Acquired cystic disease: replacing one kidney disease with another

Massive Acquired Renal Cysts Presenting with Bowel Obstruction-Like Symptoms

Acquired cystic kidney disease (ACKD) is rarely massive in size. The great majority is asymptomatic and incidentally found on imaging studies for unrelated causes. We reported a case of an 85-year-old male with bilateral multiple huge acquired renal infected cysts, initially presenting with bowel obstruction-like symptoms. The computed tomography (CT) scan later aided in an accurate diagnosis. Symptomatic huge ACKD has, to our knowledge, scarcely been described. In addition, retroperitoneal lesions resulting in abdominal pain remain unusual and underrecognized in general practice.

Wunderlich Syndrome: Wonder What It Is

Wunderlich syndrome (WS) refers to spontaneous renal or perinephric hemorrhage occurring in the absence of known trauma. WS is much less common than hemorrhage occurring after iatrogenic or traumatic conditions. Lenk's triad of acute onset flank pain, flank mass, and hypovolemic shock is a classic presentation of WS but seen in less than a quarter of patients. The majority of patients present only with isolated flank pain and often imaged with an unenhanced CT in the emergency department. The underlying etiology is varied with most cases attributed to neoplasms, vascular disease, cystic renal disease and anticoagulation induced; the etiology is often occult on the initial exam and further evaluation is necessary. Urologists are familiar with this unique entity but radiologists, who are more likely to be the first to diagnose WS, may not be familiar with the imaging work up and management options. In the last decade or so, there has been a conspicuous shift in the approach to WS and thus it will be worthwhile to revisit WS in detail. In our review, we will review the multimodality imaging approach to WS, describe optimal follow up and elaborate on management.

Acquired Cystic Disease of the Kidney in Continuous Ambulatory Peritoneal Dialysis (CAPD) Patients

Acquired Cystic Disease of the Kidney (ACDK) has been increasingly noted in patients with long-standing renal failure and in those treated with dialysis. We assessed the prevalence of different patterns of cysts in 48 randomly selected patients treated with CAPD (23.1 ± 16.0 months). Only 3 patients had been previously treated with hemodialysis. All patients underwent renal ultrasonography (US) and nine underwent computerized tomography (CT). In 22 patients no cysts were found. The other 24 patients were Included In three different groups. Group 1: Cysts that predominate In the renal cortex from 0.3 to 3.0 cm In diameter: 14 patients. Group 2: Cysts less than 0.3 cm in diameter (granular-microcystic pattern): 4 patients. Group 3: SolItary cysts 1 to 3: 6 patients.

US and CT are relIable and sensitive enough to detect cysts even smaller than 0.3 cm in diameter. The incidence of patients with renal cysts increases with the duration of CAPD. Cysts less than 0.3 cm In diameter (Group 2) could correspond to an initial stage of Group 1 cysts or to a new aspect of ACDK. Group 1 and Group 2 cysts were predominant In male patients, while Isolated renal cysts were more frequent in females.

Cancer in Patients on CAPD

Many workers have reported a high incidence of cancer in persons with uremia or on hemodialysis but there is no agreement on this point. Because the incidence of neoplasms in patients on CAPD is unknown, we reviewed the medical records of the 328 patients treated with CAPD at the TWH from 1977 to 1985. Of these, nine developed cancers, of whom three had been treated with immunosuppressive agents previously. Whether or not these three patients are included, we found no significant difference in cancer incidence between the CAPD and the control population (p = 0.12 and 0.51 respectively). In conclusion, this review found no evidence that our CAPD patients had an increased incidence of cancer.

Although an increased incidence of cancer has been reported in patients with chronic renal failure, before or while on hemodialysis, there is no agreement on the issue. The reported incidence of tumors in different studies ranged widely between 0.84 and 9.5% (I, 2). Even though an increasing number of patients have been treated on CAPD, the literature contains no information regarding the incidence of cancer in this population. The present study was undertaken to provide an answer to this question.

Acquired Renal Cystic Disease and Tumor Markers in Chronic Hemodialysis Patients

Acquired renal cystic disease (ARCD) is a well documented complication of end-stage renal disease, and it has been related to the duration of dialysis therapy. The association of this condition with renal cell adenoma or carcinoma has already been established. There have also been studies on the concentration of some tumor markers in hemodialysis (HD) patients, clinically free from neoplastic disease, where it was concluded that some tumor markers could be elevated, despite the absence of malignant disease, suggesting their altered metabolism i.e. clearance by the hemodialysis membrane. We compared the pre-dialysis serum concentration of several tumor markers in three groups of chronic HD patients, all of whom had been on maintenance HD treatment for more than 5 years. Group 1 consisted of 16 patients without ARCD with a mean HD treatment duration of 97.06 ± 28.25 months. Group 2 consisted of 32 patients with a mean HD treatment of 105.62 ± 24.4 months, who had ARCD with less than 10 renal cysts detected by ultrasonography. Group 3 consisted of 14 patients with a mean HD duration of 109.92 ± 37.72 months, with ARCD and more than 10 renal cysts. Concentration of the following tumor markers was determined by EIA or ELISA methods: carcinoembryonic antigen (CEA), mucin-like carcinoma-associated antigen (MCA), neuron-specific enolase (NSE), carbohydrate antigen 19-9 (CA 19-9), prostatic specific antigen (PSA), carbohydrate antigen 125 (CA 125), alpha fetoprotein (AFP), cytokeratin 19-fragments 21-1 (CYFRA 21-1). The concentration of all the tumor markers was comparable in all three patient groups, with no statistically significant difference between groups. The mean concentrations of MCA, PSA, CA 125 and AFP were within the normal range. CEA and CYFRA 21-1 had mean values in the upper limit of their normal values, while NSE and CA 19-9 were increased by more than twofold in all three patient groups. We concluded that (i) tumor markers should be used with caution when diagnosing neoplastic diseases in chronic HD patients, because of their altered metabolism, and (ii) that in the follow up of ARCD with possible neoplastic alteration, imaging techniques remain dominant diagnostic tools.

