Dense Deposit Disease in Adults: Recognizing and Managing a Rare Glomerulopathy

Introduction: Dense deposit disease (DDD) is a rare C3 glomerulopathy, affecting 2–3 individuals per million. It is characterized by dense glomerular basement membrane deposits and complement dysregulation. DDD commonly presents with nephrotic syndrome and progressive renal impairment, but its nonspecific features often lead to diagnostic delays. Early recognition and targeted evaluation are crucial for optimal management and preservation of renal function. Case Description: A 24-year-old woman presented with a seven-month history of progressive bipedal edema, frothy urine, and intermittent shortness of breath. Laboratory investigations revealed nephrotic-range proteinuria (8.2 g/day), hypoalbuminemia (serum albumin 1.7 g/dL), hypercholesterolemia (320 mg/dL), and normal serum creatinine (0.8 mg/dL). Complement studies showed decreased C3 levels, while C4 was within normal limits. Antinuclear antibody testing was negative. Initial management included Diuretics, ACE inhibitor (Enalapril), and a Statin. Despite partial symptomatic improvement, the patient continued to have significant proteinuria (6.1 g/day) and persistently low C3 (39 mg/dL), prompting a renal biopsy. Histopathological examination demonstrated global glomerulosclerosis in 8 of 19 glomeruli, thickened capillary loops, and dense intramembranous deposits on electron microscopy, confirming a diagnosis of dense deposit disease (DDD). The patient was started on prednisone (1 mg/kg) which resulted to partial reduction in proteinuria and resolution of symptoms. She was advised for regular outpatient follow-up for monitoring and timely adjustments of treatment plan. Discussion: Management of DDD remains challenging, as there are no established disease-specific therapies. Current strategies focus on optimizing supportive care—controlling blood pressure, reducing proteinuria, and addressing complications of nephrotic syndrome. Immunosuppressive agents may be considered in select cases with progressive disease, but robust evidence for their efficacy is lacking. Prognosis is variable, with many patients progressing to chronic kidney disease despite optimal management. This case highlights the importance of early recognition and timely renal biopsy in patients with atypical or refractory nephrotic syndrome. Multidisciplinary care and individualized management remain essential to improve outcomes in this rare and complex glomerulopathy.