Spontaneous resolution of ventricular arrhythmias with left bundle branch block morphology and abnormal endomyocardial biopsy.

Four children presenting with ventricular tachycardia with a left bundle branch block morphology were evaluated and found to have structurally normal hearts but abnormal endomyocardial biopsies. All four children had spontaneous resolution of their ventricular rhythm abnormalities during follow-up.

Neuroendocrine carcinomas: role of immunocytochemistry and electron microscopy.

Neuroendocrine tumors occur in many sites of the body and can present significant diagnostic problems when poorly differentiated. To identify a tumor as neuroendocrine, pathologists commonly use either immunocytochemistry or electron microscopy. In this report, the various immunocytochemical reagents are reviewed along with the ultrastructural features of neuroendocrine tumors. Site-specific variations in neuroendocrine tumors are discussed. A cost-effectiveness evaluation was performed on tumors from one laboratory which showed that electron microscopy was a less expensive diagnostic modality if more than three antibodies were necessary to arrive at the correct pathological diagnosis.

The repetitive histologic pattern of vascular cardiac allograft rejection. Increased incidence associated with longer exposure to prophylactic murine monoclonal anti-CD3 antibody (OKT3).

While vascular cardiac allograft rejection increases morbidity and mortality following transplantation, factors predisposing to its development have not been completely elucidated. To evaluate the influence of the duration of early rejection prophylaxis with the murine monoclonal anti-CD3 antibody (OKT3) on the development of a repetitive histologic pattern of vascular cardiac allograft rejection, endomyocardial biopsies from 344 heart transplant recipients were prospectively evaluated. The influence of clinical characteristics was assessed. Eighty-three patients (24%) developed and 261 patients (76%) did not develop a repetitive histologic pattern of vascular cardiac allograft rejection. The vascular rejection pattern was more common in patients with a positive crossmatch (89% versus 11%, P<0.0001) and OKT3 sensitization (73% versus 27%, P<0.0001), and was positively correlated with the duration of OKT3 treatment (P<0.0001). The correlation persists even after excluding patients with a positive crossmatch or OKT3 sensitization. Patients developing a repetitive histologic pattern of vascular cardiac allograft rejection early after transplantation had decreased allograft survival (P=0.0008). The development of a repetitive histologic pattern of vascular cardiac allograft rejection is positively correlated with the duration of OKT3 treatment. Judicious use of OKT3 in early rejection prophylaxis in cardiac transplantation is warranted.

Immunohistochemical analysis of platelet-derived growth factor and basic fibroblast growth factor in cardiac biopsy and autopsy specimens of heart transplant patients.

The purposes of this study were to examine 250 heart biopsy specimens and 20 autopsy specimens from heart transplant patients for the presence and localization of platelet-derived growth factor (PDGF)and basic fibroblast growth factor (bFGF) and to correlate these findings with the histologic features of rejection and the autopsy findings of graft coronary vasculopathy and global ischemia. Positive specimen staining was significantly more prevalent for PDGF (78% of specimens) than for bFGF (54% of specimens) (p< 0.001). PDGF was distributed more in an interstitial (53%) than a vascular (28%) pattern and was associated with macrophages, whereas bFGF was distributed more in a vascular (50%) than an interstitial (12%) pattern. The prevalence of PDGF (but not bFGF) staining was significantly greater in biopsy specimens with at least grade 2 vascular rejection changes (81%) than in those without vascular rejection changes (58%) (p<0.001). In autopsy specimens, PDGF staining was present in the hearts of all 5 patients (100%) who died of graft failure from coronary vasculopathy and was present in all 11 hearts (100%) with global ischemic changes, but in only 4 of 9 (44%) of the hearts without global ischemia (p<0.01). PDGF staining was absent in nontransplanted heart specimens, whereas bFGF staining in nontransplanted heart specimen was similar to that in transplanted hearts. We conclude that PDGF is increased in transplanted hearts, is distributed more in an interstitial pattern, and is associated with macrophages. Furthermore, PDGF staining is increased in transplanted hearts with evidence of vascular rejection, coronary vasculopathy, or global ischemia.

Correlation between cellular rejection of cardiac allografts and quantitative changes among T-cell subsets identified by V beta epitope expression.

