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.

Gamma interferon assay as an alternative to PPD skin testing in selected patients with granulomatous intraocular inflammatory disease

BACKGROUND

To evaluate the QuantiFERON-TB test (gamma interferon assay), approved by the Centers for Disease Control and Prevention for the detection of latent tuberculosis (LTB), in patients who potentially may require immunosuppressive therapy for ocular inflammatory disease.

METHODS

Blood samples from 12 consecutive patients with granulomatous ocular inflammatory disease were evaluated first with the purified protein derivative (PPD) skin test and then with the QuantiFERON-TB test (11 of 12 patients, 1 declined). The results of the 2 tests in both U.S.- and non-U.S.-born patients were compared with their Bacillus Calmette-Guérin (BCG) vaccination status and chest x-rays.

RESULTS

In our small series there was a high degree of concordance between the QuantiFERON-TB assay and the PPD skin test.

INTERPRETATION

The QuantiFERON-TB test did not demonstrate intrinsic merit over PPD skin testing for screening for LTB in selected patients when immunosuppressive therapy is considered. The confounding effect of BCG vaccination renders interpretation of both tests difficult. Early reports suggest the second-generation tests that are now available may hold promise for use in the uveitis clinic and should be formally evaluated.