Relationship between Albuminuria and Total Proteinuria in Systemic Lupus Erythematosus Nephritis

Abstract

Background and objectives: Albuminuria is regarded a sensitive measure of progression of glomerular disease. This study was undertaken in patients who had systemic lupus erythematosus glomerulonephritis (n ‫؍‬ 57) and were followed in the Ohio SLE Study to determine whether measuring albuminuria offered clinical advantages over that of total proteinuria. Design, setting, participants, & measurements: Twenty-four-hour urine collections (n ‫؍‬ 127) were obtained at baseline and annually for measurement of microalbumin, total protein, and creatinine.Results: There was a strong linear relationship between microalbumin-creatinine and protein-creatinine ratios over the entire range of protein-creatinine ratios; however, in the protein-creatinine ratio range 0.0 to 0.3, as the protein-creatinine ratio increased, the microalbumin-protein ratio increased much more than the protein-creatinine ratio. Also, the greater the protein-creatinine ratio, the greater was the evidence for nonselective proteinuria (protein-creatinine ratio ؊ microalbumincreatinine ratio).Conclusions: For the diagnosis of proteinuria renal flare, measuring albuminuria offers no advantage over measuring total proteinuria because changes in protein-creatinine and microalbumin-creatinine ratios are highly correlated over the designated ranges for systemic lupus erythematosus glomerulonephritis proteinuric flares. In those with normal-range proteinuria, subsequent changes in microalbumin-protein ratio might be a better forecaster of renal flare than changes in proteincreatinine or microalbumin-creatinine ratio. High protein-creatinine ratios are associated with evidence of nonselective proteinuria, which may increase the nephrotoxicity of proteinuria. Thus, using high-threshold criteria for systemic lupus erythematosus flare (allowing greater proteinuria increase before flare is declared) may expose the kidney to greater nephrotoxicity than using the low-threshold criteria for systemic lupus erythematosus flare.

Renal impairment caused by chronic occupational chromate exposure

“…Studies have shown a signiWcant correlation between the depth of GFR decline and the amount of albumin in urine (Mojiminiyi et al 2000). The prime example of using albuminuria to monitor progression of early glomerular injury is in diabetic glomerulosclerosis (Birmingham et al 2008). The urinary microalbumin excretion was also used as a functional predictor of the glomerular Table 4 The correlation between Cr-exposed level and renal injury biomarkers in Cr exposed workers and control (Awad et al 2003).…”

Random Spot Urine Protein/Creatinine Ratio Is Unreliable for Estimating 24-Hour Proteinuria in Individual Systemic Lupus Erythematosus Nephritis Patients

“…There have been numerous reports on the use of random spot urine P/C ratio to estimate 24-hour proteinuria in non-SLE CKD [5, 6]. However, it cannot be assumed that the results of proteinuria testing in non-SLE CKD will be the same as that of SLE GN [22]. Relevant differences include that SLE GN patients are overwhelmingly female, and generally smaller than non-SLE CKD.…”

“…This results in lower urine creatinine excretion rates in the SLE cohorts. In addition, SLE GN patients are more likely to manifest inflammation, which lowers serum albumin by increasing catabolism [22]. Also, data from SLE mouse models suggest that the renal tubular catabolism of filtered proteins is less than that of non-SLE models of kidney disease [22].…”

Renal arterial resistive index in Egyptian patients with lupus nephritis: Correlation with disease activity and biopsy parameters

“…The mean value of uACR was statistically significant higher in group I than group II and III. The use of uACR was also used by Birmingham et al (2008) were it was found that it is a better forecaster for proteinuric renal flare allowing early declaration of renal flare especially in 2.16 ± 1.522 4.4000 ± 2.607 0.014* RRI = renal resistive index; MBP = Mean blood pressure; eGFR = estimated glomerular filtration rate; ESR = Erythrocyte sedimentation rate; CRP = C-reactive protein; Serum C3 = Serum complement 3; Serum C4 = Serum complement 4; SLICCRAS = Systemic lupus international collaborating clinics renal activity score; SLEDAI = Systemic lupus erythematosus disease activity index.…”