Leucocitúria / Urine leukocytes

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.

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).

Nephropathy in low income diabetics: the Mexico City diabetes study

Among the most serious complications associated with diabetes mellitus (DM) is nephropathy (DN). In Mexico, there is little information on the frequency and clinical characteristics of DN in the Mexican population. We present results of a population-based survey designed to estimate the prevalence of DN. The low income population consisted of 15,532 inhabitants. All 35- to 64-year-old males and non-pregnant women residing in the survey area were identified as eligible for the study (3505; 22.6 percent). A home interview was obtained in 2810 (80.2 percent). A physical exam with oral glucose tolerance test wasobtained in 2282 (81.2 percent of those interviewed). DM was diagnosed in 304 (crude rate 13.3 percent). Mean age for men and women with DM was 51.6 ñ 8.4 and 52.2 ñ 7.5, respectively. Duration of DM in men was 9.2 ñ 8.1 and in women, 7.3 ñ 6.7 years. Hypertension was diagnosed in 19.8 percent of men and 18.1 percent of women. Diabetic retinopathy of any level was found in 55.4 percent of men and 45.7 percent of women. Mean glycohemoglobin in men was 9.6 ñ 2.1 and in women 9.5 ñ 2.2 percent (normal 4 - 8 percent). At baseline, proteinuria (1+ or more, by dipstick) was found in 24.7 percent of men and 9.6 percent of women, microalbuminuria (MA) in 84.4 percent of men and 63.8 percent of women. Quantitative albuminuria was abnormally high in 54.7 percent of men and 40.3 percent or women. In the 203 diabetic studied with 24 h urine collection from creatinine clearance, normal renal function was found in 69.1 percent of men and 47.5 percent of women, reduced renal function was found in 26 percent of men and 50 percent of women, ranl insufficiency was diagnosed in 4.9 percent of men and 1.6 percent of women. One patient was on dialysis and in a subsequent follow up, we found that 2.3 percent of the patients had died of renal failure, six men (46 -63 years) and a woman of 62 years. We concluded that DN is a very serious threat to this population. The high case fatality rate associatd with this condition maintains a low prevalence. It is important to develop a program to diminish the frequency of this condition