Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0033687 (proteinuria)
 24,015 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The urinary excretion of albumin and beta 2-microglobulin in a population of 294 persons, living in an area where Balkan nephropathy is endemic, has been studied. In fifty-six (about 19%) of the subjects the beta 2-microglobulin concentration was above the +2 SD level for a reference group of healthy individuals from non-endemic areas. Albumin elevation was found in forty-four (about 15%) of the cases. In twenty-one of the subjects the urinary concentration of both beta 2-microglobulin and albumin were increased, in sixteen of these cases the relationship between the two proteins was consistent with tubular proteinuria. An increased beta 2-microglobulin excretion is considered to be a sign of Balkan nephropathy. Radioimmunoassay of the protein is sensitive enough to detect tubular proteinuria at an early stage and is suggested as a suitable screening test for the disease.
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PMID:Urinary excretion of albumin and beta 2-microglobulin in a population from an area where Balkan nephropathy is endemic. 8 21

During the year 1974, urinary beta 2-microglobulin (beta 2mu) was measured at monthly intervals using the first-morning urine sample of randomly selected individuals from the BEN affected village of Petka (416 persons) and from the nearby situated control village of Stubica (216 persons). Initial compliance was complete; over 90% of villagers had at least 10 tests performed. beta 2mu, as assessed by radial immunodiffusion (RID), was repeatedly (at least twice) positive in 12% and 1.4% of the populations of the endemic and control villages, respectively. Over the 15 years of follow-up (1974 to 1988), none from the control village developed BEN, while many medical records of the cohort exposed to BEN contained data suggestive of BEN. Death from/with BEN was used as a measure of outcome. Incidence density of 12 was 3.3 per 1000 person/years of observation (19/5723). A single positive beta 2mu test was a sensitive predictor of BEN death (sensitivity = 89.5%). Selecting two or more positive tests as the cut-off point, the specificity and positive predictive value were considerably increased. Using the sulfosalicylic acid test for detection of significant proteinuria, a similar level of validity indices was reached only by four testings.
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PMID:Beta 2-microglobulinuria as a predictor of death in a population exposed to Balkan endemic nephropathy. 176 28

The diagnosis of BEN and its differentiation from other chronic interstitial nephropathies are difficult because of the insidious onset as well as nonspecific morphological changes in the kidney. Early diagnosis of this disease is by clinical and laboratory findings which have not been universally accepted. This study was designed to determine if the frequency of increased urinary beta 2-microglobulin (U beta 2m) in village populations at risk to develop BEN was significantly higher than that seen in a control population. Individuals in the two population samples were classified in one of three categories: healthy, suspect or diseased. There were 23 individuals who met the criteria for the clinical diagnosis of BEN. Twenty (87%) of these had one or more positive tests for increased U beta 2m. The prevalence of kidney disease in the endemic village population sample was 13.4 times that for the control village population sample. The data show that the healthy individuals living in a village where BEN is endemic have 6.4 times greater chance of having tubular proteinuria than those living in a control area. The coincidence of the finding of U beta 2m in the urine of 87% of those sick with BEN and in 37 of the 342 (10.8%) people judged to be free of kidney disease suggests that a positive U beta 2m test is an early indicator of exposure to a nephrotoxic agent.
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PMID:Beta 2-microglobulin studies in endemic Balkan nephropathy. 176 30

Baseline data from a study run in 1974, which comprised beta 2-microglobulinuria (beta 2mu) measurements at monthly intervals from 416 members in 112 households from the BEN affected village of Petka, were compared with the results of two subsequent, cross sectional studies. In June 1988, retesting involved 320 available persons from the same households. Another collection of 284 urine specimens took place in October 1989. Prevalence of tubular proteinuria was the same in 1988 and 1989 as it was in 1974, indicating that the level of exposure to nephrotoxic agent did not change over time. Over 94% of the individuals who were always beta 2mu negative in 1974 remained negative in 1988. By contrast, over two thirds (68.7%) of those who were positive two or more times 14 years ago, tested positive upon re-examination in 1988. Particular interest arises from the data on those initially repeatedly positive persons in whom the overt disease did not occur over time; moreover, some appeared to be unaffected in 1988 and 1989 according to our set of laboratory criteria. The results suggest occasional slow progression and even possible reversibility of tubular lesions in individuals living in the BEN affected environment.
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PMID:Beta 2-microglobulinuria in a population exposed to Balkan endemic nephropathy: inferences from repeated cross-sectional studies. 176 29

The occurrence of elevated urinary beta 2-microglobulin (U beta 2m) has been established to be more common in village populations living in areas where BEN is endemic when compared to appropriate control population. In addition, beta 2-microglobulinuria is associated with BEN. It has been demonstrated that there is an increase in the U beta 2m in apparently healthy populations located in high risk areas. It is 15 years since the first systematic investigations of U beta 2m in the villages of Brod Posavina were conducted. The purpose of this study was to determine the value of a positive test for tubular proteinuria as defined by increased U beta 2m, in identifying individuals at risk to develop BEN. In these studies we followed two cohorts for 15 years: one group consisted of individuals who were positive for tubular proteinuria by U beta 2m testing in 1974; the second group was an age and sex matched group from the same village who were never positive after 12 testings in 1974. The results show that a positive test for U beta 2m is associated with 9.9 times greater relative risk of developing BEN when compared to controls that had no positive U beta 2m tests.
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PMID:A fifteen year cohort based evaluation of beta 2-microglobulin as an early sign of Balkan endemic nephropathy. 176 32

