Rapid Diagnosis of Hematuria through Urinalysis

Hematuria is one of the most common symptoms in both outpatients and inpatients, accounting for 4-20% of urological admissions. Asymptomatic hematuria is believed to be more prevalent than symptomatic hematuria, with reported rates of asymptomatic microhematuria (AMH) ranging from 1.7% to 31.1%. In routine clinical practice, a prevalence rate of 4%-5% seems realistic ^[1]. Glomerular hematuria seems to be more frequent in males than in females, regardless of age. Children present more frequent macroscopic hematuria bouts than adults, whereas microhematuria is more common in adults ^[2].

The etiology of hematuria can originate anywhere along the urinary tract, including the kidneys, ureters, bladder, prostate, and urethra ^[3]. The most common cause of hematuria is lower urinary tract infections, especially bladder infections. Other causes to consider are stones (urolithiasis). Especially in older patients, tumors or benign prostates tend to proliferate (Fig.1). In younger patients, persistent microhematuria is associated with an increased risk of end-stage renal failure. This increased risk is believed to be caused by primary glomerular disease ^[4].

The color and thickness of urine can often provide important clinical information. The color of urine can indicate if there has been recent or previous bleeding. Increased thickness of urine and the presence of blood clots may suggest that the patient is retaining clots ^[7]. Urine strips are commonly used to analyze red blood cells in urine. The American Urological Association defines clinically significant microscopic hematuria as the presence of more than three red blood cells in two out of every three high-magnification fields of view in properly collected urine samples over a two to three-week period. False positive results can occur due to hemoglobinuria, hematuria, and urine contaminants, so it is important to examine the urine sediment immediately after a positive test result. The morphology of urine red blood cells is influenced by the acidity, alkalinity, and osmolality of the urine, so these factors should be considered ^[8]. The source of hematuria can be determined based on the morphology of red blood cells, so it is important to ensure consistency in their size and shape. Microscopic examination is also useful in diagnosing and predicting the outcome of urological diseases.

Urine red blood cells are categorized into normal, macrocytic, and microcytic types based on their size. The size of urine red blood cells and blood red blood cells can differ due to various factors like the origin of the cells, urine osmolality, and PH. Consequently, the diameter of normal urine red blood cells is specified as 6 to 8 μm (Fig.4).

• Temporary or transient hematuria may occur due to physiological factors such as strenuous exercise in adolescents, rapid marching, cold baths, heavy physical labor, and prolonged standing. Women should also be aware of the possibility of menstrual blood contamination during the pre-and post-menstrual periods.

• Urinary system diseases, such as urinary system inflammation, tumors, tuberculosis, stones, trauma, and congenital malformation of urinary system organs, may also present with hematuria as the only clinical manifestation of malignant tumors of the urinary system. This should be confirmed through additional clinical examinations.

• Diseases of the reproductive system, such as prostatitis and seminal vesiculitis;

• Others: bleeding disorders caused by various reasons, etc.

• Homogeneous red blood cells (non-nephrogenic hematuria) refer to the microscopic morphology, size, and hemoglobin content of red blood cells that are more consistent, with a percentage of ≥ 70%. This is considered the normal morphology of red blood cells. In some cases, there may be the presence of shadow red blood cells with a loss of hemoglobin or jagged red blood cells with a slight change in appearance. This can be attributed to the influence of urine osmolality, PH, and other factors. However, the morphology does not exceed two types of red blood cells.
• Non-homogeneous red blood cells (nephrogenic hematuria) refer to red blood cells that are abnormal in shape, size, hemoglobin content, or distribution. They exhibit various changes in appearance and more than two types of polymorphic changes. When the relative number of these abnormal red blood cells is more than 70%, they are recommended to be classified as non-homogeneous red blood cells.
• Mixed erythrocytes: This refers to a situation where the microscopy contains both normal morphology erythrocytes and abnormal morphology erythrocytes. The quantity of mixed erythrocytes is between that of the two types mentioned above, and it does not meet the criteria for either one of them.

Determining the shape of red blood cells can help distinguish between nephrogenic and non-nephrogenic causes of hematuria. Hematuria of nephrogenic origin can be seen in conditions like acute or chronic glomerulonephritis, pyelonephritis, lupus erythematosus nephritis, and nephrotic syndrome. In cases of nephrogenic hematuria, there is often a significant increase in urinary protein but not in red blood cells. It is commonly associated with tubular patterns, such as granular tubular, erythrocytic tubular, and tubular epithelial cell tubular patterns.

• Transient microscopic hematuria should be noted, especially in female patients, to determine if it is related to female physiology.

• Diseases specific to the urinary system, such as tumors, tuberculosis, trauma, and renal transplant rejection reactions.

• Others are seen in hemorrhagic diseases caused by various reasons, such as DIC, hemophilia, hypertension, arteriosclerosis, hyperthermia, and so on. Non-renal hematuria is characterized by an increase in urinary erythrocytes with no or insignificant increase in protein.

Dirui's urine analyzers are capable of automatically and precisely categorizing erythrocytes into five groups: normal, small, spiny, shadow, and other erythrocytes. Additionally, the analyzers provide data on the percentage of normal and abnormal erythrocytes, the size and distribution of erythrocytes, and the overall distribution pattern. The system also generates erythrocyte histograms and scatter plots, which offer a visual representation to assist in determining the source of hematuria.

MUS-9600 Urinalysis System

MUS-3600 Urinalysis System

FUS-3000Plus Urinalysis Hybrid

FUS-360 Urine Sediment Analyzer

Feel free to contact us if interested in Urinalysis Analyzers,

sales@jingquanmedical.com