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History of kidney stones as a possible risk factor for chronic kidney disease.

PURPOSE: The incidence of treated end-stage renal disease has increased progressively in the United States over the past several decades. It has been suggested that kidney stones may be a contributing factor for a small percentage of these patients. METHODS: We conducted a case-control study utilizing 548 hospital cases and 514 age, race and gender-matched community controls. The main outcome measure was diagnosis of chronic kidney disease, assessed by comprehensive chart review. History of kidney stones and other co-variables were obtained during telephone interviews. RESULTS: This study revealed 16.8% of cases and 6.4% of controls with reported history of kidney stones. The odds ratios (adjusted for confounding variables) for chronic kidney disease (overall), diabetic nephropathy and interstitial nephritis for patients with kidney stones were 1.9 (95% CI: 1.1, 3.3), 2.5 (95% CI: 0.87, 7.0) and 3.4 (95% CI: 1.5, 7.4), respectively. After stratifying by hypertensive status this increased risk persisted only for study participants reporting no history of hypertension. CONCLUSION: Kidney stones may play a role in the development of chronic kidney disease. Our study suggests that the prevention of kidney stones may be a means of delaying the onset of chronic kidney disease, however, further studies are needed to make conclusive recommendations.

Adult↗

Living donor kidney transplants: a biopsy study 1 year after transplantation, compared with baseline changes and correlation to kidney function at 1 and 3 years.

INTRODUCTION: Chronic changes in biopsies from long-term stable kidney allografts have been reported to correlate with graft prognosis. Morphological changes in baseline ('zero-hour') biopsies have been described as well, but their importance for long-term prognosis have been less clear. The aim of the present study was to evaluate biopsy changes from baseline to 1 year after transplantation in patients receiving kidneys from living donors, and to assess the possible prognostic implications of these findings. METHODS: Light microscopical changes in 18 gauge full-core biopsies were scored semi-quantitatively in 33 patients 1 year after transplantation, and compared to baseline changes previously reported [1]. All cases were also examined with transmission electron microscopy. The semi-quantitative data from baseline and at 1 year were correlated with kidney function 1 and 3 years after transplantation. The reproducibility of baseline findings regarding arteriosclerosis and arteriolar hyalinosis was tested by comparison with biopsies 1 week after transplantation (n = 43). RESULTS: We found a significant increase in mesangial glomerular sclerosis (P<0.001), interstitial fibrosis/tubular atrophy (if/ta) (P = 0.002), and mononuclear cell interstitial infiltration (P = 0.003) after 1 year, compared to baseline changes. There was an increase of arteriosclerosis (P = 0.028) and arteriolar hyalinosis (P = 0.006) when compared to biopsies taken 1 week after transplantation, but not when compared to the 'zero-hour' findings. Electron microscopy revealed one case of recurrent immune-complex glomerulonephritis and another case of recurrent light chain deposition kidney disease. Comparing 1-week vascular findings with baseline gave a low level of reproducibility, probably due to sampling error. Baseline biopsy findings could not predict long-term kidney function. In the 1-year biopsy, if/ta was significantly correlated with serum creatinine (P = 0.007) and glomerular filtration rate (GFR) (P<0.001) at 1 year, with serum creatinine at 3 years (P = 0.011), and with the first-year cumulative dose of methylprednisolone (P = 0.004). Serum creatinine at 1 year, however, was found to be the most accurate predictor of 3-year kidney function (P<0.001). Donor age was correlated to kidney function at 3 years (P = 0.013) but not at 1 year after transplantation. CONCLUSION: Morphological changes in baseline biopsies of living donor kidneys tend to become more pronounced in well-functioning allografts during the first year after transplantation. In the 1 year biopsy, if/ta seems to be the most reliable variate for grading of chronic changes. However, 1-year serum creatinine predicted long-term kidney function more precisely than did the biopsy scores. Based on the results of the present study, a protocol 1-year biopsy does not seem warranted in the management of the graft recipient with a stable kidney function.

Adult↗

Characteristics of specific unresponsiveness toward kidney and skin allografts in adult rats inoculated at birth with allogenic bone marrow or kidney cells across a strong H-1 barrier.

