Spirometry values in stable lung transplant recipients

To clarify the usefulness of spirometry to assess the function of the lung allograft post-transplant, we retrospectively reviewed 351 sequential spirometry measurements performed by 65 healthy recipients after the 80th postoperative day when the clinical evaluation and fiberoptic bronchoscopy with transbronchial biopsies and bronchoalveolar lavage excluded significant rejection or infection in the allograft. The mean coefficients of variation (CV) and significant values for change (SC) for the FVC, FEV1, and FEF25-75% were calculated according to the type of transplant procedure (heart-lung and double-lung [HL-DL] versus single-lung [SL]), and to the time after transplant when the spirometry measurements were obtained < or = 1 yr versus > 1 yr). The SC for the FVC decreased with time after transplantation for both HL-DL (< or = 1 yr: 17% versus > 1 yr: 7%) and SL recipients (< or = 1 yr: 13% versus > 1 yr: 8%). The higher degree of variability within the first year was primarily due to increasing values especially in the HL-DL recipients. The SC for the FEV1 also decreased over time for HL-DL recipients (< or = 1 yr: 18% versus > 1 yr: 9%) but was similar for SL recipients at both intervals (13%). Our results suggest that decreases of > or = 11% in FVC or 12% in FEV1 in HL-DL recipients and > or = 12% in FVC or 13% in FEV1 for SL recipients indicate a significant decrease in allograft function that may be due to infection or rejection.

Aerosolized cyclosporine in lung recipients with refractory chronic rejection

This study evaluated aerosolized cyclosporine as rescue therapy for lung transplant recipients with unremitting chronic rejection. Nine patients with histologic active obliterative bronchiolitis and progressively worsening airway obstruction refractory to conventional immune suppression received aerosolized cyclosporine. Improvement in rejection histology was seen in seven of nine patients. We compared the changes in the FVC and FEV1 over time using linear regression analysis in these seven histologic responders and nine historical control patients. During the pretreatment period for both the experimental and control groups, the FVC and FEV1 declined at comparable rates. After aerosolized cyclosporine there was stabilization of pulmonary function, whereas in the controls there was continued decline. Cyclosporine blood levels were less than 50 ng/ml 24 h after an aerosolized dose of 300 mg in five patients receiving oral tacrolimus. Nephrotoxicity, hepatotoxicity, and a greater than expected rate of infection was not observed. This study suggests that aerosolized cyclosporine is safe and may be effective therapy for refractory chronic rejection in lung transplant recipients.

The importance of bronchoscopy with transbronchial biopsy and bronchoalveolar lavage in the management of lung transplant recipients

Medical and surgical advances have made lung transplantation a feasible therapy for end-stage lung disease. Fiberoptic bronchoscopy with bronchoalveolar lavage (BAL) and transbronchial lung biopsy (TBBx) is an accepted technique for detecting clinically evident rejection and infection in the allograft of symptomatic recipients. The role of TBBx and BAL in managing asymptomatic recipients is less defined. We retrospectively examined the role of bronchoscopy with TBBx and BAL in 1124 bronchoscopy procedures that were performed on 161 lung transplant recipients between January 1, 1988, and December 31, 1993. Bronchoscopy was performed when there was a change in the recipient's clinical condition, to assess the response of the allograft to a prior therapy, and under a surveillance protocol for detecting asymptomatic rejection or infection. Surveillance bronchoscopy was performed according to the following schedule: 10-14 days after transplantation, every 3 mo during the first year, every 4 mo during the second year, and at 6-mo intervals thereafter. Surveillance bronchoscopies were defined as procedures where the physician felt that there was no infection or rejection in the allograft on the basis of a standardized clinical evaluation, which excluded the results of the TBBx and BAL. We compared the clinical impression recorded by the physician on the day of the procedure with the final diagnosis determined after the results of the TBBx and BAL were known. We found unsuspected rejection and/or infection that required therapy in 25% (90/355) of all surveillance bronchoscopy procedures. Most episodes (61/90, 68%) of unsuspected rejection and/or infection occurred in the first 6 mo after transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical trial of tacrolimus versus cyclosporine in lung transplantation

BACKGROUND

A prospective clinical trial was undertaken to compare the efficacy of tacrolimus (FK 506) versus cyclosporine as the primary immunosuppressive agent after lung transplantation.

METHODS

Between October 1991 and May 1994, 133 single-lung and bilateral-lung recipients were randomized to receive either cyclosporine (n = 67) or tacrolimus (n = 66). The two groups were similar in age, sex, and underlying disease.

RESULTS

One-year and 2-year survival rates were similar in the two groups, although the trend was toward increased survival with tacrolimus. Acute rejection episodes per 100 patient-days were fewer (p = 0.07) in the tacrolimus group (0.85) than in the cyclosporine group (1.09). Obliterative bronchiolitis developed in significantly fewer patients in the tacrolimus group (21.7%) compared with the cyclosporine group (38%) (p = 0.025), and there was greater freedom from obliterative bronchiolitis over time for patients receiving tacrolimus (p < 0.03). Significantly more cyclosporine-treated patients (n = 13) required crossover to tacrolimus than tacrolimus-treated patients to cyclosporine (n = 2) (p = 0.02). The switch to tacrolimus controlled persistent acute rejection in 6 of 9 patients. The overall incidence of infections was similar in the two groups, although bacterial infections were more common with cyclosporine (p = 0.0375), whereas the risk of fungal infection was higher with tacrolimus (p < 0.05).

CONCLUSIONS

This trial demonstrates the advantage of tacrolimus in reducing the risk of obliterative bronchiolitis, the most important cause of long-term morbidity and mortality after lung transplantation.

Efficacy of inhaled cyclosporine in lung transplant recipients with refractory rejection: correlation of intragraft cytokine gene expression with pulmonary function and histologic characteristics

BACKGROUND

Refractory rejection is a major cause of morbidity and death among lung transplant recipients. Traditional rescue therapies have proved only modestly successful. We recently demonstrated the safety of inhaled cyclosporine for patients with end-stage chronic rejection; this trial was extended to patients with refractory acute rejection. The present study was to determine whether effective inhaled cyclosporine therapy was correlated with suppression of cytokine gene expression.

METHODS

Twelve lung transplant recipients were studied. Maintenance therapy, cyclosporine or FK 506, azathioprine, and prednisone, was continued, and inhaled cyclosporine at a dose of 300 mg/day was added. Pulmonary function testing and histologic characteristics from transbronchial biopsy specimens were used to assess efficacy of therapy. Bronchoalveolar lavage (BAL) and peripheral blood cells were analyzed for the presence of messenger RNA by using 32P-labeled primers of cytokines interleukin-2 (IL-2), IL-6, IL-10, and interferon-gamma (gamma) via reverse transcriptase-polymerase chain reaction.

RESULTS

Nine of 12 patients (five with acute rejection, four with chronic rejection) exhibited histologic resolution of rejection within 3 months of inhaled cyclosporine therapy. Pulmonary function (forced expiratory volume in 1 second) improved from pretherapy levels in the patients with acute rejection (p < 0.05). All of the nine histologic responders exhibited 4- to 150-fold decreases (p < 0.05) in IL-6 and interferon-gamma messenger RNA levels in the BAL, whereas the three patients who failed exhibited persistent or increased cytokine profiles. IL-2 and IL-10 in BAL and peripheral blood lymphocyte cytokines were not informative.

CONCLUSIONS

These results indicate that inhaled cyclosporine is effective therapy for refractory pulmonary rejection and that its mechanism of action is associated with suppression of proinflammatory cytokines IL-6 and interferon-gamma within the allograft.