Prognosis and characteristics of renal cell carcinoma in hemodialysis patients: bilateral occurrence does not influence cancer-specific survival

OBJECTIVES

To compare characteristics and prognosis unilateral and bilateral renal cell carcinoma (RCC) in hemodialysis (HD) patients.

METHODS

Overall 246 HD patients who had undergone a radical nephrectomy for RCC were enrolled in this study. Unilateral RCC occurred in 201 patients, synchronous bilateral RCC in 15 and metachronous bilateral RCC in 30. Cancer-specific survival (CSS) was accessed by the Kaplan-Meier method.

RESULTS

Five-year CSS was not significantly different between the two groups (unilateral, 90%; bilateral, 90%; P=0.9509). In total 17 of the 201 patients (8.5%) with unilateral occurrence and four of the 45 patients (8.9%) with bilateral occurrence died from kidney cancer during the follow-up period. The presence of acquired cystic disease of kidney (unilateral, 73%; bilateral 91%; P=0.00319) and the mean duration of HD before surgery (unilateral: 157±91 months, bilateral: 189±83.5, P = 0.0319) were significantly different between the two groups. There were more multifocal tumors in bilateral than in unilateral occurrence (bilateral: 74%, unilateral: 30%, P<0.0001). There were significant differences in CSS according to HD duration before surgery (5-year CSS >180 months 82%, ≤180 months 95%; P=0.0004), tumor grade (G1 100%, G2 90%, G3 38%; P<0.0001), and tumor size (>4 cm 75%, ≤4 cm 98%; P<0.0001).

CONCLUSIONS

The type of occurrence of RCC, unilateral or bilateral, in HD patients does not appear to influence CSS. Patients with a longer duration of HD have to be followed up rigorously because they tend to have poor cancer prognosis.

Why kidneys fail in autosomal dominant polycystic kidney disease

The weight of evidence gathered from studies in humans with hereditary polycystic kidney disease (PKD)1 and PKD2 disorders, as well as from experimental animal models, indicates that cysts are primarily responsible for the decline in glomerular filtration rate that occurs fairly late in the course of the disease. The processes underlying this decline include anatomic disruption of glomerular filtration and urinary concentration mechanisms on a massive scale, coupled with compression and obstruction by cysts of adjacent nephrons in the cortex, medulla and papilla. Cysts prevent the drainage of urine from upstream tributaries, which leads to tubule atrophy and loss of functioning kidney parenchyma by mechanisms similar to those found in ureteral obstruction. Cyst-derived chemokines, cytokines and growth factors result in a progression to fibrosis that is comparable with the development of other progressive end-stage renal diseases. Treatment of renal cystic disorders early enough to prevent or reduce cyst formation or slow cyst growth, before the secondary changes become widespread, is a reasonable strategy to prolong the useful function of kidneys in patients with autosomal dominant polycystic kidney disease.

Renal Cell Carcinoma in Transplant Recipients with Acquired Cystic Kidney Disease

BACKGROUND

Acquired cystic kidney disease (ACKD) is a widely known renal cell carcinoma risk factor.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

An ultrasound screening of the native kidneys in all renal transplant patients of a renal outpatient clinic who received a transplant between 1970 and 1998 and presented between 1997 and 2003 (n = 916) was initiated prospectively. A total of 561 patients were screened.

RESULTS

A total of 129 (23%) patients had ACKD; 46 (8.2%) patients had complex renal cysts (Bosniak classification, category IIF to III); and eight (1.5%) patients had newly diagnosed renal cell carcinoma, seven of which were associated with ACKD (category IV). One patient had renal cell carcinoma in the transplanted kidney. Together with 19 patients of the cohort with formerly diagnosed renal cell carcinoma (18 of them associated with ACKD), the prevalence of renal cell carcinoma among all patients was 4.8%; among the patients with ACKD, it was 19.4% (without ACKD 0.5%; P = 0.0001); and among the patients with complex renal cysts (category IIF to III), it was 54.4%. The patients with ACKD were older (54 +/- 13 versus 51 +/- 14 yr; P = 0.048), more often male (65 versus 54%; P = 0.03), more often had heart disease (44 versus 29%; P = 0.001), had larger kidneys (6.9 and 6.8 cm versus 6.0 and 5.9 cm; P < 0.001), and had more calcifications (29 versus 15%; P = 0.002). Renal cell carcinoma was bilateral in 26% of cases. Tumor histology was clear cell carcinoma in 58% and papillary carcinoma in 42% of cases; one patient had both. Only one patient had a lung metastasis, and no patient died.

CONCLUSIONS

Renal cell carcinoma occurs often after renal transplantation and that especially patients with ACKD should routinely be screened. Because ACKD after renal transplantation seems to be less frequent (23%) than during dialysis treatment (30 to 90%), renal transplantation may inhibit renal cell carcinoma.

Cystic renal disease

Renal cysts are relatively common radiographic and clinical abnormalities. Cystic renal disease is a heterogeneous entity comprised of heritable, developmental, and acquired disorders. During the last decade, considerable progress has been made in reaching a consensus for standard terminologies and classifications of cystic renal disease among radiologists, pathologists, nephrologists, and urologists. This article discusses more common MR imaging-related types of cystic renal disease.

