Leukocyturia : Causes, Symptoms, Diagnosis & Treatment

Last Updated: 19/08/2022

Leukocyturia is a pathological condition characterized by a high concentration of leukocytes in the urine. The cause may be urinary tract infections, autoimmune inflammatory diseases of the kidneys. In rare cases, leukocyturia is a sign of oncological pathology or graft rejection. By itself, leukocyturia has no clinical symptoms. Rarely, with a large number of cells, urine can become cloudy. The level of leukocytes is determined in the general analysis of urine, the study of the Nechiporenko, Kakovsky-Addis samples. Correction of this laboratory deviation is carried out in the treatment of the underlying disease.

Classification

In the urine of a healthy person, a small number of leukocytes can be detected. With microscopy of urine sediment, the norm is up to 3-5 leukocytes per field of view. The norm of leukocytes according to the Nechiporenko method is less than 200 per 1 ml, according to the Kakovsky-Addis method - up to 20000 per day.

By origin, leukocyturia is divided into:

  • Infectious , caused by a urinary tract infection (pyelonephritis, cystitis).
  • Aseptic, associated with inflammatory processes of the urinary tract of non-infectious origin, mainly autoimmune (glomerulonephritis, rheumatological nephropathy, etc.).

According to the degree of severity, 2 large groups are distinguished: ordinary leukocyturia and pyuria, in which the number of cells is so large that the urine becomes cloudy, and under microscopy, leukocytes densely cover all fields of view. The presence of pyuria with a high probability indicates an infectious lesion of the urinary tract.

Separately, latent leukocyturia is distinguished, in which leukocytes are detected only when counting cells in special chambers (with the Nechiporenko and Kakovsky-Addis test), but are not detected during routine routine urine tests. Latent leukocyturia is often observed in young children, in patients with immunodeficiency states (decompensated diabetes mellitus, HIV infection).

When analyzing urine using test strips, incorrect results can be obtained:

  • False negatives. This is observed with a high specific gravity of urine, severe glucosuria, proteinuria. Also, an underestimation of the level of leukocytes occurs at a high concentration of ascorbic acid, taking antibacterial drugs (cephalexin, gentamicin, tetracycline).
  • False positive. Overestimation of the results is possible when using formalin as a preservative, taking drugs that change the color of urine (nitrofurantoin, clavulanic acid).

Determination of leukocytes in urine

 

Causes of leukocyturia

MEP infections

The most common cause of leukocyturia is a urinary tract infection. The penetration of microorganisms into the organs of the urinary tract causes an immune response - the migration of leukocytes into tissues, the development of an inflammatory process. As a result, part of the leukocytes enters the urine. A distinctive feature of infectious leukocyturia is the presence of bacteriuria, an alkaline urine reaction (pH above 7). Microscopic examination often reveals tripel phosphate crystals. Mostly neutrophils are found.

  • Cystitis. With inflammation of the bladder, in addition to leukocytes, erythrocytes are often found, an increase in the number of transitional epithelial cells.
  • Pyelonephritis. With inflammation of the renal pelvis, a large number of leukocytes, sometimes erythrocytes, and protein are detected. The detection of renal epithelial cells, leukocyte, waxy cylinders testifies to the renal origin.
  • Urethritis. With inflammation of the urethra, only leukocytes are observed in the urine.

More severe forms of UTI (abscess, carbuncle of the kidney) are also accompanied by massive leukocyturia. Depending on the severity of the inflammatory process, both a moderate amount and pyuria can be observed. Leukocyturia occurs acutely, against the background of bright clinical symptoms (fever, dysuria), regresses quite quickly under the action of antibiotic therapy.

Infections of other organs

With other bacterial or viral infections, secondary kidney damage with concomitant leukocyturia is also possible. Especially often this happens in inflammatory diseases of organs that are anatomically close to the urinary tract - diseases of the female (colpitis, endometritis) and male reproductive system (balanoposthitis, prostatitis), pathologies in the abdominal cavity (appendicitis, pancreatitis).

Less commonly, leukocyturia is observed in the following diseases:

  • viral hepatitis (B, C);
  • cytomegalovirus infection;
  • flu;
  • angina;
  • pneumonia;
  • otitis;
  • HIV infection;
  • sepsis.

With viral infections, the degree of leukocyturia is usually moderate; with bacterial infections, pyuria is possible. Elimination of the infectious focus leads to the disappearance of leukocytes from the urine.

Autoimmune diseases

The inflammatory process in the kidneys of an autoimmune nature is almost always accompanied by leukocyturia. Isolated leukocyturia is rarely observed, most often erythrocytes are also found in the urine, a high protein concentration, and a decrease in specific gravity. At microscopy, leukocyte, erythrocyte cylinders, epithelial cells of the kidneys are noted. Leukocytes are predominantly represented by lymphocytes.