Specific unresponsiveness inducible in newborn Lewis (Le) rats by injection of bone marrow or kidney cells from (Bu x Le)F1 hybrids was tested in adults by allografting of skin or kidneys from strongly incompatible Buffalo (Bu) strain donors. High doses of bone marrow cells (10(7) or more) proved quite effective in procuring indefinite survival of subsequent Bu kidney allografts, but not Bu skin allografts. Kidney allografts remained fully functional without modulation of their inherent immunogenicity regardless whether skin allografts were acutely rejected before or after kidney grafting on bone marrow-tolerant recipients. Lower doses of bone marrow cells were either near threshold for induction of specific Bu kidney allograft tolerance (5 x 10(6)) or, conversely, led to increased immunity(1-5 x 106). A strikingly different pattern of reactivity was found in adult Le recipients of Bu skin allografts as shown by only a moderate, but stepwise increase in survival times as a function of increasing allogeneic cell dosage at birth. Allogeneic kidney cells at all doses were surprisingly ineffective in inducing tolerance of either kidney or skin allografts, so the existence of kidney-specific transplantation antigens remains problematical. Lymphocytes from kidney allograft-tolerant recipients showed much reduced but still significant antidonor activity in several tests of cell-mediated immunity in vitro and in vivo. Blocking antibody activity was also demonstrable in these animals. Acquired tolerance (i.e., essential nonreactivity) may not only exist in degrees in either T or B cell pathways but may coexist with specific immunoblocking reactions in a dynamic equilibrium. Instead of tolerance versus enhancement, a new concept of selective specific immunoregulation emerges.

Animals↗

Quantification and longitudinal trends of kidney, renal cyst, and renal parenchyma volumes in autosomal dominant polycystic kidney disease.

ABSTRACT.: The aims of this study were to assess the accuracy and reproducibility of volumetric determinations of total kidney, renal cyst, and renal parenchymal volumes, using fast electron-beam computerized tomography scanning, and to determine the rate of change of these volumes. Nine patients with autosomal dominant polycystic kidney disease (ADPKD) and serum creatinine < or = 1.3 mg/dl and/or an initial iothalamate clearance > or = to 60 ml/min per 1.73 m(2) were imaged weekly over a 3-wk period (total of 3 times). Approximately 8 yr later, they returned for follow-up studies. The kidney volume estimation technique involved a manual segmentation (perimeter drawing) of the kidneys and a semiautomatic threshold approach, using a histogram analysis of the peak densities of renal parenchyma and renal cysts. At entry, total kidney and renal cyst volumes correlated positively with age, while renal parenchymal volumes and GFR correlated negatively with age. The average coefficient of variation values for the three initial consecutive measurements of total kidney, renal cyst (actual and as a percent of total volume), and renal parenchymal volume were 3.4, 7.2, 5.3, and 5.6%, respectively. During the 8 yr of follow-up, total kidney and renal cyst volumes increased, while renal parenchymal volumes and GFR declined. The rate of increase in total kidney and renal cyst volumes varied markedly from patient to patient. There was a significant correlation between rate of increase in renal cyst volume and the rate of decline in GFR. The patients with an initial urine protein/osmolality ratio >0.13 mg/L per mosmol per kg had a significantly higher increase in renal volume and decline in GFR than those with a lower ratio. In summary, the results of this pilot study suggest that: (1) electron-beam computerized tomography is capable of measuring total kidney, renal cyst, and renal parenchymal volumes reproducibly; (2) total kidney and renal cyst volumes increase, while parenchymal volumes decrease with time; (3) the increase in cyst volume correlates best with the decline in renal function; and (4) renal volumes appear to be good surrogate markers for disease progression in ADPKD.

Adult↗

Effect of brain death and non-heart-beating kidney donation on renal function and injury: an assessment in the isolated perfused rat kidney.

