Heart and lung transplantation pathology: the Padua experience.

Physicians caring for heart and lung transplantation patients utilize routine follow-up biopsies on a prearranged schedule unrelated to the suspicion of a clinical diagnosis of rejection. Of course biopsies are also performed outside the prearranged scheme at any time the clinician is puzzled by clinical suspicion of rejection or infections. Technical considerations are important in handling the biopsies; pathologists who are aware of bias produced by tissue processing are forced to serially section the samples to increase the sensitivity for detection of the pathological processes. During the 20 years since the first Italian cardiac transplantation was performed in our center, 600 patients have been transplanted and monitored with 12,386 endomyocardial biopsies. The overall 5-year mortality was 24.5% and 18.4% in pediatric populations; at 10 years, 34%, and at 19 years, 55%. There was a progressive decrease in mortality from 36.8% in 1985 to 1990 to 12% in the 1996 to 2000. During a decade of experience in lung transplantation from May 1995 to May 2005 (n = 129), all patients underwent surveillance bronchoscopy including transbronchial biopsy (n = 722) and bronchoalveolar lavage (n = 629). The ancillary techniques of immunohistochemistry and molecular analysis have allowed the pathologists to play a pivotal role in the pre- and posttransplant management of patients requiring thoracic organ transplantation.

HLA-class II antigen expression in human heart-lung allografts.

Long-term survival in heart-lung transplantation has ben hindered by the development of bronchiolitis obliterans (OB), which is believed to be a manifestation of chronic rejection of the lung. Since HLA-class II antigens are involved in the rejection response, the distribution of the class II products HLA-DR, HLA-DQ, and HLA-DP were studied in normal lung, and in transplanted lung with and without OB, utilizing frozen-section immunohistochemical techniques. All three allelic products are usually expressed on the epithelial, endothelial, and mesenchymal components of the lung. Sequential transbronchial biopsies from 4 recipients before and concurrent with the diagnosis of OB were stained with serial dilutions of monoclonal antibodies to assess the level of expression of the above class II products. Increased levels of HLA-DR and HLA-DP antigens may be seen on the bronchial and bronchiolar epithelium during OB, but the changes are subtle and complicated by many other variables. Additional studies are needed to confirm these preliminary results.

The significance of bronchus-associated lymphoid tissue in human lung transplantation: is there an association with acute and chronic rejection?

BACKGROUND: In animal models of acute rejection in lung allografts, bronchus-associated lymphoid tissue (BALT) plays a major role in the induction and persistence of the alloreactive response. We undertook a study of the clinical and histologic associations with BALT identified on transbronchial biopsy in human lung allograft recipients. METHODS: Transbronchial biopsies of patients receiving single lung, double lung, and combined heart-lung transplantation from 1984 to 1997 at the University of Pittsburgh Medical Center were reviewed. Seventy-seven patients had transbronchial biopsies demonstrating BALT. We examined all pathologic reports and slides, and graded rejection utilizing the Revised Working Formulation for the Classification of Pulmonary Allograft Rejection. Twenty-nine of 77 patients were selected at random to evaluate the distribution of BALT lymphocyte subsets immunohistochemically. RESULTS: There was no relationship between native disease or the transplant procedure and the identification of BALT. BALT was found from 9 days to 2431 days after transplant (average: 440 days; median: 157 days) in association with clinically insignificant acute cellular rejection (A0, A1) in 75% of cases. Bronchiolitis obliterans developed in 29% of patients with a BALT-positive biopsy, a percentage not different from that of our overall lung transplant population. Immunohistochemical examination of BALT showed helper T cells predominated over cytotoxic T cells in zones surrounding B cell-rich follicular center cells. CONCLUSIONS: The association of BALT with high-grade acute cellular rejection and with the development of bronchiolitis obliterans could not be confirmed in human lung allografts. BALT most often accompanied A0 or A1 rejection. This raises the possibility that the presence of BALT on transbronchial biopsy may be part of the evolution of immunologic tolerance in human pulmonary allografts.

Alveolar lipoproteinosis in lung allograft recipients.