Renal imaging in patients requiring renal replacement therapy

Recent advances in imaging technology and interventional radiologic procedures have resulted in an increased variety of radiological techniques that can be used to assess patients who present with renal failure and require renal replacement therapy. This chapter provides an overview of the relative strengths and weaknesses of the available imaging methods. In particular, it covers the expanding role of the cross-sectional, noninvasive, multiplanar imaging techniques such as gray-scale and Doppler ultrasound, magnetic resonance imaging (MRI) and angiography (MRA), and nonenhanced helical or multislice computed tomography (CT). These imaging methods are increasingly replacing those used in the past, such as the conventional radiographic urogram, which requires a high dose of intravenous contrast media, and digital subtraction arteriography. The chapter also covers the radiologic investigation of complications of acquired renal cystic disease, including renal cell carcinoma, hemorrhage, cyst infection and rupture, and nephrolithiasis.

Uteroglobin promoter-targeted c-MYC expression in transgenic mice cause hyperplasia of Clara cells and malignant transformation of T-lymphoblasts and tubular epithelial cells

To investigate the influence of the proto-oncogene c-MYC on tumor development in different epithelial tissues which secrete Clara Cell Secretory Protein (uteroglobin, UG), transgenic mouse lines were established expressing the human c-MYC proto-oncogene under the control of the rabbit UG-promoter. These mice expressed the c-MYC transgene in Clara cells and other UG expressing tissues like uterus and prostate. In the bronchioalveolar epithelium of the lung hyperplasias developed originating from Clara cells. Surprisingly, transgenics most frequently developed T-lymphoblastic lymphomas, a polycystic kidney phenotype and renal cell carcinoma derived from tubular epithelial cells, which are both tissues that had so far not been known to express UG. Immunohistological studies in UG/MYC transgenics and in a transgenic line (UG/eGFP) expressing Green Fluorescent Protein confirmed that the uteroglobin promoter is not only active in Clara cells, but also in tubular epithelial cells of the kidney and in lymphatic tissue. The UG/MYC transgenics will be useful to investigate the biochemical mechanisms underlying the development of carcinomas and the oncogenic properties of c-MYC in epithelial cells of various tissues.

Renal microcystic tubular lesions in two 1Year-old dogs - an early sign of hereditary renal cystadenocarcinoma?

As a part of a study of early renal changes in renal cystadenocarcinoma (RC), a 5-year-old German shepherd dog and two 1-year-old German shepherd mixed-breed dogs were examined. All three animals had bilateral, microscopic renal cysts, and the 5-year-old dog also had RC. Microscopical examination showed papillary hyperplastic tubular epithelial cells lining the inner wall of the renal cysts in all dogs. These cells showed strong reactivity with a monoclonal antibody against a broad-spectrum type of cytokeratin. The dam of the young dogs had suffered from autosomal dominant inherited RC and nodular dermatofibrosis (ND) syndrome. It is likely that the microscopic renal cystic lesions seen in the young dogs represented an early renal change in the RC/ND syndrome. This suggests that the diagnosis of RC can be made on suspected carriers by microscopical examination of renal biopsies as early as 1 year of age, i.e., before the dogs are used for breeding.

Insulin-like growth factor I plays a role in regulating erythropoiesis in patients with end-stage renal disease and erythrocytosis

Erythroid progenitor growth, the serum hormones that regulate erythropoiesis, and the effect of patient's serum on the growth of normal erythroid progenitors were assessed in eight patients with end-stage renal disease (ESRD) and erythrocytosis. All patients were male and had been on maintenance dialysis, they had a hematocrit >50% and/or a red blood cell count >6 x 10(12)/L and an arterial oxygen saturation >95%. Four had acquired cystic disease of the kidney (ACDK), and four other non-ACDK patients did not have known causes of secondary erythrocytosis after appropriate investigations and long-term follow-up. The methylcellulose culture technique was used to assay the erythroid progenitor (BFU-E/CFU-E) growth. Serum erythropoietin (EPO) and insulin-like growth factor I (IGF-I) levels were measured by RIA. Paired experiments were performed to determine the effects of 10% sera from ESRD patients and control subjects on normal marrow CFU-E growth. The numbers of EPO-dependent BFU-E in marrow and/or blood of patients with ESRD and erythrocytosis were higher than those of normal controls. No EPO-independent erythroid colonies were found. Serum EPO levels were constantly normal in one patient and elevated in three patients with ACDK; for non-ACDK patients, EPO levels were normal or low in two patients and persistently increased in one, but fluctuated in the remaining one on serial assays. There was no correlation between serum EPO levels and hematocrit values. The serum IGF-I levels in patients with ESRD and erythrocytosis were significantly increased compared with normal subjects or ESRD patients with anemia. We found an inverse correlation between serum EPO and IGF-I levels. Sera from patients with ESRD and erythrocytosis exhibited a stimulating effect on normal marrow CFU-E growth. The stimulating effect of sera from patients who had a normal serum EPO level and an elevated IGF-I level could be partially blocked by anti-IGF-I. The present study suggests that IGF-I plays an important role in the regulation of erythropoiesis in patients with ESRD and erythrocytosis who did not have an increased EPO production.

Current concepts and controversies in imaging of renal cystic diseases

Renal cystic disease compromises a diverse group of inherited and acquired entities. This article reviews the clinical, pathologic, and radiologic findings of eight renal cystic diseases. For each entity, the current concepts of pathogenesis and pathophysiology are discussed. When appropriate, controversies concerning terminology, management, and malignant potentials are addressed. Renal cystic diseases that are discussed include autosomal dominant and autosomal recessive polycystic kidney disease, medullary sponge kidney, medullary cystic disease, multicystic, dysplastic kidney, von Hippel-Lindau disease, acquired cystic kidney disease, and tuberous sclerosis.

