Factors related to renal cortical atrophy development after glucocorticoid therapy in IgG4-related kidney disease: a retrospective multicenter study

Arthritis Research & Therapy, Nov 2016

Background In immunoglobulin G4-related kidney disease (IgG4-RKD), focal or diffuse renal cortical atrophy is often observed in the clinical course after glucocorticoid therapy. This study aimed to clarify the factors related to renal atrophy after glucocorticoid therapy in IgG4-RKD. Methods We retrospectively evaluated clinical features including laboratory data and computed tomography (CT) findings before and after glucocorticoid therapy in 23 patients diagnosed with IgG4-RKD, all of whom were followed up for more than 24 months. Results Seventeen patients were men, and six were women (average age 62.0 years). Average follow-up period was 54.9 months. The average estimated glomerular filtration rate (eGFR) at diagnosis was 81.7 mL/min/1.73 m 2 . All patients had had multiple low-density lesions on contrast-enhanced CT before glucocorticoid therapy, and showed disappearance or reduction of these lesions after it. Pre-treatment eGFR and serum IgE level in 11 patients in whom renal cortical atrophy developed 24 months after the start of glucocorticoid therapy were significantly different from those in 12 patients in whom no obvious atrophy was found at that time (68.9 ± 30.1 vs 93.5 ± 14.1 mL/min/1.73 m 2 , P = 0.036, and 587 ± 254 vs 284 ± 263 IU/mL, P = 0.008, respectively). Pre-treatment eGFR and serum IgE level were also significant risk factors for renal atrophy development 24 months after the start of therapy with an odds ratio of 0.520 (per 10 mL/min/1.73 m 2 , 95% confidence interval (CI) 0.273–0.993, P = 0.048) and 1.090 (per 10 IU/mL, 95% CI: 1.013–1.174, P = 0.022), respectively, in age-adjusted, sex-adjusted, serum IgG4 level-adjusted logistic regression analysis. Receiver operating characteristic curve analysis showed that eGFR of less than 71.0 mL/min/1.73 m 2 and serum IgE of more than 436.5 IU/mL were the most appropriate cutoffs and yielded sensitivity of 63.6% and specificity of 100%, and sensitivity of 90.9% and specificity of 75.0%, respectively, in predicting renal atrophy development. Conclusions This study suggests that pre-treatment renal insufficiency and serum IgE elevation predict renal atrophy development after glucocorticoid therapy in IgG4-RKD.

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Factors related to renal cortical atrophy development after glucocorticoid therapy in IgG4-related kidney disease: a retrospective multicenter study