Three cases of pulmonary alveolar proteinosis developing in lung allograft recipients are reported. In each case, repeated bouts of alveolar damage from harvest/reperfusion injury, rejection, and infection were observed before the development of intraalveolar accumulation of granular, periodic acid-Schiff-positive material in the allograft lungs. It is speculated that iatrogenic immunosuppression combined with defective clearance of alveolar material by alveolar macrophages created a milieu conducive to the accumulation of surfactant, lipoprotein, and fibrinous debris that was morphologically identical to alveolar proteinosis.

Bronchial cartilage alterations in lung transplantation.

Changes in the hyaline cartilage of the proximal bronchial tree were investigated in a group of combined heart-lung and double-lung recipients with and without OB. Ossification, calcification and fibrovascular ingrowth into the normally avascular hyaline bronchial cartilage were observed in almost all patients and were independent of small or large airway inflammation. Alterations in the integrity of hyaline cartilage have been produced by others in animals by ligation of the blood supply. Finding similar changes in airway cartilage of all transplanted lungs argues that there is relatively poor perfusion to the proximal air-conducting passage. Such a mechanism may contribute to the development of OB, bronchiectasis and a predilection for infections following pulmonary transplantation.

Origin of pleural cells after lung transplantation: from donor or recipient?

We evaluated the change in the percentage of cells of donor origin in pleural fluid of 13 consecutive patients who underwent lung transplantation. Pleural fluid was sampled 2, 4, and 8 days after lung transplantation. DNA, which was extracted from the blood of donors and recipients and from the pleural fluid, was amplified using a polymerase chain reaction technique. The reaction products were electrophoresed, and bands indicating amplified human leukocyte antigen (HLA)-DR alleles were quantified by determining the area under the curve (AUC) by a densitometric analysis. HLA-DR alleles, which were present only in recipient cells (recipient allele), were analyzed and compared to HLA-DR alleles that were present only in donor cells (donor allele). A dilution study was first performed to provide a standard curve relating the percentage of donor and recipient cells in a mixture to their AUC. The AUC of the recipient alleles did not change significantly over the first 8 postoperative days. The AUC of the donor alleles was less on postoperative days 4 and 8 than on day 2 (p<0.05). The donor allele AUC on day 8 was <20% of the shared allele AUC, corresponding to <1% of all cells by the dilution study. We conclude that donor cells are rapidly cleared from the pleural space after lung transplantation, with <1% of cells of donor origin by postoperative day 8.

Adenovirus infection in the lung results in graft failure after lung transplantation.

OBJECTIVES: Our goal was to examine the relationship between viral pneumonia and outcome in pediatric patients undergoing lung or heart-lung transplantation. METHODS: Prospective surveillance for common respiratory viruses of childhood was performed in all patients undergoing lung or heart-lung transplantation. Specimens were examined for the presence of replicating virus (by culture), viral genome (by polymerase chain reaction), and viral antigen (by immunofluorescence and immunohistochemical staining). The relationship between viral infection and outcome was examined. RESULTS: Sixteen patients underwent 19 transplants during the study period, with follow-up of 1 to 26 months. Virus was identified in the transplanted lung in 29 instances; adenovirus was identified most commonly (8/16 patients) and had the greatest impact on outcome. In 2 patients with early, fulminant infection, adenovirus was also identified in the donor. Adenovirus was significantly associated with respiratory failure leading to death or graft loss and with the histologic diagnosis of obliterative bronchiolitis (P < or = .002 in each case). CONCLUSIONS: Adenovirus infection in the transplanted lung is significantly associated with graft failure, histologic obliterative bronchiolitis, and death. Health care personnel and families must be vigilant in preventing exposure of transplant recipients to this virus. Availability of a rapid and reliable test for adenovirus in donors and recipients would have an impact on management and could improve outcome for pediatric lung recipients.

Bronchoalveolar lavage and transbronchial biopsy in children following heart-lung and lung transplantation.