Polycystic kidney disease: etiology, pathogenesis, and treatment

Once viewed as hopelessly incurable disorders and the dustbin for careers in academic medicine, the polycystic kidney diseases have emerged as prime targets of pathophysiologic study and palliative and definitive treatment in the era of molecular medicine. Polycystic kidney disease (PKD) may be hereditary or acquired. The major inherited types are autosomal dominant (AD) and autosomal recessive (AR). ADPKD is caused by at least two (and possibly three) genes located on separate chromosomes, while ADPKD-1 is due to a 14 kb transcript in a duplicated region on the short arm of chromosome 16 very near the alpha-globin gene cluster and the gene for one form of tuberous sclerosis. ADPKD-2 has been assigned to the long arm of chromosome 4. ARPKD is due to a mutated gene on both copies of the long arm of chromosome 6. Cysts originate in renal tubules. Proliferation of tubule epithelial cells modulated by endocrine, paracrine, and autocrine factors is a major element in the pathogenesis of renal cystic diseases. In addition, fluid that is abnormally accumulated within the cysts is derived from glomerular filtrate and, to a greater extent, by transepithelial fluid secretion. Abnormal synthesis and degradation of matrix components associated with interstitial inflammation are additional features in the pathogenesis of renal cystic diseases. The ADPKD genotypes are characterized by bilateral kidney cysts, hypertension, hematuria, renal infection, stones, and renal insufficiency. ADPKD is a systemic disorder; cysts appear with decreasing frequency in the kidneys, liver, pancreas, brain, spleen, ovaries, and testis. Cardiac valvular disorders, abdominal and inguinal hernias, and aneurysms of cerebral and coronary arteries and aorta are also associated with ADPKD. Treatment is supportive: dietary regulation of salt and protein intake, control of hypertension and renal stones, and dialysis and transplantation at the end stage. ARPKD is a relatively rare disease that causes clinical symptoms at birth, with significant mortality in the first month of life. The cysts develop primarily in the collecting ducts because of a failure in the maturation process. Early complications include Potter's syndrome; excessive size of the kidneys, causing respiratory dysfunction; hypertension; and renal insufficiency. Hepatic fibrosis is an associated extrarenal problem that results in significant morbidity in young children and adolescents. Treatment includes supportive care, dialysis, and renal transplantation. Acquired cysts (solitary/simple) are commonplace in older persons. Multiple cysts may be seen in association with potassium deficiency, congenital disorders, metabolic diseases, and toxic renal injury.(ABSTRACT TRUNCATED AT 400 WORDS)

Partial nephrectomy: technique, complications and pathological findings

PURPOSE

We evaluate whether partial nephrectomy can be performed safely and efficaciously for renal tumors.

MATERIALS AND METHODS

The results of 67 partial nephrectomies performed between 1977 and 1994 for renal cell carcinoma (51), oncocytoma (9), angiomyolipoma (3), transitional cell carcinoma (3) and other nonneoplastic lesions (2) were analyzed retrospectively in detail.

RESULTS

Diminished complication rates were noted after 1988, and were attributed to improvements in surgical technique and an increased incidence of smaller, serendipitously discovered tumors. Although 35.5% of the patients had preoperative renal impairment (mean serum creatinine 2.1 mg./dl.), there were minimal changes in renal function and no patient required acute hemodialysis following partial nephrectomy. Among 42 patients with clinical stage T1 to T2 renal cell carcinoma undergoing partial nephrectomy local recurrence was identified in 8.3% of those with primary neoplasms. All 6 patients with local recurrence had negative surgical margins, recurrence often, distant from the operative site and multifocal disease, implicating multicentricity as the etiology of local recurrence. Five patients (83.3%) with local recurrence were alive and asymptomatic at a mean of 138 months after partial nephrectomy. Since capsular penetration was identified in 5 of 27 renal cell carcinomas (18.5%) with a diameter of 3.5 cm. or less, aggressive surgical resection with adequate tumor-free parenchymal and perinephric margins is necessary even for small lesions.

CONCLUSIONS

With improved surgical techniques, including regional hypothermia, intraoperative sonography, meticulous dissection and injection of the collecting system with methylene blue, partial nephrectomy is safe and effective in properly selected patients.

Screening for acquired cystic kidney disease: a decision analytic perspective

Acquired cystic kidney disease (ACKD) increases the risk of renal malignancy, and many authors suggest routine screening of dialysis patients for ACKD and renal tumors. However, they have defined neither the target population, the optimal screening strategy, the magnitude of its benefit, nor its risk. We used decision analysis to evaluate strategies of performing either computed tomography (CT) or ultrasound every three years on all dialysis patients and annually on patients found to have cysts. We compared these strategies to a strategy of seeking cysts and cancer only if these are clinically suspected. The baseline analysis shows that both CT and ultrasound may decrease cancer deaths by half for patients with a life expectancy of 25 years. Screening for ACKD offers these patients as much as a 1.6 year gain in life expectancy. However, for the majority of patients beginning renal replacement therapy, age or comorbid disease substantially limits life expectancy. For such patients, the gain in life expectancy from an ACKD screening program is measured in days. Sensitivity analyses show that the benefit of screening depends on the rate of malignant transformation, which needs better definition. The gain in life expectancy does not appear to be large enough to justify an ACKD screening program for the entire ESRD population. However, for the youngest and healthiest patients, a screening program would be of benefit. The magnitude of this benefit is uncertain, because the analysis was consistently biased in favor of the screening strategies.

