Graves' orbitopathy, idiopathic orbital inflammatory pseudotumor and Epstein-Barr virus infection: a serological and molecular study

OBJECTIVE

One of the hypotheses on the pathogenesis of autoimmune diseases, including Graves' disease (GD) and Graves' orbitopathy (GO), involves bacterial or viral infections. Recently, Epstein-Barr virus (EBV) has been proposed to play a role in the pathogenesis of idiopathic orbital inflammatory pseudotumor (IOIP) in Asians. The aim of the present study was to investigate the possible association of GO with EBV infection/exposure, as compared with IOIP, using serum and tissue samples, as well as primary cultures of orbital fibroblasts.

METHODS

Thirty-one patients were studied, including four with IOIP, ten with GO, nine with GD without GO and eight control patients without IOIP, GD and GO. All patients with IOIP and GO underwent orbital decompression. Control patients underwent palpebral surgery. Fibroadipose orbital tissue samples were collected. Serum anti-EBV antibodies were measured in all patients. EBV-DNA was measured in blood samples, orbital tissue samples and primary cultures of orbital fibroblasts.

RESULTS

Serum assays showed that the vast majority of patients have had a previous exposure to EBV, but no one had an acute infection. EBV-DNA was detected in ~40% of blood samples from GO, GD and control patients, but in none of the IOIP samples. EBV-DNA was not detected in any of the orbital tissue samples tested or in primary cultures of orbital fibroblasts.

CONCLUSIONS

EBV infection does not seem to be associated with GD, GO and IOIP in Caucasians. Whether EBV is involved in IOIP in Asians or other populations remains to be confirmed.

Quantification of Epstein-Barr virus DNA in patients with idiopathic orbital inflammatory pseudotumor

Inflammatory pseudotumors (IPT) are soft tissue tumors that include a diverse group of lesions characterized by inflammatory cell infiltration and variable fibrotic responses. Idiopathic orbital inflammatory pseudotumors (IOIP) are IPTs of unknown etiology that develop in the orbit. Due to the lack of well-defined pathogenic mechanisms, diagnosis and treatment of this disease remain a significant challenge. Epstein-Barr virus (EBV) infection, which causes significant lymphocyte infiltration, has been proposed to be involved in IOIP. This study tries to validate the relationship between EBV infection and the development of IOIP. Sixteen IOIP tissue samples were obtained from patients during surgical resection of the lesion. One Graves' ophthalmopathy tissue sample and 20 normal donors' plasma serves as controls. The plasma level of five EBV antibodies, including VCA-IgG, VCA-IgA, VCA-IgM, EA-IgG and EBNA1-IgG were examined. All plasma samples were EB-VCA-IgG positive and EB-VCA-IgM negative, suggesting that all people tested had been infected with EBV but not in the acute infection stage. EBV-DNA was detected in 15/16 (94%) of IOIP tissue samples despite different levels of lymphocyte infiltration and 5/16 plasma samples (31%) were detected EBV DNA positive which is higher than the normal controls (10%). Percent of positive plus suspected positive samples with one or more of the three important risk markers (VCA-IgA, EA-IgG, EBV-DNA) is 50% of the patients (8/16) which is much higher compare with the normal controls (20%). The results further reveal the relationship between IOIP and EBV infection.

Orbital myositis involving the oblique muscles associated with herpes zoster ophthalmicus

An 81-year-old woman with right orbital inflammation and acute retinal necrosis following Herpes zoster ophthalmicus was evaluated and treated. CT showed right massive superior and inferior oblique enlargement and moderate enlargement of the remaining extraocular muscles with tendon sparing. The myositis and acute retinal necrosis dramatically improved following prednisone and intravenous acyclovir therapy.

Acute orbital myositis. Case report

The case of 22-year old, white woman with bilateral orbital myositis following an acute upper respiratory tract infection is reported. The most important clinical findings were ocular pain, proptosis, restricted eye motility and swelling of the eyelids. The enlarged eye muscles were seen on orbital computerized tomography scan. The clinical findings of inflammatory orbital myositis and clinical response to corticotherapy are emphasized.