Between July 1985 and March 1992, 20 children received either heart-lung (11), double lung (8), or single lung (1) transplants at our center. Since 1988, flexible fiberoptic bronchoscopy with bronchoalveolar lavage and transbronchial biopsy have been carried out to monitor for rejection or infection in these patients. As of March 31, 1992, we have performed a total of 112 transbronchial biopsies in our patients, who ranged from 6.8 to 18 years of age and 19.3 to 67.3 kg in weight. All but two of these procedures were carried out using conscious sedation and a transnasal approach. Four to seven biopsy samples were obtained at each procedure. One patient had hemorrhage (< 100 ml) and no patient had pneumothorax as a complication. Of the biopsy samples, 72.4 percent had a surface area of greater than 2 mm2, and 89.5 percent of the biopsy samples were deemed adequate for pathologic interpretation. We believe that for the majority of pediatric lung or heart-lung recipients, flexible bronchoscopy and transbronchial biopsy using conscious sedation and a transnasal approach is safe and permits the recovery of adequate tissue for pathologic evaluation. The avoidance of general anesthesia, endotracheal intubation, and mechanical ventilation at the time of bronchoscopy and transbronchial biopsy probably decreases the likelihood of pneumothorax as a complication of the procedure.

Outcome of lung transplantation in patients with mycetomas.

BACKGROUND: Lung transplantation has become an acceptable treatment option for many end-stage lung diseases. Pulmonary mycetomas are found in patients with end-stage lung diseases, especially sarcoidosis. The clinical course and long-term outcome of these patients after transplantation remains unknown. METHODS: We reviewed retrospectively the pathology reports of the explanted lungs from all lung and heart-lung transplantations performed at our institution between January 20, 1992, and June 26, 2000. Patients were included in our study if mycetomas were present on the specimens. Information on transplant date and type, diagnosis, information on antifungal therapy and fungal infections pretransplant and posttransplant, and clinical course after transplantation was recorded. RESULTS: Mycetomas were present in 3.0% of transplant recipients (9 of 303 patients). The underlying pulmonary diagnoses were sarcoidosis (six patients), and emphysema, idiopathic pulmonary fibrosis, and pneumoconiosis (one patient each). Seven patients received bilateral lung transplants, one patient received a heart/lung transplant, and one patient received a single lung transplant. Aspergillus was isolated from culture in five patients pretransplant and from five patients posttransplant. Six patients received treatment with itraconazole, or IV or inhaled amphotericin B prior to transplantation. All patients who survived transplantation received posttransplant antifungal therapy. Four patients died in the first month after transplantation. Two patients died at 17 months and 24 months posttransplant, respectively; one patient received a second transplant 30 months later; and two patients are alive and free from fungal infections 17 months and 18 months, respectively, after transplantation. All of the medium-term survivors received lengthy therapy with inhaled and systemic amphotericin B and itraconazole before and after transplantation. CONCLUSIONS: Lung transplant recipients with mycetomas have significantly reduced posttransplant survival. Careful selection of patients and aggressive antifungal therapies before and after transplantation have led to improved outcomes in patients with mycetomas. Additional research is needed to define the best therapeutic strategy for these patients during transplantation.

Asymmetric intramyocardial lymphocytic accumulation during acute rejection in rat heart and heart-lung transplantation.

Lymphocytic accumulation in different areas of the myocardium during different phases of acute rejection were studied in rat heterotopic cardiac and cardiopulmonary allograft and isograft transplantation models. Indium 111-labeled syngeneic lymphocytes were injected 1 to 7 days after transplantation, and accumulation of the labeled cells in the graft was determined 24 hours later. The cardiac graft was divided into three segments: right ventricular (RV) free wall, epicardial portion of the left ventricle (LV) plus RV septum, and endocardial portion of the LV. In the subsequent heart-lung transplantation group, the LV epicardial portion plus RV septum segment was subdivided into LV epicardial portion and RV septum. Lymphocytic accumulation in each segment was compared between three groups according to the day the animal was killed after transplantation: days 2, 3 (group 1), days 4, 5 (group 2), and days 6, 7, 8 (group 3). Lymphocytic accumulation caused by rejection in group 1 and group 2 of both the cardiac and cardiopulmonary allografts showed significantly different intramyocardial distribution (p less than 0.01). Lymphocytic accumulation was consistently highest in RV free wall and lowest in LV endocardial portion. In group 3 specimens, lymphocytic accumulation was symmetrical in both the cardiac and cardiopulmonary allografts. In the cardiac allograft, the lymphocytic accumulation increased sharply on day 4 then declined to a nadir. This transient increase was not so pronounced in the cardiopulmonary allografts. The significantly decreased intramyocardial lymphocytic accumulation in group 2 of the cardiopulmonary allografts when compared with the cardiac allografts (p less than 0.01) is compatible with the clinical observation of a lower incidence of acute heart rejection in heart-lung transplant recipients. These data show an asymmetric accumulation of lymphocytes during acute heart rejection, which is due to increased lymphocytic affinity for the RV free wall.

