We would like to thank Kubota and colleagues1 for sharing their case that may help explain the link between GO and IOI. In response, we performed histology on IgG4 on available specimens of our cases. Samples were available for case 1 and 4. Only case 4, who had developed unilateral IOI at 22 years of age and GO at 27 years, showed greater than 30% IgG4-positive plasma cells. We did not have the opportunity to determine IgG4 serum levels. Typically, IgG4-related ocular adnexal infiltration presents at a later age and is more often bilateral.1 We agree that T helper cell imbalance may explain the co-occurrence of IOI and GO, but because of negative IgG4 findings in another case, other common pathogenetic causes may also exist.
Bijlsma WR, Kalmann R, Leguit RJ. Ocular Adnexal IgG4-Related Lymphoplasmacytic Infiltrative Disorder and Graves Ophthalmopathy—Reply. Arch Ophthalmol. 2011;129(6):805-820. doi:10.1001/archophthalmol.2011.139