OBJECTIVES: Ischemic injury to the renal allograft prior to implantation is considered as the major cause of primary non and never-function (PNF) and delayed graft function (DGF). Evidence has been put forward that brain dead and non-heart-beating (NHB) donor organs are of marginal quality compared to living donors. The purpose of this study was to evaluate renal function and injury of brain dead and NHB donor kidneys using the isolated perfused rat kidney. MATERIAL AND METHODS: Fisher F344 rats were either maintained brain death for 4 hr or subjected to cardiac arrest for 45 min (NHB). Living rats served as controls. To omit additional effects of cold ischemia, kidneys were immediately reperfused. Renal function and injury were assessed by monitoring urine production, glomerular filtration rate (GFR), Na+ and K+ reabsorption, glucose metabolism and reabsorption, as well as release of brush border, lysosomal, and intracellular enzymes. RESULTS: Renal dysfunction and injury were most pronounced in NHB donor kidneys reflected by a highly reduced urine production, anaerobic glucose metabolism resulting in lactate formation, and significant higher luminal release of intracellular and lysosomal enzymes. Brain dead kidneys showed an increased urine production and were functionally abnormal in K+ reabsorption showing a net excretion of K+, probably as a result of ATP depletion. Loss of brush border occurred during brain death and cardiac arrest. CONCLUSIONS: Both, brain death and cardiac arrest have deleterious effects on renal function and renal injury. The ischemically injured NHB donor kidney was functionally inferior compared to the brain dead donor kidney and living donor kidneys. However, both brain dead and NHB kidneys showed considerable renal damage compared to kidneys from living donors.

Alkaline Phosphatase↗

Excellent outcome in recipients of dual kidney transplants: a report of the first 50 dual kidney transplants at Stanford University.

HYPOTHESIS: Recipients of dual kidney transplants from older expanded criteria donors (ECDs) have outcomes similar to recipients of single kidneys from younger donors. Dual transplantation is the use of both adult donor kidneys into a single adult recipient. DESIGN: Donor and recipient variables were entered into a database. Analysis was performed in a retrospective fashion. The unpaired t test and chi2 test were used as appropriate. SETTING: A university teaching hospital. PATIENTS: All adult recipients of cadaveric kidney-only transplants from adult donors between November 1991 and January 1999. Patients were grouped based on whether they received a dual or single transplant and whether the donor was an ECD. The control group of patients received non-ECD cadaveric kidneys. RESULTS: Donors for recipients of dual kidneys were older and had a lower creatinine clearance on hospital admission than recipients of single control kidneys. Recipients of dual transplants were older, had fewer rejections, and had similar 3-month and 1-year serum creatinine levels vs controls. Predictors of an elevated serum creatinine level or graft loss at 3 months in recipients of ECD dual and single transplants included kidneys from donors with unstable preprocurement renal function, and recipients who developed delayed graft function. CONCLUSION: Recipients of dual kidney transplants from ECDs have excellent outcomes similar to recipients of single control kidneys.

Adult↗

Kidney-specific enzyme expression by human kidney cell lines generated through oncogene transfection.

The human kidney cell line 293 was generated by transfection of adenovirus DNA into normal human embryonic kidney (HEK) cells (Graham et al., 1977), whereas the human kidney cell lines ST-1i and STt-4i were generated by transfection of HEK cells with plasmids encoding SV40 viral oncogenes (Abcouwer et al., 1989). In this study, we examined kidney-specific enzyme activity levels in 293, ST-1i, and STt-4i cells to determine their ability to exhibit kidney-specific gene expression. Enzymes examined were leucine aminopeptidase (LAP), gamma-glutamyl transpeptidase (gamma-GTP), and the disaccharidases trehalase and maltase. Enzymatic activity levels were compared to three other kidney cell lines (MDCK, OK, and LLC-PK1) as well as to normal human embryonic kidney (HEK) cells and the human hepatoma cell line, Hep G2. Modulation of kidney-specific enzyme activities was assessed in response to several differentiation-inducing agents (adenosine, n-butyric acid, hexamethylene bisacetamide (HMBA), dimethyl sulfoxide (DMSO), N,N'-dimethylformamide (DMF), isobutyl methyl xanthine (IBMX), di butyryl cAMP, and retinoic acid). ST-1i and STt-4i exhibit elevated levels of LAP, gamma-GTP, trehalase, and maltase, consistent with their kidney cell origin, whereas 293 cells exhibit elevated levels of just gamma-GTP and maltase. Maltase and gamma-GTP enzyme activities in ST-1i and STt-4i cells were very responsive to the various inducing agents; 293 cells were less responsive at the inducer concentrations examined. None of the three human cell lines formed domes under any of the experimental conditions. In summary, ST-1i and STt-4i are comparable to normal HEK cells in expression of kidney-specific enzymes and in responsiveness to differentiation-inducing agents, in spite of continued expression of SV40 oncogenes.

Animals↗

Effects of nitric oxide synthesis inhibition on the Na,K-ATPase activity in the kidney.