Audit of referral and explant diagnoses in lung transplantation: a pathologic study of lungs removed for parenchymal disease.

BACKGROUND: Lung transplantation is performed for an increasing range of pulmonary conditions in which the diagnosis is often clinical or based on limited biopsy material. Diagnosis may be made late in the course of the disease where specific features are no longer present. Posttransplantation complications and disease recurrence may relate to the primary disease, and accurate diagnosis is therefore essential. METHODS AND RESULTS: A pathologic review of 183 explanted lungs over a 10-year period (heart-lung = 109, single lung = 65, double lung = 9) showed 29 significant discrepancies or additional features likely to effect outcome. The final pathologic diagnosis was cystic fibrosis (n = 66), emphysema (59), bronchiectasis (17), pulmonary fibrosis (19), sarcoidosis (10), Langerhans cell histiocytosis (3), pulmonary veno-occlusive disease (3), posttransplantation obliterative bronchiolitis (2), primary hemosiderosis (1), rheumatoid obliterative bronchiolitis (1), extrinsic allergic alveolitis (1), pneumoconiosis (1). Unsuspected diagnoses included tuberculosis (8) (four cases of which were active and in single lung recipients requiring antituberculous chemotherapy), sarcoidosis (9), (of which, six were unsuspected primary diagnoses and three were additional diagnoses), veno-occlusive disease (3), carcinoma (1), pneumoconiosis (1), and pulmonary fibrosis (2). Aspergillus infection (2) and bronchocentric granulomatosis (3) were found in patients with cystic fibrosis. One active tuberculosis case also showed an aspergilloma. Unsuspected infections requiring therapy in immunosuppressed patients and previously unsuspected sarcoidosis, which is known to recur in the graft, were the major novel diagnoses. Discrepancy rate was 12 of 65 in single lungs (19%) and 17 of 109 in heart-lungs (16%). CONCLUSIONS: These results emphasize the need for accurate preoperative diagnosis especially when the similarly diseased native lung remains in situ.

Transbronchial biopsy in heart and lung transplantation: clinicopathologic correlations.

BACKGROUND AND METHODS: We reviewed and correlated the histologic and clinical records for the 1027 transbronchial biopsies performed, as clinically indicated, in 313 heart and lung transplant recipients in the Harefield Transplant Unit from 1988 through 1991. Three pieces of lower lobe or radiologically abnormal lung were routinely sent for histologic diagnosis. Clinical diagnoses of rejection and infection were based on symptomatologic, radiologic, and bacteriologic findings and response to appropriate therapy. Standard histopathologic technology and diagnostic criteria were used, including the Working Formulation for the standardization of nomenclature in the diagnosis of heart and lung rejection grading. RESULTS: Rejection was the most common finding (22.2%) and showed good clinicopathologic correlation. With unequivocal histologic features of rejection (Working Formulation grade A1 or above), specificity (clinical agreement with biopsy diagnosis) was 93.1% and sensitivity (clinical rejection confirmed by transbronchial biopsy) was 61%. Sensitivity increased to 77% if unsatisfactory specimens were excluded. Possible/probable rejection only was reported in 83 specimens; there were technically unsatisfactory, showed only minimal perivascular infiltrates, or had infiltrates limited to one vessel; 71% of these did have clinical rejection. Infection, excluding opportunistic, was reported in 18.5% of biopsy specimens; specificity was 70.5% and sensitivity 51.3% (both rising by 9%), with unsatisfactory specimens excluded. Histologic features of both rejection and infection were seen in 47 transbronchial biopsy specimens (4.7%). Where both components appeared definite specificity was 66.7%, but where either had been doubtful the clinical diagnosis was most often rejection. Sensitivity was also 66.7%. Cytomegalovirus inclusions were identified in 12.1% of biopsy specimens, with specificity of 91% and sensitivity of 83.5%. Sensitivity (88%) and specificity (100%) were both high for the 17 cases with pneumocystis infections. Sensitivity for the 25 transbronchial biopsy specimens from fungal infections was only 20%. Sensitivity was also poor (27.7%) in obliterative bronchiolitis, although specificity was 75%. Almost a third of transbronchial biopsy specimens from patients with obliterative bronchiolitis were unsatisfactory. Pneumonitis was the only change noted in 68 biopsy specimens. Most correlated with clinical status, but 26.5% were from patients with active rejection. Nonspecific changes or no significant pathologic condition was seen in 278 transbronchial biopsy specimens; over a third of these were from patients with clinical rejection (17.7%) or infection (18%) and 6.5% were from obliterative bronchiolitis cases. Excluding 78 technically unsatisfactory specimens reduced the proportion of false negative findings in rejection and infection by 6% and 4%, respectively. CONCLUSIONS: We found that transbronchial biopsies consisting of three adequate pieces of lung parenchyma correlated well with clinical rejections and infections other than fungal but was of limited value in confirming a diagnosis of obliterative bronchiolitis or fungal infection.

