A. Trinchieri

A prospective study of recurrence rate and risk factors for recurrence after a first renal stone.

PURPOSE We investigate further the recurrence rate and risk factors for recurrence in 300 consecutive patients who presented to our stone clinic after a first stone episode 7 to 17 years ago. MATERIALS AND METHODS The medical records of the patients who presented consecutively with a first stone episode from 1980 to 1990 were studied and supplemented by a followup mail questionnaire and telephone interviews. At first visit serum samples were taken from all patients and 24-hour urine samples were collected for metabolic testing. RESULTS A total of 195 patients were followed successfully, of whom 52 (27%) experienced symptomatic stone recurrence after a mean plus or minus standard deviation of 7.5+/-5.9 years. However, ultrasound examination of 36 symptom-free patients showed recurrent stones in 28%. Comparison of patients with or without recurrence confirmed that recurrence was not influenced by sex, family history of stones and urinary risk factors. However, age at onset of the disease was lower for patients who had 2 or more stones during followup than those who had only 1 stone or no recurrence. CONCLUSIONS Stones can recur as long as 10 years after the first episode, although the rate is lower than previously reported. The metabolic evaluation after a first stone episode needs to be reappraised in terms of its cost-effectiveness, since recurrences do not seem to be predictable from standard laboratory tests.

Increase in the Prevalence of Symptomatic Upper Urinary Tract Stones during the Last Ten Years

Purpose: In industrialized countries the prevalence of upper urinary tract stones has continually increased during the 20th century, but there are considerable differences between countries and also within the same country. To study whether there is still an increase in the frequency of renal stones, an investigation was undertaken to determine the prevalence of stone formers in a village near Milan, Italy, during two time periods, with an interval of 12 years.Materials and Methods: Questionnaires were administered in 1986 and 1998 to all adult (age >25 years) occupants of two random samples of households in the village. Participants were asked whether they had experienced a kidney stone during their lifetime.Results: The overall prevalence of stone formers among males was 6.8% in 1986 and 10.1% in 1998; that among females was 4.9% in 1986 and 5.8% in 1998. In all age classes, the respondents in the 1998 survey more frequently reported a history of stones than in 1986, but the prevalence of renal stones was significantly higher in 1998 than in 1986 only among males aged 31–40 and 51–60 years. The yearly incidence was estimated at 0.4%, with 0.6 and 0.18% in men and women, respectively.Conclusions: This marked increase in renal stones could be the result of environmental factors such as dietary habits and lifestyle, in particular the influence of an increased consumption of animal protein should be considered.

Renal stone fragments following shock wave lithotripsy

PURPOSE We describe a select group of asymptomatic patients with fragments and dust 3 months after extracorporeal treatment, who were followed to evaluate the long-term outcome and therapeutic implications. MATERIALS AND METHODS A total of 129 patients with dust and residual fragments (less than 4 mm.) at 3 months was re-examined at 12 months, and 95 were also evaluated at 24 months. Followup examinations consisted of radiographic studies, renal ultrasonography and urine culture. Dust and residual fragments were sought, and patients were defined as free or as having persistent lithiasis or stone regrowth. At 24 months recurrences in the patients stone-free at 12 months also were considered. RESULTS At the 12-month followup 60 patients (46.5%) were stone-free and 56 (43.5%) still had dust or residual fragments. The localization of the stones or fragments at 3 months and their sizes did not have a significant influence on the stone-free rate but regrowth was greater in patients with stones larger than 10 mm. (11 of 40 patients, 27.5% versus 2 of 89, 2.2%, p = 0.001). The probability of eliminating residual lithiasis at 12 months was significantly greater in patients with dust than in those with residual fragments (42 of 79 patients, 58% versus 18 of 50, 36%, p = 0.026). Regrowth of residual lithiasis was observed in 13 patients (10%). CONCLUSIONS Based on our results, we do not believe that patients with fragments require systematic re-treatment in the short term but they may be followed long term and re-treated if symptoms persist or stones recur.