Obliterative bronchiolitis after lung and heart-lung transplantation. An analysis of risk factors and management

With a prevalence of 34% (55/162 at-risk recipients) and a mortality of 25% (14/55 affected recipients), obliterative bronchiolitis is the most significant long-term complication after pulmonary transplantation. Because of its importance, we examined donor-recipient characteristics and antecedent clinical events to identify factors associated with development of obliterative bronchiolitis, which might be eliminated or modified to decrease its prevalence. We also compared treatment outcome between recipients whose diagnosis was made early by surveillance transbronchial lung biopsy before symptoms or decline in pulmonary function were present versus recipients whose diagnosis was made later when symptoms or declines in pulmonary function were present. Postoperative airway ischemia, an episode of moderate or severe acute rejection (grade III/IV), three or more episodes of histologic grade II (or greater) acute rejection, and cytomegalovirus disease were risk factors for development of obliterative bronchiolitis. Recipients with obliterative bronchiolitis detected in the preclinical stage were significantly more likely to be in remission than recipients who had clinical disease at the time of diagnosis: 81% (13/15) versus 33% (13/40); p < 0.05). These results indicate that acute rejection is the most significant risk factor for development of obliterative bronchiolitis and that obliterative bronchiolitis responds to treatment with augmented immunosuppression when it is detected early by surveillance transbronchial biopsy.

Comparison of outcomes after single and bilateral lung transplantation for obstructive lung disease

BACKGROUND AND METHODS

To determine the long-term functional outcome for single versus bilateral lung transplant for nonseptic obstructive lung disease, we compared the results from 39 single and nine bilateral lung transplant procedures. The nine bilateral lung transplants included three en bloc double lung and six bilateral sequential lung transplants.

RESULTS

Early deaths within 30 days of transplantation occurred in two of nine (22%) bilateral and 4 of 39 (10%) single lung transplants (p = Not significant). Compared with pretransplant values, pulmonary function as assessed by the spirometric indexes of the percent predicted forced vital capacity, forced expiratory volume in one second, forced expiratory volume in one second/forced vital capacity, and forced expiratory flow at 25% and 75% of forced vital capacity improved significantly up to at least 12 months after transplantation for both single and bilateral lung transplant recipients. The degree of pulmonary function improvement was better in single as compared with bilateral lung recipients. By 6 months after transplantation, all but one single and all bilateral lung recipients were in New York Heart Association class I or II (p = Not significant). One-year survival was significantly better after single (77%) compared with after bilateral lung transplantation (35%) (p < 0.05).

CONCLUSIONS

These results suggest that single lung transplantation is the procedure of choice for patients with nonseptic obstructive lung disease.

Lung reduction as bridge to lung transplantation in pulmonary emphysema

We present a case of bridging to lung transplantation by means of laser ablation of emphysematous bullae in a lung transplant candidate. The patient underwent successful left single-lung transplantation 17 months after lung reduction. He is now well 3 months after transplantation.

Analysis of time-dependent risks for infection, rejection, and death after pulmonary transplantation

Infection and rejection remain the greatest threats to the survival of pulmonary allograft recipients. Furthermore, a relationship may exist between these events, because the occurrence of one may predispose to the other. By using multivariate analysis for repeated events, we analyzed the risk factors for bacterial, fungal, and viral infection, grade II or greater acute rejection, and death among 239 lung transplant recipients who received 250 allografts between January 1988 and September 1993. A total of 90 deaths, 491 episodes of acute rejection, and 542 infectious episodes occurred during a follow-up of 6 to 71 months. The hazard or risk patterns of death, infection, and rejection each followed an extremely high risk during the first 100 days after transplantation, a second modest risk period at 800 to 1200 days, and a lower constant risk. Infection and graft failure manifested by diffuse alveolar damage were the major causes of early death (< 100 days), whereas infection and chronic rejection were primary causes of later death after pulmonary transplantation. By multivariate analysis, cytomegalovirus mismatching risk for primary infection was the most significant risk factor for death, rejection, and infection. Absence of cytomegalovirus prophylaxis was also a risk factor for early and late death and late infection. Survival of recipients who received cytomegalovirus prophylaxis was significantly improved. Immunosuppression based on cyclosporine versus FK 506 was a risk factor for late death and late infection. Graft failure manifested by diffuse alveolar damage/adult respiratory distress syndrome was a significant risk for death late after transplantation. These data suggest the following: (1) The hazard for death, infection, and rejection after pulmonary transplantation appears biphasic; (2) lower survival is associated with ischemia-reperfusion lung injury represented by diffuse alveolar damage/adult respiratory distress syndrome; (3) cytomegalovirus mismatch, absence of cytomegalovirus prophylaxis, and development of cytomegalovirus disease are significant threats for death, rejection, and infection after pulmonary transplantation; (4) prevention of cytomegalovirus disease should improve survival by decreasing the prevalence of infection and rejection.

Indications for and results of single, bilateral, and heart-lung transplantation for pulmonary hypertension

The indications for single, bilateral, and heart-lung transplantation for patients with pulmonary hypertension remain controversial. We retrospectively analyzed the results from 11 single, 22 bilateral, and 24 heart-lung transplant procedures performed between January 1989 and January 1993 on 57 consecutive patients with pulmonary hypertension caused by primary pulmonary hypertension (n = 27) or Eisenmenger's syndrome (n = 30). Candidates with a left ventricular ejection fraction less than 35%, coronary artery disease, or Eisenmenger's syndrome caused by surgically irreparable complex congenital heart disease received heart-lung transplantation. All other candidates received single or bilateral lung transplantation according to donor availability. Although postoperative pulmonary artery pressures decreased in all three allograft groups, those in single lung recipients remained significantly higher than those in bilateral and heart-lung recipients. The cardiac index improved significantly in only the bilateral and heart-lung transplant recipients. A significant ventilation/perfusion mismatch occurred in the single lung recipients as compared with bilateral and heart-lung recipients because of preferential blood flow to the allograft. Graft-related mortality was significantly higher and overall functional recovery as assessed by New York Heart Association functional class was significantly lower at 1 year in the single as compared with bilateral and heart-lung recipients. Thus bilateral lung transplantation may be a more satisfactory option for patients with pulmonary hypertension with simple congenital heart disease, absent coronary arterial disease, and preserved left ventricular function. Other candidates will still require heart-lung transplantation.

Impact of pulmonary hypertension on outcome after single-lung transplantation

Single lung transplantation for pulmonary hypertension (PH) remains a controversial therapy. We retrospectively studied 48 consecutive recipients of single-lung allografts to determine if preoperative PH was associated with increased mortality or morbidity. Recipients were divided into two groups; those who did have preoperative PH, defined as mean pulmonary arterial pressure less than or equal to 30 mm Hg (n = 29; group 1), and those recipients with PH who had a mean pulmonary arterial pressure greater than 30 mm Hg (n = 19; group II). Mean pulmonary arterial pressure and pulmonary vascular resistance decreased significantly after transplantation in recipients with PH. These values remained significantly higher as compared with those in recipients without pretransplantation PH. Postoperative pulmonary ventilation/perfusion scans demonstrated significant ventilation/perfusion mismatch in lung allografts with pretransplantation PH (p < 0.05). The mean duration of intensive care unit stay was significantly longer in recipients with PH. Although operative mortality was similar between the groups, preoperative PH was associated with significantly lower 1-year survival (53% versus 72%; p < 0.05) and New York Heart Association functional class (p < 0.05). We conclude that preoperative PH in single-lung transplant recipients is associated with significantly increased mortality, prolonged intensive care unit stay, and less symptomatic improvement. Thus, despite a shortage of donor organs, single-lung transplantation may be suboptimal therapy in patients with PH. Further study comparing single versus bilateral lung transplantation for PH is necessary.

