IgG4-Related Disease Presenting as or With Isolated Giant Cell Temporal Arteritis
Archives of Pathology and Laboratory Medicine
Immunoglobulin G4 (IgG4)-related diseases are a group of disorders that can afflict multiple organs and have well-defined diagnostic characteristics. Its presentation as giant cell temporal arteritis (GCTA) is largely unrecognized. We report a single case here of an 81-year-old woman with no significant medical history. The patient presented with progressive right-sided vision loss. Concurrent laboratory workup showed elevated C-reactive protein (CRP) 53 mg/L and erythrocyte sedimentation rate (ESR) 42 mm/hr. A 3.2-cm segment of temporal artery was biopsied for pathologic examination. Histologically, severe active arteritis with lymphohistiocytic infiltrates, mural thickening, severe (.90%) luminal stenosis, and giant cells were noted (Figure 4.133, A and B)—typical findings of conventional GCTA. However, the inflammatory infiltrates also included many peripheral plasma cells confirmed by positive MUM1 immunostain, of which .90% were strongly positive for IgG4 by immunohistochemistry (Figure 4.133, C and D). The diagnosis of ‘‘giant cell temporal arteritis with features of IgG4-related disease’’ was rendered. Other types of arteritis including microscopic polyangiitis, Buerger disease, and granulomatosis with polyangiitis were excluded. She received high-dose intravenous methylprednisolone therapy for 3 days and was switched to oral prednisone therapy with taper. The vision in her right eye stabilized on day 4 of treatment and her ESR and CRP returned to normal. She was discharged home with ongoing rheumatologic follow-up. Serum immunoglobulin testing performed shortly after discharge showed decreased IgG-1 and IgG-2 levels with normal IgG-3 and IgG-4, consistent with posttreatment effects. Evaluation of the findings thus far are suggestive of IgG4-related disease presenting as isolated giant cell temporal arteritis.
Mahalingam VD, Zhang PL, Qu Z. IgG4-related disease presenting as or with isolated giant cell temporal arteritis. Archives of Pathology and Laboratory Medicine. 2021 Sept; 145(9):194.