Prevalence, diagnosis and treatment of prostatitis in Italy: a prospective urology outpatient practice study

To report a prospective, multicentre descriptive study designed to determine the prevalence of the diagnosis of prostatitis in male outpatients examined by urologists in Italy, and to further examine the diagnostic evaluation and treatment of patients identified with a clinical diagnosis of prostatitis.

A STUDY OF DIETARY CALCIUM AND OTHER NUTRIENTS IN IDIOPATHIC RENAL CALCIUM STONE FORMERS WITH LOW BONE MINERAL CONTENT

PURPOSE Patients with calcium renal stone are reported to have lower bone mineral density. The state of bone density in patients with renal stones have different explanations but the role of nutritional factors seems to be crucial. A group of 48 consecutive male calcium renal stone formers was studied to investigate the relationship between bone density and dietary intake. MATERIALS AND METHODS Patients completed a dietary diary for a 3-day period during normal diet. Nutrients and calories were calculated by food composition tables using a computerized procedure. Bone densitometry was assessed at the lumbar spine and femoral neck, and expressed as Z score. A blood sample was collected and was analyzed for serum biochemistry including alkaline phosphatase, parathyroid hormone and 1,25 vitamin D. A 24-hour urine sample was analyzed for calcium, phosphate, oxalate, citrate and other electrolytes. RESULTS Dietary calcium intake was significantly lower (p < 0.01) in patients with low than in those with normal bone mineral density. There was no difference in serum parathyroid hormone levels, phosphate and alkaline phosphatase between the 2 groups. The results suggest that some renal stone formers seem to be unable to decrease renal excretion of calcium on a low calcium diet leading to a negative calcium balance. CONCLUSIONS A primary abnormality of bone metabolism could be a reasonable explanation of reduced bone density observed in renal stone formers on a low calcium diet since serum parathyroid hormone levels are in the normal range. From a therapeutic point of view these data confirm that restriction of dairy products in renal stone formers should be avoided.

Evaluation of Urinary Level of NMP22 as a Diagnostic Marker for Stage pTa-pT1 Bladder Cancer: Comparison with Urinary Cytology and BTA Test

Background: In the present study we compared the clinical value of two new specific tests for transitional cell carcinoma, urinary nuclear matrix protein (NMP22) levels and bladder tumor antigen (BTA) test, with that of urinary cytology in the follow-up of patients with superficial bladder cancer. Materials and Methods: Hundred and five bladder cancer patients were recruited: 30 stage pTa and 45 stage pT1 (group A), and 30 with a history of bladder cancer but no recurrence at the time of the study (group B). Urine samples were collected before any instrumental manipulation of the genitourinary tract. All patients were negative for urinary tract infections at conventional urine analysis. Results: NMP22 at a cutoff value of 6 U/ml showed a sensitivity of 83.3% in pTa cases and 97.7% in pT1 cases, with a false-positive rate of 23.3%. The BTA test was positive in 26.6% of patients with cancer stage pTa and in 66.6% of pT1 stage, with 30% false-positives in the non-neoplastic group. Urinary cytology, performed on three consecutive samples, was positive in 20% of patients with cancer stage pTa and in 64.4% of pT1 stage and did not show any false-positive cases. Stratifying the neoplastic patients according to lesion grade, NMP22 (at a cutoff value of 6 U/ml) was positive in 86.2% of G1, 97.2% of G2 and 90% of G3. BTA was positive in 37.9, 52.7 and 70% of G1, G2 and G3, respectively, while urinary cytology was positive in 37.9, 44.4 and 80%.

Renal tubular damage after renal stone treatment.

Summary50 patients were studied with respect to renal tubular damage related to open operative, percutaneous and extracorporeal shock wave treatment of renal stones. Preoperative and postoperative urinary N-acetyl-glucosaminidase (NAG) levels were measured as a marker of renal damage. There was no significant evidence of renal tubular damage in patients who underwent a conventional or percutaneous nephrolithotomy; urinary NAG excretion was significantly increased after ischaemic surgery. After extracorporeal shock wave lithotripsy (ESWL) serum NAG levels increased, probably because a damage of the white blood cells in cutaneous and renal circulation, but a slight increase of urinary NAG excretion could suggest a mild renal tubular damage especially in case of more than 2,000 shocks.

