reassessed.

Pulmonary cytology in lung transplant recipients: recent trends in laboratory utilization

The value of bronchoscopy for the diagnosis of rejection and opportunistic infection in lung transplant recipients is controversial. We review our experience with pulmonary cytology obtained from 10 lung transplant recipients during the first 15 mos of the transplantation program at Cedars-Sinai Medical Center and compare the efficacy of pulmonary cytology for the diagnosis of opportunistic infectious agents with that of histology and microbiology. Our study encompasses 1,465 post-transplant days during which 70 bronchoscopies were performed yielding 94 cytologic specimens (44 bronchial washes, 25 bronchial brushings, and 25 bronchoalveolar lavages) and 55 transbronchial biopsies. The major advantages of cytology in this setting are short turn around time and high specificity for nonbacterial agents. All of the patients experienced episodes of bacterial pneumonia as well as fungal and viral infections. None developed Pneumocystis carinii infection during the study period. Simultaneous and concurrent infections were diagnosed. The initial diagnosis of bacterial pneumonia and herpes simplex virus preceded the diagnosis of cytomegalovirus; the former infections tended to persist and/or recur. Cytology was more effective than histology in establishing the diagnosis of Candida sp. and herpes simplex virus, while histology was more effective in establishing the diagnosis of cytomegalovirus. Increased numbers of polymorphonuclear cells did not constitute a consistent finding in cytologic or histologic samples during episodes of bacterial infection; cultures were most sensitive for detection of bacterial infection. Histochemical and immunohistochemical stains as well as in situ hybridization studies confirmed diagnoses rendered on routine Papanicolaou and hematoxylin and eosin stained material but did not provide additional diagnoses.(ABSTRACT TRUNCATED AT 250 WORDS)

Critical care management of lung transplant recipients

In the last 10 years, lung transplantation has become an increasingly common procedure for patients with end-stage respiratory disease. Although long-term survival can be achieved, there is still significant morbidity within the first year. Early postoperative problems that may be anticipated include respiratory insufficiency, airway anastomotic problems, hemorrhage, infection, and episodes of acute rejection. These problems and others make the immediate perioperative period particularly challenging. With aggressive management, however, the probability of a successful outcome can be enhanced.

Heart-lung transplantation in infants, children, and adolescents

We have performed heart-lung transplantation in 10 children for the preoperative diagnoses of primary pulmonary hypertension (4), complex congenital heart disease with pulmonary hypertension (4), pulmonary atresia (1), and cystic fibrosis (1). Ages ranged from 4 months to 18 years. There were 15 episodes of pulmonary rejection, with an occurrence rate of 1.67 episodes per patient. Pulmonary infections occurred frequently, with an occurrence rate of 3.3 episodes per patient. The actuarial survival rate at 1 and 2 years was 78% and 47%, respectively. Patient attrition between 1 and 2 years was attributable to the complications of obliterative bronchiolitis, which has effected 71% (5/7) of the long-term survivors. Four of the 5 surviving children have minimal physical limitation and are in functional class I. These data support continued investigation into heart-lung transplantation in children and set the stage for further program development into single-lung transplantation in children.

Reduction in bleeding after heart-lung transplantation. The importance of posterior mediastinal hemostasis

To reduce perioperative hemorrhage following heart-lung transplantation, several technical modifications were introduced in June 1988 to secure better posterior mediastinal hemostasis. The intraoperative and postoperative use of blood and blood products, as well as the chest tube drainage in the first 24 hours postoperatively, were compared in the seven patients operated on since June 1988 with the nine patients operated on before that date. Significant (p less than 0.05) reductions were demonstrated in the intraoperative and postoperative transfusion of packed cells, in the postoperative administration of fresh frozen plasma, and in the chest tube drainage within the first 24 hours postoperatively. The one-month and total hospital mortality rates were 6 percent and 12.5 percent, respectively. It is concluded that newer techniques to obtain optimal posterior mediastinal hemostasis have significantly reduced blood loss following heart-lung transplantation in our experience and have contributed to our excellent early postoperative results.