Fractional Excretion Magnesium (FE Mg) in Systemic Lupus Erythematosus
Tawatchai Deekajorndech, MD*
Affiliation : * Department of Pediatrics, King Chulalongkorn Memorial Hospital
Background : Tubulointerstitial fibrosis is an index of clinical severity. FE Mg has been delineated to correlate
directly with the magnitude of tubulointerstitial fibrosis in clinical setting of glomerulonephropathy.
A correlation between FE Mg tubulointerstitial fibrosis has never been assessed in nephritis associated
with systemic lupus erythematosus.
Materials and Methods : Thirty-six patients diagnosed of having lupus nephritis were included for the determi-
nation of renal functions namely creatinine clearance, FE Mg, urinary protein. Of these 36 patients, 18
patients were associated with intact tubulointerstitial structure (group I) and 18 age matched patients were
associated with tubulointerstitial fibrosis (group II)
Results : The mean FE Mg observed in group I was 1.5 + 0.3 which differed significantly from that observed
in group II; 2.6 + 1; p = 0.006. CCr, total urinary protein, systolic and diastolic pressure were not signifi-
cantly different between the two groups.
Conclusion : FE Mg is a sensitive marker for the detection of tubulointerstitial disease in lupus nephritis. It
is useful in early screening of disease severity in systemic lupus erythematosus.
Keywords : Lupus nephritis, FE Mg, Tubulointerstitial fibrosis, Tubular function, Clinical severity
