Response to comments on: Maleszewski JJ et al. IgG4-related disease of the aortic valve: a report of two cases and review of the literature. Cardiovasc Pathol 2015;24(1)56-9.
We thank Drs. Steiner and Laco for their interest in our report of IgG4-related disease (IgG4-RD) of the aortic valve [1]. Indeed, involvement of the aortic valve by this rare disease is likely to be an unusual circumstance. This is evidenced by the fact that none of their 178 aortic valve cases had features of IgG4-RD despite a staining protocol that would have been certain to uncover it [2]. At the Mayo Clinic, resected stenotic aortic valves are not routinely evaluated histologically, unless there are vegetations or unusual gross features. At The Johns Hopkins Hospital, all valves are examined by histology, but these cases are typically evaluated by general surgical pathologists who may have been unlikely to further evaluate cases with dense inflammation. Thus, the true incidence of valvular IgG4-RD and the role that it plays in valve dysfunction are in need of further study.