BACKGROUND: Cellular rejection of an allograft is mediated in part by peripheral blood T cells. We tested the hypothesis that quantitative changes in T-cell subsets can be detected in the peripheral blood and that these changes correlate with rejection. METHODS AND RESULTS: T-cell subset analysis was performed by flow cytometry using monoclonal antibodies recognizing six isotypic epitopes of the T-cell receptor beta-chain variable (V) region. These analyses were done at 7-day (mean) time intervals. Fluctuations within a given subset were determined by dividing the number of positive cells observed by the number of positive cells found on the previous analysis. For healthy volunteers observed over a period of 30 days, 119 of 120 subset ratios (99.2%) fell between 0.5 and 2.0. For patients, 57 of 240 subset ratios (23.8%) fell outside of this range (P < .004, chi 2). The occurrence of the abnormal ratios coincided more closely with cellular rejection (mean +/- SD, 7.7 +/- 6.2 days from a positive biopsy; median, 5 days; range, 0 to 28 days) than did the occurrence of normal subset ratios (mean +/- SD, 14.4 +/- 10.9 days from a positive biopsy; median, 11 days; range, 0 to 44 days; P < .005 by Mann-Whitney U test). Regression analysis confirmed a significant (P < .001, R = .91) temporal association between cellular rejection and abnormal subset fluctuations. No correlation was found between abnormal subset ratios and either vascular rejection or use of high-dose prednisone. CONCLUSIONS: T-cell subset measurement may be a method of noninvasive monitoring of cellular rejection after transplantation and may provide insights into the physiology of graft rejection with the potential for the development of more specific immunosuppressive therapy.

Cardiac paraprotein associated with Waldenstrom's macroglobulinemia: a case report.

A case of myocardial paraprotein deposition in a patient with Waldenstrom's macroglobulinemia is presented. Routine light microscopy revealed diffuse widening of interstitial regions by pale eosinophilic material that had a grayish cast on trichrome stains and was Congo red negative. Immunofluorescence showed strong immunoglobulin M and kappa light chain staining around blood vessels but predominantly around myocytes. Ultrastructural examination revealed massive deposition of flocculent electron-dense material around myocytes and occasionally around blood vessels.

Ultrastructural findings in cardiac transplant recipients.

Ultrastructural findings in 350 endomyocardial biopsy specimens and 59 autopsy or explanted hearts from cardiac transplant recipients are reviewed. Myocyte degeneration can be readily distinguished from necrosis by the technique described. Vascular changes of endothelial activation, endothelial cell damage, and basement membrane reduplication can be readily identified. In addition, the myofilament composition of ischemic hearts in patients with allograft coronary artery disease is distinctive: There is a disproportionate loss of actin over myosin, giving a coarse appearance to the myofilaments. These changes are useful in further defining the morphologic features associated with rejection and ischemia in cardiac transplant recipients.

The first pediatric Japanese case to undergo heart transplantation in the Utah Cardiac Transplant Program in the United States.

A seven-year-old girl underwent heart transplantation because of progressive congestive heart failure resulting from familial dilated cardiomyopathy. Her parents were second cousins to each other and her brother had died of dilated cardiomyopathy. Her symptoms of congestive heart failure began four months before the transplantation and became gradually worse. Left ventricular ejection fraction was 10 to 20% echocardiographically, and mitral and tricuspid valve regurgitation were present. Her condition of NYHA IV was not improved by treatment with dobutamine infusion and isosorbide dinitrate. She was transported to the Primary Children's Medical Center in Utah, USA, on July 22, 1991 in critical condition to undergo heart transplantation. Despite treatment with amrinone and additional catecholamines, she became semicomatose due to ischemic liver injury on July 24, 1991. A donor became available on July 25, 1991, and the transplantation was performed. Cardiac ischemic time was 97 min. Although she had transient OKT3 monoclonal antibody-related encephalopathy on her fifth postoperative day, she recovered normally. She had moderate rejection on the 20th postoperative day and mild rejection on the 79th and 149th postoperative days. She has had no significant infectious diseases. The baseline examination performed three months after heart transplantation revealed no abnormal findings on her coronary arteriogram. She returned to Japan and has been attending elementary school. The annual examination of her transplanted heart showed neither stenosis nor occlusion in her coronary angiogram. She has been receiving cyclosporine, azathioprine, and a low dose of prednisone as an immunosuppressive regimen. If she does not exhibit rejection, the use of steroids will be decreased or discontinued.

