Giant cell myocarditis after mitral valve replacement: case report and studies of the nature of giant cells

Giant cell polymyositis and myocarditis associated with myasthenia gravis and thymoma

We describe an unusual case of myasthenia gravis. Our patient had been diagnosed as having myasthenia gravis with thymoma at the age of 64 years, and died of acute respiratory failure at the age of 80 years. Post mortem examination revealed CD8-positive lymphocytic infiltration with numerous giant cells in the skeletal muscles and myocardium. Immunohistochemical and ultrastructural studies revealed that there were two types of giant cells: histiocytic and myocytic in origin. Furthermore, both types of giant cells were immunopositive for proteins implicated in the late endosome and lysosome-protease systems, suggesting that endocytosis may be the key mechanism in the formation of giant cells. The present case, together with a few similar cases reported previously, may represent a particular subset of polymyositis, that is, giant cell polymyositis and myocarditis associated with myasthenia gravis and thymoma.

Combined immunosuppression for the treatment of idiopathic giant cell myocarditis

Giant cell myocarditis (GCM) is a rare and frequently fatal disorder with no proven treatment. Case reports and data from a rat model of GCM suggest that immunosuppressive therapy directed against T lymphocytes may have clinical benefit. We describe a 47-year-old man with severe acute heart failure due to GCM in whom the left ventricular ejection fraction normalized and the myocardial inflammatory infiltrate resolved rapidly after treatment with muromonab-CD3, cyclosporine, azathioprine, and corticosteroids. Three previously published cases with less impressive responses to treatment including muromonab-CD3 and a critical review of the published data on immunosuppressive therapy are included in this report. The response to immunosuppressive therapy is highly variable, and direct comparisons between immunosuppressive regimens do not exist. Therefore, despite individual reports of dramatic improvement after immunosuppressive treatment, firm conclusions cannot be made about the benefit of immunosuppression for GCM. The benefits of immunosuppressive therapy must be confirmed in a prospective, randomized trial.

Giant cell myocarditis: monocytic immunophenotype of giant cells in a case associated with ulcerative colitis

Giant cell myocarditis (GCM) is a rare condition whose histologic hallmark, the multinucleate giant cell, is of debated origin (monocytic v myogenic). We report the case of a 46-year-old woman with a previous diagnosis of ulcerative colitis who rapidly deteriorated and died as the result of refractory ventricular tachyarrhythmias. Postmortem examination showed a diffuse infiltration of the myocardium by round cells and multinucleate giant cells. Immunohistochemically, round cells were demonstrated to be T lymphocytes admixed with monocytes. Multinucleate giant cells expressed monocytic markers (MAC 387, lysozyme) and were negative for muscle markers (actin, desmin, myoglobin). This case illustrates the monocytic and macrophagic nature of multinucleate giant cells and lends support to the autoimmune hypothesis of GCM by the concurrence of the latter with ulcerative colitis.

An investigation into the nature of giant cells in cardiac and skeletal muscle

In an immunohistochemical study of six cases of giant cell myocarditis, the typical giant cells have been shown to express up to four different macrophage-associated antigens, but not desmin, the intermediate filament protein characteristic of muscle cells. These results support the view that the giant cells have a macrophage rather than a myogenic origin. In contrast, the giant cells found in regenerating skeletal muscle have the immunophenotype of muscle cells and not of macrophages supporting their muscle origin.

Myocarditis with multinucleated giant cells detected in biopsy specimens

A 42-year-old woman was transferred to our hospital for evaluation of bradycardia with a complete atrioventricular block. Her pulse was 41 regular beats/min with blood pressure 166/92 mmHg. There were no skin lesions, edema, or lymphadenopathy. The white blood cell count was 6300/mm3. The serum glutamic oxaloacetic transaminase was 21 IU and creatine phosphokinase was 34 IU. C-reactive protein was negative. The level of serum angiotensin converting enzyme was slightly increased at 25.8 IU/l/37.0 degrees C (normal range: 7-24.0). Chest radiography showed congestive heart failure with a cardiothoracic ratio of 54%. There was no bilateral lymphadenopathy or fibrous changes during her clinical course. The coronary arteries were completely normal angiographically. Left ventriculograms revealed slight hypokinesis and dilatation (end-diastolic volume index of 112 ml/m2, ejection fraction of 53%). Left ventricular end-diastolic pressure was slightly abnormal at 16 mmHg. Two right and two left ventricular endomyocardial biopsies were performed. Right ventricular biopsy demonstrated edematous tissue and a slight mononuclear cell infiltration with little fibrosis. Left ventricular specimens showed an extensive area of fibrosis, with large, multinucleated giant cells with an asteroid body and chronic inflammation without epithelioid cells. The less affected areas of another specimen showed mild interstitial fibrosis and degenerative myocytes with vacuolation, and some multinucleated myocytes without an asteroid body were present. This case was diagnosed as cardiac sarcoidosis rather than idiopathic giant cell myocarditis. The patient has been implanted with a permanent pacemaker.(ABSTRACT TRUNCATED AT 250 WORDS)

