Relationship between Fractional Excretion of Magnesium and Renal Histology in Glomerulonephritis

Progressive pediatric glomerularnephroses can lead to tubulointerstitial fibrosis (TIF) and chronic kidney disease (CKD). Fractional excretion of magnesium (FEMg) is a sensitive tubular function test (Ref). FEMg correlates positively with TIF (Ref). The purpose of the study was to correlate FEMg with renal histolopathology in pediatric glomerular nephrosis (GN). Sixty three cases, between 1-12 years, of biopsy diagnosed GN were included purposively in this cross sectional study from November 2008 to April 2010. Cases were taken from Department of Paediatric Nephrology, Dhaka Shishu (Children) Hospital and Department of Paediatric Nephrology, National Institute of Kidney Diseases & Urology, Sher-e-Bangla Nagar, Dhaka, Bangladesh. Minimal change disease (MCD) was most common at 27% and remaining 73% were other than MCD. The mean FEMg in MCD was normal (1.81 0.34%) but in other than MCD as a group it was significantly elevated (7.60 ± 19.23%; p<0.001). and significantly elevated separately in diffuse mesangial proliferative glomerulonephritis (3.96 ± 1.06%; p<0.001), focal segmental glomerulosclerosis (9.99± 4.45%; p<0.01), focal segmental proliferative glomerulonephritis (4.63 ± 2.29%; p<0.05) and crescentic glomerulonephritis (17.74 4.93%; p<0.01).