Lymphangioleiomyomatosis: recurrence after lung transplantation

Pulmonary lymphangioleiomyomatosis is a disease principally affecting women during child-bearing years that eventually leads to respiratory failure. Recently, it has been listed as an indication for lung transplantation. To date, no cases of recurrent lymphangioleiomyomatosis after lung transplantation have been reported, unlike the experience with sarcoidosis and giant cell interstitial pneumonia. At the University of Pittsburgh Medical Center, four patients have undergone single-lung transplantation for lymphangioleiomyomatosis. We now report that one of these cases developed recurrent lymphangioleiomyomatosis in the allograft lung.

A new complication related to laser bronchoscopy in a single lung transplant recipient

We report a nearly complete obstruction of the left mainstem bronchus by a fibrinomyxoid plaque about 12 h after laser resection of scar/granulation tissue at a left bronchial anastomosis 27 days after a left single lung transplant. The formation of this plaque was associated with respiratory failure. The plaque was removed by grasping the plaque with biopsy forceps inserted through a fiberoptic bronchoscopy that was placed into the left mainstem bronchus via an endotracheal tube while the patient was receiving manual ventilation under general anesthesia. The respiratory failure resolved with removal of the plaque. To our knowledge, this is a complication that has not been reported previously.

A comparison of ganciclovir and acyclovir to prevent cytomegalovirus after lung transplantation

In an attempt to modify the sequelae of cytomegalovirus (CMV) infections after lung transplantation, 25 allograft recipients were randomized to either ganciclovir 5 mg/kg once a day 5 d/wk (Group G) or acyclovir 800 mg four times a day (Group A). All subjects received ganciclovir during postoperative Weeks 1 through 3, and they were then given either A or G regimens until Day 90. At termination of study enrollment, the cumulative incidence of all CMV infections (including seroconversions) was increased in Group A compared with that in Group G (75% versus 15%, p < 0.01), as was the incidence of overt CMV shedding and/or pneumonitis (50% versus 15%, p < 0.043). In comparison with those in Group G, subjects in Group A were also afflicted with an increased prevalence of obliterative bronchiolitis (OB) during the first year after transplantation (54% versus 17%, p < 0.033). Intravenous catheters for ganciclovir administration resulted in four complications among three of the subjects in Group G (23%). The short-term benefits of ganciclovir were ultimately limited, moreover, in that cumulative rates of CMV and prevalence of OB are now similar in both treatment groups after approximately 2 yr of observation. We conclude that prolonged ganciclovir prophylaxis decreases the early incidence of CMV and OB among lung transplant recipients, but these effects are of finite duration. Although CMV prevention appears to have considerable potential value in this population, definitive viral prophylaxis will require development of protracted or repeated treatment regimens, or longer-acting agents.

Can immunohistological analysis of transbronchial biopsy specimens predict responder status in early acute rejection of lung allografts?

Acute cellular rejection (ACR) in the early posttransplant period is recognized as one predictor of the development of bronchiolitis obliterans in lung transplant recipients. Using an immunohistochemical panel of antibodies to CD3, L26, HLA-DR, collagenase IV, proliferating cell nuclear antigen (PCNA), KPI, and S100 antigens we analyzed cases of moderate ACR that did respond (n = 11) and that did not respond (n = 10) to bolus solumedrol therapy early in the postoperative period (< 100 days) to determine if we could identify predictors of histological response. Responders who had follow-up negative biopsies after therapy had biopsy specimens containing an average of 41.1% T cells (range, 15.1 to 69.8), 8.8% B cells (range, 0.6 to 20), 18.1% HLA-DR-positive cells (range, 3 to 29.6), 12.2% PCNA-positive cells (range, 2.7 to 22.6), 8.9% collagenase IV-positive cells (range, 0.7 to 20.9), and rare dendritic cells. Nonresponders who had follow-up biopsies that failed to show a significant change in rejection grade had biopsy specimens with the following average cell profiles: 35.8% T cells (range, 7 to 70.7), 21.6% B cells (range, 3.7 to 39.5), 14.2% HLA-DR-positive cells (range, 1.8 to 24.7), 11.4% PCNA-positive cells (range, 0.8 to 22), 12.6% collagenase IV-positive cells (range, 0.6 to 34.1), and occasional dendritic cells. Statistical analysis suggested that large numbers of B lymphocytes in early acute rejection predicts non-responsiveness to interventional immunosuppressive therapy and may indicate a significant role of humoral rejection in the behavior of early allograft rejection.

A prospective randomized trial of FK506 versus cyclosporine after human pulmonary transplantation

We have conducted a unique prospective randomized study to compare the effect of FK506 and cyclosporine (CsA) as the principal immunosuppressive agents after pulmonary transplantation. Between October 1991 and March 1993, 74 lung transplants (35 single lung transplants [SLT], 39 bilateral lung transplant [BLT]) were performed on 74 recipients who were randomly assigned to receive either FK or CsA. Thirty-eight recipients (19 SLT, 19 BLT) received FK and 36 recipients (16 SLT, 20 BLT) received CsA. Recipients receiving FK or CsA were similar in age, gender, preoperative New York Heart Association functional class, and underlying disease. Acute rejection (ACR) was assessed by clinical, radiographic, and histologic criteria. ACR was treated with methylprednisolone, 1 g i.v./day, for three days or rabbit antithymocyte globulin if steroid-resistant. During the first 30 days after transplant, one patient in the FK group died of cerebral edema, while two recipients treated with CsA died of bacterial pneumonia (1) and cardiac arrest (1) (P = NS). Although one-year survival was similar between the groups, the number of recipients free from ACR in the FK group was significantly higher as compared with the CsA group (P < 0.05). Bacterial and viral pneumonias were the major causes of late graft failure in both groups. The mean number of episodes of ACR/100 patient days was significantly fewer in the FK group (1.2) as compared with the CsA group (2.0) (P < 0.05). While only one recipient (1/36 = 3%) in the group treated with CsA remained free from ACR within 120 days of transplantation, 13% (5/38) of the group treated with FK remained free from ACR during this interval (P < 0.05). The prevalence of bacterial infection in the CsA group was 1.5 episodes/100 patient days and 0.6 episodes/100 patient days in the FK group. The prevalence of cytomegaloviral and fungal infection was similar in both groups. Although the presence of bacterial, fungal, and viral infections was similar in the two groups, ACR occurred less frequently in the FK-treated group as compared with the CsA-treated group in the early postoperative period (< 90 days). Early graft survival at 30 days was similar in the two groups, but intermediate graft survival at 6 months was better in the FK group as compared with the CsA group.

