Abstract
Purpose:
Blau's syndrome (BS) is an inherited multisystem auto-inflammatory granulomatous inflammation due to mutations in the CARD15/NOD2 gene located on chromosome 16q. 3 sites of clinical involvement include the eyes, skin and joints. While the eyes are the most important affected tissues, to date, no examples of the ocular pathology of this condition exist. We report the first ocular histopathologic and immunopathologic findings from an enucleated BS eye as well as from an iridectomy specimen.
Methods:
A 14 year old patient with BS had a blind painful eye that underwent enucleation. Patient 2 underwent incidental iridectomy at the time of cataract surgery at age 16. The clinical medical and ophthalmic histories of both cases were reviewed. The eye underwent standard pathologic processing and the sections stained for H&E PAS. Granulomas were seen and special stains for microorganisms and polarization were performed. Immunopathologic analysis of inflammatory cells was done for CD 3,10, 20, 68, 79, and to identify CD4 and CD8+ cells. The iris specimen had no granulomas and was probed for CD4,CD8, CD68, HLA-DR, NF-kB and IL-17.
Results:
Both patients had CARD15/NOD2 mutations. Pt 1 had a more severe history with greater involvement, had greater visual loss and required more surgeries. Pt 2 had maintained almost normal vision in one eye. The eye which had shown anterior uveitis, chorioretinitis and band keratopathy showed multiple isolated diffusely distributed epithelioid granulomas which involved the iris, ciliary body, retina, choroid and sclera. All special stains for microrganisms were negative. Immunopathology showed the granulomas composed of CD68 + cells. Lymphocytes expressing CD3,CD8,CD4 were seen. CD20 was negative. The iris tissue did not contain any granulomas but showed lymphocytes expressing CD4,CD8, IL-17 and NF-kB.
Conclusions:
Blau's syndrome is an example of genetically induced auto-inflammatory disease whose ocular involvement can be devastating. In the first whole BS eye to be evaluated, there was excellent correlation between the clinical, pathologic and immunopathologic findings. Granuloma distribution was sporadic. This represents the true picture of treated BS. Pt 2's iris showed findings that may represent tissue between granulomas or might reflect the lesser degree of severity in Pt 2. The combined findings suggest that biopsy of BS patients should include specifically targeted tissue.
Keywords: 432 autoimmune disease •
639 pathology techniques •
555 immunomodulation/immunoregulation