From the Guidelines
The most likely cause of proteinuria, hematuria, and leukocytes in urine with normal renal function and no UTI is a glomerular disease, such as glomerulonephritis.
Possible Causes
- Glomerulonephritis is a common cause of hematuria and proteinuria, and can be associated with leukocytes in the urine 1.
- Other possible causes include interstitial nephritis, which can be caused by certain medications or infections, and can also present with hematuria, proteinuria, and leukocytes in the urine.
- The presence of proteinuria, hematuria, and leukocytes in the urine suggests a renal parenchymal disease, such as glomerulonephritis or interstitial nephritis, rather than a urologic cause such as a urinary tract infection or kidney stones 1.
Evaluation
- A thorough evaluation of the urine, including a urinalysis and urine culture, is necessary to determine the cause of the proteinuria, hematuria, and leukocytes 1.
- Imaging studies, such as ultrasound, may be necessary to evaluate the kidneys and urinary tract, but are not always indicated in patients with isolated microscopic hematuria without proteinuria or dysmorphic red blood cells 1.
- A renal biopsy may be necessary to diagnose certain causes of glomerular disease, such as glomerulonephritis or Alport syndrome 1.
Key Points
- The presence of proteinuria, hematuria, and leukocytes in the urine with normal renal function and no UTI suggests a renal parenchymal disease.
- A thorough evaluation of the urine and imaging studies may be necessary to determine the cause.
- A renal biopsy may be necessary to diagnose certain causes of glomerular disease.
- Patients with microscopic hematuria, a negative initial urologic evaluation and no evidence of glomerular bleeding are considered to have isolated hematuria, and the role of renal biopsy in this setting has not been defined 1.
From the Research
Causes of Proteinuria, Hematuria, and Leukocytes in Urine
- Proteinuria, hematuria, and leukocytes in urine with normal renal function and no UTI can be caused by various factors, including glomerulonephritis, which is a group of diseases that injure the part of the kidney that filters blood 2
- IgA nephropathy is the most common cause of primary glomerulonephritis and can present with isolated hematuria, little or no proteinuria, and normal renal function, usually having a low risk of progression 3
- Other causes of asymptomatic proteinuria include idiopathic asymptomatic proteinuria, which has a generally favorable outlook, but microscopic hematuria may raise some questions about prognosis 4
Diagnostic Evaluation
- A clinical and laboratory search for systemic disease, repeated urinalyses, quantitative measurements of proteinuria, determination of creatinine clearance, protein electrophoresis, and intravenous pyelography are necessary for an accurate diagnostic work-up 4
- Leukocyturia in the absence of significant bacteriuria mandates a further diagnostic evaluation, including appropriate urine sampling, rapid examination of the samples obtained, and standardized examination conditions 5
- Renal biopsy may be necessary in some cases, especially if there is a decline in creatinine clearance, an increase in proteinuria, or both 4, 2
Prognosis
- The long-term outcome of patients with minimal urinary abnormalities and normal renal function is not always favorable, and tubular atrophy and interstitial fibrosis are correlated with a worse prognosis 2
- Patients with greater proteinuria and/or an elevation in the serum creatinine concentration have a different rate of progression to end-stage renal disease 3