Hormonal abnormalities in renal transplantation

It is generally maintained that the variety of endocrine disorders which occur in uraemia and persist in dialysis (above all hormones whose production and/or metabolic clearance are pertinent functions of the kidney) usually abate after successful renal transplantation. However, a retrospective analysis of long-term results in 71 out of 275 cases serially studied by regular checks, indicates that this event occurs in no more than 2/3 of successfully transplanted patients. In the other patients various endocrine abnormalities may be documented: some seem apparently 'inherited' from uraemia (hyperparathyroidism, sexual dysfunction, growth retardation); some are mainly related to steroids (hyperinsulinism), and some have a de novo origin (erythrocytosis, reno-vascular hypertension). These endocrine abnormalities may occur with a normal or reduced graft function, have a baseline or stimulated expression, a clinical or subclinical course, and a reversible or irreversible outcome. A proper grasp of these events in renal transplantation is of clinical significance particularly for the long-term patient and graft prognosis.

Family recurrence and oligo-anuria predict uremic restless legs syndrome

OBJECTIVES

To determine clinical and laboratory predictors of restless legs syndrome (RLS) in patients with end-stage kidney disease (ESKD) undergoing long-term hemodialysis (HD).

MATERIALS AND METHODS

One hundred and sixty-two consecutive patients were assessed. History of sleep disturbances, neurological examination, clinical, and laboratory data were collected. Patients with and without RLS were compared, and a logistic regression model described the relations between independent predictors and RLS.

RESULTS

Fifty-one patients (32%) currently had RLS (RLS+). RLS+ vs RLS- patients were more frequently women (49% vs 29%, P = 0.012), had first-degree relative with RLS (22% vs 6%, P = 0.004), insomnia (59% vs 36%, P = 0.007), peripheral neuropathy (41% vs 21%, P = 0.006), and low residual diuresis (92% vs 68% with below 500 ml/24 h, P = 0.001). Low (OR = 8.71, CI = 2.27-33.41; P = 0.002) and absent (OR = 4.96, CI = 1.52-16.20; P = 0.008) residual diuresis, peripheral neuropathy (OR = 4.00, CI = 1.44-11.14; P = 0.008), and first-degree relative with RLS (OR = 3.82, CI = 1.21-12.13; P = 0.023) significantly predicted RLS in ESKD patients undergoing HD.

CONCLUSION

Positive family history for RLS together with reduced/absent residual renal function and peripheral neuropathy predicts the risk for RLS in ESKD patients undergoing HD. Longitudinal studies are warranted to correlate RLS occurrence with genetic and environmental factors.

[Therapy strategies in the prevention of chronic allograft nephropathy]

Chronic allograft nephropathy (CAN) is an anatomical and clinical alteration, characterized by proteinuria, hypertension and a progressive decline in kidney function, which begins at variable times (months, years) and can lead to the loss of the transplanted organ. CAN pathogenesis, which remains to be fully clarified, involves both immunological (early acute rejection, hyperimmunization, HLA-mismatches between donor and recipient, suboptimal immunosuppression, etc) and non-immunological factors (ischemia/reperfusion injury, reduced nephron mass, age differences between donor and recipient, dialysis time, hypertension, dislipidemia, proteinuria, etc). The possible prevention strategies for CAN consist of procedures aimed at the reduction of some potential risk factors: optimization of the conditions for organ explantation, diminution of ischemia/reperfusion injury, aggressive pharmacological treatment of acute rejection episodes, routine utilization of anti-hypertensive and hypolipidemic agents, and appropriate and rational immunosuppressive regimen. Moreover, some categories of immunosuppressive drugs, such as calcineurin inhibitors, can have a nephrotoxic effect, often regardless of therapeutic dosage. The introduction in clinical practice of novel immunosuppressive drugs with no nephrotoxicity, like mycophenolate mofetil and rapamycin, makes therapeutical strategies able to reduce the incidence of CAN feasible.