Diagnostic yield and therapeutic impact of flexible bronchoscopy in lung transplant recipients.

BACKGROUND: Bronchoalveolar lavage and transbronchial biopsy are often used for definitive diagnosis of lung rejection and infection in lung transplant recipients. Although protected specimen brushing is of value in nosocomial bacterial pneumonia, its role in lung transplant recipients had not been widely reported. The aim of the study is to review the diagnostic yield and therapeutic impact of flexible bronchoscopy with the use of a combination of bronchoalveolar lavage, protected specimen brushing, and transbronchial biopsy in lung transplant recipients. METHODS: We reviewed flexible bronchoscopy data in 83 transplant recipients between February 1990 and March 1995. Only those with bronchoalveolar lavage, protected specimen brushing, and transbronchial biopsy were included in the analysis. There were 282 bronchoscopies performed for clinically suspected lung rejection or infection (clinical bronchoscopy) and 38 bronchoscopies for follow-up of a previously detected histologic abnormality (follow-up bronchoscopy). RESULTS: The total yields for rejection and infection for clinical and follow-up bronchoscopies were 67.4% and 58.9%, respectively. Acute rejection was detected with transbronchial biopsy in 26.2% and 34.2% of clinical and follow-up bronchoscopies, respectively. Cytomegalovirus pneumonitis was detected with transbronchial biopsy in 4.0% and 11.4% of clinical and follow-up bronchoscopies, respectively. Overall, bacteria was the most common cause of lower respiratory tract infection. When used together, protected specimen brushing and bronchoalveolar lavage were complementary techniques for detection of bacterial lower respiratory tract infection with a significantly higher proportion detected with protected specimen brushing ( > or = 10(3) colony forming units/ml) compared with bronchoalveolar lavage ( > or = 10(5) colony forming units/ml) (p < 0.001). Complications were hemorrhage (1.9%), pneumothorax (2.5%) and transient hypoxemia (10.5%). The results had an impact on management of rejection and infection in 57.8% of clinical and 39.5% of follow-up bronchoscopies. CONCLUSIONS: We conclude that bronchoscopy, with the use of a combination of bronchoalveolar lavage, protected specimen brushing, and transbronchial biopsy, is safe with a high diagnostic yield and therapeutic impact for treating lung transplant recipients.

Prospective study of transbronchial biopsies in the management of heart-lung and single lung transplant patients.

