Immunotactoid glomerulopathy: report of a case

We report a 51-year-old man diagnosed as having immunotactoid glomerulopathy (IT) who achieved partial remission after approximately 1 year of a low-dose prednisolone regimen. On admission, he was noted to show proteinuria, hypoproteinemia, and hypocomplementemia. On electron microscopy of the renal biopsy specimen, the mesangial and subendothelial areas were expanded because of the electron-dense deposits, which were represented by mostly straight and nonbranching hollow microtubule structures. The microtubular width was on average 22.0 nm. Clinical and histological findings did not support the diagnosis of amyloidosis, cryoglobulinemic glomerulonephritis, systemic lupus erythematosus, or paraproteinemias. Under treatment with oral prednisolone, 4 months later, the patient's serum albumin level increased from its lowest level of 2.3 to 3.6 g/dL, and CH50 from the lowest level of less than 6.3 to 32.4 U/mL. A 24-hour collection of urine showed that the protein had decreased from its highest level of 3.9 g to 2.0 g. This case suggests the effectiveness of long-term, low-dose prednisolone therapy for IT.