Tacrolimus-Associated myositis: a case report in a renal transplant patient

A 55-year-old Caucasian man who had received a second kidney graft in July 1993, was switched from cyclosporine to tacrolimus in June 2000 due to deterioration of renal function. Thereafter, he began to complain of muscle cramps in both quadriceps with an increased CPK and EMG findings of polyneuropathy. A muscle biopsy demonstrated acute myositis. Prednisone was administered with amelioration of the patient's symptoms, but with persistently increased CPK and myoglobin levels. In February 2001, mycophenolate mofetil was introduced and tacrolimus tapered to 3 mg daily to seek a toxic role of this immunosuppressant, since there was no other cause of myositis. A sudden decrease in CPK was observed, but the complete normalization took place only after its withdrawal in September 2002. This case represents a tacrolimus-associated myositis.

[Renal transplantation and malignancies: A single-centre experience (25 years)]

BACKGROUND

The prevalence of post-transplant malignancies, in renal transplant recipients, is higher than that expected in age and sex-matched controls from the general population, and there is a markedly increased incidence of certain cancers.

METHODS

In 1137 renal transplant recipients (1020 from cadaveric and 117 from living donors, M/F 771/366) performed at the S. Orsola Renal Transplantation Centre since 10/1976 to 9/2001, we studied the post-transplant cancer prevalence, the correlation between cancer prevalence and population characteristics, the risk factors (smoke, cancer history, positive HBsAg and antiHCV infection) and the immunosuppressive therapy.

RESULTS AND CONCLUSIONS

The prevalence of malignancies was 3.86% (52 malignancies in 44 patients). The period between transplant and diagnosis of malignant disease was 59 +/- 85 months. Skin cancer was the most common (n=16; 30.7%), followed by lymphoproliferative disorders (n=8; 15.4%), Kaposi s sarcoma (n=6; 11.5%), uterine cancer (n=6; 11.5%), renal carcinoma of native kidney (n=5; 9.6%), cancer of breast/stomach/pancreas and urinary bladder (n=2; 3.8%) and other cancers (n=5; 9.6%). The mean duration of dialysis before transplantation was longer in cancer patients (41+/- 32.1 vs. 33.5 +/- 32.4 months). We found a correlation between types of malignancies and viral infection in NH-lymphoma (EBV positive 4/4) and skin cancer (HZV positive 13/16). We also detected a correlation between Aza and skin cancer (16/22) and CyA and lymphoproliferative disorders (7/8).

Reduction of oxaluria after an oral course of lactic acid bacteria at high concentration

BACKGROUND

Hyperoxaluria is a major risk factor for renal stones, and in most cases, it appears to be sustained by increased dietary load or increased intestinal absorption. Previous studies have shown that components of the endogenous digestive microflora, in particular Oxalobacter formigenes, utilize oxalate in the gut, thus limiting its absorption. We tested the hypothesis of whether oxaluria can be reduced by means of reducing intestinal absorption through feeding a mixture of freeze-dried lactic acid bacteria.

METHODS

Six patients with idiopathic calcium-oxalate urolithiasis and mild hyperoxaluria (>40 mg/24 h) received daily a mixture containing 8 x 10(11) freeze-dried lactic acid bacteria (L. acidophilus, L. plantarum, L. brevis, S. thermophilus, B. infantis) for four weeks. The 24-hour urinary excretion of oxalate was determined at the end of the study period and then one month after ending the treatment. The ability of bacteria to degrade oxalate and grow in oxalate-containing media, and the gene expression of Ox1T, an enzyme that catalyzes the transmembrane exchange of oxalate, also were investigated.