Renal neoplasm in acquired cystic kidney disease

The development of renal cell neoplasms ranging from adenoma to metastatic carcinoma is the most serious complication of acquired cystic kidney disease (ACKD). A comprehensive review of the pertinent literature shows that there is up to 50-fold increased risk of renal cell carcinoma in ACKD compared to the general population. The ACKD-associated renal cell carcinoma is seen predominantly in males, occurs approximately 20 years earlier than in the general population, and is frequently bilateral (9%) and multicentric (50%). Acquired cystic kidney disease-associated renal cell carcinoma is frequently asymptomatic (86%), but may be associated with bleeding, abrupt changes in hematocrit, fever, and flank pain or rarely with hypoglycemia, hypercalcemia, or metastases at presentation. Computed tomography seems to provide a better diagnostic yield than sonography or magnetic resonance imaging; nevertheless, large (up to 8 cm) tumors not visualized by any imaging techniques have been reported. It is generally agreed that there is a need for regular screening of symptomatic ACKD patients for early detection of renal cell carcinoma; however, whether screening is needed for asymptomatic patients remains controversial. Nephrectomy is indicated for tumors larger than 3 cm. Management for tumors smaller than 3 cm with persistent symptoms, such as back pain or hematuria, remains controversial, but nephrectomy may be recommended since many of these tumors turn out to be unequivocal renal cell carcinoma. Asymptomatic tumors smaller than 3 cm should be serially screened, and tumor enlargement may be an indication for nephrectomy. Acquired cystic kidney disease-associated renal cell carcinoma accounts for approximately 2% of deaths in renal transplant patients. A median length of survival of approximately 14 months and a 5-year survival rate of 35% are comparable to the same data for renal cell carcinoma in the general population. Successful renal transplant probably decreases the risk of renal cell carcinoma in ACKD patients, but this preliminary observation needs confirmation. The development of ACKD-associated renal carcinoma is a continuous process with evolving phenotypic expression, including damaged renal tubule, simple cyst, cyst with atypical lining, adenoma, and, finally, carcinoma. The pathogenesis of this continuous process is not entirely known, but growth factor-induced compensatory growth of tubular epithelium initiated by the changes of end-stage kidney disease, and probably perpetuated by activation of proto-oncogenes, seems to be the most significant factor.

DNA flow cytometric analysis in renal neoplasms associated with acquired renal cystic disease

In order to better understand the potential malignancy of renal neoplasms arising in patients with acquired renal cystic disease and to try and establish differences from other renal tumours we analysed DNA ploidy as well as the level of S-phase fraction in 11 neoplasms associated with acquired cystic disease by means of flow cytometry. The results were correlated with known prognostic factors such as nuclear grade, size and stage, as well as the clinical behaviour of the tumours. We found a close relationship between DNA aneuploidy and high S-phase fraction and a poor clinical outcome. We also found some differences in the DNA ploidy profile of these tumours when compared with those reported in other renal neoplasms.

Association of cyclosporin A with acquired cystic kidney disease of the native kidneys in renal transplant recipients

Acquired cystic kidney disease (ACKD) is a common complication in patients treated with long-term dialysis. Previous studies performed prior to the cyclosporin A (CsA) era indicate that successful renal transplantation causes regression of ACKD. Little has been published, however, on the occurrence of ACKD in CsA-treated transplant recipients. We conducted a prospective sonographic study in 33 renal transplant recipients and 32 dialysis patients to evaluate the effect of CsA on ACKD in transplant recipients. Transplant recipients had a lower prevalence (39% vs. 56% in dialysis patients) and severity (smaller kidneys and lower cyst grades) of ACKD when compared with dialysis patients. Renal cell carcinoma was found in two dialysis patients. Using multiple regression analysis, we found that the use of CsA was significantly correlated with the presence of ACKD in transplant recipients (57% in CsA-treated vs. 8% in non-CsA-treated patients). We conclude that renal transplantation reduces the prevalence and severity of ACKD in the native kidneys; however, among transplant patients, CsA administration is associated with a greater prevalence of ACKD.

High incidence of papillary renal cell tumours in patients on chronic haemodialysis

Papillary and nonpapillary renal cell tumours can be differentiated according to their genetic constitution. In this study, their incidence in end stage kidney disease has been investigated histologically. Nonpapillary renal cell carcinoma was observed in 22 cases (51.2%) whereas papillary renal cell tumours were diagnosed in 21 (48.8%) of the 43 patients with end stage kidney disease. The incidence of papillary renal cell tumours in end stage kidney disease is significantly higher (chi 2 = 31.9; P < 0.001) than in the general population (4.8%). Haemodialysis patients with nonpapillary and papillary renal cell tumours did not show significant differences in age, sex or size of tumour. However, patients with papillary renal cell tumours had received longer duration of haemodialysis than patients with nonpapillary renal cell carcinomas. These data suggest that not only different genetic events but also different aetiological factors are involved in the development of the two types of tumour in end stage kidney disease.

Polycystic kidney disease: primary extracellular matrix abnormality or defective cellular differentiation?

Polycystic kidney disease (PKD) is inherited as a dominant or recessive trait or can be provoked by environmental factors. The disease is characterized by the growth of large epithelial-lined cysts derived from the nephrons and collecting ducts of affected kidneys. Cysts are thought to initiate as small dilations in renal tubules, which then expand into fluid-filled cavities of relatively large size. Cyst formation appears to involve increased cell proliferation, reversal of tubular epithelial polarity, and epithelial fluid secretion. In addition, a number of pronounced extracellular matrix changes have been found in the cystic kidneys of several animal models and in human autosomal dominant PKD. These abnormalities include thickened, laminated basement membrane, increased expression of alpha 1 type IV collagen and laminins B1 and B2, and changes in heparan sulfate proteoglycan and fibronectin. Some of these changes can also be seen in vitro, reflecting intrinsic abnormalities, and may be associated with abnormal tubular morphogenesis early in cyst formation as well as later in cyst expansion. We have been investigating gene expression in the C57BL/6J-cpk mouse, which has an autosomal recessive form of PKD, to determine the genetic basis of the abnormal tubule cell growth and morphology manifested during cyst formation.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired cystic disease of the kidney and renal carcinoma in haemodialysis patients: ultrasonographic evaluation

