Cutaneous plasmacytoma in a hemodialysis patient.

BACKGROUND: Extramedullary plasma cell dyscrasias are rare. CASE REPORT: We report a case of a 56-year-old male Caucasian hemodialysis patient with cutaneous plasmacytoma. The diagnosis was made a few months after surgical removal of his renal graft due to chronic rejection. Investigations for the presence of an associated myeloma were negative. He underwent local radiotherapy with complete resolution of the skin lesion. CONCLUSIONS: Nephrologists should be aware that the frequency of post-transplant lymphoproliferative disorders is increasing in the dialysis population, especially in those previously or currently treated with immunosuppressive drugs.

[Diabetes and atherosclerotic coronary damage in uremia]. / Diabete e danno coronarico negli uremici.

BACKGROUND: Cardiovascular risk factors are common findings in uraemics, but the impact of each single factor on the development of atherosclerosis is still a matter of debate. PATIENTS AND METHODS: In order to evaluate the relationship between diabetes and ischaemic heart disease (IHD) in uraemia, we carried out a retrospective study comparing the results of 33 coronary angiographies performed in non-diabetic patients with those of 13 diabetics (2 had type 1 diabetes, 8 were treated with insulin, 2 with sulfonylureas and 3 received no therapy). Coronary angiography was performed in 29 patients awaiting kidney transplantation and in 17 subjects with IHD. RESULTS: Age, sex, length of time on renal replacement therapy, smoking history, clinical diagnosis of cerebrovascular and peripheral vascular disease, systolic blood pressure (BP), cholesterol, triglycerides, calcium, phosphate, albumin and degree of anaemia were comparable in the two groups. On the contrary, frequency of IHD (77 vs. 30%, p<0.01) and atrial fibrillation (23 vs. 3%, p<0.05) were higher, while diastolic BP (79 +/- 7 vs. 85 +/- 8 mmHg, p<0.05) and calcium phosphate product (47 +/- 10 vs. 57 +/- 15 mg2/dL2, p<0.05) were lower in diabetics than in non-diabetics. Stenotic lesions of the three major coronary arteries were more prevalent in diabetics than in non-diabetics (left anterior descending artery (LAD) 100 vs. 48%, p<0.01; right coronary artery (RCA) 77 vs. 39%, p<0.05; left circumflex artery (LCA) 69 vs. 24%, p<0.01) and in the same way diabetics showed higher narrowing percentage (LAD 74 +/- 30 vs. 30 +/- 36%, p<0.01; RCA 71 +/- 41 vs. 26 +/- 38, p<0.01; LCA 41 +/- 38 vs. 15 +/- 29, p<0.05). CONCLUSIONS: Our study demonstrates that although the uraemic milieu is a risk factor for IHD, diabetes increases the degree of atherosclerotic vascular damage independently of the other cardiovascular risk factors.

Relationship between diabetes mellitus and degree of coronary artery disease in uraemic patients investigated with coronary angiography.

Prevalence of cardiovascular disease is high in diabetic patients on renal replacement therapy (RRT); therefore we examined the role of diabetes mellitus on determining the degree of coronary artery stenosis. Twenty-five patients underwent coronary angiography, 12 were awaiting kidney transplantation and the examination was performed regardless of cardiac symptoms, 13 were affected by ischaemic heart disease (IHD). Diabetic and nondiabetic status together with the other risk factors for cardiovascular disease such as age, sex, length of time on RRT, smoking and elevated phosphorus levels history, clinical diagnosis of IHD, cerebrovascular and peripheral vascular disease, mean blood pressure, cholesterol, triglycerides, calcium, phosphate, albumin, haemoglobin, haematocrit and weekly dose of erythropoietin were derived from clinical records. All investigated parameters were matched in diabetic (group 1, n=10) and nondiabetic patients (group 2, n=15) and showed no differences. Clinical evidence of IHD was detected in 80% of patients in group 1 and 46% in group 2 and the percentage of patients on the renal transplant waiting list was not statistically different in the two groups (30 vs 60%). In 60% of patients in group 1 there were 3 or more stenotic lesions equal or greater than 75% of normal reference segment in the major coronary arteries, whilst in 53% in group 2 there were no haemodynamically significant narrowings. Narrowing percentage of the coronaries in group 1 and 2 were: right coronary artery 83 +/- 30 vs 32 +/- 41 (p<0.05), left anterior descending artery 80 +/- 25 vs 44 +/- 34 (p<0.05), left circumflex artery 46 +/- 37 vs 18 +/- 29 (p=0.05) respectively. Our study confirms that IHD is a clinical feature of uraemic diabetic patients and that diabetes is the main cardiovascular risk factor for determining the degree of coronary stenosis.