RESULTS

The treatment resulted in a great reduction of the 24-hour excretion of oxalate in all six patients enrolled. Mean levels +/- SD were 33.5 +/- 15.9 mg/24 h at the end of the study period and 28.3 +/- 14.6 mg/24 h one month after treatment was interrupted compared with baseline values of 55.5 +/- 19.6 mg/24 h (P < 0.05). The treatment was associated with a strong reduction of the fecal excretion of oxalate in the two patients tested. Two bacterial strains among those used for the treatment (L. acidophilus and S. thermophilus) proved in vitro to degrade oxalate effectively, but their growth was somewhat inhibited by oxalate. One strain (B. infantis) showed a quite good degrading activity and grew rapidly in the oxalate-containing medium. L. plantarum and L. brevis showed a modest ability to degrade oxalate even though they grew significantly in oxalate-containing medium. No strain expressed the Ox1T gene.

CONCLUSIONS

The urinary excretion of oxalate, a major risk factor for renal stone formation and growth in patients with idiopathic calcium-oxalate urolithiasis, can be greatly reduced with treatment using a high concentration of freeze-dried lactic acid bacteria. We postulate that the biological manipulation of the endogenous digestive microflora can be a novel approach for the prevention of urinary stone formation.

Impaired fecal elastase excretion in uremic pancreopathy

To evaluate pancreatic exocrine function in uremia, 25 patients undergoing regular hemodialysis without clinical evidence of pancreatic disease and 25 healthy control subjects were studied by fecal elastase 1 and chymotrypsin. Abdominal ultrasonography and measurement of serum lipase, calcium, phosphate, and parathormone were also carried out. Fecal elastase was significantly lower (P < 0.001) in patients than in controls. Abnormally low values were found in 12/25 patients of whom six had values <100 microg/g. Fecal chymotrypsin was significantly lower (P < 0.05) in patients than in controls, with lower than normal values found in 10/25 patients. Fecal elastase was not related to the serum calcium, phosphate, or parathormone levels or to the period of dialysis. In patients serum lipase was normal or slightly elevated (<300 units/liter), and there was no evidence of pancreatic disease at ultrasound examination. The results lend further support to the existence of pancreatic function impairment in a significant number of patients with renal failure despite the absence of clinical and morphological evidence of pancreatic disease.

The Academy of Science of Bologna and the kidney

The Academy of Science of Bologna, founded in 1711, played an important role in the development of medicine. Receiving the heritage of Malpighi's and Morgagni's researches, the academy encouraged nephrological studies, which produced articles published in its journal, the Commentarii. Since the Commentarii were widely distributed all over Europe, the nephrological research practiced in Bologna reached all the main academies of science, in a fruitful circulation of knowledge. The paper presents the nephrological contributions to the Commentarii in the 18th century, thus introducing physicians, like Domenico Galeazzi and Luigi Galvani, who were both professors at the University of Bologna and at the Academy of Science. In their work three main topics can be identified: uroscopy, anatomy of the kidney and renal pathologies.

3 R study: renal outcome in renal ischemia: revascularisation or medical treatment

Ischemic nephropathy refers to the kidney damage following stenosis or an obstructive lesion in the main kidney arteries. This disorder has been overlooked in the past and a more rational and specific use of clinical criteria, and the development of not very invasive techniques with a good diagnostic accuracy such as spiral CT angiography, NMR angiography and echo-colour-Doppler have improved our ability to identify these patients. It is therefore likely that, in the next few years, we will find ourselves treating an increasing number of patients with renovascular ischemic disorders. Transluminal angioplasty and, more recently, the use of endovascular stents, have led to a marked improvement in the treatment of stenoses and, together with vascular surgery, allow to treat almost all patients with this disorder. There is, however, a lack of prospective and controlled studies, which demonstrate the long term benefit of revascularization treatment, as compared with optimum conservative treatment in reducing cardiovascular mortality, cardiovascular events and preserving renal function. The Ischemic Nephropathy Study Group of the Italian Society of Nephrology has organized a prospective, controlled study over a period of three years, aimed at comparing the effect of revascularization versus medical therapy in 300 patients with renal artery stenosis, ranging between 50 and 90 per cent, who will be randomly assigned to the two treatments. End point will be cardiovascular mortality and morbidity and need for renal replacement therapy.

