Long-term Prognosis of thin Glomerular Basement Membrane Nephropathy in Children: A Retrospective Single Center Study

PURPOSE: Thin glomerular basement membrane nephropathy (TBMN) is, along with the IgA nephropathy, the most common cause of asymptomatic hematuria in Korean children. TBMN is usually a benign renal disease not requiring treatment and is associated with a good prognosis, but some cases hematuria is indicative of a state of progressive renal insufficiency. We aimed to retrospectively evaluate clinical manifestations and renal prognosis of patients with TBMN. METHODS: Among the 428 renal biopsies performed on children at Yeungnam University Hospital between January 2000 and February 2017, 167 patients were diagnosed as having TBMN. We retrospectively investigated 167 pediatric patients and identified 59 children with follow-up duration >3 years. RESULTS: Among 59 patients, there were 33 boys and 26 girls. Mean age of onset of hematuria was 7.18±2.64 years, and mean time from onset of disease until a renal biopsy was performed was 2.48±2.10 years. There were no clinical features or laboratory findings among studied children to indicate decreased renal function during follow-up; however, one case progressed to chronic kidney disease (CKD) due to an unknown cause. There were seven patients among these related a positive family history of hematuria or renal insufficiency. CONCLUSION: Although almost all patients had normal renal functions during follow-up, there were one patient who progressed to CKD and seven patients with family history of hematuria or renal insufficiency. Moreover, four among the 428 patients over 17 years underwent repeat renal biopsies, which showed results different from their earlier biopsies.Thus, large-scales studies may be required to determine long-term prognosis of TBMN in children, and further evaluation for Alport syndrome in TBMN cases is essential.

Long-term Prognosis of thin Glomerular Basement Membrane Nephropathy in Children: A Retrospective Single Center Study

PURPOSE: Thin glomerular basement membrane nephropathy (TBMN) is, along with the IgA nephropathy, the most common cause of asymptomatic hematuria in Korean children. TBMN is usually a benign renal disease not requiring treatment and is associated with a good prognosis, but some cases hematuria is indicative of a state of progressive renal insufficiency. We aimed to retrospectively evaluate clinical manifestations and renal prognosis of patients with TBMN. METHODS: Among the 428 renal biopsies performed on children at Yeungnam University Hospital between January 2000 and February 2017, 167 patients were diagnosed as having TBMN. We retrospectively investigated 167 pediatric patients and identified 59 children with follow-up duration >3 years. RESULTS: Among 59 patients, there were 33 boys and 26 girls. Mean age of onset of hematuria was 7.18±2.64 years, and mean time from onset of disease until a renal biopsy was performed was 2.48±2.10 years. There were no clinical features or laboratory findings among studied children to indicate decreased renal function during follow-up; however, one case progressed to chronic kidney disease (CKD) due to an unknown cause. There were seven patients among these related a positive family history of hematuria or renal insufficiency. CONCLUSION: Although almost all patients had normal renal functions during follow-up, there were one patient who progressed to CKD and seven patients with family history of hematuria or renal insufficiency. Moreover, four among the 428 patients over 17 years underwent repeat renal biopsies, which showed results different from their earlier biopsies.Thus, large-scales studies may be required to determine long-term prognosis of TBMN in children, and further evaluation for Alport syndrome in TBMN cases is essential.

Asymptomatic Primary Hematuria in Children

PURPOSE: Present study has been undertaken to determine the distribution of various renal diseases causing asymptomatic hematuria in children and to evaluate the benefit of doing renal biopsy in these children. METHODS: Study population consisted of 146 children with asymptomatic primary hematuria who had been admitted to the pediatric department of Kyungpook National University Hospital for the past 4 years from 1999 to 2002. In 122 out of 146 cases, renal biopsy was performed percutaneously and in 24 out of 146 cases, diagnosed as idiopathic hypercalciuria, oral calcium loading test was performed. RESULTS: The age(mean+/-SD) at onset or discovery of hematuria of the 146 children included in this study was 8.0+/-3.2 years and the proportion of boys and girls was 54.8% and 45.2%, respectively. In 76 out of 146 cases(52%), asymptomatic hematuria was first diagnosed by school urinalysis screening. The proportion of histopathologic findings based on 122 biopsies was as follows : Thin Glomerular Basement Membrane(TGBM) 73 cases(50%); IgA nephropathy 20 cases(14%); Alport syndrome 6 cases(4%); Membranous Glomerulonephropathy(MGN) 4 cases(3%); Membranoproliferative Glomerulonephritis(MPGN) 2 cases(1%); IgA nephropathy with TGBM 3 cases(2%); "normal" glomeruli 14 cases(10%). Twenty four cases (16%) were diagnosed as idiopathic hypercalciuria. During follow-up periods, 15% of 146 cases became hematuria-free and renal function did not deteriorate in any cases. CONCLUSION: Unless hematuric children manifest poor prognostic indicators for renal survival, we would recommend long term regular follow-up prior to a renal biopsy.