Response to: ‘Is rituximab effective for IgG4-related disease in the long term? Experience of cases treated with rituximab for 4 years’ by Yamamotoet al

Long-Term Outcomes of IgG4-Related Ophthalmic Disease in a Chinese IgG4-Related Disease Cohort

Purpose: To define the treatment response and long-term outcomes of a large IgG4-related ophthalmic disease (IgG4-ROD) cohort.

Methods: A total of 132 patients with a minimum follow-up of 1 year were included in this study. Demographic, clinical, and laboratory data were collected. Treatment response was assessed by the IgG4-RD responder index (IgG4-RD RI). Risk factors for relapse were analyzed with the multivariate Cox regression analysis.

Results: The median follow-up time was 39 months. Lacrimal gland involvement was detected in 87.9% of cases. Extraocular muscles, the trigeminal nerve, and other soft tissue were affected in 25.8, 6.1, and 18.2% of patients. The relapse rate of watchful waiting, glucocorticoid monotherapy, immunosuppressant monotherapy, and combination therapy was 50.0, 51.7, 50.0, and 26.7% (p = 0.038), respectively. The combination therapy group exhibited shorter glucocorticoids therapy duration (36 vs. 48 months, p = 0.009) and maintenance period (24 vs. 42 months, p = 0.003). At the 6th month, the median IgG4-RD RI declined from 12 to 1 and 105 (79.5%) patients achieved complete response (CR). Relapse occurred in 49 (37.1%) patients. The multivariate Cox regression analysis exhibited that CR at the 6th month was an independent protective factor for relapse. Patients with multiple ocular lesions suffered from a higher risk of relapse. No patient had severe adverse reactions to the treatment in this study.

Conclusion: Relapse was common in patients with IgG4-ROD. Patients receiving combination therapy showed a lower relapse rate and a shorter glucocorticoids therapy period. The presence of multiple ocular lesions was associated with a higher risk of relapse. CR at the 6th month might be a predictor for a better prognosis in IgG4-ROD. Thus, a more aggressive regimen should be prescribed for patients with a poor initial response.

Comparative Study of Clinical, Pathological, Radiological, and Genetic Features of Patients With Adult Ocular Adnexal Xanthogranulomatous Disease, Erdheim-Chester Disease, and IgG4-Related Disease of the Orbit/Ocular Adnexa

PURPOSE

To compare and contrast the clinical, radiologic, pathologic, and genetic features of patients with ocular adnexal IgG4-related disease (IgG4-RD) and patients with adult ocular adnexal xanthogranulomatous disease (XG).

METHODS

This retrospective review study identified patients with histological evidence of either disease from records of the pathology department of our hospital from 1996 to 2014. Clinical, imaging, and a variety of histopathologic features were collected for 23 patients with IgG4-RD and 13 patients with XG. Next generation sequencing with a 50-gene cancer screening panel was performed on biopsy tissues from 10 patients in each group.

RESULTS

Statistical differences between the 2 groups include eyelid (67%; p = 0.0002) and anterior orbital (75%; p = 0.0352) predilection for XG except for Erdheim-Chester disease subgroup which was more posterior and diffuse. Eyelid involvement was rare (4%) for IgG4-RD. Involvement of orbital nerves was seen in 30% of IgG4-RD and 0% in XG (p = 0.0695). Five patients with IgG4-RD developed malignancy (4 lymphoma, 1 leiomyosarcoma), but none of XG patients. Discriminating pathological features were the presence of any IgG4+ plasma cells (p = 0.0121) and the ratio of IgG4+/IgG+ plasma cells (p =0.0294) for IgG4-RD. Five of 12 (42%) patients with XG had sufficient numbers of IgG4+ plasma cells/high power field to fulfill published diagnostic criteria for IgG4-RD, and 5 (42%) had a ratio of IgG4+/IgG+ plasma cells over 40%, but the numbers overall were less than seen in the IgG4-RD patients. The only genetic difference between the 2 groups was that BRAF V600E mutation was found in 1 of the 2 Erdheim-Chester disease patients, which form a subgroup of XG.

CONCLUSIONS

IgG4-RD and XG share clinical, imaging, and histopathological features including IgG4+ plasma cells. Significant differences were the eyelid involvement in XG, orbital nerve involvement, and an elevated IgG4+/IgG+ ratio in IgG4-RD and the only genetic abnormality found was BRAF V600E mutation in the Erdheim-Chester disease subgroup of XG.