Recurrence of sarcoidosis in pulmonary allograft recipients

Lung transplantation is a potentially curative therapy for the end-stage pulmonary sequelae of sarcoidosis. We reviewed the course of five lung allograft recipients with underlying sarcoidosis (S) at the University of Pittsburgh Medical Center and compared them with a control group (C) of 44 contemporaneous transplant recipients with other respiratory diseases. Sarcoid granulomata have developed in the allografts of 4 S, although these lesions have not yet been demonstrated to result in clinically significant abnormalities. In comparison with C, sarcoidosis patients had significantly greater mean grades of acute rejection during the first 3 months after transplantation (2.1 +/- 0.3 versus 1.6 +/- 0.1, S and C, respectively, p < 0.042) and larger proportions of lung biopsies showing more than mild acute rejection (40 versus 18%, p < 0.012) and lymphocytic bronchitis (30 versus 13%, p = 0.02), as well as a greater percentage of polymorphonuclear leukocytes in BAL returns (34.9 +/- 5.4 versus 19.0 +/- 1.6, p < 0.01). The two groups did not differ, however, in frequency of obliterative bronchiolitis, survival, or pulmonary function. We conclude that lung transplant recipients with underlying sarcoidosis are very likely to develop recurrent disease in the allograft and have more severe acute rejection responses, especially in the first weeks after transplantation. Pulmonary transplantation appears to be an efficacious therapy for end-stage sarcoidosis, but the long-term sequelae of the increased acute rejection and recurrent sarcoidosis in the allograft remain to be determined.

Infection after lung transplantation

Infections have been and still are the major cause of morbidity and mortality after lung transplantation. Nevertheless, the negative impact of infection on outcome has lessened considerably over the last decade because of lessons learned in the prevention, identification, and treatment of infection. Antibiotics tailored to the results of cultures and stains of respiratory-tract secretions obtained from both the donor and recipient have markedly decreased the prevalence of bacterial pneumonia early after lung transplantation. Ganciclovir treatment has reduced the mortality of cytomegalovirus (CMV) disease from 27% to 1%. Ganciclovir as prophylaxis has modestly reduced the prevalence of CMV illness from 80% to 60%. Pneumocystis infection has been nearly eliminated with low-dose trimethropin/sulfamethoxazole prophylaxis. Treating all Candida/Aspergillus isolates from respiratory-tract secretions with fluconazole or itraconazole has reduced the prevalence of fungus infections from 14% to 5%. Challenges still remain. The ideal regimen to prevent CMV illness is yet to be determined, and treating all fungal isolates from the allograft is not cost effective. Recurrent airway infection and late bacterial pneumonia caused by Pseudomonas species when obliterative bronchiolitis is present remain a major cause of concern. Surely the next decade will provide new insights into these problems.

Sequelae of cytomegalovirus pulmonary infections in lung allograft recipients

Indirect effects of cytomegalovirus (CMV) infections in lung transplant recipients (LTX) have not previously been described in detail. We compared spirometric results, development of chronic rejection, rates of respiratory superinfections, and mortality as long as 2 yr after transplantation, between 62 LTX who never developed CMV (CMV-) and 56 LTX with a history of CMV pulmonary infections (CMV+). Initial spirometric parameters were near identical for both groups, but determinations > or = 6 months after transplantation showed that expiratory flows of the CMV+ were significantly reduced. Actuarial prevalences of chronic allograft rejection (CR) at 2 yr were highest among CMV+ with biopsy-proved pneumonitis (74%) compared with 22% among CMV- (p < 0.038). Bacterial or fungal pneumonias developed in 58.9% of the CMV+, whereas the rate among CMV- was 38.7% (p < 0.05). Only 36% of LTX with CMV pneumonitis lived 2 yr compared with 70% survival for CMV- (p < 0.016). Ganciclovir treatment of CMV infections decreased rates of respiratory superinfections and improved survival of patients, but it did not appear to affect subsequent development of CR. We conclude that CMV pulmonary infections among LTX result in serious late sequelae and that current treatment is ineffectual for prevention of viral-associated CR in these patients.

Flow cytometric analysis of lymphocyte phenotypes in bronchoalveolar lavage fluid: comparison of a two-color technique with a standard immunoperoxidase assay

Characterization of lymphocytes in bronchoalveolar fluid has provided insight into the pathogenesis of many pulmonary diseases. Identification of lymphocyte phenotypes has become highly successful due to development of specific monoclonal antibodies and reliable methods for detecting labeled cells such as flow cytometry (FCM) and immunocytochemistry. FCM permits rapid screening of many cells, but this analysis may be confounded by heterogeneity in the size and granularity of the cells being evaluated. Such heterogeneity may lead to exclusion of cells of interest and inclusion of unwanted cells. Often peripheral blood leukocytes are used to define the gate for lung lymphocytes, but this gate may be inappropriate due to considerable variation in size and granularity of cells in bronchoalveolar lavage (BAL) fluid. Here we report an alternative method for generating a gate which employed fluorescence and side scatter signals to analyze lymphocyte subsets in BAL fluid by FCM. This gating technique avoids the pitfalls inherent in using the conventional lymphocyte gate to analyze lung cells. To validate this approach, we compared the results generated by this gate and those from the conventional forward/side light scatter gate to results derived from an immunocytochemical technique (ABC) that has been extensively employed in our laboratory to identify lymphocyte subsets in blood and lavage fluid. FCM tended to underestimate the proportions of T-cell subsets compared with ABC when the conventional gate was used. Counting only cells that stained with fluorescein-conjugated anti-CD45 antibody and that had side scatter properties of lymphocytes, however, resulted in excellent agreement between FCM and ABC. It appears that the CD45+/side scatter gate includes the vast majority of lymphocytes in BAL fluid while excluding most of the nonlymphoid cells that contaminate the conventional gate. It was this latter group of cells, and erythrocytes in particular, that led to the artificially low values for lymphocyte phenotypes in BAL fluid by FCM when the conventional lymphocyte gate was used. Although erythrocytes in BAL fluid may be eliminated by hypotonic lysis, this may also result in contamination of the conventional lymphocyte gate with nuclear debris and particulates from macrophages. Despite these advantages, the fluorescence/side scatter gate may not always be optimal for the evaluation of T lymphocytes if BAL fluid contains CD45+, nonlymphoid cells with low side light scatter. In these instances, additional antibodies such as anti-CD14 and anti-CD11 may be employed to determine the size of contaminant monocytic cells and neutrophils.(ABSTRACT TRUNCATED AT 400 WORDS)

Ganciclovir prophylaxis for cytomegalovirus infections in pulmonary allograft recipients

Cytomegalovirus (CMV) is a substantial cause of morbidity in pulmonary allograft recipients. In an attempt to decrease the prevalence of this infection, we treated 13 recipients at risk for cytomegalovirus with 3 wk of intravenous ganciclovir (5 mg/kg twice a day for 14 days, starting 5 days after the procedure, followed by 1 wk of the drug at a dose of 5 mg/kg/day). Following the ganciclovir course, patients received oral acyclovir, 800 mg three times a day for at least 2 months more. CMV infections developed in 5 recipients (38%), and none of these episodes occurred during the ganciclovir therapy. Neither of the 2 deaths in this group could be attributed to CMV. In comparison, the prevalence of CMV in the preceding cohort of 11 transplant recipients who were administered acyclovir alone was 91% (p << 0.01 by log-rank test), and there were 3 deaths due to viral infections (p = 0.08 by Fisher's exact test). Groups were similar in terms of immunosuppression and renal function during treatment, and none of the recipients developed leukopenia. We conclude that ganciclovir prophylaxis is well tolerated and appears to have considerable efficacy for prevention of CMV infections in pulmonary transplant recipients.