Ultrasonography was performed in 661 dialysis patients and acquired cystic disease of the kidney was found in 156 (125 men and 31 women). A higher incidence of cystic disease was found in males. There was no significant difference between the patients with and those without acquired cystic disease in terms of average age, but the duration of haemodialysis in those with acquired cystic disease was significantly longer. There was an increased incidence of cystic disease in patients with glomerulonephritis and the duration of haemodialysis in these patients was significantly longer. This suggests that the increased incidence of acquired cystic disease of the kidneys in the patients with glomerulonephritis is simply related to the longer duration of treatment. Twelve patients with renal carcinoma were found in this study. The average age at diagnosis of renal carcinoma was not significantly different between the patients with and those without acquired cystic disease, but the duration of dialysis was significantly longer in renal carcinoma patients with acquired cystic disease. The incidence of renal carcinoma in dialysis patients with acquired cystic disease was 3.85% and in those without it was 1.19%. These rates are considerably higher than those found in the general population and indicate that the risk of renal carcinoma is higher in dialysis patients both with and without acquired cystic disease.

In vitro formation and expansion of cysts derived from human renal cortex epithelial cells

Acquired renal cysts derive from terminally differentiated tubular epithelium in adults as a consequence of increased epithelial cell proliferation, fluid accumulation and extracellular matrix remodelling. To understand better how human epithelial cysts may be initiated and progressively expand, cells from primary cultures of normal human adult renal cortex were dispersed in polymerized type I collagen. The transparent matrix permitted repeated observation by light microscopy of cyst formation from individual renal cells. The cyst cells reacted strongly with distal nephron histochemical markers (cytokeratin antibodies AE1/AE3, epithelial membrane antigen, and Arachis hypogaea lectin) but inconsistently or not at all to markers of proximal tubules (Tetragonolobus purpureas lectin and Phaseolus vulgaris erthroagglutinin lectin). The number of spherical, fluid-filled epithelial cysts that developed in a standardized microscope field quantified cyst initiation. Cyst progression was determined from the increase in the diameter (surface area) of cysts and represents a hyperplastic event. EGF or TGF alpha, were required in serum-free defined medium to cause cysts to develop from individual epithelial cells dispersed in the matrix; insulin was required as a co-factor. The EC50 for EGF was approximately 0.1 ng/ml, and for insulin 1 microgram/ml. Early cultures of normal cortex formed cysts more efficiently when dispersed in collagen matrix than cells passaged several times before suspension in the gel. Agonists of adenylate cyclase (PGE1, AVP, VIP, PTH, forskolin, cholera toxin), methylisobutylxanthine, and 8-Br-cAMP, though incapable of causing cyst formation alone in defined medium, enhanced cyst initiation and progression in the presence of EGF and insulin. Angiotensin II, TNF alpha, beta-estradiol, and pertussis toxin had no effect in the absence or presence of EGF and insulin. Pertussis toxin inhibited cyst initiation and expansion caused by EGF and forskolin but potentiated cyst initiation and expansion caused by EGF and PGE1. Cyst formation and expansion were inhibited by TGF beta 1 and 2-chloroadenosine. Polarized monolayers of human renal cortical cells grown on permeable membranes were used to independently quantify the effects of agonists on the net secretion of solute and water from the basolateral to the apical surface of the cells. PGE1, forskolin, and 8-Br-cAMP stimulated net fluid secretion that was sustained for several days; EGF enhanced forskolin-stimulated fluid secretion. We conclude that the formation and expansion of in vitro cysts derived from solitary human cortex cells depends on the coordinated interplay between cellular proliferation and fluid secretion.(ABSTRACT TRUNCATED AT 400 WORDS)

Localization of overexpressed c-myc mRNA in polycystic kidneys of the cpk mouse

The C57BL/6J-cpk mouse has a form of autosomal-recessive polycystic kidney disease characterized by the rapid growth of large collecting duct cysts and the development of severe renal failure usually by three to four weeks of age. Previous studies had shown higher steady-state levels of proto-oncogene mRNA in these cystic kidneys. It is now shown using nuclear run-on transcription that the c-fos and c-myc proto-oncogenes are transcribed at higher rates in cystic kidneys, and thus that increased transcription, in part, may account for the increased mRNA levels. c-myc mRNA was detected by in situ hybridization in nephron anlagen and elongating tubules of normal and cystic kidneys during late fetal and early neonatal kidney development. Localization of c-myc expression in the normal kidney decreased with age over the three-week postnatal period. By contrast, c-myc mRNA was found in cysts as early as three days of age, with increased levels at two and three weeks. c-myc expression was also elevated in apparently normal, non-dividing proximal tubules in three-week-old cystic animals. On the basis of these findings, we suggest that c-myc expression is linked to the proliferation of cells engaged in the primary cystogenic process, and that expression of this gene in proximal tubule cells of severely azotemic animals reflects the compensatory response of residual tubular epithelial cells to progressive renal dysfunction.

Renal cell carcinoma in uremic acquired renal cystic disease: incidence, detection, and management

Patients with end-stage kidney disease, particularly those treated with dialysis, have an increased risk of renal cell carcinoma. Renal cell carcinoma may also develop in the native kidneys of renal transplant recipients with good graft function many years after transplantation. Recent studies suggest that the incidence of renal carcinoma among dialysis patients is 3-6 times greater than in the general population. However, annual imaging of the native kidneys of all dialysis patients is not justified because it has not been shown to have a significant effect on patient outcome. Screening may, however, be useful in selected patients with good general medical conditions and who have known risk factors for renal carcinoma.