Guilielmus de Saliceto and his contributions to renal medicine

Guilielmus, one of the most outstanding physicians of the 13th century practised a bedside teaching method and gave guidelines for diagnosing and treating diseases. Written summaries of clinical case histories were his basic didactic instruments and his practise was characterized by a high awareness of doctor-patient relations.

Posttraumatic chyluria due to lymphorenal fistula regressed after somatostatin therapy

A sudden-onset chyluria after trauma was evaluated giving evidence of a lymphatic-urinary fistula in the right kidney. Treatment with somatostatin normalized the urinary pattern and the result was maintained even after the discontinuation of the therapy.

Alterations of exocrine pancreas in end-stage renal disease. Do they reflect a clinically relevant uremic pancreopathy?

Serum pancreatic enzyme behavior, exocrine function, and morphology of the pancreas were studied in 28 patients with end-stage renal disease undergoing regular hemodialysis, in order to better delineate and assess the clinical relevance of the pancreatic alterations that occur in these patients. Twenty-eight healthy subjects served as controls. Initial studies included serum amylase, isoamylase, and lipase assays; fecal chymotrypsin measurement; and abdominal ultrasonography. The amylase, lipase, and chymotrypsin determinations, as well as ultrasound examination, were repeated four years later. None of the patients had clinical evidence of pancreatic disease at entry into the study, but one had had previous attacks of pancreatitis and another developed mild acute pancreatitis one month after entry. Initial mean serum enzyme levels were significantly higher in patients than in controls (amylase, pancreatic isoamylase, and lipase, P < 0.001; salivary isoamylase P < 0.05). Serum amylase was raised in 16/28 patients; pancreatic isoamylase in 15/28, and lipase in 7/28; these elevations were generally mild. Mean fecal chymotrypsin was significantly lower (P < 0.001) in patients than in controls: abnormally low values were found in 9/28 patients. Amylase, lipase and chymotrypsin measurements repeated after four years showed no significant difference with respect to the first study. Ultrasonographic changes were rare and mild: one patient had a small cyst in the pancreas head, another, an increase in echogenicity of the gland not related to age; these findings were unchanged at repeat examination. The results demonstrate that the frequent elevations of serum pancreatic enzymes and the rare sonographic changes found in patients undergoing hemodialysis do not generally reflect a relevant pancreopathy. However, the finding of significantly decreased fecal chymotrypsin may indicate the presence of pancreatic dysfunction in end-stage renal disease.

Is Ace inhibitor treatment a possible cause of better cardiovascular remodelling in well functioning kidney transplant?

Diseases of the cardiovascular system are a common cause of death in renal transplanted patients. In this study we assessed the echocardiographic morphological and functional findings after renal transplantation of two homogenous groups of transplanted patients with normal renal function. The first (A) with spontaneously normotensive patients, the second (B) with moderate hypertension treated mainly with Ace inhibitors. Analysis of these data highlights two noteworthy results: the similar left ventricle hypertrophy found in both groups and the existence of better diastolic compliance among the hypertensive transplanted patients. If this is confirmed by studies currently in progress, the importance of Ace-inhibitors treatment in remodelling cardiac dysfunction after long term dialysis treatment might be seriously considered.

Is Ace Inhibitor Treatment a Possible Cause of Better Cardiovascular Remodelling in Well Functioning Kidney Transplant?

Diseases of the cardiovascular system are a common cause of death in renal transplanted patients. In this study we assessed the echocardiographic morphological and functional findings after renal transplantation of two homogenous groups of transplanted patients with normal renal function. The first (A) with spontaneously normotensive patients, the second (B) with moderate hypertension treated mainly with Ace inhibitors. Analysis of these data highlights two noteworthy results: the similar left ventricle hypertrophy found in both groups and the existence of better diastolic compliance among the hypertensive transplanted patients. If this is confirmed by studies currently in progress, the importance of Ace-inhibitors treatment in remodelling cardiac dysfunction after long term dialysis treatment might be seriously considered.