The present study was aimed at investigating the role of endogenous nitric oxide (NO) in regulating Na,K-ATPase activity in the kidney. The expression of alpha-1 and beta-1 subunits; and the enzymatic activity of Na,K-ATPase were determined in the kidney of rats treated with an NO synthase inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME). Following the treatment with L-NAME in the drinking water for 4 weeks, Na,K-ATPase activity was increased while tissue nitrite/nitrate levels were decreased in the kidney. Supplementation with L-arginine prevented the L-NAME-induced changes. The expression of either alpha-1 or beta-1 subunit protein of Na,K-ATPase, assessed by Western blot analysis, was not affected by L-NAME-treatment. An acute in vitro treatment of the kidney with L-NAME also caused an increase of Na,K-ATPase activity; which was again prevented by cotreatment with L-arginine. On the contrary, treatment with sodium nitroprusside significantly decreased Na,K-ATPase activity. These results suggest that the endogenous NO plays a direct inhibitory role on Na,K-ATPase activity in the kidney.

Animals↗

Progesterone metabolism in the microsomal fraction of the testis, head kidney, and trunk kidney from the rainbow trout.

In the present study on male rainbow trout, well-defined microsomal fractions from gonad, trunk kidney, and head kidney were used to study enzymes active on progesterone. The metabolites produced were identified by mass spectrometric analysis. In the testis the main metabolite was 17 alpha-hydroxyprogesterone which is an intermediate in the steroid biosynthetic pathway. 17 alpha-Hydroxyprogesterone was also identified in incubations from head and trunk kidney. The 17 alpha-hydroxylase activity was higher in the head kidney than in the trunk kidney which probably reflects the presence of steroid producing interrenal cells in this part of the kidney. The conversion of progesterone to 17 alpha-hydroxylated products in the testis and head kidney was NADPH dependent and inhibited by carbon monoxide, indicating the participation of cytochrome P450 monooxygenase in this reaction. NADH supported the reaction to some extent (27% of the NADPH-dependent activity) in the testis but not in the head kidney. In addition to 17 alpha-hydroxyprogesterone the head and trunk kidney microsomes gave rise to 16 alpha- and 6 beta-hydroxyprogesterone. These activities were low or absent in testis microsomes. Progesterone 5 alpha-reductase activity was only detected in trunk kidney microsomes.

17-alpha-Hydroxyprogesterone↗

Monitoring of kidney and simultaneous pancreas-kidney transplantation rejection by release of donor-specific, soluble HLA class I.

Using an HLA-A2-specific ELISA we monitored daily pretransplantation and posttransplantation sera from five kidney and eight simultaneous pancreas-kidney HLA-A2-negative recipients of HLA-A2-positive transplants during hospitalization. We found that, unlike liver transplants, neither kidney nor simultaneous pancreas-kidney transplants continuously secreted donor HLA proteins. However, three of four rejection episodes in kidney recipients and seven of seven rejection episodes in simultaneous pancreas-kidney recipients were accompanied by elevated serum levels of donor sHLA-A2 (> 5 ng/ml). In only one kidney patient was there a release of donor antigen without evidence of rejection, but in the simultaneous pancreas-kidney group most patients had at least one time point of detectable sHLA-A2 without strong evidence of kidney rejection. While total sHLA levels were also elevated during rejection, the rise in donor-specific sHLA was more dramatic when compared to pretransplantation background levels. We hypothesized that the release of donor sHLA class I proteins by transplanted organs might be a systemic indication of rejection in both pancreas and kidney allografts. The detection of donor sHLA in recipient sera could be an important noninvasive monitor of rejection, especially in the pancreas, which is currently difficult to monitor as a single-organ transplant.

Adult↗

Inhibition of renal ornithine decarboxylase activity fails to reduce kidney size and urinary albumin excretion in diabetic rats with manifest kidney hypertrophy.

