Leucocitúria / Urine leukocytes
Rev. méd. Minas Gerais
;
14(3): 185-189, jul.-set. 2004.
Article
in Portuguese
| LILACS
| ID: lil-576349
RESUMO
A leixocitúria pode ser detectada, no exame de urina rotina, pela pesquisa de esterase leucocitária e pelo exame do sedimento urinário. Admitem-se 5 leucócitos/campo como ponto de corte do valor de referência. O jato médio urinário constitui a amostra mais utilizada para a avaliação de leucocitúria. A causa mais comum de leucocitúria é a infecção bacteriana do trato urinário. Outras causas incluem doenças inflamatórias renais ou do trato urinário, calculose, exercício físico extenuante e febre. O uso de nitrofurantoina e o emprego de formalina como conservante são causas de falso positivo no teste da esterase leucocitária e proteinúria (> 500 mg/dl), glicosúria (> 3g/dl), densidade elevada e a eliminação de alguns antimicrobianos e de ácido ascórbico são causas de falso negativo. A densidade baixa é a principal causa de falso negativo observada na sedimentoscopia.
ABSTRACT
Leukocyturia is usually detected by a positive leukocyte esterase test and/or by the microscopic examination of urine sediment. Although there is not an agreement on the number of urine leukocytes that means leukocyturia, the cut off used by most authors is 5 leukocytes/high power field. First-morning clean-catch midstream specimens are preferred but other samples such as timed, catheterized, or suprapubic ones may occasionally be colected. Any blood leukocyte may be found in the urine but the most common are polymorphonuclear neutrophils, that are frequently associated with bacterial urinary rract infections. Other causes of leukocyturia are renal diseases (tumors, glomerulonephritis, interstitial nephritis), nephrolithiasis, fever, and strenuous exercise. Cellular lysis, common in low specific graviry urine, is the most common cause of false negative results in the microscopic analysis. False positive results are commonly due to specimen contamination. Leukocyte esterase false results are due to pigmented foodstuffs or drugs (positive) or increased proteinuria, glucosuria, and specific graviry or the presence of gentamycin or cephalosporin (negative).
Full text:
Available
Index:
LILACS (Americas)
Main subject:
Pyuria
/
Urinary Tract Infections
Type of study:
Diagnostic study
Limits:
Humans
Language:
Portuguese
Journal:
Rev. méd. Minas Gerais
Journal subject:
Medicine
Year:
2004
Type:
Article
Affiliation country:
Brazil
Institution/Affiliation country:
Universidade Federal de Minas Gerais/BR
Similar
MEDLINE
...
LILACS
LIS