The age-old spirit of nephrology from the oldest university in the world

The University of Bologna began teaching in 1088, and the Faculty of Medicine was granted the same rights as lawyers in 1288, largely due to the reputation and teaching skills of Taddeo Alderotti. Among the other famous names associated through the ages with the Bologna School of Medicine are Malpighi, Valsalva and Murri. From the earliest times in Bologna, nephrologists attempted to show an interaction of the kidney with the outer environment (astronomy and astrology) and with other organs (anatomy) and an integration of the sophisticated structures within the kidney itself (microscopy). At the turn of the 19th century, the biochemical frontier was reached, and a new teaching methodology emphasizing careful consideration of all possible differential diagnoses was developed.

Low-dose angiotensin converting enzyme inhibitors: effect on renal function in normo- and hypertensive type 1 diabetic patients

OBJECTIVES

To investigate the effect of low doses of the angiotensin converting enzyme inhibitor enalapril on renal haemodynamics and albuminuria in normotensive and hypertensive type 1 (insulin-dependent) diabetic patients with incipient or overt nephropathy.

METHODS

Twenty-two type 1 (insulin-dependent) diabetic patients with persistent microalbuminuria or macroalbuminuria and normal serum creatinine were studied. Of all patients, 16 males and 6 females, age 45 +/- 13 years, diabetes duration 19 +/- 11 years, insulin dose 38 +/- 11 U/day, 10 were normotensive and 12 were hypertensive. After 3 months of run-in period the patients were assigned to treatment with 5 mg or 10 mg enalapril based on the presence of normotension or hypertension respectively. Before and after 6 months of treatment, renal function was assessed by evaluation of glomerular filtration rate (99m Tc-DTPA), renal plasma flow (131-I iodohippurate), filtration fraction and renal vascular resistance. Mean arterial pressure, albumin excretion rate, urinary urea excretion and glycated haemoglobin were also determined.

RESULTS

Administration of enalapril resulted in both groups of patients in a significant fall in mean arterial pressure, albumin excretion rate, glomerular filtration rate, filtration fraction, and renal vascular resistance. Decreasing albumin excretion did not correlate with a drop in systemic blood pressure or filtration fraction. No significant variations were observed in renal plasma flow, in urinary urea excretion or in glycated haemoglobin.

CONCLUSIONS

Our results suggest that low doses of enalapril are effective in influencing renal haemodynamics and reducing urinary albumin excretion in both normotensive and hypertensive type 1 (insulin-dependent) diabetic patients with incipient or overt nephropathy. The lowering effect of the angiotensin converting enzyme inhibitor on albuminuria seems to be independent of the action on systemic blood pressure and renal haemodynamic changes.

Epidemiology of hepatitis C in a population of hemodialysis patients

A search for antibodies against hepatitis C virus (HCV) was performed in 185 patients on chronic hemodialysis by means of 1st and 2nd generation ELISA tests. Immunoblot assays were performed on positive sera. This study shows a 38% prevalence of HCV-positive patients in our dialysis population according to the 2nd generation ELISA test which shows a higher specificity and sensitivity when compared to the 1st generation one (38 vs. 20%). A correlation was found between the prevalence of HCV-positive patients and how long they had been on dialysis and how many blood transfusions they had received.

Normalization of renal function and blood pressure after dissolution with intra-arterial fibrinolytics of a massive renal artery embolism to a solitary functioning kidney

The intra-arterial administration of fibrinolytics in a massive embolism to the renal artery of a solitary functioning kidney determined quick normalization of the severe renal failure and hypertension.

Percutaneous transluminal dilatation of posttransplant renal artery stenosis: beneficial effects in two cases at high surgical risk

Two clinical cases are described in which percutaneous transluminal dilatation (PTD) determined the correction of hypertension and renal hypoperfusion due to renal artery stenosis of the transplanted kidney.