A prospective study of 219 bronchoscopies in 54 heart-lung and in 2 single lung transplant recipients was undertaken over a 12-month period by a single operator. For histologic study, an average of 17.3 transbronchial biopsy specimens (range, 6 to 56) were taken from three lobes (or from two lobes and lingula of one lung). A further two specimens were taken for culture. The average procedure time was 14.4 minutes (SE 0.31). An estimate of the probability of rejection being missed, depending on the number of specimens taken and based on the method of Gilman and Wang, suggests 18 biopsy specimens are required to have 95% confidence of diagnosing rejection. Sensitivity for diagnosing rejection by histologic study of transbronchial biopsy specimens was 94%, and specificity was 90%. The simple grading of severity of rejection that was used was related both to the number of specimens demonstrating rejection and to the severity of graft airway mucosal inflammation seen at bronchoscopy. The major complication encountered, on 27 occasions, was bleeding of more than 100 ml. On no occasion did bleeding result in any long-term complication. Extensive transbronchial biopsy is a simple, relatively safe, and quick procedure, with a high sensitivity and specificity for diagnosing rejection and lung infection.

Mediastinal irradiation for graft-versus-host disease in a heart-lung transplant recipient.

Graft-versus-host disease in solid organ transplantation is very rare, but the prognosis is poor when the condition causes pancytopenia. We report a case of graft-versus-host disease in a heart-lung transplant recipient who at 2 weeks after transplantation had development of features of graft-versus-host disease, including bone marrow aplasia, that could not be attributed to drugs or viral infections. The diagnosis was confirmed by skin biopsy and demonstration of chimerism of peripheral lymphocytes. Augmentation of immunosuppression with intravenous methylprednisolone resulted in improvement in liver function but had no effect on the pancytopenia. Mediastinal irradiation was given with increase in both white blood cell and platelet counts. Unfortunately the patient eventually died of gastrointestinal bleeding and fungemia.

The diagnosis of obliterative bronchiolitis after heart-lung and lung transplantation: low yield of transbronchial lung biopsy.

Obliterative bronchiolitis is the most significant long-term complication of lung and heart-lung transplantation characterized by the rapid development of obstructive airway disease. It is thought to be a manifestation of chronic rejection and has been treated, with limited success, with augmentation of immunosuppression. Early detection of obliterative bronchiolitis and prompt initiation of therapy may result in an improved outcome. The role of transbronchial biopsy has been reported in the diagnosis of acute rejection and infection but not for obliterative bronchiolitis. To study this problem we retrospectively reviewed the transbronchial biopsy results of patients with advanced clinical obliterative bronchiolitis, as defined physiologically. Between January 1, 1988, and December 31, 1991, 46 "sets" of adequate transbronchial biopsy specimens were obtained from 16 patients (15 heart-lung recipients and one double lung recipient). Seven sets of transbronchial biopsy specimens (15.2%) showed obliterative bronchiolitis by pathologic study. In four patients with severe clinical obliterative bronchiolitis, only one transbronchial biopsy specimen of seven (14.3%) showed obliterative bronchiolitis. The pathologic diagnosis of obliterative bronchiolitis was confirmed in three of these patients at the time of autopsy or retransplantation. Twelve patients were still alive at the end of the study period, and all experienced further deterioration of lung function typical for obliterative bronchiolitis. We conclude that the sensitivity of transbronchial biopsy for obliterative bronchiolitis is poor. Possible explanations for these results are explored.

Does the donor-recipient ABO blood group compatibility status predict subsequent lung transplantation outcomes?

BACKGROUND: The study was conducted to compare lung transplantation outcomes between ABO-identical (AI) and ABO-compatible (AC) recipients. METHODS: Charts of lung allograft recipients transplanted between February, 1990 and October, 1995 were reviewed. Standard triple-drug immunosuppression and general antimicrobial prophylaxis were provided. Surveillance spirometry was administered every three months. Flexible bronchoscopy (FB) with transbronchial biopsies (TBBs) were undertaken for clinical indications. Time to event analysis on acute (AR) and chronic (CR) rejection and actuarial survival were determined by Kaplan-Meier analysis. Cumulative curves were compared with a log rank test. Comparisons of age, maximum forced expiratory volume in one second (FEV1) in the single (SLT) and double (DLT) lung recipients, duration of intensive care unit and hospital stay were carried out using the Wilcoxon Rank Sum test. Gender, race, underlying diagnoses, cytomegalovirus (CMV) status and pulmonary reimplantation response (PRR) were compared by Chi-square or Fisher's exact test where appropriate. RESULTS: Of the 100 lung recipients (age = 42.5 +/- 13.4 years; M:F = 50:50), 64 were AI and 36 AC. Median follow-up was 22 (range = 0-78) months. Outcome did not differ significantly between the 2 groups in terms of intensive care unit and hospital stay, PRR incidence and grade, incidence and frequencies of AR, median time and grade of first AR, maximum FEV1 for SLT and DLT recipients, incidence of CR and survival at 12 months. CONCLUSIONS: As the donor supply remains limited, this could considerably simplify the logistics of future transplantation.

