case_images: PMC10465303_01
case_images: (A) First kidney biopsy. PAS staining of the cortex shows normal to mild mesangial hypercellularity with normal tubules and interstitium (100x). (B) First kidney biopsy. Immunohistochemistry for IgA reveals intense granular staining, predominantly mesangial (200x). (C) Second kidney biopsy. Glomerulus with fibrinoid necrosis and karyorrhexis. HE staining (400x). (D) Second kidney biopsy. Glomerulus with a cellular crescent. HE staining (600x). (E) Second kidney biopsy. Immunohistochemistry reveals a significant reduction of IgA reactivity in glomeruli (200x).
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case_images: T0, C0 ( Figures 1A, B ). Such a possible negativation of proliferative lesions could have been a result of commenced immunosuppressive treatment. Therefore, MTPD pulses 4x250 mg with conversion to prednisone 40 mg/day and methotrexate (MTX) 7.5 mg were introduced. A low intensity of chronic inflammation (TIN Grade 0/1) in the interstitium with mild fibrosis was observed (2-3% of the available renal cortex) ( Figures 1C, D ). An immunohistochemistry examination of the kidney specimen did not show IgA deposition ( Figure 1E ).
case_images: (A) Line graph showing the patient's cANCA (PR3-ANCA) levels and proteinuria throughout therapy. The two exacerbations are marked with red lines (6 January 2019 and 30 June 2021), consistent with cANCA and proteinuria level elevation. PD, prednisone; MTX, methotrexate; AZT, azathioprine; CYC, cyclophosphamide; MTPD, methylprednisolone. (B) Line graph representing the patient's CRP level and eGFR ratio changes.
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case_images: Although laboratory tests and the patient's clinical state were well controlled, a gradual increase in PR3-ANCA antibodies was noted ( Figure 2A ). CRP levels were within normal limits ( Figure 2B ). In subsequent monthly follow-up visits, the patient received 800 mg of CYC (a total dose of 5000 mg; 62.5 mg/kg) ( Figure 2A ).