Early detection of prostate cancer in the ESRD population.

BACKGROUND: There are currently no prostate cancer screening guidelines specific to the end-stage renal disease (ESRD) population. With this in mind, we evaluated the clinical usefulness of digital rectal examination (DRE), serum total prostate-specific antigen (PSA), prostate-specific antigen density (PSAD) and transrectal ultrasound (TRUS) in predicting prostate cancer in men with ESRD. METHODS: Fifty male ESRD patients age 40 years and older with no prior history of prostate cancer were enrolled in the study. All patients underwent PSA measurement and a DRE followed by a TRUS. PSAD was calculated as the total PSA divided by the prostate volume. Ultrasound-guided prostate biopsies were performed on any patient with 1 or more of the following abnormal findings: a nodule detected on DRE; an abnormal TRUS; PSA > 4.0 ng/ml, or a PSAD > 0.15 ng/ml/cm3. RESULTS: Abnormal findings were detected in 19 patients. Two (4%) had an abnormal DRE, 3 (6%) had PSA > 4.0 ng/ml, 3 (6%) had PSAD > 0.15 ng/ml/cm3 and 16 (32%) had abnormal findings on TRUS. Three patients had 2 abnormal findings and 1 had 3. Of the 15 prostate biopsies performed, 4 (27%) revealed prostate cancer and 3 (20%) high-grade prostatic intraepithelial neoplasm (HGPIN) comprising 8% and 6%, respectively, of the studied population. Of the 4 patients diagnosed with prostate cancer, none had abnormal DRE, 2 (50%) had PSA > 4.0 ng/ml (sensitivity = 66.7% and PPV = 50% (p = 0.236)), 3 (75%) had PSAD > 0.15 ng/ml/cm3 (sensitivity = 100% and PPV = 75% (p < 0.018)), and 3 (75%) had abnormal findings on TRUS (sensitivity = 30% and PPV = 75% (p = 1.000)). CONCLUSION: Routine screening with PSA and DRE does not seem sensitive enough to predict the presence of the disease. Although TRUS detected abnormalities in 16 patients (32%), sensitivity was very low (30%). In our patients, PSAD increased the sensitivity and positive predictive value (PPV) of detecting prostate cancers compared to PSA alone.

Effect of biocompatibility of hemodialysis membranes on serum albumin levels.

Hypoalbuminemia in end-stage renal disease is a marker of high morbidity and mortality. In some patients, the cause of low serum albumin levels is easily identified and therefore treatable, but in many patients, the cause is not clear. We studied the effect of changing the dialysis membrane from a bioincompatible to a biocompatible membrane on serum albumin level. Stable hemodialysis patients dialyzed with cuprammonium membranes who had serum albumin levels less than 3.5 g/dL were switched to the more biocompatible membrane, polysulfone. Serum albumin levels increased from 3.22 +/- 0.037 to 3.35 +/- 0.038 g/dL (mean +/- SE; P < 0.002). The increase was seen in patients both with and without diabetes. Thus, dialyzer membrane may affect serum albumin levels and should be considered in the differential diagnosis of hypoalbuminemia in patients undergoing hemodialysis with bioincompatible membranes. Membrane choice may have an important effect on the outcome of morbidity and mortality of hemodialysis patients.

Extraskeletal Ewing's sarcoma in a kidney transplant patient.

Organ transplant recipients are prone to develop a variety of malignancies, most of which are encountered uncommonly in the general population. Approximately 5% to 7% of these malignancies are sarcomas, of which most are Kaposi's sarcomas. Ewing's sarcoma is an extremely uncommon tumor in organ transplant recipients, and only one case of skeletal Ewing's sarcoma has been reported in the transplant literature. We present a case of extraskeletal Ewing's sarcoma (EES) in a renal transplant patient.

Captopril renal scintigraphy in renovascular hypertension.

Renovascular disease is a common cause of secondary hypertension. Renal artery stenosis is present in up to one third of patients with clinical markers suggestive of renovascular hypertension, such as hypertension refractory to medical management, severe hypertension in a young patient and worsening of renal function after the use of an angiotensin-converting enzyme inhibitor. Early discovery of renal artery stenosis may allow amelioration or cure of the hypertension and halt progressive loss of renal function. Although renal arteriography remains the gold-standard aid to diagnosis and to planning surgical intervention, it is an invasive procedure that may cause deterioration of renal function. In the presence of renal artery stenosis, glomerular filtration is maintained by angiotensin. Administration of captopril in renal scintigraphy removes this compensatory mechanism and causes a temporary impairment of renal function in the affected kidney. Nuclear tracers can visualize this impairment, thus allowing assessment of the physiologic significance of a renal artery stenosis. The test can be done as a outpatient procedure.

Dialysate sodium delivery can alter chronic blood pressure management.

Low dialysate sodium concentrations can reduce postdialysis thirst and serum sodium activity, but patients typically experience dialysis hypotension, fatigue, disequilibrium, and cramps. "High-sodium" hemodialysis minimizes dialysis disequilibrium but increases the serum sodium activity of most patients. Programmed "variable-sodium" dialysis can minimize dialysis discomfort but may also alter the sodium kinetics from those of "high-sodium" dialysis. We designed a cross-over study with random order assignment to determine whether a "variable-sodium" dialysis program could reduce the blood pressure of dialysis patients without increasing dialysis morbidity. Dialysis with a dialysate sodium of 140 mEq/L was compared with dialysis with a programmed exponential decrease of dialysate sodium from 155 mEq/L to 135 mEq/L. Dialysate sodium was then held constant at 135 mEq/L for the final half hour of dialysis. Eighteen patients completed the 7-month study, each receiving 3.5 months of experimental and 3.5 months of standard therapy. Programmed "variable-sodium" dialysis resulted in a reduction in antihypertensive drug use without alterations in predialysis blood pressure, interdialytic weight gain, ultrafiltration tolerance, or the frequency of symptomatic dialysis cramps or hypotension. Patients did, however, have lower postdialysis standing blood pressures and higher postdialysis target weights during programmed "variable-sodium" dialysis.