Mizushima et al. Arthritis Research & Therapy Factors related to renal cortical atrophy development after glucocorticoid therapy in IgG4-related kidney disease: a retrospective multicenter study Ichiro Mizushima 0 Motohisa Yamamoto Dai Inoue Shinichi Nishi Yoshinori Taniguchi Yoshifumi Ubara Shoko Matsui Tetsuhiko Yasuno Hitoshi Nakashima Hiroki Takahashi Kazunori Yamada 0 Hideki Nomura Masakazu Yamagishi Takao Saito Mitsuhiro Kawano 0 0 Division of Rheumatology, Department of Cardiovascular and Internal Medicine, Kanazawa University Graduate School of Medicine , Takara-machi 13-1, Kanazawa, Ishikawa 920-8640 , Japan Background: In immunoglobulin G4-related kidney disease (IgG4-RKD), focal or diffuse renal cortical atrophy is often observed in the clinical course after glucocorticoid therapy. This study aimed to clarify the factors related to renal atrophy after glucocorticoid therapy in IgG4-RKD. Methods: We retrospectively evaluated clinical features including laboratory data and computed tomography (CT) findings before and after glucocorticoid therapy in 23 patients diagnosed with IgG4-RKD, all of whom were followed up for more than 24 months. Results: Seventeen patients were men, and six were women (average age 62.0 years). Average follow-up period 2 was 54.9 months. The average estimated glomerular filtration rate (eGFR) at diagnosis was 81.7 mL/min/1.73 m . All patients had had multiple low-density lesions on contrast-enhanced CT before glucocorticoid therapy, and showed disappearance or reduction of these lesions after it. Pre-treatment eGFR and serum IgE level in 11 patients in whom renal cortical atrophy developed 24 months after the start of glucocorticoid therapy were significantly different from 2 those in 12 patients in whom no obvious atrophy was found at that time (68.9 ± 30.1 vs 93.5 ± 14.1 mL/min/1.73 m , P = 0.036, and 587 ± 254 vs 284 ± 263 IU/mL, P = 0.008, respectively). Pre-treatment eGFR and serum IgE level were also significant risk factors for renal atrophy development 24 months after the start of therapy with an odds ratio of 0.520 (per 10 mL/min/1.73 m2, 95% confidence interval (CI) 0.273-0.993, P = 0.048) and 1.090 (per 10 IU/mL, 95% CI: 1.013-1.174, P = 0.022), respectively, in age-adjusted, sex-adjusted, serum IgG4 level-adjusted logistic regression analysis. Receiver operating characteristic curve analysis showed that eGFR of less than 71.0 mL/min/1.73 m2 and serum IgE of more than 436.5 IU/mL were the most appropriate cutoffs and yielded sensitivity of 63.6% and specificity of 100%, and sensitivity of 90.9% and specificity of 75.0%, respectively, in predicting renal atrophy development. Conclusions: This study suggests that pre-treatment renal insufficiency and serum IgE elevation predict renal atrophy development after glucocorticoid therapy in IgG4-RKD. IgG4-related disease; IgG4-related kidney disease; Atrophy; Glucocorticoid - Background Immunoglobulin G4 (IgG4)-related disease (IgG4-RD) is a recently recognized systemic fibro-inflammatory disorder that can affect almost all organs in the body [1, 2]. It frequently causes various renal lesions, which are collectively referred to as IgG4-related kidney disease (IgG4-RKD) [3]. Many studies have clarified the clinical, radiographic, and histopathological features of this disease [3–6]. Clinical and histopathological responses to glucocorticoid therapy in IgG4-RKD have been characterized by several recent studies [7–10], and the prognosis of this disease is not always favorable. Although glucocorticoid therapy results in a rapid improvement of renal function and radiologic findings within one month after the start of therapy in most cases of IgG4RKD, recovery of renal function is suboptimal in the patients with moderate to severe renal dysfunction before therapy [8]. Moreover, in the clinical course after glucocorticoid therapy, focal or diffuse renal cortical atrophy is observed in a considerable proportion of treated patients. However, the factors related to such renal atrophy have not been well-clarified. This state of affairs prompted us to undertake the present study to clarify the factors related to renal atrophy after glucocorticoid therapy in IgG4-RKD. Methods Patients and materials Between 1 January 2007 and July 2015, 27 patients with IgG4-RD were enrolled as candidates for this study from seven collaborating institutions in Japan. Among them, we identified 23 patients with IgG4-RKD with typical renal radiological findings, whose follow-up period was more than 24 months, and who had sufficient follow-up data (Table 1). We diagnosed them as having IgG4-RKD based on their fulfillment of the criteria proposed by the Japanese Society of Nephrology [3] and exclusion of other diseases. All patients had IgG4-related involvement of more than one extra-renal organ. Renal biopsy was performed in 11 patients, and biopsy of the affected extra-renal organs including salivary and lacrimal glands in the other 10 patients. (...truncated)


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Ichiro Mizushima, Motohisa Yamamoto, Dai Inoue, Shinichi Nishi, Yoshinori Taniguchi, Yoshifumi Ubara, Shoko Matsui, Tetsuhiko Yasuno, Hitoshi Nakashima, Hiroki Takahashi, Kazunori Yamada, Hideki Nomura, Masakazu Yamagishi, Takao Saito, Mitsuhiro Kawano. Factors related to renal cortical atrophy development after glucocorticoid therapy in IgG4-related kidney disease: a retrospective multicenter study, Arthritis Research & Therapy, 2016, pp. 273, 18, DOI: 10.1186/s13075-016-1175-y