Prevention of adverse clinical outcome by monitoring of cardiac transplant patients for murine monoclonal CD3 antibody (OKT3) sensitization.

We have previously reported that patients sensitized to murine monoclonal CD3 antibody (OKT3) and maintained on such therapy for induction of immunosuppression have a high mortality and/or allograft loss. In this follow-up study, we retrospectively reviewed all patients routinely and serially monitored by flow cytometry for plasma levels of OKT3 during a 21-month period beginning 1/90. A total of 112 patients were monitored during this period. We retrospectively tabulated the incidence of OKT3 sensitization, rejection pattern and impact on survival of withdrawal of OKT3 at the time of sensitization as compared with the previous study in which withdrawal was not done. Nine patients were excluded from analysis because of withdrawal for reasons other than sensitization: cytokine encephalopathy, infection, postoperative complications, or severe rejection. Twelve patients had OKT3 therapy aborted because of failure to achieve steady-state OKT3 levels or because of decline in levels while on therapy. These patients were thus defined as being sensitized to OKT3. No patient was aborted because of return of CD3 cells in the blood. Only one of the 12 patients sensitized to OKT3 died. Of 91 patients with steady-state OKT3 levels, 6 had high plasma levels (> 1000 ng/ml) and 6 had low plasma levels (< 500 ng/ml). None of these patients had OKT3 therapy aborted and all are alive. Twelve of these 91 patients had successful retreatment with OKT3 for refractory rejection, indicating that absence of sensitization on induction predicts safety of retreatment with OKT3. We also examined the frequency of associated human antimouse antibody (HAMA) production using the blocking assay modified from Jaffers and Mayes. Only the sensitized patients exhibited a significant association with HAMA production (6/7 tested, P = 0.05) Classification of the rejection pattern of the sensitized patients confirmed our previous results: eight of 12 had vascular rejection and 4/12 had mixed rejection. These patterns were prospectively determined. We conclude that serial monitoring of patients for plasma levels of OKT3 is an effective strategy to prevent adverse outcomes of induction with this agent.

Immunofluorescence of endomyocardial biopsy specimens: methods and interpretation.

On the basis of our experience with prospective observation of immunofluorescence microscopy in 5775 biopsy specimens from 335 consecutively followed heart transplant cases, we describe the immunofluorescent method in detail and the potential artifacts and method of interpretation of the findings. A strategy for use of the method on the basis of the experience of the authors is proposed.

Vascular rejection in heart transplantation: clinical correlation, treatment options, and future considerations.

Vascular rejection injures the vascular endothelium in cardiac allografts in the absence of significant intramyocardial lymphocytic infiltration. When compared with cellular rejection, vascular rejection occurs earlier after transplantation, is more resistant to immunosuppressive augmentation, causes more allograft dysfunction, and is associated with a higher frequency of allograft loss. Between January 1990 and October 1992, acute hemodynamically significant vascular rejection developed in 13 of 170 patients (8%). Endomyocardial biopsy specimens revealed the typical findings of endothelial cell activation, immune complex deposition, and interstitial fibrin deposition in the absence of significant lymphocytic infiltration. All patients had clinical evidence of allograft dysfunction. In addition to high-dose corticosteroids, all patients received cyclophosphamide as an oral pulse for 4 days and underwent plasmapheresis for 3 consecutive days. Eight patients received OKT3 (n = 6) or antilymphoblast globulin (n = 2), and nine patients underwent systemic anticoagulation. Six patients required inotropic therapy for hemodynamic instability. Although one patient died during the initial episode, rejection resolved and left ventricular function returned to normal in 12 of 13 patients. However, vascular rejection recurred in three patients, two of whom subsequently died. Two other patients died during late follow-up because of noncompliance. Eight patients remain alive with normal allograft function and angiographically normal coronary arteries. Whereas the addition of cyclophosphamide and plasmapheresis may improve the outcome of vascular rejection, the results of treatment with currently available treatment modalities remain unacceptably poor.

