Immunotactoid glomerulonephritis (ITG) may cause slowly progressing renal failure. Here we present a case of acute renal failure in a patient with ITG that completely recovered after steroids.
A 79-year-old woman was admitted to our department for anuria. She had been followed by urologists for incontinence. No previous serum creatinine was documented and urinary sediment was repeatedly normal. Five days before admission she underwent cystoscopy. The following day she had 39°C fever and vomited and had diarrhoea.
The physical exam was normal except for hyperhydration. Initial investigations showed serum creatinine 772 µmol/l, urea 25.8 mmol/l, normal blood cell count, ESR 35 mm/hod, C-reactive protein 1 mg/l. Blood, sputum, urine and faeces cultures produced no growth. Renal biopsy showed diffuse endocapillary proliferative glomerulonephritis, with focal segmental granular positivity for IgG, C3, C1q and lambda chain in the mesangium and periphery. Serum immunoglobulins were normal, complement low both in C3 (0.24 g/l) and C4 (0.06 g/l); autoantibodies, cryoglobulins, antistreptolysin and hepatitis markers were all negative. We have performed colonoscopy, gastroscopy, gynaecologic examination and mammography to exclude paraneoplastic aetiology of the glomerulopathy; all were normal. Serum immunoelectrophoresis revealed biclonal gammapathy IgG lambda (12 g/l). Sternal puncture, X-rays of the bones and CT scans ruled out haematologic malignancy. The ultrastructure of glomerulus showed numerous deposits of microtubules arranged in parallel arrays in mesangial, subendothelial and subepithelial locations. The morphological picture was compatible with that of ITG. After 10 days of continuous corticotherapy she was switched to pulse i.v. dexamethasone. Four days later (after 3 weeks of complete anuria) diuresis started to resume. Urinalysis revealed proteinuria (4.12 g/24 h), lambda light chains (2.41 g/l) and microhaematuria. Subsequently, complement normalized and urinalysis became negative. Creatinine dropped to 106 µmol/l and no paraprotein was detectable in neither serum nor urine. In conclusion, this report describes one of the oldest patients with ITG. ITG has been associated with haematologic malignancies, hepatitis C, cryoglobulinaemia or autoimmune disease [13]. All these were excluded. The presentation by acute renal failure with an improvement of renal fuction after therapy has not been reported previously. Patients with ITG usually present with proteinuria, microhaematuria, hypertension and renal insufficiency, that may gradually progress to end-stage renal disease [3,5]. In this case the illness started with dehydration. However, there were no features of acute tubular necrosis in the biopsy, and we assume that initial dehydration was a cause of accelerated fibrillogenesis. Successful treatment with steroid pulse therapy has been reported previously [4,6]. Our patient showed a dramatic response to pulse steroids, although a lower continuous dose was ineffective. At present, 13 months after the diagnosis, the patient is still in complete remission.
Conflict of interest statement. None declared.
Nephrology Department First Medical Faculty Charles University U nemocnice 2 Praha 2 Czech Republic Email: zrihova{at}centrum.cz
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