An increase in the percentage of lymphocytes indicates an exacerbation of the disease. The level of leukocytes decreases under the influence of specific anti-inflammatory therapy when remission is achieved, a small leukocyturia can persist for a long time. Autoimmune diseases in which leukocyturia occurs:

Oncology

With malignant neoplasms of the urinary system (cancer of the kidney, bladder), leukocyturia develops gradually. It may appear long before any clinical signs appear. Lymphocytes predominate. In oncohematological pathologies (leukemias, lymphomas), immature forms of leukocytes are often found - myelocytes, promyelocytes, blasts. Leukocyturia is usually moderate, decreasing after courses of chemotherapy or surgical removal of the neoplasm.

Other reasons

  • Interstitial nephritis. It develops as a reaction to the intake of certain drugs, especially NSAIDs (analgin, diclofenac), as well as helminthiases (ascariasis). There is an increase in eosinophils - more than 5% and lymphocytes.
  • Tuberculosis of the kidney. Tuberculous lesions of the kidneys are characterized by persistent moderate leukocyturia with an acid reaction (pH 5-6) of the environment and microhematuria.
  • Rejection of a kidney transplant. With acute rejection in the urine, an increase in eosinophils is detected, with chronic rejection, leukocytes are represented by lymphocytes.
  • Amyloidosis. With amyloidosis of the kidneys, in some cases, against the background of massive proteinuria, leukocyturia is observed.

Diagnostics

If leukocyturia is detected, it is necessary to consult a general practitioner or nephrologist to find out the cause of its occurrence. The doctor asks the patient in detail about his complaints, the presence of diagnosed chronic diseases, about what medications the patient is taking. A physical examination is carried out - measuring body temperature, blood pressure, checking for the presence of peripheral edema, Pasternatsky's symptom.

It should be noted that urinalysis test strips detect only neutrophils. In diseases accompanied mainly by lymphocyturia (mainly autoimmune), in some patients the result will be negative. Lymphocytes and eosinophils can only be detected by microscopic examination of the native preparation or after its staining. If kidney tuberculosis is suspected, the urine sediment preparation is stained according to Ziehl-Neelsen.

To determine the source of leukocyturia, a 3-glass urine sample is performed. The predominance of leukocytes in the first portion indicates inflammation of the urethra, in the 3rd portion - about cystitis or prostatitis. The uniform presence of leukocytes in all portions is characteristic of kidney damage. For differential diagnosis of the etiological factor, an additional examination is prescribed:

  • Blood tests. In the general analysis of blood, leukocytosis, an increase in ESR are noted. In a biochemical blood test, an increase in CRP, RF is detected, with glomerulonephritis - ASLO. In case of violation of the excretory function of the kidneys, the concentration of creatinine and urea increases.
  • Microbiological research. In case of urinary tract infections, it is mandatory to culture the urine sample on nutrient media with the determination of sensitivity to antibiotics.
  • Immunological research. Examines the presence of antibodies or antigens of infectious agents - viral hepatitis, influenza, HIV infection, etc. Autoantibodies are also analyzed - antibodies to double-stranded DNA, topoisomerase, antinuclear (ANA) and antibodies to neutrophil cytoplasm (ANCA).
  • ultrasound. On ultrasound of the kidneys with pyelonephritis, an expansion of the pelvicalyceal system is detected, with cystitis - a thickening of the walls of the bladder.
  • Biopsy. In case of suspected oncological disease, a biopsy of the kidney or bladder is performed, followed by a histological examination. To confirm amyloidosis, a tissue sample is taken from the lining of the mouth or rectum.
  • Consultation of other specialists. If there are clinical signs of pathology of the genital area, a consultation with a urologist or gynecologist is prescribed for examination, manual examination, and sampling of material for further research.

Leukocytes in urine under a microscope

 

Correction

Conservative therapy

There are no independent methods for correcting leukocyturia. Treatment of the underlying disease is required. With interstitial nephritis caused by taking the drug, it is necessary to cancel it. Therapy can be carried out on an outpatient basis or in a hospital, it depends on the severity of the patient's condition. The following drugs are used:

  • Antibiotics. For cystitis, fosfomycin trometamol is prescribed, for pyelonephritis antibiotics from the groups of penicillin (amoxicillin), cephalosporins (cefexime), fluoroquinolones (ciprofloxacin, levofloxacin) are used.
  • Anti-inflammatory drugs. To suppress autoimmune inflammation, glucocorticosteroids (prednisolone), cytostatic agents (cyclophosphamide, azathioprine) are effective. With lupus nephritis, synthetic antimalarials (hydroxychloroquine) are additionally used, with scleroderma kidney - D-penicillamine.
  • Chemotherapy. In oncological diseases, it is necessary to conduct courses of polychemotherapeutic drugs - sorafenib, sunitinib, bevacizumab. In amyloidosis, melphalan, bortezomib is prescribed.

Surgery

In case of kidney cancer, the main method of treatment is surgical treatment - resection of the kidney or its complete removal (nephrectomy) by an open or laparoscopic method. With amyloidosis, in case of development of terminal renal failure, kidney transplantation is indicated. Patients with oncohematological pathologies undergo bone marrow transplantation.

Forecast

Based on one leukocyturia, it is difficult to predict any prognosis. The outcome is determined by the disease against which this laboratory deviation arose, as well as the timeliness of its diagnosis and treatment. Therefore, when receiving a positive result of a urine test for leukocytes, you should immediately consult a doctor.

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