Subclinical pneumonitis due to Pneumocystis carinii in a young adult with elevated antibody titers to Epstein-Barr virus

Pneumocystis carinii was recovered from the lungs of a 20-year-old woman in apparent good health who had volunteered to undergo bronchoalveolar lavage (BAL) as a normal control subject. Total and differential cell counts in the BAL fluid revealed a significantly increased number and proportion of T lymphocytes, although the CD4:CD8 ratio was in the normal range. Despite the lack of specific antibiotic therapy, in a subsequent lavage no P. carinii were recovered, and the total and differential cell counts returned to normal, suggesting that the infection had resolved. Serologic evaluation revealed no evidence of human immunodeficiency virus infection, although elevated titers of antibodies to Epstein-Barr virus were demonstrated, suggesting ongoing or resolving viral infection. These findings suggest that P. carinii may cause subclinical pneumonitis even in the absence of a clinically evident immune deficient state. Furthermore, an increase in cell count and in the proportion of lymphocytes in an otherwise unremarkable BAL may indicate the presence of P. carinii in the airways and may be the only sign of subclinical infection of the respiratory tract by this organism.

Distinguishing between infection, rejection, and the adult respiratory distress syndrome after human lung transplantation

The adult respiratory distress syndrome, bacterial pneumonia, cytomegalovirus pneumonitis, acute rejection, or a combination thereof were the primary causes of radiographic infiltrates or gas exchange abnormalities that occurred early after lung transplantation. The time of occurrence after transplantation, standard measures of clinical assessment as for nontransplant patients (i.e., vital signs, weight, white blood cell count, sputum, and cultures, etc.), bronchoalveolar lavage, and transbronchial lung biopsy were the primary tools used to analyze these situations. Bacterial pneumonia always occurred after postoperative day 2, acute rejection after postoperative day 5, and cytomegalovirus pneumonitis after postoperative day 16. Although cultures of bronchoalveolar lavage fluid were useful to detect pneumonia caused by bacteria, virus, and fungus, the types of cells recovered by bronchoalveolar lavage were not diagnostic of any type of disorder. Transbronchial lung biopsy was necessary to detect acute rejection and cytomegalovirus pneumonitis. Thus the cause of an early radiographic infiltrate or impairment of gas exchange was almost always reliably determined by using standard tools of clinical assessment, knowledge of the usual temporal sequence of the complications, and judicious use of bronchoalveolar lavage and transbronchial lung biopsy.

Accessory cell function of blood monocytes and alveolar macrophages after human lung transplantation

Infection is a major complication of organ transplantation, and the lung is the most common site in recipients of a pulmonary allograft. The generation of an immune response both systemically and in the lungs is a major line of defense against infection. Therefore, we examined the ability of blood monocytes (BM) and alveolar macrophages (AM) recovered from lung transplant recipients without evidence of infection or rejection and from normal subjects to act as accessory cells in mitogen- and antigen-induced proliferation of autologous lymphocytes (Ly) and to stimulate an allogeneic (MLR) and autologous mixed lymphocyte reaction (AMLR). Proliferation of autologous Ly in the presence of mitogen and antigen and of allogeneic Ly stimulated by BM was significantly reduced in the lung recipients when compared with those in the normal subjects. Impaired Ly proliferation may result from inadequate presentation of antigen by recipient BM, heightened suppressive activity of BM, or the inability of recipient Ly to respond to proliferative signals. We believe that our results strongly support a role for inadequate presentation of antigen by BM. Inadequate antigen-driven stimulation could be one reason why transplant recipients have an increased susceptibility to infection. Somewhat unexpected was the finding that AM from lung recipients functioned nearly as well as AM from normal subjects as accessory cells. Although they failed to support mitogen-induced stimulation normally, AM from lung recipients were as efficient as autologous BM and AM from normal subjects in supporting Ly proliferation for soluble antigen and alloantigen.(ABSTRACT TRUNCATED AT 250 WORDS)

Cytomegalovirus infection and survival in lung transplant recipients

Fifty-nine patients who survived more than 30 days after lung transplantation (52 heart-lung, seven double lung, and two single lung) were studied for mortality and morbidity related to cytomegalovirus (CMV) infection. CMV infection developed in 32 patients (54%) and was more common in the preoperatively CMV seropositive group (95%) as compared with the seronegative group (38%). Symptomatic infections, pneumonitis, and CMV-related mortality, however, were higher in the seronegative (primary infection) group and actuarial survival was worse in these patients (40% and 23% at 1 and 5 years, respectively). Transplantation of CMV-seropositive donor organs was associated with a significantly higher incidence of primary infection and use of seronegative blood products led to a decrease in the primary CMV infection rate. The mortality of primary CMV infection was 54% and this was associated with a significantly higher rate of pulmonary superinfections in the first year after transplantation. The incidence of late pulmonary infections was associated with the development of chronic rejection rather than CMV status. We conclude that primary CMV infection has a major impact on the outcome after lung transplantation. The high mortality of primary infections justifies an aggressive approach to prevention and treatment in the at-risk seronegative group.

Does histologic acute rejection in lung allografts predict the development of bronchiolitis obliterans?

Clinical acute lung rejection (AR) occurs in lung allografts usually within 50 days after transplantation. While perivascular infiltrates characterize AR, with moderate-to-severe acute rejection small airway injury occurs. We investigated the significance of small airway injury in AR and its relationship to the development of bronchiolitis obliterans (OB) in 11 recipients of combined heart-lung or double-lung allografts. In general, the intensity and persistence of early acute rejection episodes associated with injury to bronchioles correlated with the development of histologic bronchiolitis obliterans. Early AR may "prime" lymphocytes for subsequent respiratory epithelial injury and airway fibrosis late in the postoperative period.

The effect of obliterative bronchiolitis on breathing pattern during exercise in recipients of heart-lung transplants

The more rapid and shallow ventilation pattern seen during exercise in patients with obstructive and/or restrictive lung disease has been attributed by some investigators to the effects of vagal afferents from intrapulmonary receptors. Recipients of heart-lung transplants (HLTR) offer a unique opportunity to test this hypothesis since they have denervated lungs and may develop obliterative bronchiolitis after organ rejection. We thus compared the ventilation responses to incremental bicycle ergometry of five HLTR with relatively normal pulmonary function (HLTR-N) and four with bronchiolitis obliterans (HLTR-O). We compared the slopes of the linear portion of the tidal volume versus inspired minute ventilation relationship of both groups. The rate of rise of tidal volume (VT) (slope of VT versus VI) was greater in HLTR-N (0.31 +/- 0.004) than in HLTR-O (0.023 +/- 0.007) (p less than 0.05). This corresponded to a slower increase in respiratory rate (RR) (slope of RR versus Vl/cm) in HLTR-N (0.055 +/- 0.005) than in HLTR-O (0.083 +/- 0.019) (p less than 0.01). Furthermore, values for VT, inspiratory time (TI), and duty cycle (TI/Ttot) measured during exercise at the VT break point were all significantly lower in the HLTR-O than in HLTR-N. We also evaluated the ability of HLTR with lung disease to regulate their ultimate level of ventilation during maximal exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

Alveolar macrophage migration after lung transplantation

Pulmonary infection is a major source of morbidity and mortality in recipients of lung allografts. The alveolar macrophage plays an important role in pulmonary host defense, and to fulfill this role it must have the ability to orient and migrate in the direction of a stimulus. Thus migratory activity was measured in cells recovered from lung transplant recipients by bronchoalveolar lavage. The primary patient group consisted of recipients who had no evidence of infection or rejection at the time of bronchoalveolar lavage. These patients were further subdivided into an early postoperative group (less than 6 wk posttransplant) and a late postoperative group (greater than 6 wk posttransplant). Other categories included patients with chronic rejection and a small group of patients with Pneumocystis carinii pneumonia. Alveolar macrophages recovered by bronchoalveolar lavage were assayed for migratory response to N-formylmethlonylphenylalanine and endotoxin-activated human serum. Stimulated migration of cells from healthy recipients obtained in the late postoperative course was similar to that of normal control subjects, but stimulated migration of cells from healthy recipients in the early postoperative period and those undergoing chronic rejection was greater than expected. Spontaneous migration was similar in all groups except those with P. carinii pneumonia, in whom it was greatly increased. We conclude that alveolar macrophage migration is not impaired in lung allograft recipients without apparent signs of infection or rejection and is in fact increased during periods of possible macrophage activation (shortly after transplantation and during chronic rejection).