Vascular rejection in cardiac transplantation: Histologic, immunopathologic, and ultrastructural features.

Although the majority of rejection found in cardiac transplant biopsies is cellular in type, a variety of vascular alterations occur in cardiac biopsies, constituting different forms of rejection that can be recognized using light microscopic and immunopathologic criteria. In this report, pathologic aspects of the vascular alterations associated with vascular and mixed rejection of cardiac allografts are described in detail. Methods and controls used in this report are identical to those previously reported. The histologic, immunopathologic, and ultrastructural findings associated with vascular rejection and other vascular processes in cardiac allografts are discussed. The relationship of these findings to chronic allograft rejection and potential pathogenetic mechanisms of these vascular changes are also detailed.

Vascular rejection and its relationship to allograft coronary artery disease.

We have prospectively monitored 268 patients by our previously described method of routine immunofluorescence of endomyocardial biopsy specimens. We have classified these patients according to their rejection pattern: cellular, vascular, and mixed. The criteria for these designations have been previously described. In this study we retrospectively reviewed coronary angiograms of these patients to assess the presence and time-course of developing allograft coronary artery disease. All available explanted hearts and postmortem hearts were also assessed by light microscopic examination for acute coronary vasculitis and allograft coronary artery disease and by immunofluorescent microscopy for vascular immune complex deposition in a manner identical to immunofluorescent microscopic examination of endomyocardial biopsy specimens. Patients were also monitored for sensitization to immunoprophylactically administered murine monoclonal CD3 antibody (OKT3) and those demonstrated to be sensitized were separately analyzed. Clinical features and treatment of patients were retrospectively reviewed. We found that 141 patients could be classified as having cellular rejection, 76 as having vascular rejection, and 52 as having a mixed rejection pattern. The allograft survival in vascular rejection patients was significantly worse than in allografts of patients with cellular or mixed rejection, confirming our earlier results. Most importantly, we found a significant difference in the time to the development of allograft coronary artery disease based on the rejection pattern. This difference existed whether or not patients sensitized to OKT3 were excluded from evaluation. Patients with mixed rejection had an intermediate time to the development of allograft coronary artery disease between that of patients with cellular and vascular rejection.(ABSTRACT TRUNCATED AT 250 WORDS)

The role of electron microscopy in evaluating ciliary dysfunction: report of a workshop.

This report summarizes the proceedings of a workshop organized with the purpose of bringing together many of those with substantial experience in this troublesome area of pathology for an active interchange of ideas, opinions, problems, and solutions. Recognition was given the fact that current knowledge and technical capabilities are woefully inadequate for dealing with the diagnostic questions now being asked. Until such time as these inadequacies can be remedied, a very conservative approach to the interpretation of ultrastructural studies is advocated.

Sensitization to OKT3 monoclonal antibody in heart transplantation: correlation with early allograft loss.

Because administration of murine monoclonal anti-CD3 antibody (OKT3) may result in the formation of human antimouse antibody, which complexes with OKT3, we conducted this study to assess the incidence and effect of human antimouse antibody formation during prophylactic administration of OKT3 in heart transplantation. Human antimouse antibody developed in eight of 55 (14%) cardiac allograft recipients receiving OKT3 prophylaxis as measured by enzyme-linked immunosorbent assay. Additionally, two recipients had an inexplicable rise in CD3+ lymphocytes during therapy without detectable antibody. The outcome of these 10 sensitized recipients was compared with that of 45 nonsensitized recipients. Age, preoperative diagnosis, hemodynamics, and the need for intravenous inotropes or mechanical assistance before transplantation were similar in both groups. No female patients were in the sensitized group, whereas 33% of the nonsensitized group were female patients. A trend toward greater sensitization when prophylaxis was extended to 21 days (28%) compared with the more conventional 14-day administration (10%) was not statistically significant. Retransplantation because of rejection was required in a single patient in each group. Allograft survival was significantly lower by 3 months in the sensitized group, and allograft loss caused by rejection selectively accounted for that difference. In survivors, rejection frequency and infectious complications were similar. These findings suggest that sensitization to OKT3 occurs at low frequency after prophylactic administration in heart transplantation but is associated with an increased frequency of graft loss because of rejection.