Giant cell myocarditis associated with lymphoma: an immunocytochemical study

A case of giant cell myocarditis in a patient with non-Hodgkin's lymphoma is reported. To our knowledge, this is a previously unrecorded association and supports the hypothesis that the aetiology of giant cell myocarditis is related to a changed immune state. Immunohistochemical investigation of this case with a panel of monoclonal antibodies against a range of leucocyte and muscle antigens supports the view that the giant cells have a histiocytic rather than a myogenic origin.

Giant cell myocarditis in association with drug-induced skin eruption

A case of giant cell myocarditis in a 19-year-old woman is presented. She had high fever, vomiting, epigastralgia, cardiomegaly, and disseminated papular erythema probably due to anti-epileptic agents. At autopsy, giant cell myocarditis and the myositis of the systemic skeletal muscles were found. To our knowledge, no case of giant cell myocarditis in association with drug-induced skin eruption was reported. This is a rare case of giant cell myocarditis.

Acute idiopathic interstitial myocarditis: case report with special reference to morphological characteristics of giant cells

Necropsy findings of an acute fatal case of idiopathic interstitial myocarditis were reported. The patient was a 33 year old housewife who had acute cardiac failure on the sixteenth day after the onset of the disease. Necropsy showed important pathological changes confined to the heart. Both ventricles were affected by confluent granulomas with an ill defined patchy appearance. Histologically these lesions consisted of round cells, histiocytes, eosinophils and myogenic giant cells. The findings were compatible with those of interstitial myocarditis associated with a proliferation of giant cells. Both atriums were also affected to a minor extent, detectable only by histological examination. Electron microscopy and cytochemistry showed that most giant cells noted in the lesion showed myofibrils and primary lysosomes in the cytoplasm. Giant cells were positive for myoglobin. Though the macrophage origin of the giant cell in this disorder has been emphasised in a recent report, these cytological results suggest that giant cells observed in the cardiac granulomatous lesions of this case were mainly myogenic in origin.

Giant-cell myocarditis in a newborn with congenital herpes simplex virus (HSV) infection: an immunohistochemical study on the origin of the giant cells

Giant-cell myocarditis is a rare inflammatory disorder characterized by degeneration and necrosis of myocardial fibers and presence of chronic inflammatory infiltrates associated with multinucleated giant cells forming a granulomatous inflammatory reaction. The etiology of giant-cell myocarditis is unknown. Many conditions have been reported as associated with this phenomenon such as fungi, virus, sarcoidosis, and hypersensitivity or autoimmune reactions. We are reporting a case of giant-cell myocarditis discovered in a newborn with congenital herpetic sepsis. The myogenic origin of the giant-cells of this case is supported by the positivity for desmin and myoglobin and negativity for muramidase and alpha-1-antichymotrypsin after immunoperoxidase procedure. The presence of Herpes simplex virus type II was confirmed by indirect immunoperoxidase reaction in most of the viscera including the heart, but is not considered a factor in the production of giant cells.

Giant cell myocarditis

The present report describes a 45-year-old man with giant cell myocarditis who died of heart failure eight months after the onset of symptoms. On postmortem examination, the heart showed extensive myocardial fibrosis with numerous multinucleated giant cells. The lungs and a series of 20 lymph nodes showed no evidence of granulomatous disease, thereby excluding a diagnosis of sarcoidosis. Circumstantial evidence supports the view that giant cell myocarditis may have an autoimmune origin, and the histopathology suggests that cellular immune mechanisms might have a role in the pathogenesis of this disease. On this basis, it is suggested that cyclosporine, a selective inhibitor of T lymphocyte-mediated immune responses, may be useful for the treatment of this presently fatal disease.