Cytomegalovirus detection in lung transplant biopsy samples by polymerase chain reaction.

Cytomegalovirus lung infection may produce perivascular lymphocytic infiltrates indistinguishable from those found in lung biopsy samples obtained from lung transplant recipients with acute rejection. With the polymerase chain reaction used to detect cytomegalovirus DNA, 43 transbronchial samples from 26 lung or combined heart-lung transplant recipients were analyzed, as were lung biopsy samples (devoid of characteristic cytomegalic cells) obtained from 18 non-lung transplant recipients who were not immunosuppressed. Of 25 samples manifesting acute rejection, nine contained cytomegalovirus DNA. Eight samples negative for rejection also contained cytomegalovirus DNA. Cytomegalovirus DNA was detected in 2 of 18 samples from the patients not undergoing transplantation. A significant correlation was noted between cytomegalovirus culture and polymerase chain reaction results (p = 0.01). There was no association between the presence of cytomegalovirus DNA sequences and patient antibody titer status or histologic evidence of rejection (p > 0.5). Cytomegalovirus sequences were found in 44% of transplant lung samples that did not manifest perivascular infiltrates or other evidence of rejection and 36% of transplant samples manifesting perivascular infiltrates. From these results it would seem that cytomegalovirus infection is just as likely not to be accompanied by perivascular infiltrates as to be associated with them. It may be appropriate to regard perivascular lymphoid infiltrates as more likely a sign of acute rejection.

In situ hybridization studies for viral nucleic acids in heart and lung allograft biopsies.

In situ hybridization has been shown to be a useful technique for the identification of specific viruses in pathologic tissues. The authors studied 313 lung and 164 heart biopsies from 20 heart-lung recipients to assess its utility in this clinical setting, employing biotinylated probes for the cytomegalovirus, herpes simplex, and adenovirus genomes. Twenty-five lung biopsies and one heart biopsy had detectable cytomegalovirus DNA by in situ hybridization. As compared to histopathology, in situ hybridization had a sensitivity of 85% and a specificity of 99%. None of the biopsies had detectable herpes simplex or adenovirus by either in situ hybridization or routine histopathology. In situ hybridization studies may be of greatest use when the results of conventional histopathology are equivocal and in the patients with radiologic or clinical evidence of pulmonary disease.

Relation between polymerase chain reaction findings and morphological changes during cytomegalovirus infection in transplanted lung.

Cytomegalovirus (CMV) can be present as a latent or productive infection resulting in disease. The polymerase chain reaction (PCR) is a sensitive technique to document the presence of CMV (DNA). Negative reactions are indicative of its absence. The presence of CMV (DNA) was assessed longitudinally in 261 transbronchial lung biopsy (TBB) specimens from 37 patients over a 6-month period. The TBB specimens from six serologically CMV-negative recipients who received lungs from serologically CMV-negative donors never showed a positive CMV-PCR(DNA) reaction during the study. Based on a study of their TBB specimens, 10 serologically CMV-positive recipients who received lungs from serologically CMV-negative donors all developed a CMV-PCR(DNA)-positive reaction and five (50%) morphologically manifested CMV disease. The remaining 21 serologically CMV-positive recipients who received lungs from serologically CMV-positive donors all developed a CMV-PCR(DNA)-positive reaction and 15 (71%) developed CMV pneumonitis. The data show that development of a positive CMV-PCR(DNA) reaction in a TBB sample within the first month after transplantation indicates a greatly increased risk of developing CMV disease. In addition, a positive CMV-PCR(DNA) reaction preceded morphologically manifest disease on average by 2 weeks. Comparisons between TBB and bronchoalveolar lavage show the former to provide a more dependable template.