ABSTRACT
A 69-year-old man presented with acute kidney injury, hypocomplementemia, antinuclear antibody, and anti-dsDNA antibody. He had no signs of systemic lupus erythematosus or Sjögren syndrome. He had not begun taking any new drugs in the preceding 6 months. Kidney biopsy revealed 13 glomeruli, 3 with global sclerosis. The remaining glomeruli showed slight mesangial proliferation. The interstitial inflammation was extensive, comprising mainly mature lymphocytes and plasma cells, neutrophils, and a few eosinophils. Remarkable granular and diffuse deposition of IgG and C1q was observed along the tubular basement membranes. Electron microscopy showed electron-dense deposits in the tubular basement membrane. Immunohistochemistry showed only 1 - 4 IgG4-positive plasma cells per high-power field and an IgG4/CD138 ratio of ~ 10%. He was treated with oral prednisolone 35 mg/day, and his kidney function gradually improved. This is a unique case that is not consistent with any known disease entities with immune complex-mediated tubulointerstitial nephritis.â©.
Subject(s)
Glomerulonephritis, Membranoproliferative , Immune Complex Diseases , Nephritis, Interstitial , Neutrophils/immunology , Aged , Humans , MaleABSTRACT
A 22-year-old woman had been diagnosed with idiopathic thrombocytopenic purpura (ITP) 5 years earlier. After undergoing splenectomy, she relapsed frequently following prednisolone tapering. She was complicated with minimal change nephrotic syndrome (MCNS) while taking 20 mg of prednisolone. Despite treatment with prednisolone, cyclosporin and low-density lipoprotein-apheresis, MCNS and ITP did not improve. We added rituximab in 4 weekly infusions of 375 mg/m2. MCNS and ITP were in complete remission. After administering rituximab once, all medicines were discontinued. No relapse had occurred by 50 months following the first rituximab administration. Rituximab affects steroid-resistant MCNS and ITP for a long time without complications.