Cytomegalovirus serologic status and postoperative infection correlated with risk of developing chronic rejection after pulmonary transplantation

Twenty-seven patients received pulmonary transplants during the period since we began routine use of cytomegalovirus-seronegative blood products for CMV-seronegative recipients. Preoperative serologic status of the recipient and the occurrence of cytomegalovirus infection in the postoperative period were correlated with development of obliterative bronchiolitis (OB) as diagnosed by transbronchial biopsy (TBB). Patients included 20 heart-lung and 7 double-lung recipients. OB occurred in 18 of 27 patients. All 3 CMV seronegative recipients receiving lungs from a seropositive donor and 9 of 10 CMV recipients seropositive at the time of transplantation developed OB compared with only 6 of 14 CMV seronegative patients receiving seronegative grafts (P = 0.018). CMV infection occurred in 10/27 patients, of whom 5 were asymptomatic; 90% of these patients developed OB. Donor-specific alloreactivity, based on primed lymphocyte testing (PLT) of bronchoalveolar lavage cells was found at the time of diagnosis of OB in 23 of 27 patients. A positive PLT was significantly associated with the presence of OB (P = 0.017). We conclude that preoperative seropositive status for CMV, grafting of organs from seropositive donors, and postoperative CMV infection are significant risk factors for developing OB. That OB is, in part, an immunologically mediated form of injury and represents chronic rejection is supported by the presence of donor-specific alloreactivity in BAL lymphocytes from all recipients with OB.

Similarity of pulmonary rejection patterns among heart-lung and double-lung transplant recipients

The transbronchial biopsy and clinical courses of 9 double-lung and 1 single-lung recipients surviving greater than 10 days were analyzed and compared to those of 15 heart-lung transplants performed during the same time period. Of these, 8 isolated lung (LT) and 11 heart-lung transplant (HLT) recipients survived greater than 50 days and were at risk of developing obliterative bronchiolitis believed to be a form of chronic rejection. Cyclosporine-based immunosuppression, in combination with azathioprine and steroids, was used for 22 of 25 patients. Two double-lung recipients and 1 heart-lung patient received FK506 as the sole immunosuppressive agent; 90% and 62% of LT, and 67% and 54% of HLT recipients developed acute and chronic rejection, respectively (P = NS). The average time to first episode of acute (30.2 days [LT] versus 21.5 days [HLT]) and chronic rejection (146 days [LT] versus 193.7 days [HLT]) was not different between groups (P = NS). Age (34.2 [LT] versus 29.1 [HLT]) and sex (M:F, 5:5 [LT] versus 5:10 [HLT]) were also not found to be discriminators. The histologic diagnosis of chronic rejection was associated with significant declines in FEV1.0 and FEF25-75 (P less than 0.02). There was only one instance of cardiac rejection among the heart-lung transplant recipients. Heart-lung and isolated lung transplant patients appear to be at similar risk for developing acute or chronic pulmonary rejection.

A comparison of modified methenamine silver and toluidine blue stains for the detection of Pneumocystis carinii in bronchoalveolar lavage specimens from immunosuppressed patients

Pneumonia due to Pneumocystis carinii is an increasingly frequent occurrence; a prompt, accurate diagnosis is important to successfully manage this infection. Methenamine silver and toluidine blue stainings of material recovered by bronchoalveolar lavage (BAL) have been the most widely employed techniques for detecting Pneumocystis organisms. The value of these two staining techniques for the detection of Pneumocystis organisms was prospectively compared in 220 BAL specimens obtained from 186 immunosuppressed individuals. The patients included those with disease-related and therapy-related immunosuppression; half of the BAL specimens came from organ transplant recipients. The results indicate that neither method is superior to the other and that both will correctly identify almost all Pneumocystis infections if a sufficient aliquot of BAL material is examined systematically by trained individuals. The toluidine blue method is somewhat simpler to perform, however. The reasons for discrepant results between the two staining methods were analyzed.

Infectious complications in pulmonary allograft recipients

This article has outlined the features of the major types of infections encountered in pulmonary allograft recipients. Virtually any pathogen can cause infection in these immunocompromised subjects, and there is a distinct propensity for these organisms to invade the transplanted lung. As is the case with other major organ recipients, there is a temporal sequence in the types of infection lung allograft recipients contract. Bacteria are the most frequent cause of pneumonia in the first postoperative month. After this period, infection with CMV, particularly CMV pneumonitis, becomes most common. Following the "window" for CMV infection, the risk for infestation with P. carinii becomes the primary concern. The latter two types of infection pose a double risk for the recipient: (1) morbidity and mortality from the infection itself and (2) chronic rejection following on the heels of these infections and producing morbidity and mortality on its own. Pulmonary allograft recipients are also susceptible to fungi, particularly C. albicans. Although these infections rarely produce an overwhelming pneumonia, they nonetheless carry a grave prognosis because they usually become widely disseminated. Better selection of donor lungs and prophylactic measures such as the use of broad-spectrum antibiotics and amphotericin B in the early postoperative period, the use of CMV-negative blood products in seronegative recipients, and the chronic administration of trimethoprim-sulfamethoxazole have reduced the rate of infection with bacteria, fungi, CMV (primary infections only), and P. carinii, respectively. Despite these relative successes, however, the risk for infection of the allograft remains high because the defense mechanisms in the lung allograft are breached by the effects of surgery, the "allogeneic environment" in the allograft and systemic immunosuppression, and the fact that chronic rejection causes structural changes that predispose to bacterial colonization of the airways and the need for increased levels of immunosuppression. Despite the formidable barrier that infection of the lung allograft poses, the procedure of pulmonary transplantation clearly holds sufficient promise that all efforts possible should be made to hurdle this barrier. Achieving such a goal would ensure a place for pulmonary transplantation in the armamentarium of treatment for irreversible pulmonary disease.

Potential role of dendritic cells in bronchiolitis obliterans in heart-lung transplantation

Dendritic cells are essential for the activation of the type IV immunological reactions that are intrinsic to rejection of transplanted organs. We evaluated the number of dendritic cells in the recipient and donor portions of the trachea and donor bronchi of 6 heart-lung transplant recipients, 3 of whom had evidence of bronchiolitis obliterans, a presumed manifestation of chronic rejection of the lung. As compared with recipients without bronchiolitis obliterans, patients with it showed a significant increase in the number of S100-protein-positive dendritic cells in the tracheal and bronchial epithelium and submucosa of the donor organs. This finding of increased accessory cells in the transplanted mucosa provides support for the belief that bronchiolitis obliterans is an immunologically mediated form of chronic rejection.