Formation of polyamines has previously been shown to play an important role for initial kidney growth in experimental diabetes, as treatment of diabetic rats with a selective ornithine decarboxylase (ODC) inhibitor, initiated immediately after diabetes induction, abolishes the initial kidney growth. In order to investigate the role of polyamine formation for the maintenance of diabetic kidney hypertrophy, ODC inhibition was initiated after manifest kidney hypertrophy had occurred. The kidney weight in diabetic rats was significantly larger than in control rats after a diabetes duration of 7, 14, 50 and 71 days and the total glomerular volume was increased in kidneys from diabetic rats after a diabetes duration of 71 days. Renal activity of ODC was increased in diabetic rats throughout the study period of 71 days. Treatment of diabetic rats with the selective ODC inhibitor di-fluoro-methyl-ornithine (DFMO) was maintained for two periods (days 7-14 and days 50-71). DFMO treatment had no effect on 24-h food consumption, blood glucose concentration or body weight. However, despite almost total inhibition of the kidney ODC activity, there was no effect on kidney growth or total glomerular volume in the DFMO treated diabetic rats compared to placebo treated diabetic rats. Finally, the urinary albumin excretion was markedly increased in diabetic rats with no effects of ODC-inhibition. In conclusion, inhibition of ODC initiated in diabetic rats with manifest kidney enlargement had no effect on renal size, glomerular volume or urinary albumin excretion. These findings together with our previous findings indicate that the role of polyamines in diabetic kidney enlargement is restricted to the first week after diabetes induction.

Albuminuria↗

The expression of renin-binding protein and renin in the kidneys of rats with two-kidney one-clip hypertension.

OBJECTIVE: To test the hypothesis that renin-binding protein (RnBP) is involved in modulating the intracellular processing or release of renin, we examined the expression of RnBP in clipped and contralateral kidneys of rats with two-kidney one-clip hypertension, and in left and right kidneys from sham-operated control rats. DESIGN AND METHODS: Kidneys from rats with two-kidney one-clip hypertension and from control rats were either snap-frozen for extraction of mRNA or fixed for in-situ hybridization and immunochemistry. Reverse-transcription polymerase chain reaction on renal mRNA was performed using primers for renin, RnBP, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and angiotensin-converting enzyme (ACE). In addition, renal total RNA was analysed by Northern blotting for RnBP, GAPDH and angiotensin II type 1A (AT1A) receptor mRNA, and the intensity of the bands was measured by laser densitometry. In situ hybridization for renin mRNA was carried out using digoxygenin-labelled antisense oligonucleotides and for RnBP using labelled antisense oligonucleotides and an antisense riboprobe. Controls included sections treated with RNase and sections stained with sense oligonucleotides. RESULTS: The level of expression of mRNA for RnBP is similar in clipped and contralateral kidneys of renal hypertensive rats; in contrast, renin mRNA expression is upregulated in the clipped kidney. Renin-binding protein is expressed mainly in renal tubules and collecting ducts unlike renin, which is expressed in the glomerular afferent arteriole. We did not detect lateralization of expression for ACE or the AT1A receptor between clipped and contralateral kidneys. CONCLUSION: Renin-binding protein expression is unchanged between clipped and contralateral kidneys. Therefore, a physiological stimulus that upregulates renin gene expression in clipped kidneys does not affect RnBP expression. The main sites of RnBP expression are the renal tubules and collecting ducts; in contast renin is expressed at the glomerular pole. The results show that RnBP is not colocalized or coregulated with renin in this model of hypertension.

Animals↗

Expression of adrenomedullin in hypoxic and ischemic rat kidneys and human kidneys with arterial stenosis.

To investigate regional aspects of hypoxic regulation of adrenomedullin (AM) in kidneys, we mapped the distribution of AM in the rat kidney after hypoxia (normobaric hypoxic hypoxia, carbon monoxide, and CoCl(2) for 6 h), anemia (hematocrit lowered by bleeding) and after global transient ischemia for 1 h (unilateral renal artery occlusion and reperfusion for 6 and 24 h) and segmental infarct (6 and 24 h). AM expression and localization was determined in normal human kidneys and in kidneys with arterial stenosis. Hypoxia stimulated AM mRNA expression significantly in rat inner medulla (CO 13 times, 8% O(2) 6 times, and CoCl(2) 8 times), followed by the outer medulla and cortex. AM mRNA level was significantly elevated in response to anemia and occlusion-reperfusion. Immunoreactive AM was associated with the thin limbs of Henle's loop, distal convoluted tubule, collecting ducts, papilla surface epithelium, and urothelium. AM labeling was prominent in the inner medulla after CO and in the outer medulla after occlusion-reperfusion. The infarct border zone was strongly labeled for AM. In cultured inner medullary collecting duct cells, AM mRNA was significantly increased by hypoxia. AM mRNA was equally distributed in human kidney and AM was localized as in the rat kidney. In human kidneys with artery stenosis, AM mRNA was not significantly enhanced compared with controls, but AM immunoreactivity was observed in tubules, vessels, and glomerular cells. In summary, AM expression was increased in the rat kidney in response to hypoxic and ischemic hypoxia in keeping with oxygen gradients. AM was widely distributed in the human kidney with arterial stenosis. AM may play a significant role to counteract hypoxia in the kidney.