[Mesenteric ischemia in hemodialysis patients: case report and review of the literature]. / L'ischemia mesenterica negli emodializzati: descrizione di un caso e revisione della letteratura.

Mesenteric infarction is increasingly observed in uremic elderly patients with widespread atherosclerosis. A 77-year-old man on renal replacement therapy since June 1997 was admitted because of abdominal pain. The surgical diagnosis was massive intestinal infarction and the patient died a few hours later. A colonoscopy had been performed a few weeks before and a well-limited necrosis of the caecum mucosa had been detected. Hypotensive episodes were frequent during his hemodialysis sessions. In this work we discuss age, symptoms, laboratory investigations, risk factors and the evolution of case reports published during the last few years. Nephrologists should take into account the possibility of mesenteric ischemia in uremic patients with manifest arterio-occlusive disease, abdominal pain and leukocytosis, especially if hypotension is the major complication of the hemodialysis sessions.

Progression of renal failure in diabetic nephropathy.

The onset of renal damage in diabetes mellitus may be influenced by several factors which largely result from genetic predisposition, hereditary factors and the early appearance of microalbuminuria and/or systemic hypertension. Most of these factors are also implicated in the progression of nephropathy from microalbuminuria to overt proteinuria and to end-stage renal failure (ESRF). Over the last few years, the role of hyperglycaemia has emerged as critical in mediating the progressive renal damage in diabetes. However, hyperglycaemia leads to increased formation of glycated proteins which may act as promoters of progression by localizing in renal tissue. In addition, hyperglycaemia may have a synergistic effect with some other risk factors, such as growth factors and the renin angiotensin system, in accelerating renal deterioration.

Systemic hemodynamic pattern in primary hyperparathyroidism and its changes after parathyroidectomy.

Twelve patients (7 men and 5 women) with an average age of 53 years (range 37-69) were hospitalized for renal stones and found to have primary hyperparathyroidism. Five were hypertensive and 7 normotensive. The systemic hemodynamics, plasma renin activity and glomerular filtration rate were evaluated before and at least 6 months after removal of a parathyroid adenoma. After surgery the mean intra-arterial blood pressure fell in almost all patients, due to some reduction in the peripheral vascular resistance index with no change in the cardiac index. However, the hemodynamic variations were not uniform in all patients. No change was seen in plasma renin activity and glomerular filtration rate. A positive correlation between the percent change in mean arterial pressure and percent decrease in total serum calcium was found. The results obtained indicate that it is likely that hypercalcemia plays some role both in patients with high and those with normal blood pressure. The systemic hemodynamic changes after parathyroidectomy indicate that the fall in peripheral vascular resistance could have a certain influence.

Clinical features of patients with solitary kidneys.

A clinical study was performed in 2 groups of patients with solitary kidneys, followed for 11-146 months. Group 1 had 9 patients (7 males and 2 females, aged between 23 and 68 years) with unilateral renal agenesis. Group 2 had 13 patients (9 females and 4 males, aged between 27 and 70 years) who underwent unilateral nephrectomy for the following reasons: hydronephrosis secondary to ureteropelvic junction stenosis, 7 patients; renal trauma, 4 patients; benign neoplasia, 2 patients. During the follow up, urinary protein excretion of more than 300 mg/day was observed in 9 patients, 3 in group 1 and 6 in group 2. Eleven patients, 8 in group 1 and 3 in group 2, were hypertensive (diastolic blood pressure higher than 95 mm Hg). Hyperuricemia was observed in 14 patients, 10 in group 1 and 4 in group 2. Seven patients, 4 in group 1 and 3 in group 2, had a significant deterioration of renal function. Neither proteinuria nor renal failure were observed before at least 10 years had elapsed since the anatomic condition of solitary kidney had been established. A surgical renal biopsy was performed in 1 patient with unilateral renal agenesis and showed focal glomerular sclerosis. This study adds support to the view that the reduction of 50% of the renal tissue may be a risky situation in humans as well as in animals.

