case_images: PMC11754060_01
case_images: Chest computed tomography images on admission (A, B) and half a year after therapy (C, D), showing that diffuse miliary changes in both lungs (green arrows in A, C) were almost absorbed and the polymorphic lesions in the upper lobe of the right lung were controlled (red arrows in B, D). Axial and coronal images of a renal magnetic resonance imaging (MRI) scan showing the enlargement of the two kidneys on admission (E, F, red arrow).
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case_images: Chest and abdominal computed tomography (CT) scans showed diffuse miliary lesions in both lungs ( Figure 1A , green arrow), old lesions in the upper lobe of the right lung that may have been due to TB ( Figure 1B , red arrow), mediastinal lymph node calcification, and enlargement of both kidneys. A renal magnetic resonance imaging (MRI) scan also showed enlargement of the two kidneys ( Figures 1E, F , red arrow). Moxifloxacin and linezolid were stopped because both chest CT ( Figures 1C, D ) and an ultrasound of the lymph nodes (the size of the biggest ones was reduced to 31*7mm on the right and 40*9mm on the left) showed partial foci absorption of the TB.
case_images: Renal biopsy: a histological section of the kidney parenchyma was consistent with the diagnosis of acute interstitial nephritis. (A) Hematoxylin and eosin staining (x200) showed normal glomeruli (blue arrow) and tubulointerstitial lymphoplasmacytic infiltration (yellow arrow); (B) Periodic acid-Schiff staining (x200) showed dilated lumen in some renal tubules, the disappearance of brush edges (red arrow), and interstitial edema (blue arrow); (C) Masson trichrome staining (x200) showed a small number of proteins and granular tubular types (red arrow). Immunohistochemical staining (x200): (D) CD38 staining was diffusely positive for CD38-positive plasma cells; (E, F) IgG and IgG4 staining showed >10 IgG4-positive plasma cells per high powered field and the ratio of IgG4/IgG plasma cells was >40%, consistent with a diagnosis of IgG4-related kidney disease.
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case_images: Finally, a renal biopsy suggested acute tubulointerstitial nephritis ( Figures 2A-C ) with a large number of infiltrated plasma cells and multifocal interstitial infiltration of CD38-, IgG-, and IgG4-positive cells, with an IgG4-positive plasma cell level >10/HP, and the ratio of IgG4/IgG plasma cells was >40% ( Figures 2D-F ).
case_images: Laboratory findings. Serum levels of serum creatinine (sCR) (A), globulin (B), Immunoglobulin G (IgG), and Immunoglobulin G4 (IgG4) (C) of the patient during the follow-up.
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case_images: Figures 3A-C ); urine PCR: 624.1mg/g, ACR:28.8mg/g]. FLCs were decreased to 154.35mg/L in the serum and 362.32mg/L in the urine for kappa light chains and 39.68mg/L in the serum and 948.06mg/L in the urine for the lambda light chains.