Proliferative responses of bronchoalveolar lavage lymphocytes from heart-lung transplant patients

Donor-specific alloreactivity of bronchoalveolar lavage (BAL) lymphocytes was evaluated in the immunologic monitoring of lung transplant patients. The study dealt with 161 BAL performed on 28 transplant recipients. Unseparated BAL cells, separated BAL lymphocytes, and PBL were tested for donor-specific proliferative responses in 3-day primed lymphocyte testing (PLT), and for nonspecific proliferative responsiveness to exogenous IL-2. The proliferation data were analyzed for correlation with the status of the lung allograft assessed clinically, histologically, and by pulmonary function testing. Positive PLT responses of BAL lymphocytes were observed in 20 of 22 acute rejection episodes (91%) and in 24 of 35 cases (69%) when chronic rejection was diagnosed. During clinical quiescence donor-specific proliferative activity was demonstrated in only 4 of 35 cases (11%). Thus, acute rejection and chronic rejection correlated significantly (P less than 0.001) with donor-specific PLT reactivity of BAL lymphocytes. Though significant association with rejection was observed for the alloreactivity of unseparated BAL cells and PBL, the sensitivity of the PLT test with these cells was significantly lower than that with BAL lymphocytes. Similarly, the IL-2 proliferative activity of BAL lymphocytes was significantly increased during acute and chronic rejection. However, this test had lower sensitivity and specificity than did the donor-specific PLT. These findings suggest the usefulness of the donor-specific PLT of BAL lymphocytes as a reliable method for monitoring pulmonary rejection.

Proteins of the respiratory tract after heart-lung transplantation

Heart-lung transplant recipients represent a unique population who experience episodic lung injury caused by infection or rejection. We hypothesized that the proteins in the respiratory lining fluids of these patients might reflect and provide insights into the in vivo immunologic and inflammatory events that occur in the transplanted lung. Structural, inflammatory, and immune proteins were quantitated in 57 samples of BAL fluid recovered from 17 heart-lung recipients when infections, rejection, or neither was present. Protein levels were compared with those of normal subjects and between the clinical transplant groups. When neither infection nor rejection was present, levels of albumin, fibronectin, and immunoglobulins G, M, and A were all higher in the transplanted lungs as compared with the normal lungs. These findings suggest that a new steady state of these proteins is established in the transplanted lungs. When infection or rejection was present, there was a further significant increase in albumin, fibronectin, IgG, and especially C5a in the transplanted lungs. These findings suggest that at least some elements of host defense remain intact in the posttransplantation period despite the use of immunosuppressive drugs and a HLA-incompatible microenvironment. The profiles of recovered alveolar proteins did not, however, help to differentiate infection from rejection. This is disappointing because distinguishing between infection and rejection without examination of lung tissue remains an unresolved and important clinical problem. Nevertheless these data provide new insights into organ tolerance and defense of the newly transplanted lung from infection or rejection.

Pulmonary capillary hemangiomatosis. A report of three cases and a review of the literature

Pulmonary capillary hemangiomatosis (PCH) is a rare cause of pulmonary hypertension. At present, only eleven cases have been reported. This report describes the clinical and pathologic findings in three additional cases who presented to the University of Pittsburgh for heart-lung transplantation and integrates the clinical features of all fourteen cases. Clinically, this disorder should be suspected in a patient who presents with pulmonary hypertension, hemoptysis, a reticulonodular infiltrate on chest radiograph, a lung scan showing inhomogeneously enhanced perfusion (particularly in the lower lobes), and pulmonary angiography showing increased peripheral vascularity corresponding to both the radiographic infiltrate and the areas of enhanced perfusion on lung scan. Histologic features consist of nodular proliferation of capillary-sized vessels that infiltrate the pulmonary interstitium, vascular walls, and lumens as well as the alveolar septa. The vascular invasion results in a secondary veno-occlusive phenomenon that explains the clinical confusion with pulmonary veno-occlusive disease.

The clinical spectrum, pathology, and clonal analysis of Epstein-Barr virus-associated lymphoproliferative disorders in heart-lung transplant recipients

This study presents the clinical and laboratory observations on posttransplant lymphoproliferative disorders (PTLDs) occurring in 5 of 53 heart-lung transplantation recipients. Cervical lymph nodes, tonsils, lungs, and gastrointestinal tract were the common sites of involvement by PTLDs. The histopathologic findings showed a spectrum of lymphoid and immunoblastic proliferation ranging from diffuse hyperplasia to malignant lymphoma, immunoblastic or large cell type. All cases were associated with a primary Epstein-Barr virus infection, and viral DNA was demonstrated within the lesional tissue in three cases. Immunohistochemical and immunoglobulin gene rearrangement studies revealed a B-cell proliferation that was monoclonal in three cases and polyclonal in two cases. Compared with PTLDs arising in other organ transplant recipients, this series is remarkable for a high incidence of PTLDs (9.4%), a short interval to tumor diagnosis (2.2 months, mean), involvement of the primary allograft in three cases (60%), and the frequent development of bronchiolitis obliterans. Possible reasons for this distinct clinicopathologic profile are discussed.

Breathing during wakefulness and sleep after human heart-lung transplantation

To study the effects of pulmonary denervation on breathing during sleep, sleep studies were conducted on seven heart-lung transplant recipients (H-LT) and a comparable number of sex-matched normal subjects of similar age. Four of the H-LT patients had a restrictive pattern on spirometry. The time since transplantation ranged from 45 to 1,102 days. There were no significant differences between the groups with respect to total sleep time or distribution of sleep stages. There were no significant differences between the H-LT recipients and normal subjects with respect to baseline awake oxyhemoglobin saturation (SaO2) or the nadirs of SaO2 during REM and non-REM sleep, the absolute number and frequency (number per hour of sleep) of apneas, hypopneas, desaturation events, both over the whole night of study or separately during non-REM and REM sleep. Across wakefulness and all sleep stages, the H-LT patients tended to have shorter total respiratory cycle times (Ttot) (p = 0.052) and more rapid breathing frequency (F) than the normal subjects. This was associated with significantly shorter inspiratory times (Tl) (p less than 0.001) and smaller duty cycles (Tl/Ttot) (p less than 0.005) in the H-LT recipients. During non-REM and REM sleep, F tended to be higher in the H-LT recipients with pulmonary restriction than in the nonrestricted patients. There were no significant differences between the H-LT recipients and the normal subjects with regard to the periodicity of breathing, either in terms of timing parameters or breath amplitude.(ABSTRACT TRUNCATED AT 250 WORDS)

Ventilation and breathing pattern during progressive hypercapnia and hypoxia after human heart-lung transplantation

The effects of human pulmonary denervation on the ventilatory responses to progressive hyperoxic hypercapnia and isocapnic hypoxia as well as the effect on resting breathing pattern were evaluated in nine female heart-lung transplant (H-LT) recipients. The results were compared to those obtained from 10 normal women of comparable age and stature. Testing was performed 2 to 37 months after H-LT (median, 7.5 months). Cardiac function was normal in all H-LT recipients. None of the patients had spirometric evidence of airway obstruction, while six had a restrictive pattern with forced vital capacities less than 80% of predicted values. Resting minute ventilation (VE), tidal volume (VT), and ventilatory drive (VT/TI) in the H-LT recipients were not significantly different from those of the normal subjects. Inspiratory time (TI), however, was significantly shorter in the H-LT patients (1.64 +/- 0.2 versus 2.09 +/- 0.13 s, p = 0.035), and resting breathing frequency (F) tended to be greater in the H-LT recipients (16.27 +/- 2.04 versus 12.82 +/- 0.53 breaths/min, p = 0.052). The overall ventilatory response to hypercapnia was reduced after H-LT (0.91 +/- 0.17 versus 1.5 +/- 0.27 L/min/mm Hg CO2, p less than 0.043), as was the F response (0.2 +/- 0.09 versus 0.65 +/- 0.13 breaths/min/mm Hg CO2, p less than 0.01). The VT and VT/TI responses to hypercapnia did not differ between the H-LT recipients and normal subjects. There were no significant differences between the two groups with respect to the responses to progressive hypoxia.(ABSTRACT TRUNCATED AT 250 WORDS)

Posttransplant lymphoproliferative disorders in heart-lung transplant recipients: primary presentation in the allograft

Heart-lung transplant recipients are predisposed to acute rejection episodes, bronchiolitis obliterans, and opportunistic infections. In 9.4% of recipients at the University of Pittsburgh, a posttransplant lymphoproliferative disorder (PTLD) developed, and in 60% of cases, it presented in the allografted lungs and was associated with primary infection by Epstein-Barr virus (EBV). The PTLD is histologically indistinguishable from a primary pulmonary lymphoma and consists of a mixed population of large lymphoid cells, immunoblasts, and plasma cells. Two cases of PTLD were monoclonal with immunohistochemical and Southern blot analysis. Despite this, there was clinical recovery with reduced immunosuppression and acyclovir. We discuss the role of EBV in the development of PTLD and the pathogenesis of primary presentation in the allograft.