Hypertension of polycystic kidney disease: mechanisms and hemodynamic alterations.

32 polycystic kidney disease (PKD) patients, 16 with normal 16 with variably decreased renal function, were studied; 12 were normotensive, 20 were hypertensive. Mean arterial pressure (MAP) was 90 +/- 8 mm Hg in the normotensive group and 117 +/- 17 in hypertensive patients; plasma renin activity (PRA) was similar. The glomerular filtration rate (GFR) was lower, but not significantly, in the hypertensive group and plasma volume (PV) was higher in hypertensive patients (normotensive 40.25 +/- 3.47 ml/kg body weight; hypertensive 46.30 +/- 3.54). No correlation was found between MAP, and PRA or GFR but MAP correlated with PV. Cardiac output was higher in hypertensive patients (normotensive 3.48 +/- 0.70 l/min/m2; hypertensive 3.89 +/- 1.47), also total peripheral resistance was higher in the hypertensive group (normotensive 2,035 +/- 503 dyn/s/cm-5/m2; hypertensive 2,577 +/- 808). Cardiac output and PV showed a high degree of correlation, but no correlation was seen between total peripheral resistance and PV, or PRA. The hypertensive patients were divided into two groups: one with hypertension of less than 2 years duration and one with more than 2 years but with similar GFR, PRA, PV and hemodynamic pattern. Our data indicate that hypertension in PKD is volume-dependent; that the increase in PV was not related to the loss of GFR, and that the role of the renin-angiotensin system in maintaining the hypertensive state is not well defined. Hemodynamically hypertension is characterized by high cardiac output and total peripheral resistance independent of the duration of hypertension.

Renal acidification defects in patients with recurrent calcium nephrolithiasis.

The frequency of renal tubular acidosis was evaluated in 28 adult patients with recurrent calcium nephrolithiasis (19 with 'renal' hypercalciuria, 9 with normocalciuria and no metabolic abnormality) and no evidence of obstruction or infection of the urinary tract. Eight patients with hypercalciuria (42%) had a defective renal reabsorption of bicarbonate, based on a fractional excretion of bicarbonate higher than 7% and a TmHCO3/GFR lower than 2.2 mEq/dl; 2 of them had an associated distal defect of acidification, as judged by a U-B pCO2 lower than 18 mm Hg in maximally alkaline urine. One patient with hypercalciuria had distal tubular acidosis, based on a urine pH higher than 5.3 during acidosis. Only 1 patient with normocalciuria had associated proximal and distal acidification defects. The remaining 8 patients displayed a normal renal acidifying capacity. The bicarbonate wastage was independent of serum PTH levels, vitamin D status and hypercalciuria and was associated with a defective tubular reabsorption of phosphate, increased random urinary pH and more active nephrolithiasis, with a prevalence of mixed calcium oxalate and phosphate stones. Our study shows a high incidence of defective tubular reabsorption of bicarbonate in patients with calcium nephrolithiasis and 'renal' hypercalciuria and suggests that the proximal acidification defect plays a pathogenetic role in promoting calcium nephrolithiasis.

Effects of timolol on blood pressure, systemic hemodynamics, plasma renin activity, and glomerular filtration rate in patients with essential hypertension.

Timolol, a non-cardioselective beta-blocking agent, was administered orally after 2 weeks of placebo to 14 patients with essential hypertension for 8 weeks following 1-4 weeks of dose-ranging period. Patients were first hospitalized and submitted to a diagnostic workup. They were placed on a diet containing 100 mEq of Na+ and 65 mEq of K+; this regimen was also prescribed during outpatient treatment. The changes in blood pressure, systemic hemodynamics, plasma renin activity, urine aldosterone, and glomerular filtration rate were evaluated. A significant and stable decrease in systolic and diastolic blood pressure associated with a fall in cardiac output (-21%), heart rate (-17%), plasma renin activity, and urine aldosterone were observed. The blood pressure lowering effect was unrelated to the decrease in cardiac output and plasma renin activity. Glomerular filtration rate was unchanged. No important side effects were observed during the treatment.