Adrenomedullin↗

Effect of puberty on initial kidney growth and rise in kidney IGF-I in diabetic rats.

Prepubertal subjects have a low incidence of diabetic nephropathy compared with duration-matched postpubertal subjects. At puberty, there is an increase in insulinlike growth factor I (IGF-I) levels, and because IGF-I has been implicated in the early kidney enlargement of experimental diabetes, we studied the development of kidney enlargement and kidney IGF-I levels in prepubertal (aged 5 wk) and postpubertal (aged 13 wk) Sprague-Dawley rats during the 7 days after induction of diabetes with streptozocin. Kidney weight in postpubertal diabetic animals was significantly greater than in postpubertal controls by day 2 (1.46 +/- 0.06 vs. 1.16 +/- 0.09 g, P less than 0.05), and by day 7, kidney weight had increased by 36% (1.61 +/- 0.07 vs. 1.18 +/- 0.08 g, P less than 0.001). Despite comparable blood glucose levels in the prepubertal and postpubertal diabetic rats, kidney weight in prepubertal diabetic animals was significantly greater than in prepubertal controls by 14% on day 7 only (0.84 +/- 0.01 vs. 0.73 +/- 0.03 g, P less than 0.05). Kidney IGF-I content was significantly elevated in diabetic postpubertal rats, peaking on day 1 (diabetic vs. control, 1082 +/- 156 vs. 543 +/- 21 ng/g, P less than 0.001) and day 2 but not in prepubertal diabetic rats. Thus, prepubertal diabetic rats have reduced and retarded kidney growth and attenuated kidney IGF-I levels, suggesting that local IGF-I accumulation may play an important role in diabetes-associated kidney enlargement.

Animals↗

Kidney growth and renal function in unilateral multicystic dysplastic kidney disease.

The natural history of multicystic dysplastic kidney (MCDK) is not well established. We analyzed kidney growth and renal function in 33 children with prenatally diagnosed unilateral MCDK in a long-term study. The mean observation period was 4.9 years with a range of 1-11.6 years. Abnormalities of the contralateral kidney were found in 10 of 33 patients (30%): ureteropelvic junction obstruction (5), ureterovesical junction obstruction (2), and vesicoureteral reflux (3). In 6 children the dysplastic kidney had been removed. Complete involution was observed in 48% and a decrease of size in 33% of 27 dysplastic kidneys. At the time of last examination, 27 of 29 children showed a volume of the contralateral kidney above the normal range (>145%). Hypertrophy of the contralateral kidney, defined as kidney length above 2 standard deviation scores (SDS), was seen in 24% of 33 children at birth, thus showing that hypertrophy of the contralateral kidney starts in utero and continues throughout childhood. The extent of contralateral hypertrophy was independent of associated abnormalities in this study. Mean creatinine was increased in the whole group (mean +1.13 SDS). Calculated creatinine clearance in 21 patients over 2 years was within normal limits, with a median of 102 ml/min per 1.73 m2 (range 84-143). Based on the results of this and previous studies, nephrectomy cannot be recommended in typical cases, but a regular follow-up of these patients seems necessary.

Child↗

Localization of major histocompatibility complex (HLA-ABC and DR) antigens in 46 kidneys. Differences in HLA-DR staining of tubules among kidneys.

Biopsies from 46 kidneys that were subsequently transplanted were examined with monoclonal antibodies and the peroxidase-antiperoxidase technique to localize HLA-ABC and DR antigens. There was no variation in the expression of HLA-ABC which was present on all cells of the renal parenchyma. HLA-DR was found consistently on the endothelium of glomeruli and of intertubular capillaries but was only weakly expressed, or not expressed at all, on the endothelium of large vessels. The mesangium of glomeruli also stained for HLA-DR. But there was a striking variation in the expression of HLA-DR by proximal renal tubular cells in the 46 kidneys. HLA-DR was absent from tubules in 11 of 46 kidneys (23%) and probably absent or very weakly expressed in a further 8 kidneys (17%). The expression of HLA-DR in tubular epithelium was not related to the donor's age, sex, blood group, or ischemia times. However, the frequency of HLA-DR3 increased (55%) in donors of kidneys with tubular DR-negative kidneys, as compared with a frequency of 15% in donors of tubular DR-positive kidneys. Although this difference was not significant after a correction for the number of comparisons made, it suggests a genetic influence on the expression of tubular DR. The survival of tubular DR-negative kidneys was better at 1 year than that of tubular DR-positive kidneys (70% vs. 57%--not significant), and tubular DR-positive grafts may have had a higher rate of delayed function when transplanted in cases with a donor-specific positive B cell crossmatch. There was no obvious variation in the number of dendritic cells stained with antibodies to HLA-DR and the leukocyte common antigen despite prior administration of high doses of steroids to some donors before nephrectomy.