Acquired cystic disease of the kidney analyzed by microdissection

Four cases of acquired cystic disease of the kidney (ACDK) were studied by the microdissection technique (MD) of Darmady and Baert to analyze the cystic transformation. No patient had a history or clinical evidence of the adult polycystic disease of the kidney (APDK). Hypothetical models related the pathogenesis of cystic transformation to either obstructive or degenerative factors. Microdissection was performed in four nephrectomy specimens of hemodialyzed patients and a total of 155 nephrons were isolated. The atrophy of the glomeruli has already been described histopathologically but MD demonstrated the existence of nephrons consisting of sclerotic glomeruli and enlarged segments between the atrophic convoluted proximal and distal tubules. Diverticula and cysts were located, above all along the proximal (mainly dilated) convoluted tubules: they were always in continuity with the tubules. Phase contrast microscopy showed a patent lumen in 80% of the proximal and distal convoluted tubules, and a regular lining of the cysts. These data support the hypothesis that ACDK is the result of hyperplasia and dilation of remaining nephrons, rather than a result of obstruction and/or fibrosis.

C-erb B-2 amplification in cystic renal disease

Gene amplification (overexpression) of c-erb B-2 was tested in a variety of cystic renal diseases, renal cell neoplasms (adenomas and carcinomas) and end stage kidneys without cysts. C-erb B-2 encodes a receptor-like protein that shares homology with, but is distinct from the epidermal growth factor (EGF) receptor. A monoclonal antibody that immunoprecipitates a protein of approximately 185 kD from a lysate of NIH/3T3 cells transfected with the c-erb B-2 gene was utilized for testing. Simple renal cysts, cystic renal dysplasia, autosomal recessive polycystic kidney disease (ARPKD), and non-cystic, essentially normal kidneys failed to show c-erb B-2 overexpression. In contrast, autosomal-dominant polycystic kidney disease (ADPKD), acquired (dialysis-associated) cystic disease (ACD), non-cystic end stage kidneys and renal cell neoplasms revealed overexpression of c-erb B-2 with some frequency (40% or more of cases tested). Three cystic disorders revealing c-erb B-2 overexpression also showed platelet-derived growth factors (PDGFs) expression in similar locations (cyst lining and adjacent tubules). Other growth factors [insulin-like growth factor (IGF-I), fibroblast growth factor (FGF) and beta transforming growth factor (TGF beta)] were not noted to be overexpressed in either c-erb B-2 positive or negative cystic diseases. C-erb B-2 may be a marker related to the proliferative/growth capabilities of selected cystic diseases, including potential for associated genesis of benign and malignant renal cell tumors.

The SGP-2 gene is developmentally regulated in the mouse kidney and abnormally expressed in collecting duct cysts in polycystic kidney disease

Sulfated glycoprotein-2 (SGP-2) is a secreted, dimeric, glycosylated protein synthesized by a number of different epithelial cell types. Although its function is not yet understood, SGP-2 has been hypothesized to be involved in such diverse processes as the promotion of cell-cell interactions, spermatogenesis, modulation of the complement system, and programmed cell death. We have now found that the SGP-2 gene is developmentally regulated in the mouse kidney. SGP-2 gene expression is first detected in the condensing nephrogenic mesenchyme and is subsequently down-regulated during the maturation of the glomerular epithelia, proximal tubules, and collecting ducts. SGP-2 continues to be expressed in the mature kidney in distal tubules and in the urothelial lining of the calyx and papilla. We have also examined the expression of the SGP-2 gene in polycystic kidneys of the C57BL/6J-cpk mouse, a model of autosomal recessive polycystic kidney disease in which there is development of epithelial-lined cysts arising primarily from the collecting duct system. Abnormally high levels of SGP-2 mRNA were found in the cyst wall epithelium of polycystic kidneys. The expression of the SGP-2 gene in normal development suggests that it plays a role in differentiating epithelial structures; and the abnormally high levels of SGP-2 gene expression in polycystic kidneys suggests that the cells lining cysts are not fully differentiated. It is possible, therefore, that polycystic kidney disease is caused by a defective developmental process in which there is a delay in terminal differentiation.

The urine urokinase concentration in end stage renal disease with acquired renal cyst

To see whether there was any difference in the urine urokinase concentration between acquired cystic kidney disease (ACKD) group and control (non cyst) group in end stage renal disease patients (ESRD), we evaluated fifty ESRD patients who had been maintained on chronic hemodialysis for various period. The urine urokinase concentration was higher in the ACKD group (17.5 +/- 14.7 unit/ml, range 13.5-47.0 unit/ml, n = 9) than the control group (4.1 +/- 3.4 unit/ml, range 0.5-12.0 unit/ml, n = 36) (p less than 0.001), and polycyst group (2.6 +/- 1.8 unit/ml, range 1.0-5.1 unit/ml, n = 5) (p less than 0.01). But there was no difference between the control group and polycyst group. In the control group and the ACKD group, there was a direct relation between the dialysis duration and the urokinase concentration and the longer the dialysis duration, the higher the urine urokinase concentration (r squared = 0.424, p = 0.0001). The hemodialysis duration was longer in the ACKD group (42 +/- 17.0 months) than the control group (20.0 +/- 12.5 months) (p less than 0.005). These findings suggest that urokinase may be responsible for cystogenic degeneration in ESRD.

Plasma erythropoietin levels and acquired cystic disease of the kidney in patients receiving regular haemodialysis treatment

Acquired cystic disease of the kidney (ACDK) in patients with end-stage renal failure can be associated with development of polycythaemia. The relationship between plasma erythropoietin levels and ACDK in 17 patients on long-term haemodialysis treatment was studied. There was a significantly higher level of plasma erythropoietin in patients with multiple renal cysts than in those patients with less than five cysts or no cysts. Haemoglobin tended to be higher in the ACDK group, but the difference was not significant. These results indicate that the development of renal cysts results in increased secretion of erythropoietin.