The urinary proteins of 40 patients with Balkan endemic nephropathy from the Tuzla region were examined using ultrathin-layer SDS pore-gradient polyacrylamide gel electrophoresis in combination with silver staining. The typical urinary protein spectrum contained immunoglobulin G, Tamm-Horsfall protein, transferrin, albumin, beta 2-microglobulin (beta 2m), immunoglobulin light chains, retinol-binding protein, and alpha 1-microglobulin (alpha 1m). Densitometric measurements were used to derive glomerular tubular protein ratios (GTPR) and to characterize protein excretion patterns in the 28 patients who excreted more than 150 mg/liter of protein. Results showed that proteinuria of Balkan nephropathy is predominantly tubular, consisting of low-molecular-weight species. The most commonly identified proteins were alpha 1m, light chains, retinol binding protein, and beta 2m. The pattern of proteinuria based on GTPR did not correlate with the underlying histology or the degree of renal failure. These findings, using the ultrathin-layer SDS pore-gradient method of protein separation, more accurately demonstrates the low-molecular-weight proteinuria characteristic for the early stages of BEN.
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PMID:Renal function, protein excretion, and pathology of Balkan endemic nephropathy. II. Protein excretion. 176 36

This study was performed to evaluate histomorphological features of BEN in 50 kidney biopsies from patients who met the epidemiologic, clinical and laboratory criteria for BEN. This is the first such study reported in detail. The patients were divided into three groups based on the DTPA clearance values: group 1, greater than 99 ml/min, group 2, 51 to 99 ml/min, and group 3, 29 to 50 ml/min. All patients in all groups had an increase in proteinuria consisting of proteins less than 25,000 daltons. Multifocal interstitial sclerosis spreading from the superficial into the deep cortex was found in 49 (98%), tubular atrophy in 48 (96%), and global glomerular sclerosis with microvascular hyalinosis/sclerosis of sclerotic and atrophic changes were significantly increased when compared to age-related standards. An accelerated aging process may be assumed to occur in BEN. More peculiar additional findings with much lower incidence and extent included multifocal vascular and glomerular capillary changes resembling the chronic form of thrombotic microangiopathy group of diseases. These findings, together with the presence of arteriolar hyalinosis and tubulointerstitial sclerosis seen in patients with cyclosporine nephrotoxicity suggest that the mechanism of toxicity may be similar to BEN. We conclude that the histopathology is predominantly tubulointerstitial sclerosis without infiltrates. The combination of the histology, tubular proteinuria, geographic distribution, familial occurrence, and the remarkable association with papillary transitional cell carcinoma of the renal pelvis and ureters, qualifies BEN as a unique disease.
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PMID:Renal function, protein excretion, and pathology of Balkan endemic nephropathy. III. Light and electron microscopic studies. 176 37

The urinary alpha 1-microglobulin (alpha 1m) concentration was measured in 644 adults living in districts where Balkan nephropathy (BEN) is endemic. Comparison of alpha 1m with other indicators of tubular proteinuria, which is a classical sign of BEN, showed alpha 1m was a satisfactory marker. Using a cut-off of 20 mg alpha 1m/L none of 102 normal UK residents had a positive level. Whilst a raised level of alpha 1m was present in 85.7% of definitive cases of BEN and in 8.1%, 10.2% and 50% of subjects previously classified as normal, at risk and suspicious respectively according to the criteria used for epidemiological surveys of BEN.
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PMID:Urinary alpha 1 microglobulin levels in surveys of Balkan endemic nephropathy. 349 13

Tubular proteinuria, or low molecular weight (LMW) proteinuria, is less common than glomerular proteinuria, but is often of clinical significance. Both qualitative analysis of the urinary protein pattern by electrophoresis and quantitative estimations of various LMW-proteins are now usually available in the clinical routine laboratories. It is thus possible to look for LMW-proteinuria, as a sign of damage to the function of proximal renal tubules. For this purpose beta 2-microglobulin may be used as marker protein. Chronic cadmium poisoning and the Balkan nephropathy are examples of conditions which have been extensively studied by the use of LMW-protein determinations. In this context also some rare hereditary disorders deserve to be specially mentioned. Toxic injury to the kidneys, by drugs or other agents, often affect the kidney tubules early in the course and may be identified by LMW-protein analysis. Also in other clinical situations LMW-proteins in the urine may be used for investigative or research purposes.
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PMID:Aspects on tubular proteinuria. 389 Mar 21

The pattern of proteinuria found in patients during the administration of methotrexate (MTX) or aminoglycosides (AG) and in cadmium or Balkan nephropathy was investigated using the technique of sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). As renal tubular dysfunction increased, measured by the urinary concentration of 4 low molecular mass (LMr) proteins, SDS-PAGE bands appeared in the following order of molecular mass (Mr): 59, 44, 31, then below 31 000. The presence of bands less than 31 000 was not an early indicator of drug-induced renal damage. Tubular proteinuria could be monitored more easily by the serum and urinary measurement of any one of the LMr proteins: alpha-1-microglobulin (alpha 1m), retinol-binding protein (RBP), beta-2-microglobulin (beta 2m), except alpha-1-acid glycoprotein (AGP), than by SDS-PAGE.
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PMID:Comparison of tubular proteinuria, using sodium dodecyl sulphate polyacrylamide gel electrophoresis, in patients during methotrexate or aminoglycoside treatment or with cadmium or Balkan nephropathy. 646 14


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