[Clinical and pathological characteristics of children with dense deposit disease].

Objective: To analysis the clinical and pathological characteristics of children with dense deposit disease (DDD).

Methods: 12 Children diagnosed as DDD by electron microscope were enrolled in this study. The clinical and pathological data were analyzed.

Results: Of the 12 cases, 7 were males and 5 females, mean age 9.1 +/- 3.9 (5-13) years at onset, the duration from onset to renal biopsy was 1 month to 5 years and the follow-up period was 1-9 years. All cases had heavy proteinuria >50 mg/(kg x d), and persistent microscopic hematuria with recurrent gross hematuria during the course. Seven cases had hypertension (> or = 140/100 mm Hg, 1 mm Hg =0. 133 kPa), 5 cases had transient or recurrent abnormal renal function, and mild to severe anemia were observed in 8 cases respectively. All the cases had lower serum C3 (0.15-0.55 g/L). Clinically, 10 cases were diagnosed as nephritic syndrome (one case had partial lipodystrophy at the same time), and 2 cases were diagnosed as acute nephritic syndrome. Immunofluorescence study showed intense deposition of C3 along GBM, TBM and the wall of Bowman's capsule in a ribbon-like pattern and in the mesangial regions as coarse granules in all the cases. Under light microscopy, 9 cases showed the feature of membrane proliferative glomerulonephritis (MPGN), 1 case with focal segmental glomerulosclerosis (FSGS), 1 case with endocapillary proliferative glomerulonephritis (EnPGN) and 1 case with proliferative sclerosis (PSGN). Crescents were seen in 3 cases. Under electron microscopy, ribbon-like or linear electron-dense intramembranous deposits were identified in the lamina dense of GBM, and often along TBM and the wall of Bowman's capsule. All patients showed steroid resistance. After methylprednisone treatment, some patients showed transient remission. During the follow- up stage of 1-9 years, 3 cases showed normal urinalysis, 5 cases showed partial remission, 2 cases progressed to end stage renal disease (ESRD) and 2 cases were lost.

Conclusion: DDD is an in dependently rare disease with pathological-clinical varieties. Children with DDD presented with persistently lower C3, heavy proteinuria, recurrent gross hematuria and anemia. The characteristic immunopathologic finding is intense deposition of C3 along the GBM. Under electron microscopy, ribbon-like or linear electron-dense deposits in the lamina dense of the GBM, TBM and the wall of Bowman's capsule. Electron microscopic examination to demonstrate the intramembranous dense deposits is definitive diagnosis, regardless of the finding of light microscopy. All of them showed steroid resistant. Patients with steroid and CTX treatment showed some clinical improvement of their urinalysis.