Evidence of an altered pattern of breathing during exercise in recipients of heart-lung transplants

Recipients of heart-lung transplants represent an unusual opportunity to study the regulation of ventilation, because the neural pathways between the lungs and the central nervous system are disrupted in these patients. We compared the ventilation response in seven recipients of heart-lung transplants who had normal pulmonary function and seven recipients of heart transplants, all of whom performed incremental bicycle ergometry. The level of ventilation in recipients of heart-lung transplants was similar to that in heart-transplant recipients for equivalent levels of carbon dioxide production. Arterial pH and partial pressure of carbon dioxide at maximal exercise were normal and not significantly different in the two groups, also suggesting that levels of ventilation were appropriate in both groups. However, the rate of the rise in respiratory rate for increasing levels of ventilation was significantly lower in recipients of heart-lung transplants than in heart-transplant recipients, and the initial increase in tidal volume was more rapid in the former group than in the latter. Thus, recipients of heart-lung transplants have an appropriate level of ventilation during exercise as the result of a disproportionate increase in tidal volume at a reduced respiratory rate. We speculate that intrapulmonary receptors are important in regulating the pattern, but not the absolute level, of ventilation during exercise.

Rapid detection of cytomegalovirus pneumonia from lung lavage cells

Because cytomegalovirus (CMV) is a common cause of fatal pneumonia in the immunocompromised host, a rapid and reliable method to confirm this diagnosis is essential. Bronchoalveolar lavage (BAL) has proved to be a rapid, safe, and sensitive method for the diagnosis of several forms of pneumonia in these patients, but its efficacy for confirming CMV pneumonia remains to be established. In this study, we compared the sensitivity and specificity of conventional viral culture, immunocytochemical staining, and cytological examination performed on cells recovered by BAL for establishing CMV as the cause of pneumonia in 71 BAL specimens from 56 immunocompromised patients. Pneumonia due to CMV was confirmed by stated criteria in 14 of these patients. Virus was isolated by culture in BAL specimens from all patients with CMV pneumonia (sensitivity 100%), but also in 17 specimens from patients who did not have CMV pneumonia (specificity 70%). On cytologic examination, CMV inclusions were found in 3 of the 14 specimens from patients with CMV pneumonia (sensitivity 21%) and also in 1 patient at risk for pneumonia but who did not fulfill the criteria (specificity 98%). Thus, a positive culture and positive cytology virtually confirmed CMV pneumonia, whereas a negative culture excluded it. Immunocytochemistry proved to be particularly useful when the culture was positive and cytology was negative. In this situation, specific labeling of CMV antigen by monoclonal antibody was found in 9 of the 11 patients with CMV pneumonia (sensitivity 82%). Thus, the absence of specific staining in BAL cells tended to exclude CMV as a cause of pneumonia in patients with positive cultures and negative cytologies.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunologically mediated disease of the airways after pulmonary transplantation

Obliterative bronchiolitis has occurred in eleven of 30 recipients of cardiopulmonary allografts who survived at least 4 months after transplantation, has caused significant morbidity, and has been associated with four of eleven late deaths in this series. Although some improvement, or at least stability, of pulmonary function has followed augmented immune suppression, it appears that once the process is recognized clinically, much of the damage to the airways is irreversible. The histopathology, response to therapy, and, most important, the response of donor specific alloreactivity in the lymphocytes from the lung (bronchoalveolar lavage and peripheral blood) suggest immune- mediated basis for bronchiolitis obliterans. The presence of donor specific alloreactivity detected by primed lymphocyte testing predicted obliterative bronchiolitis in five of six recipients (83% sensitivity, 91% specificity) was absent in ten of eleven recipients who have not as yet developed the process (negative predicted value of 91%). Currently, the presence of a positive primed lymphocyte test in the bronchoalveolar lavage of the cardiopulmonary recipient is an indication for early treatment by augmented immune suppression.

Unexpectedly high incidence of Pneumocystis carinii infection after lung-heart transplantation. Implications for lung defense and allograft survival

Pneumonia due to Pneumocystis carinii (PCP) is regularly encountered in organ allograft recipients who are immunosuppressed to prevent rejection. Recipients of lung/heart allografts may be particularly prone to pulmonary infection due to systemic immunosuppression and the fact that defense mechanisms in the transplanted lung may be further impaired through tissue incompatibility and the effects of surgery. In this study, we monitored 16 lung transplant recipients for infection with Pneumocystis carinii using serial bronchoalveolar lavage (BAL) and found the prevalence of Pneumocystis infection of the lung to be 88%. Six episodes were associated with the usual symptoms of pneumonia, whereas 10 episodes were associated with minimal or no symptoms. In 3 of the 6 symptomatic episodes, a concurrent bacterial infection was also found. The total number of cells recovered from the lung by BAL, the proportion of T-lymphocytes, and the number of cytotoxic/suppressor and helper/inducer cells were elevated during infection with Pneumocystis compared to before and after. Spontaneous and interleukin-2-induced proliferation of BAL cells in vitro was also higher during infection, suggesting that there was an increased number of activated T-lymphocytes in the airspaces of the infected allograft. BAL cells cultured with irradiated spleen cells from the donor proliferated at higher levels when obtained after Pneumocystis infection than when obtained before or during infection even for subclinical infections. These results indicate that in the absence of prophylaxis, the prevalence of Pneumocystis infestation is very high after lung/heart transplantation. Impaired defense of the transplanted lung does not seem to stem from the inability of activated T-lymphocytes to accumulate in the allograft.(ABSTRACT TRUNCATED AT 250 WORDS)

Identification, cellular localization, isolation, and characterization of human Clara cell-specific 10 KD protein

Human lung lavage proteins were fractionated by centrifugation and molecular sieving. An antiserum to the post-albumin fraction of the soluble proteins reacted with a 10 KD protein and this protein was isolated by conventional chromatography. The protein, which has a pI of 4.8, consists of two 5 KD polypeptides and is rich in glutamic acid, leucine, serine, and aspartic acid amino acids. The protein does not bind to concanavalin A, pancreatic elastase, leukocyte elastase, or trypsin, and lacks anti-protease activity. It constitutes about 0.15% of the soluble proteins in lung lavage. Antibodies to the 10 KD protein specifically and exclusively stain Clara cells in human, dog, and rat. Staining of granules of Clara cells was prominent in the distal bronchioles; however, the non-ciliated cells of respiratory bronchioles did not stain for the 10 KD protein. This 10 KD protein appears in fetal lungs at 21 weeks of gestation, and was present in about 10% of the primary pulmonary adenocarcinomas. As a specific marker for Clara cells, this protein could be useful in the study of development, regulation of secretion, and pathobiology of these cells.