Adolescent↗

Early embryonic renal tubules of wild-type and polycystic kidney disease kidneys respond to cAMP stimulation with cystic fibrosis transmembrane conductance regulator/Na(+),K(+),2Cl(-) Co-transporter-dependent cystic dilation.

Metanephric organ culture has been used to determine whether embryonic kidney tubules can be stimulated by cAMP to form cysts. Under basal culture conditions, wild-type kidneys from embryonic day 13.5 to 15.5 mice grow in size and continue ureteric bud branching and tubule formation over a 4- to 5-d period. Treatment of these kidneys with 8-Br-cAMP or the cAMP agonist forskolin induced the formation of dilated tubules within 1 h, which enlarged over several days and resulted in dramatically expanded cyst-like structures of proximal tubule and collecting duct origin. Tubule dilation was reversible upon withdrawal of 8-Br-cAMP and was inhibited by the cAMP-dependent protein kinase inhibitor H89 and the cystic fibrosis transmembrane conductance regulator (CFTR) inhibitor CFTR(inh)172. For further testing of the role of CFTR, metanephric cultures were prepared from mice with a targeted mutation of the Cftr gene. In contrast to kidneys from wild-type mice, those from Cftr -/- mice showed no evidence of tubular dilation in response to 8-Br-cAMP, indicating that CFTR Cl(-) channels are functional in embryonic kidneys and are required for cAMP-driven tubule expansion. A requirement for transepithelial Cl(-) transport was demonstrated by inhibiting the basolateral Na(+),K(+),2Cl(-) co-transporter with bumetanide, which effectively blocked all cAMP-stimulated tubular dilation. For determination of whether cystic dilation occurs to a greater extent in PKD kidneys in response to cAMP, Pkd1(m1Bei) -/- embryonic kidneys were treated with 8-Br-cAMP and were found to form rapidly CFTR- and Na(+),K(+),2Cl(-) co-transporter-dependent cysts that were three- to six-fold larger than those of wild-type kidneys. These results suggest that cAMP can stimulate fluid secretion early in renal tubule development during the time when renal cysts first appear in PKD kidneys and that PKD-deficient renal tubules are predisposed to abnormally increased cyst expansion in response to elevated levels of cAMP.

8-Bromo Cyclic Adenosine Monophosphate↗

Prevalence of family history of kidney disease and perception of risk for kidney disease: a population-based study.

BACKGROUND: A family history of kidney disease is associated with an increased risk for end-stage renal disease (ESRD). However, it is unclear whether blacks are more likely to have a family history of ESRD than other groups independently of kidney disease risk factors. Moreover, their risk perception for kidney disease is unknown. METHODS: The association of race with family history of ESRD and perception of risk for kidney disease was examined in a representative random sample of 402 Georgia residents who completed a telephone interview. Logistic regression analysis was used to derive adjusted odds ratios and 95% confidence intervals for the association between race and family history of ESRD, controlling for age, sex, education level, being a Georgia native, diabetes, hypertension, and personal history of kidney disease. A multinomial logit model was used to derive adjusted estimates for the association between race and perception of risk for kidney disease. RESULTS: Mean age was 43.2 years, 41.0% of respondents were men, 20.1% were black, 6.6% had diabetes, 21.4% had hypertension, 1.6% had a personal history of kidney disease, and 3.7% reported a family member with ESRD. Although blacks were more likely to report a family history of ESRD (odds ratio, 6.43; 95% confidence interval, 2.02 to 20.43), their perception of risk was not greater. CONCLUSION: Although blacks are approximately 6 times as likely to report a family history of ESRD independently of a personal history of kidney disease, diabetes, or hypertension, they do not perceive themselves as more vulnerable for kidney disease.

Adult↗