SUN-460 RECURRENT ACUTE KIDNEY INJURY AND GROSS HEMATURIA IN A CHILD WITH DENSE DEPOSIT DISEASE (DDD) AND PRESERVED KIDNEY FUNCTIONS ON LONG TERM FOLLOW-UP

Abstract

Glomerulonephritis (GN) in children are in most cases post infectious GN (PIGN), characterized by complement activation with reduction of serum C3 levels that usually normalizes within four to eight weeks. When serum C3 levels are persistently low, other GN needs to be ruled out such as membranoproliferative GN (MPGN). Cases with MPGN and reduction of C3 levels in the absence of Ig on biopsy are now classified as “C3 GN” a member of “C3 glomerulopathies” (C3Gs); this also includes dense deposit disease (DDD). DDD is a rare disorder that most commonly affects children. The rarity of DDD, which afflicts 2 - 3 only two to three individuals per million populations, has impeded studies into its clinical course and optimal treatment. Its natural history is variable, but approximately 50% of patients progress to ESRD within 8 to 10 year. Case Report A previously healthy 11-year-old child was admitted at age of 8 years with history of fever, vomiting and red color urine since 4 days before admission. He had history of Upper Respiratory Tract Infection (URTI) 2 weeks before presentation without any history of skin rash or bleeding tendency or trauma or any drug ingestion. Family history was negative for any renal disease or bleeding tendency. At the presentation, he had oliguria, mild generalized body edema with acceptable blood pressure readings. Urinalysis showed proteinuria (2+) and dysmorphic erythrocytes in the urinary sediment. Laboratory tests showed picture of acute kidney injury(AKI) serum creatinine was 463 umol/l, hypocomplementemia C3 (0.51 mg/dL; normal rang value 0.9-1.8 g/l), high C-reactive protein (113 mg/l ; normal range <3 mg/l), High microalbuminuria (1088.4 mg/l ;, normal range 4-25 mg/l) & Microalbumine/creatinine ratio of 194 mg/mmol( N.R:0-2.5 mg/mmol) with low serum albumin of 29 g/l. The other immunological workup was normal. The initial diagnosis was acute post-streptococcal GN. Three days later, his urine output was improving with trending down of renal profile on conservative management till normalization on follow up. However, due to persistent hypocomplementemia C3 (0.6 mg/dl) after twelve weeks of onset. His Complement analysis revealed alternate pathway activation, persistent low levels of C3, low CH50 but normal levels of C5b-C9 and negative C3 nephritic factor (C3Nef) auto-antibodies. To exclude secondary G.N, a renal biopsy was performed and the result was consistent with C3glomuralopathy-DDD. Subsequently, genetic evaluation was performed for complement genes which were negative. On follow up, he was doing well with persistent microscopic hematuria and low C3. Then, he developed another episode of AKI with gross hematuria which was 2 years from the first presentation and resolved spontaneously. We repeated renal biopsy to determine disease activity and exclude other causes of GN. Again, the biopsy result was consistent with DDD. During his long term follow-up (over 36 months), he was doing well with persistent low C3, microscopic hematuria and non-significant proteinuria (24hr urine for protein was 0.1g/l) with preserved renal functions (creatinine 59 0-60 umol/l).View Large Image Figure ViewerDownload Hi-res image Download (PPT)View Large Image Figure ViewerDownload Hi-res image Download (PPT) We report a unique case of DDD in a child with preserved renal functions who had persistent microscopic hematuria and with hypocomplementemia (C3) on long term follow-up.