Comparison of proteoglycans synthesized by porcine normal and polycystic renal tubular epithelial cells in vitro

Newly synthesized porcine tubular epithelial cell proteoglycans were labeled in vitro with Na2[35S]SO4. At the beginning of the labeling period (24 h) [35S] sulfate incorporated into macromolecules was measured following PD-10 chromatography. There was a significant reduction in the amount of 35S-labeled macromolecules isolated from polycystic cells compared to that from normal cells. The distribution of recovered radiolabeled material among the medium, cell surface, and intracellular fractions was similar for both normal and polycystic cells. Analysis of the proteoglycans in polycystic cells demonstrated that 86 and 73% of 35S-labeled macromolecules were of the heparan sulfate type in polycystic and normal cells, respectively. The remainder was chondroitin sulfate. Proteoglycans were characterized using DEAE-Sephacel ion-exchange chromatography, chondroitinase ABC, heparitinase, and nitrous acid digestion followed by Sepharose CL-4B gel permeation chromatography. The majority of radiolabeled material in the medium, cell surface, and intracellular fractions eluted between 0.35 and 0.39 M NaCl. However, a second peak (peak II) that eluted at 0.25 M NaCl was found in the medium from polycystic cells. This peak accounted for 27% of the total macromolecules secreted into the medium. Proteoglycans in the major peak were susceptible to nitrous acid and chondroitinase ABC digestion. A similar proportion of peak II was degraded by chondroitinase ABC. However, the remainder was only slightly susceptible to treatment with nitrous acid or heparitase. In normal cells a small amount of material eluted at a similar low charge; the proteoglycans were the same as those found in the major peak and appeared as a shoulder on this peak.

End stage renal disease serum contains a specific renal cell growth factor

End stage renal disease (ESRD) kidneys display abnormal growth characterized by a continuum of cystic disease, adenoma and carcinoma. This study evaluates the hypothesis that serum of patients with ESRD contains increased amounts of a growth factor which specifically induces proliferation of renal cells. ESRD sera compared to sera from normal controls induced a two to three-fold increase in the proliferative rate of renal cell carcinoma cell lines and normal kidney explants compared to cell lines from other sites. The increased proliferative activity of ESRD sera on renal cells was paralleled by an increase in cytosolic free calcium. The growth factor activity was encoded by a polypeptide of between 15 and 30 kd. The activity of ESRD sera on renal cells was not mimicked or inhibited by epidermal growth factor, basic fibroblast growth factor and platelet derived growth factor indicating that the renal cell specific growth factor activity in ESRD is different from these factors.

Ten-year prospective study on the development of renal cell carcinoma in dialysis patients

A prospective study was undertaken to investigate the development of renal cell carcinoma in dialysis patients. Three renal cell carcinomas were detected among 96 hemodialysis patients in 1979, and screening by computed tomographic (CT) scan was continued yearly until 1989. During this 10-year period, one renal cell carcinoma was found in the second year and another in the ninth year. Autopsy performed on seven of 19 patients who died showed one case of small clear cell carcinoma accompanying acquired cystic disease. In 33 males, kidneys were found to have enlarged 2.7 +/- 1.7 times over the 10-year follow-up due to acquired cysts, while no change in kidney volume was noted in 24 females. Native kidneys in nine of 12 patients who maintained functioning grafts were reduced in size. The patient with the largest kidney enlargement (11.5 times) died from retroperitoneal bleeding in 1989. These prospective study results suggest that both the incidence and prevalence of renal cell carcinoma in dialysis patients is high. Furthermore, major complications of acquired renal cystic disease seem to occur predominantly in males.

Metastatic malignant tumor in native kidney with acquired cystic disease after renal transplantation

Patients on long-term hemodialysis frequently develop Acquired Cystic Renal Disease (ACRD). When hematuria or flank pain occurs, the possibility of malignant renal tumors should be investigated. We present an ACRD patient who received a kidney transplant and developed malignancy in a native kidney, the first manifestation being bone metastases, and discuss the role of CT in evaluating these patients.

Intra- and extracellular proteins in human normal and polycystic kidney epithelial cells

A tissue culture method was established for the continuous growth of epithelial cells from the cortex of human normal kidney (HNC) and from the epithelial layer of kidney cysts from autosomal dominant polycystic kidney disease (ADPKD) patients. Primary cells were grown to 80 to 90% confluency from 1 mm2 slices of tissue, and subcultured up to 10 times. The subcultured HNC and ADPKD cells retained characteristic epithelial polygonal and elongated shape and positive immunofluorescent staining for cytokeratin. The cell doubling time for both HNC and ADPKD epithelia was three to four days at a fetal calf serum (FCS) concentration of 5%. Using these culturing procedures 1 to 5 x 10(9) epithelial cells could be obtained from each kidney specimen. Profiles of 35S-methionine radiolabeled intracellular proteins of HNC and ADPKD cells qualitatively demonstrated a high degree of similarity, thus confirming a similarity of epithelial origin and protein biosynthesis. Both the underexpression of three proteins (a) protein p2, Mr approximately 47 kDa, pI approximately 6.0; b) protein p3, Mr approximately 50 kDa, pI approximately 5.9; and c) protein p4, Mr approximately 44 kDa, pI approximately 5.8) and the overexpression of several proteins (including: a) p5, Mr approximately 56 kDa, pI approximately 7.3; b) protein p6, Mr approximately 32 kDa, pI approximately 7.3; c) protein p7, Mr approximately 33 kDa, pI approximately 5.3; d) protein p8, Mr approximately 45 kDa, pI approximately 6.9; e) protein p9, Mr approximately 35 kDa, pI approximately 6.7; and f) protein p10, Mr approximately 30 kDa, pI approximately 6.6) were found in ADPKD cells.(ABSTRACT TRUNCATED AT 250 WORDS)