Familial Aggregation of Renal Calcium Stone Disease

The question of a familial predisposition towards stone formation in primary nephrolithiasis has not been explored completely. In a sample of 214 calcium stone patients, and 428 age and sex-matched controls we observed a higher frequency of stones among the first degree relatives of stone patients compared to the relatives of controls. A family history of renal stones was more common among the female (45 per cent) than among the male patients (31 per cent). There was no relationship between family history of renal stones, and abnormal calcium and oxalate excretion rates. A significant association between a family history and a higher urinary pH was observed among the female calcium stone patients. A genetic defect in urinary acidification with variable expressivity might be associated with a high frequency of stone formation. Moreover, uric acid excretion was higher in male stone patients with a family history of stones. Finally, the parents and siblings of the renal stone patients were affected more by calculi than were the corresponding relatives of their spouses.

Calcium stone disease: a multiform reality

In calcium renal stones, calcium oxalate and calcium phosphate in various crystal forms and states of hydration can be identified. Calcium oxalate monohydrate (COM) or whewellite and calcium oxalate dihydrate (COD) or weddellite are the commonest constituents of calcium stones. Calcium oxalate stones may be pure or mixed, usually with calcium phosphate or sometimes with uric acid or ammonium urate. The aim of this study was to compare the clinical and urinary patterns of patients forming calcium stones of different composition according to infrared spectroscopic analysis in order to obtain an insight into their etiology. The stones of 84 consecutive calcium renal stone formers were examined by infrared spectroscopy. In each patient, a blood sample was drawn and analysed for serum biochemistry and a 24-h urine sample was collected and analysed for calcium, phosphate, oxalate, citrate and other electrolytes. We classified 49 patients as calcium oxalate monohydrate (COM) stone formers, 32 as calcium oxalate dihydrate (COD) stone formers and three as apatite stone formers according to the main component of their stones. Patients with COM stones were significantly older than patients with COD stones (P<0.002). Mean daily urinary calcium and urinary saturation with respect to calcium oxalate were significantly lower in patients with COM than in those with COD stones (P<0.000). Patients with calcium oxalate stones containing a urate component (≤10%) presented with higher saturation (P<0.012) with respect to uric acid in their urine (and lower with respect to calcium oxalate and calcium phosphate, respectively P<0.024 and P<0.003) in comparison with patients without a urate component in the stone. Patients with calcium oxalate stones with a calcium phosphate component (≥15%) showed higher (P<0.0016) urinary saturation levels with respect to calcium phosphate (and lower with respect to uric acid (P<0.009), compared with patients forming stones without calcium phosphate or with a low calcium phosphate component. Patients with calcium stones mixed with urate had a significantly lower urinary pH (P<0.002) and urinary calcium (P<0.000), and patients with calcium phosphate >15%, higher urinary pH (P<0.004) and urinary calcium (P<0.000). In conclusion, in the evaluation of the individual stone patient, an accurate analysis of the stone showing its exact composition and the eventual presence of minor components of the stone is mandatory in order to plan the correct prophylactic treatment. Patients with “calcium stones” could require various approaches dependent on the form and hydration of the calcium crystals in their stones, and on the presence of “minor” crystalline components that could have acted as epitaxial factors.

Dietary treatment of urinary risk factors for renal stone formation. A review of CLU Working Group

