Dense deposit disease: a 29-years electron microscopy experience.

INTRODUCTION: Dense Deposit Disease (DDD) is a devastating renal disease that leads to renal failure within 10 years of diagnosis in about half of affected patients. In this study, we evaluated the relative prevalence and pathological features of DDD diagnosed at our center over a 29 years period. METHODS: We reviewed the clinical and pathological features of all cases of DDD diagnosed at the Electron Microscopy Unit of Ain Shams University (ASUSH) between January 1983 and December 2011. RESULTS: From a total of 3283 renal biopsies, 33 (1%) were diagnosed with DDD (10 children and 23 adults). Nephrotic syndrome was the predominant clinical presentation of DDD (51.5%), and was commoner in children than adults (80% vs. 43%, p=0.03). Capillary wall thickening was seen in all cases (100%). Crescents were more commonly seen in children than adults (70% vs. 21.7%, p=0.008) while interstitial fibrosis was more commonly seen in adults (78.3% vs. 40%, p=0.03). The commonest histological pattern seen under light microscopy was membranoproliferative (27.3%), followed by crescentic (21.2%), membranous (21.2%), diffuse proliferative (18.2%), lobular (6.1%) and mesangial proliferative (6.1%) patterns. Immunohistochemistry was available for 25 cases and showed intense linear staining for C3 along capillary walls. Electron microscopic examination revealed glomerular basement membrane (GBM) thickening and intra-membranous and tubular basement membrane deposits in all cases (100%). CONCLUSION: DDD is a rare disease in Egypt, found in only 1% of renal biopsies. Pathological features of the disease differ between adults and children; children have predominantly glomerular damage whereas tubuleinterstitial lesions are more often encountered in adults.