OBJECTIVE Diet interventions may reduce the risk of urinary stone formation and its recurrence, but there is no conclusive consensus in the literature regarding the effectiveness of dietary interventions and recommendations about specific diets for patients with urinary calculi. The aim of this study was to review the studies reporting the effects of different dietary interventions for the modification of urinary risk factors in patients with urinary stone disease. MATERIALS AND METHODS A systematic search of the Pubmed database literature up to July 1, 2014 for studies on dietary treatment of urinary risk factors for urinary stone formation was conducted according to a methodology developed a priori. Studies were screened by titles and abstracts for eligibility. Data were extracted using a standardized form and the quality of evidence was assessed. RESULTS Evidence from the selected studies were used to form evidence-based guideline statements. In the absence of sufficient evidence, additional statements were developed as expert opinions. CONCLUSIONS General measures: Each patient with nephrolithiasis should undertake appropriate evaluation according to the knowledge of the calculus composition. Regardless of the underlying cause of the stone disease, a mainstay of conservative management is the forced increase in fluid intake to achieve a daily urine output of 2 liters. HYPERCALCIURIA: Dietary calcium restriction is not recommended for stone formers with nephrolithiasis. Diets with a calcium content ≥ 1 g/day (and low protein-low sodium) could be protective against the risk of stone formation in hypercalciuric stone forming adults. Moderate dietary salt restriction is useful in limiting urinary calcium excretion and thus may be helpful for primary and secondary prevention of nephrolithiasis. A low-normal protein intake decrease calciuria and could be useful in stone prevention and preservation of bone mass. Omega-3 fatty acids and bran of different origin decreases calciuria, but their impact on the urinary stone risk profile is uncertain. Sports beverage do not affect the urinary stone risk profile. HYPEROXALURIA: A diet low in oxalate and/or a calcium intake normal to high (800-1200 mg/day for adults) reduce the urinary excretion of oxalate, conversely a diet rich in oxalates and/or a diet low in calcium increase urinary oxalate. A restriction in protein intake may reduce the urinary excretion of oxalate although a vegetarian diet may lead to an increase in urinary oxalate. Adding bran to a diet low in oxalate cancels its effect of reducing urinary oxalate. Conversely, the addition of supplements of fruit and vegetables to a mixed diet does not involve an increased excretion of oxalate in the urine. The intake of pyridoxine reduces the excretion of oxalate. HYPERURICOSURIA: In patients with renal calcium stones the decrease of the urinary excretion of uric acid after restriction of dietary protein and purine is suggested although not clearly demonstrated. HYPOCITRATURIA: The administration of alkaline-citrates salts is recommended for the medical treatment of renal stone-formers with hypocitraturia, although compliance to this treatment is limited by gastrointestinal side effects and costs. Increased intake of fruit and vegetables (excluding those with high oxalate content) increases citrate excretion and involves a significant protection against the risk of stone formation. Citrus (lemons, oranges, grapefruit, and lime) and non citrus fruits (melon) are natural sources of dietary citrate, and several studies have shown the potential of these fruits and/or their juices in raising urine citrate levels. CHILDREN There are enought basis to advice an adequate fluid intake also in children. Moderate dietary salt restriction and implementation of potassium intake are useful in limiting urinary calcium excretion whereas dietary calcium restriction is not recommended for children with nephrolithiasis. It seems reasonable to advice a balanced consumption of fruit and vegetables and a low consumption of chocolate and cola according to general nutritional guidelines, although no studies have assessed in pediatric stone formers the effect of fruit and vegetables supplementation on urinary citrate and the effects of chocolate and cola restriction on urinary oxalate in pediatric stone formers. Despite the low level of scientific evidence, a low-protein (< 20 g/day) low-salt (< 2 g/day) diet with high hydration (> 3 liters/day) is strongly advised in children with cystinuria. ELDERLY: In older patients dietary counseling for renal stone prevention has to consider some particular aspects of aging. A restriction of sodium intake in association with a higher intake of potassium, magnesium and citrate is advisable in order to reduce urinary risk factors for stone formation but also to prevent the loss of bone mass and the incidence of hypertension, although more hemodynamic sensitivity to sodium intake and decreased renal function of the elderly have to be considered. A diet rich in calcium (1200 mg/day) is useful to maintain skeletal wellness and to prevent kidney stones although an higher supplementation could involve an increase of risk for both the formation of kidney stones and cardiovascular diseases. A lower content of animal protein in association to an higher intake of plant products decrease the acid load and the excretion of uric acid has no particular contraindications in the elderly patients, although overall nutritional status has to be preserved.